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Biomedical subjects

H Sugimoto

Publications and source records attributed to H Sugimoto.

At least 55 records · Page 3Linked to original sources
PubMed2001

Enhanced expression of heat shock proteins in leukocytes from trauma patients.

BACKGROUND: Heat shock proteins (HSPs) play essential roles as molecular chaperones in cells to assist in the repair of degenerated proteins. The expression of HSPs in polymorphonuclear leukocytes (PMNLs) following insult has not been delineated. The objective of this study was to clarify the serial changes in HSP expression in PMNLs from trauma patients. METHODS: Fifty severely injured patients (mean Injury Severity Score of 31.8 +/- 10.8) and 17 healthy volunteers were included as study subjects. Blood samples were serially obtained at three time points: days 0 to 1, days 2 to 5, and days 6 to 14 after the trauma event. We measured expressions of HSP27, HSP60, HSP70, and HSP90 in permeabilized PMNLs by flow cytometry using a monoclonal antibody generated against each HSP and fluorescein isothiocyanate-conjugated antimouse immunoglobulins as secondary reagents. We also evaluated the expression of HSP70 mRNA in PMNLs by Northern blot hybridization and the expression of HSP70 in PMNLs by fluorescence microscopy. RESULTS: Expressions of HSP27, HSP70, and HSP90 in PMNLs from trauma patients were significantly greater than in PMNLs from healthy volunteers in all three periods (days 0-1, days 2-5, and days 6-14). The expression of HSP60 in PMNLs from trauma patients was significantly greater than normal expression on days 2 to 5 and days 6 to 14. The values for HSP27, HSP60, and HSP70 on days 2 to 5 were significantly higher than those on days 0 to 1. The expression of HSP70 mRNA in PMNLs was significantly enhanced for as long as 2 weeks after trauma compared with that in normal volunteers. CONCLUSION: Severe trauma causes demonstrated enhanced expression of HSPs in PMNLs during the acute phase. This enhanced expression of HSPs may regulate PMNL functions.

Adolescent↗
PubMed2001

Activated platelets enhance microparticle formation and platelet-leukocyte interaction in severe trauma and sepsis.

BACKGROUND: Activated platelets have been recently reported to produce platelet microparticles and to enhance platelet-leukocyte interaction. The precise role of platelets in systemic inflammatory response syndrome (SIRS) has not been clarified. The objective of this study was to evaluate microparticle formation and platelet-leukocyte interaction in severe trauma and sepsis. METHODS: Twenty-six patients with severe SIRS (SIRS criteria and serum C-reactive protein > 10 mg/dL) and 12 healthy volunteers were studied. The severe SIRS was caused by trauma in 12 patients and sepsis in 14. Microparticle formation, P-selectin expression on platelets, platelet-monocyte binding, and platelet-polymorphonuclear leukocyte (PMNL) binding were measured by flow cytometry in the presence or absence of ionomycin, N-formyl-methionyl-leucyl-phenylalanine, or anti-CD62p monoclonal antibody. Soluble P-selectin, thrombomodulin, neopterin, and PMNL elastase in blood were also measured. RESULTS: Microparticle formation, P-selectin expression on platelets, platelet-monocyte binding with or without ionomycin, and platelet-PMNL binding with ionomycin significantly increased in patients with severe SIRS in comparison with values in normal volunteers. The increased platelet-leukocyte binding in severe SIRS patients was markedly inhibited by P-selectin blockade and was not enhanced by N-formyl-methionyl-leucyl-phenylalanine. Soluble P-selectin, thrombomodulin, neopterin, and PMNL elastase in blood also increased in these patients. CONCLUSION: Activated platelets enhance microparticle formation and platelet-leukocyte interaction in severe trauma and sepsis. Enhanced platelet-leukocyte interaction is dependent on P-selectin expression and may be involved in the systemic inflammatory response after severe inflammatory insult.

Adolescent↗
PubMed2001

Enhanced expression of heat shock proteins in activated polymorphonuclear leukocytes in patients with sepsis.

