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Biomedical subjects

H Sugimoto

Publications and source records attributed to H Sugimoto.

At least 19 recordsLinked to original sources
PubMed2006

Anisotropy and corotation of galactic cosmic rays.

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.

Journal Article↗
PubMed2006

[Infectious tricuspid valve endocarditis in a chronic hemodialysis patient; report of a case].

We report a rare case of isolated infectious tricuspid valve endocarditis. A 67-year-old male patient with chronic renal failure complained of fever up to 38 degrees C after hemodialysis. WBC was not elevated, but CRP was increased. Transthoracic and transesophageal echocardiography for investigating his chest discomfort demonstrated a large 13 x 25 mm vegetation on the tricuspid valve. Blood culture was negative. The tricuspid valve was replaced with a bioprosthetic valve. The extensive vegetation was found in the anterior, septal and posterior cusps and diagnosed as infectious endocarditis pathologically. The postoperative course was uneventful. WBC and CRP remained normal 9 months after surgery and no signs of recurrence were observed. The cause of the infectious endocarditis seemed to be the insertion of a double lumen catheter for dialysis or the puncture of the arteriovenous shunt.

Aged↗
PubMed2005

Reduced DNA gap repair in aging rat neuronal extracts and its restoration by DNA polymerase beta and DNA-ligase.

Synthetic deoxy-oligo duplexes containing short gaps of 1 and 4 nucleotides were used as model substrates to assess the DNA gap repair ability of the neuronal extracts prepared from cerebral cortex of rats of different ages. Our results demonstrate that gap repair activity in neurons decreases markedly with age. The decreased activity could be restored by supplementing the neuronal extracts with pure recombinant rat liver DNA polymerase beta. High levels of DNA polymerase beta supplementation resulted in gap-filling activity that proceeded essentially through addition of nucleotides through a slow distributive strand displacement mode to achieve full template length (32-mer). However, at lower concentrations of DNA polymerase beta, the gap repair takes place quickly through gap filling followed by ligation to downstream primer, in an energy efficient manner. For this to happen, the conditions required are the presence of 5'-PO4 on the downstream primer and supplementation of aging neuronal extracts with DNA-ligase in addition to recombinant DNA polymerase beta. These results demonstrate that aging neurons are unable to affect base excision repair (BER) due to deficiency of DNA polymerase beta and DNA-ligase and fortifying aged neuronal extracts with these two factors can restore the lost BER activity.

Aging↗
PubMed2004

Semicarbazide-sensitive amine oxidase in transgenic mice with diabetes.

Semicarbazide-sensitive amine oxidase (SSAO) activity in plasma is increased in diabetes, and in particular, in diabetic patients with vascular complications. It has been speculated that SSAO is involved in the development of such complications due to the production of cytotoxic compounds. In this work, we have induced diabetes in a previously described mouse-model, overexpressing SSAO in smooth muscle cells. SSAO activity was estimated as well as expression of the endogenous mouse gene and human transgene using real-time PCR. Diabetes induced an increase in SSAO activity in serum, kidney, and adipose tissue of transgenic animals. An inverse correlation between SSAO activity and mouse SSAO mRNA levels was observed in transgenic animals with diabetes. These results further support the suggestion of a negative feedback control of the SSAO gene expression. The increased SSAO activity in diabetes is most likely dependent on post-transcriptional modifications or activation of existing inactive enzyme molecules.

Adipose Tissue↗
PubMed2004

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun.

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

Journal Article↗
PubMed2004

Critical progressive small-graft injury caused by intrasinusoidal pressure elevation following living donor liver transplantation.

In adult-to-adult living liver transplantation, small-for-size graft syndrome sometimes occurs. The relationship between the hemodynamic changes and histologic findings has not been studied in patients with failure of small-for-size grafts. We analyzed the relationship between the postoperative hemodynamic changes and pathologic findings in patients with small-for-size grafts that ended in graft failure. From March 1999 to December 2002, adult-to-adult living-donor liver transplantation with small-size grafts (graft volume/standard liver volume less than 40%) was performed in eight patients. Three patients died from graft failure caused by overperfusion, which was diagnosed from pathologic findings. We analyzed the relation between hepatic hemodynamic parameters, such as portal venous blood velocity or splenic arterial pulsatility index, and histologic changes in patients with graft failure. Severe portal hyperperfusion (90 cm/sec at the umbilical portion) was observed on postoperative day 1. Among patients with graft failure, critical hemodynamic changes, such as sudden onset of extremely deteriorated portal venous blood flow, occurred during the early postoperative period (postoperative day 5, 3, 6, respectively). Histologic examination revealed vacuolar changes in the cytoplasm of hepatocytes, and submassive necrosis indicated intrasinusoidal pressure elevation. These changes were not observed in the biopsy obtained soon after reperfusion. In conclusion, critically decreased vascular beds may cause intrasinusoidal pressure elevation and sinusoidal circulatory disturbances.