BACKGROUND: Heat shock proteins (HSPs) in cells, as molecular chaperons, have been reported to regulate cell functions. The objective of this study was to investigate the HSP expression in polymorphonuclear leukocytes (PMNLs) from severe septic patients and the relation between the expression of HSPs and PMNL function. METHODS: In blood samples from 21 patients with sepsis and serum C-reactive protein levels more than 10 mg/dL, we used flow cytometry to measure expressions of HSP27, HSP60, HSP70, and HSP90; oxidative activity; and levels of apoptosis in PMNLs during sepsis. In in vitro studies, we used cells from 14 healthy volunteers to examine the relation between the expression of HSP70 and PMNL function. Quercetin (30 microM), a suppressor of HSP, and sodium arsenite (100 microM), an inducer of HSP, were used to regulate the expression of HSP70 in PMNLs, and oxidative activity and apoptosis in these cells were measured. RESULTS: In patients with sepsis, the expressions of HSP27, HSP60, HSP70, and HSP90 and oxidative activity in PMNLs were significantly increased. Apoptosis of these PMNLs was markedly inhibited. In the in vitro studies, administration of sodium arsenite enhanced the expression of HSP70, significantly increased oxidative activity, and inhibited apoptosis. Administration of quercetin before sodium arsenite prevented the expression of HSP70, the increase in oxidative activity, and the inhibition of apoptosis. CONCLUSION: Sepsis causes the enhanced expression of HSPs in activated PMNLs. In PMNLs with enhanced expression of HSP70, oxidative activity is increased and apoptosis is inhibited. The enhanced expression of HSPs may play a role in regulating PMNL function in patients with sepsis.

Adult↗
PubMed2001

Granulocyte colony-stimulating factor (G-CSF) stiffens leukocytes but attenuates inflammatory response without lung injury in septic patients.

OBJECTIVE: To determine whether granulocyte colony-stimulating factor (G-CSF) administration changes leukocyte deformability resulting in lung injury in patients with sepsis. METHODS: Twenty-five consecutive septic patients were divided randomly into two groups. Twelve patients were given recombinant human G-CSF subcutaneously at 2 microg/kg once a day for 5 days (group G). The remaining 13 patients were given sterilized saline as placebo (group N). Leukocyte count; concentrations of C-reactive protein (CRP) and thrombomodulin (TM); respiratory index (RI) and lung injury score (LIS); and APACHE II score and Goris MOF index were determined before and after G-CSF or placebo administration. Leukocyte deformability was observed in a microchannel array etched on a single-crystal silicon tip, which simulates the microvasculature. The number of microchannels obstructed (NOM) by stiffened leukocytes was counted. Transit time (TT), that is, the time taken for 100 microL of whole blood to pass through the microchannel, was determined. RESULTS: G-CSF administration significantly increased leukocyte count and decreased CRP concentration. In group G, both NOM and TT increased significantly 5 days after G-CSF administration; they did not change in group N. However, RI, LIS, and TM did not change, suggesting that no patient developed lung injury. CONCLUSION: G-CSF causes leukocyte stiffness but attenuates inflammatory response without inducing lung injury in septic patients.

APACHE↗
PubMed2001

Analytic validation of the enzyme multiplied immunoassay technique for the determination of mycophenolic acid in plasma from renal transplant recipients compared with a high-performance liquid chromatographic assay.

The analysis of mycophenolic acid (MPA) has proved a valuable adjunct to the clinical care of organ transplant recipients. The analytic validation of the enzyme multiplied immunoassay technique (EMIT) for the determination of MPA in plasma is described. The EMIT MPA standard curve was 0 to 15.0 microg/mL, and curve storage was maintained for 4 weeks. The MPA EMIT assay proved reliable and reproducible, as shown by the intra-assay and interassay coefficients of variation (1.58-3.68% and 1.23-7.57%, respectively). Excellent linear correlation ( r = 0.999) was observed for dilution linearity. The sensitivity of the assay was 0.01 microg/mL. Recoveries of 99.4% to 104.2% were obtained by spiking aliquots of three controls of known MPA concentrations with MPA. No interference was observed for endogenous substances and coadministered immunosuppressant drugs, and no cross-reactivity from the major metabolite MPA glucuronide was found. The high-performance liquid chromatography (HPLC) assay used protein precipitation and C18 ion-pair chromatography with ultraviolet detection at 304 nm. Plasma concentrations of MPA were measured using EMIT and HPLC. A linear relationship was observed between EMIT and HPLC (EMIT = 1.091 x HPLC - 0.089; r 2 = 0.990, n = 129). These results indicate that EMIT is a simple, rapid, and sensitive assay method for the measurement of MPA in plasma.

Chromatography, High Pressure Liquid↗
PubMed2001

Dynamic in vitro quantification of bioprosthetic heart valve leaflet motion using structured light projection.

Quantification of heart valve leaflet deformation during the cardiac cycle is essential in understanding normal and pathological valvular function, as well as in the design of replacement heart valves. Due to the technical complexities involved, little work to date has been performed on dynamic valve leaflet motion. We have developed a novel experimental method utilizing a noncontacting structured laser-light projection technique to investigate dynamic leaflet motion. Using a simulated circulatory loop, a matrix of 150-200 laser light points were projected over the entire leaflet surface. To obtain unobstructed views of the leaflet surface, a stereo system of high-resolution boroscopes was used to track the light points at discrete temporal points during the cardiac cycle. The leaflet surface at each temporal point was reconstructed in three dimensions, and fit using our biquintic hermite finite element approach (Smith et al., Ann. Biomed. Eng. 26:598-611, 2001). To demonstrate our approach, we utilized a bovine pericardial bioprosthetic heart valve, which revealed regions of complex flexural deformation and substantially different shapes during the opening and closing phases. In conclusion, the current method has high spatial and temporal resolution and can reconstruct the entire surface of the cusp simultaneously. Because it is completely noncontacting, this approach is applicable to studies of fatigue and bioreactor technology for tissue engineered heart valves.

Algorithms↗
PubMed2001

Human fibroblasts ubiquitously express glutamic acid decarboxylase 65 (GAD 65): possible effects of connective tissue inflammation on GAD antibody titer.

BACKGROUND: Type 1 diabetes is caused by a destruction of pancreatic beta cells due to autoimmunity. Autoantibody against glutamic acid decarboxylase (GAD) 65 expressed in pancreatic beta cells is widely used as a predictive marker for pancreatic destruction. In this study, we hypothesized that if certain cells in periodontal tissues could express GAD, then it may influence GAD antibody titer. METHODS: We used: 1) reverse transcription-polymerase chain reaction (PCR) analysis to detect GAD 65 mRNA in various cells; 2) nucleotide sequencing analysis to confirm that amplified PCR product is the gene encoding GAD; and 3) Western blotting to determine the expression of GAD 65 protein in human gingival fibroblasts. Immunohistochemical staining of GAD 65 protein in normal and inflamed gingiva was performed to examine the potential influence of periodontal inflammation on GAD 65 expression. GAD antibody titer in sera of periodontal patients as well as healthy subjects was measured to determine if periodontal patients could develop autoantibody against GAD 65. RESULTS: Cultured human gingival, periodontal, and dermal fibroblasts and mesangial cells expressed GAD mRNA. Nucleotide sequencing analyses confirmed the amplified PCR product as GAD 65. Western immunoblotting analyses and immunohistochemical staining revealed that the GAD 65 protein was expressed in vitro and in vivo. The expression of GAD 65 in inflamed tissue was higher than that in normal tissues. Two of 62 periodontal patients without diabetes showed an increased antibody titer against GAD 65, while none of the systemically healthy subjects showed an increased antibody titer against this antigen. CONCLUSIONS: We concluded that periodontal inflammation may result in higher levels of GAD and influence GAD antibody titer, and, hence, affect diabetic diagnosis based upon GAD antibody production.

Actins↗
PubMed2001

The effect of antimicrobial periodontal treatment on circulating tumor necrosis factor-alpha and glycated hemoglobin level in patients with type 2 diabetes.

BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) may play an important role in insulin resistance. In this study, we hypothesized that TNF-alpha produced due to periodontal inflammation synergistically affects insulin resistance as well as TNF-alpha produced from adipose tissues in insulin-resistant type 2 diabetes patients. Therefore, to understand the effects of antimicrobial periodontal therapy on serum TNF-alpha concentration and subsequent metabolic control of diabetes, we examined the periodontal and diabetic status on 13 type-2 diabetes patients. METHODS: These patients were treated with local minocycline administration in every periodontal pocket around all existing teeth once a week for a month. Before and after treatment, the number of total bacteria in the periodontal pockets and circulating TNF-alpha concentration were measured and the HbA1c value was assessed. RESULTS: Antimicrobial therapy significantly reduced the number of microorganisms in periodontal pockets (P <0.01). After treatment, the circulating TNF-alpha level was significantly reduced (P <0.015). The HbA1c value was also reduced significantly (P <0.007). In addition, the 6 patients who were not receiving insulin therapy demonstrated decreased fasting insulin levels (P <0.03), and HOMA-R (P <0.03) indices. The average reductions in circulating TNF-alpha concentration and HbA1c value were 0.49 pg/ml and 0.8%, respectively. CONCLUSION: The results indicate that anti-infectious treatment is effective in improving metabolic control in diabetics, possibly through reduced serum TNF-alpha and improved insulin resistance.

Adult↗
PubMed2001

A multicenter prospective randomized controlled trial of the efficacy of mild hypothermia for severely head injured patients with low intracranial pressure. Mild Hypothermia Study Group in Japan.

OBJECT: The criteria for the use of mild hypothermia (34 degrees C) in severely head injured patients have not been standardized. A prospective randomized controlled trial was conducted to determine whether mild hypothermia is essential in the treatment of severely head injured patients with low intracranial pressure (ICP). METHODS: At 11 medical centers, 91 severely head injured patients with an admission Glasgow Coma Scale score of 8 or less in whom ICP could be maintained below 25 mm Hg by conventional therapies were divided randomly into two groups: the mild hypothermia group (HT group, 45 patients) and the normothermia group (NT group, 46 patients). Patients in the HT group were exposed to mild hypothermia (34 degrees C) for 48 hours, followed by rewarming at 1 degrees C per day for 3 days, whereas patients in the NT group were exposed to normothermia (37 degrees C) for 5 days. The two groups were similar with respect to prognostic factors, and there was no difference in clinical outcome at 3 months postinjury. During treatment, there was a significantly greater use of neuromuscular blocking agents in the HT group (p = 0.011). During the initial 2 weeks postinjury, the incidences of pneumonia, meningitis, leukocytopenia, thrombocytopenia, hypernatremia, hypokalemia, and hyperamylasemia were significantly higher in the HT than in the NT group (p < 0.05). CONCLUSIONS: Mild hypothermia should not be used for the treatment of severely head injured patients with low ICP because this therapy conveys no advantage over normothermia in such patients.

Adolescent↗
PubMed2001

[Magnetic resonance (MR) imaging of the shoulder, elbow, and wrist].

Thorough knowledge of small structures in the joints is becoming important as the resolution of magnetic resonance (MR) imaging has improved during the past decade. The author discusses the MR anatomy and pathology of three representative structures in the joints of the upper extremities: the labral-ligamentous complex of the shoulder, ulnar collateral ligament(UCL) of the elbow, and triangular fibrocartilage complex(TFCC) of the wrist. The labral-ligamentous complex is composed of the anterior labrum and three glenohumeral ligaments. Because of their similar MR appearance, the labral sulcus is difficult to differentiate from traumatic detachment of the labrum, even with the aid of MR arthrography. Insertion of the UCL to the medial condyle in the growing elbow presents different MR appearances according to age. Acute and chronic UCL tears are commonly seen in elbows with medial tension overload and are well depicted with three-dimensional Fourier transform(3DFT) gradient-echo images. 3DFT images are the most suitable for observation of the TFCC as well. Since abnormally high signals of the articular disc suggestive of tear are often seen in asymptomatic subjects, MR imaging may not reliably be used to differentiate clinically significant tears from asymptomatic defects. In this review article, the author emphasizes developmental anatomy and normal variations in the interpretation of MR images.

Collateral Ligaments↗
PubMed2001

[Assessment of intra and extrahepatic perfusion during hepatic artery infusion chemotherapy using slow-injected gadolinium-enhanced MR imaging through implanted catheter-port-system].