Adult↗
PubMed2004

Nutcracker syndrome associated with severe anemia and mild proteinuria.

A 70-year-old man was referred to our hospital with the chief complaint of gross hematuria. Urinalysis revealed gross hematuria (3+, RBC 100/HPF or more) and mild proteinuria (3+, 1.8 g/day) with no urinary casts. Computed tomography of the abdomen showed compression of the left renal vein between the superior mesenteric artery and the aorta. Ultrasonography showed an increased flow velocity at the stenotic portion of the left renal vein. An aortography and selective left renal arteriography showed that there was no evidence of tumor vessels or arterial abnormalities in the arterial phase. However, the venous phase revealed a stenosis of the left renal vein just lateral to the aorta as well as a reflux of contrast material toward the left gonadal vein which was dilated. In addition, cystoscopy revealed left ureteral bleeding. Based on these findings, we made the diagnosis of gross hematuria caused by nutcracker syndrome (NCS). We concluded that the main cause of the anemia and proteinuria in our patient was leakage of blood and this is confirmed by the relationship of red blood cells to protein in the urine because we proved whole blood and plasma protein loss in the urine by calculation. Fourteen months after discharge, both the gross hematuria and proteinuria spontaneously disappeared. This case strongly suggested that the first therapy for hematuria and proteinuria with NCS should be observation.

Aged↗
PubMed2002

Molecular cloning and functional characterization of Cynomolgus monkey (Macaca fascicularis) CC chemokine receptor, CCR3.

We have cloned and performed the first functional characterization of the chemokine receptor, CCR3, of Cynomolgus monkey (Macaca fascicularis). The deduced amino acid sequence of the cloned Cynomolgus CCR3 was found to be more similar to that of a previously-reported Rhesus (Macaca mulatta) CCR3 (99.4%) than that of a reported Cynomolgus CCR3 (98.0%). Stably-transfected Cynomolgus CCR3 bound human eotaxin (CCL11) with similar kinetics (Kd 240 pM) and was responsive to human CCR3 ligands (eotaxin [CCL11], eotaxin-2 [CCL24], and MCP4 [CCL13]) in Ca(2+) mobilization and chemotaxis assays, thus provides a useful alternative species model system for the analysis of modulators of eotaxin--CCR3 induced signaling and activation.

Amino Acid Sequence↗
PubMed2002

Semiquantitative analysis of corpus callosum injury using magnetic resonance imaging indicates clinical severity in patients with diffuse axonal injury.

OBJECTIVE: To evaluate the hypothesis that the extent of corpus callosum injury indicates the depth of shearing lesions in the central brain structure and therefore relates to the clinical severity of diffuse axonal injury. METHODS: A simple and objective procedure for semiquantitative analysis of magnetic resonance images (MRI)-the maximum signal intensity ratio (MSIR)-was employed prospectively in 21 patients with diffuse axonal injury but without apparent injury to the ventral pons. All were diagnosed using serial combination MRI scans of fluid attenuated inversion recovery (FLAIR) and T2* weighted gradient echo imaging during the initial two weeks after the injury. The signal intensity ratio between the two regions of interest-the corpus callosum and the normal appearing ventral pons-was calculated serially in mid-sagittal and parasagittal FLAIR image sections in each patient. The MSIR during the study period was determined as a semiquantitative index of corpus callosum injury in each patient. The correlations between MSIR and the duration of unconsciousness, Glasgow outcome scale at six months, and the presence of apparent midbrain injury were investigated. RESULTS: The mean (SD) MSIR value was 1.12 (0.18) at 7.4 (3.1) days after the injury (n = 21). MSIR correlated strongly with the duration of unconsciousness (n = 19, R(2) = 0.74, p < 0.0001), and was higher in patients with both an unfavourable GOS outcome (p = 0.020) and apparent midbrain injury (p < 0.001). CONCLUSIONS: MSIR, which is a simple and objective procedure for semiquantitative analysis of corpus callosum damage in diffuse axonal injury, correlated with clinical severity. A high MSIR value may indicate the presence of concomitant midbrain injury.