Twenty-four studies of intra-arterially slow-injected gadolinium-enhanced MR imaging through an implanted catheter-port system (reservoir-MR) were carried out in 15 patients with liver tumor. The flow rate of gadolinium injection was 0.1 ml/sec and a total of 3 mL was injected. Six consecutive phases, each with an acquisition time of 14 seconds, were obtained every 30 seconds. In all studies, the signal intensity of the drug delivery portion became very high. Twenty-three of 24 studies showed intrahepatic perfusion in the first phase. The hepatic vein was enhanced at the first phase in 10 and the second phase in 14. The abdominal aorta was enhanced at the second phase in all 24 studies. The portal vein was enhanced at the first phase in 4, the second phase in 13, and the third phase in 7 studies. Both intra- and extrahepatic perfusion were more clearly demonstrated by reservoir-MRI than by digital subtraction angiography through an implanted catheter-port system (reservoir-DSA); however, morphological changes in the hepatic artery were better demonstrated by reservoir-DSA than by reservoir-MRI.

Adult↗
PubMed2001

[Assessment of intraperitoneal drug distribution during intraperitoneal chemotherapy using saline-injected MR imaging through an implanted catheter-port system].

Intraperitoneal saline-injected MR imaging through an implanted catheter-port system (saline-MRI) was conducted in 7 patients with ovarian tumor after surgical removal of the primary tumor. Two types of T2 weighted coronal images of the abdomen were obtained after saline injection through the implanted catheter-port system. One uses long TE (about 1000 msec) with fat-saturation and thick slices (100 mm thickness) to depict the injected saline alone. The other uses medium TE (about 100 msec) without fat-saturation and thin slices (10 mm thickness) to depict both intraperitoneal saline and abdominal structures. Saline sequentially fills the Douglas pouch, paracolic gutter, Morison's pouch and subphrenic space in most patients. The relation between injected saline and abdominal structures was seen well on T2-weighted images using medium TE. Adhesions of the peritoneum were well demonstrated. In one patient, a catheter perforation to the bowel loop was diagnosed, because the small bowel loop was immediately filled with injected saline. Saline-MRI can be used to depict intraperitoneal drug distribution during intraperitoneal chemotherapy and can diagnose complications related to intraperitoneal chemotherapy.

Adolescent↗
PubMed2000

Sema4c, a transmembrane semaphorin, interacts with a post-synaptic density protein, PSD-95.

Semaphorins are known to act as chemorepulsive molecules that guide axons during neural development. Sema4C, a group 4 semaphorin, is a transmembrane semaphorin of unknown function. The cytoplasmic domain of Sema4C contains a proline-rich region that may interact with some signaling proteins. In this study, we demonstrate that Sema4C is enriched in the adult mouse brain and associated with PSD-95 isoforms containing PDZ (PSD-95/DLG/ZO-1) domains, such as PSD-95/SAP90, PSD-93/chapsin110, and SAP97/DLG-1, which are concentrated in the post-synaptic density of the brain. In the neocortex, S4C is enriched in the synaptic vesicle fraction and Triton X-100 insoluble post-synaptic density fraction. Immunostaining for Sema4C overlaps that for PSD-95 in superficial layers I-IV of the neocortex. In neocortical culture, S4C is colocalized with PSD-95 in neurons, with a dot-like pattern along the neurites. Sema4C thus may function in the cortical neurons as a bi-directional transmembrane ligand through interacting with PSD-95.

Animals↗
PubMed2000

Neuroendocrine-like differentiation in patients with pancreatic carcinoma.

BACKGROUND: The accurate estimation of the rate and the clinicopathologic significance of neuroendocrine-like differentiation (NED) in patients with pancreatic carcinoma have not been studied in detail. METHODS: Forty-four patients with pancreatic carcinoma who underwent surgical resection at the Department of Surgery II, Nagoya University Hospital, were included in this study. For immunostaining, antibodies against neural cell adhesion molecule (NCAM), neuron-specific enolase (NSE), synaptophysin, CD57, and chromogranin A (CGA) were used at given dilutions. At least two positive results with antibodies were considered as NED. Statistical analysis was performed by chi-square and Spearman rank correlation tests for group differences. Survival rates were calculated by the Kaplan-Meier method, and statistical significance was examined using the log rank test. Prognostic factors were tested by univariate and multivariate analyses (proportional hazards regression model). P < 0.05 was considered statistically significant. RESULTS: Of 44 patients examined, 20 showed NED. The distribution of patients with positive or negative NED in terms of age, tumor differentiation, tumor size, and the extent of tumor or lymph node metastasis showed no significant difference. The cumulative survival rates of patient groups according to NED status were then calculated, and NED positive patients showed a significantly better survival rate (P < 0.05). Univariate and multivariate analyses of those factors showed that only NED status and TNM stage were significantly related to overall survival. CONCLUSIONS: The current study suggests the significance of NED status in determining the outcome of patients with pancreatic adenocarcinoma, giving solid evidence to encourage further studies on the differentiation and origin of tumor cells in the pancreas.

Adult↗
PubMed2000

Crystal structure of 1-aminocyclopropane-1-carboxylate deaminase from Hansenula saturnus.

The pyridoxal 5'-phosphate (PLP)-dependent enzyme 1-aminocyclopropane-1-carboxylate deaminase (ACCD) catalyzes a reaction that involves a ring opening of cyclopropanoid amino acid, yielding alpha-ketobutyrate and ammonia. Unlike other PLP-dependent enzymes, this enzyme has no alpha-hydrogen atom in the substrate. Thus, a unique mechanism for the bond cleavage is expected. The crystal structure of ACCD from Hansenula saturnus has been determined at 2.0 A resolution by the multiple wavelength anomalous diffraction method using mercury atoms as anomalous scatterers. The model was built on the electron density map, which was obtained by the density averaging of multiple crystal forms. The final model was refined to an R-factor of 22.5% and an R(free)-factor of 26.8%. The ACCD folds into two domains, each of which has an open twisted alpha/beta structure similar to the beta-subunit of tryptophan synthase. However, in ACCD, unlike in other members of the beta family of PLP-dependent enzymes, PLP is buried deep in the molecule. The structure provides the first view of the catalytic center of the cyclopropane ring opening.

Amino Acid Sequence↗
PubMed2000

E-73, an acetoxyl analogue of cycloheximide, blocks the tumor necrosis factor-induced NF-kappaB signaling pathway.

Proinflammatory cytokines such as tumor necrosis factor (TNF) and interleukin (IL)-1 activate the NF-kappaB signaling pathway which induces the expression of a variety of genes such as the encoding intercellular adhesion molecule (ICAM)-1. We have found that E-73, an acetoxyl analogue of cycloheximide, specifically blocks TNF-induced ICAM-1 expression even at concentrations unable to affect protein synthesis. By contrast, cycloheximide inhibited both TNF- and IL-1-induced ICAM-1 expression primarily due to the blockage of protein synthesis. The nuclear translocation of NF-kappaB as well as the IkappaB degradation induced by TNF, but not by IL-1, was significantly prevented by E-73. These observations suggest that E-73 blocks the TNF-induced NF-kappaB signaling pathway upstream of IkappaB degradation.

Blotting, Western↗
PubMed2000

Intrahepatic anastomosis formation between the hepatic veins in the graft liver of the living related liver transplantation: observation by Doppler ultrasonography.

In living related liver transplantation, the right lobe has come to be used as a graft to meet the metabolic demands of adult or adolescent recipients. In harvesting the right lobe as a graft, however, there is controversy as to whether or not the middle hepatic vein (MHV) should be included and reconstructed. Anatomical intrahepatic anastomosis between the right hepatic vein (RHV) and MHV is considered to exist, but the formation process of this functional anastomosis has not been demonstrated by Doppler ultrasonography (US). In our case, a right lobe including a right branch of the MHV was used as a graft. In implanting, the RHV was anastomosed to the inferior vena cava and the right branch of the MHV was ligated. Using Doppler US, we checked the blood flow in the hepatic vein after transplantation. Within 3 days of surgery, no flow was detected in the right branch of the MHV. A flow around the right branch of the MHV was observed at postoperative day 6. At postoperative day 9, a reverse flow was detected in which the right branch of the MHV drained into the RHV via the anastomosis between them. Based on our results, it appears that a functional intrahepatic anastomosis between hepatic veins formed gradually within 10 days of ligation of an afferent branch, during which time the graft function did not deteriorate.

Adolescent↗