Adolescent↗
PubMed2002

[Basaloid-squamous carcinoma of the esophagus: report of a case].

We report herein the case of a 66-year-old man with basaloid squamous cell carcinoma (BSCC) of the esophagus. There are only 60 cases of BSCC of the esophagus previously reported in Japan. In our patient, endoscopic findings revealed a type 2 in the lower intrathoracic esophagus (Lt), and the tumor was intact with the aorta (T2). A biopsy suggested that it was adenosquamous cell carcinoma. An operation was done on June 11, 1996. With open thoracotomy, esophagectomy was performed with mediastinal lymphnode dissection by posterior mediastinal esophagogastrostomy. Histologically, the lesion of the tumor with ulceration was composed of BSCC, and other lesion was composed of typical squamous cell carcinoma (SCC). The immunohistochemical findings of the respected specimens led us to suspect that the basal-layer-type SCC had transformed into BSCC by undergoing differentiation and expansive proliferation. According to the prognosis, eventually the patient died of pneumonia due to methicillin resistant Staphylococcus aureus (MRSA) and candida 4 years and 9 months after the surgery.

Aged↗
PubMed2001

FK506 suppressed the inflammatory change of EAM in SJL/J mice.

Experimental autoimmune myositis (EAM) is a good model of human inflammatory myopathy. We induced EAM in SJL/J mice by injection with myosin and treated inflammatory changes with FK506. The mice developed inflammatory changes after the fifth myosin injection. After treatment with FK506, inflammation was suppressed and central nuclei of the muscle fibers increased. These findings indicate that FK506 is effective in the treatment of EAM. The data suggests that FK506 inhibits interaction with calcineurin. Intercellular adhesion molecule-1 (ICAM-1) positive cells were present in the inflammatory and non-inflammatory areas of EAM. The FK506-treated group stained more weakly for ICAM-1 than the untreated EAM group.

Animals↗
PubMed2001

Hypothermic treatment restores glucose regulated protein 78 (GRP78) expression in ischemic brain.

Mild hypothermia is a well-known method of reducing brain damage caused by traumatic, hypoxic, and ischemic injury. To elucidate the neuroprotective mechanism induced by hypothermic treatment, we compared gene expression profiles in the hippocampus of gerbils rendered ischemic for 15 min and then reperfused for 3 h under conditions of normothermia (37+/-0.5 degrees C) or hypothermic treatment (34+/-0.5 degrees C). Using the differential display method, we observed significantly reduced expression of the 78 kDa glucose regulated protein (GRP78), in ischemic gerbil hippocampus that underwent normothermic reperfusion, but normal GRP78 expression in animals that underwent hypothermic reperfusion. In situ hybridization and Northern blot analysis showed GRP78 mRNA expression was reduced in the CA1 region of the hippocampus under normothermic conditions, but was not reduced under hypothermic conditions. Western blot analysis also showed the levels of immunoreactive GRP78 protein decreased in neurons of the hippocampal CA-1 region under normothermia, but not under hypothermic treatments. Furthermore, adenovirus-mediated overexpression of GRP78 protects rat hippocampal neurons from cell death and inhibits the rise in intracellular calcium concentration normally induced by hydrogen peroxide. These results suggest that reduction in GRP78 expression contributes to cell damage in the ischemic brain and that hypothermia-mediated restoration of GRP78 expression is one mechanism that enhances neuronal survival.

Amino Acid Sequence↗
PubMed2001

Anti-influenza virus activities of 2-alkoxyimino-n-(2-isoxazolin-3-ylmethyl)acetamides.

A series of 2-alkoxyimino-N-(2-isoxazolin-3-ylmethyl)acetamides and related compounds were synthesized and their antiviral activities against human influenza A virus were assessed. Studies of the structure-activity relationships revealed the strongest antiviral activity when position-5 of the isoxazoline ring was substituted with a tert-butyl group. When the alkoxyimino moiety was substituted with a methyl, ethyl, isopropyl or allyl group, good antiviral activity was obtained. Among the geometrical isomers at the oxime moiety, the E-isomers were more active than the Z-isomers. Among the compounds examined, (E)-2-allyloxyimino-2-cyano-N-(5-tert-butyl-2-isoxazolin-3-ylmethyl)acetamide (1j) was the most active inhibitor with an EC(50) of 3 microg/mL in vitro.

Antiviral Agents↗