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Biomedical subjects

H Taniguchi

Publications and source records attributed to H Taniguchi.

At least 145 records · Page 8Linked to original sources
PubMed1999

Cutting edge: an inducible sialidase regulates the hyaluronic acid binding ability of CD44-bearing human monocytes.

Previous studies established that variable degrees and types of glycosylation can account for differences in the ability of CD44 to function as a receptor for hyaluronic acid. We have now used neuraminidase treatment to conclude that sialylation negatively regulates CD44 on the human monocytic cell line THP-1 and peripheral blood monocytes. Both of these cell types displayed increased receptor activity after overnight culture with LPS. Of particular interest, the sialidase inhibitor 2-deoxy-2, 3-dehydro-N-acetylneuraminic acid completely blocked the LPS induced recognition of hyaluronic acid by THP-1 cells. Furthermore, acquisition of this characteristic paralleled induction of one type of sialidase activity. Monocytes may be capable of enzymaticly remodeling cell surface CD44, altering their ability to interact with the extracellular matrix.

Azides↗
PubMed1999

Identification of the calmodulin-binding domain of neuron-specific protein kinase C substrate protein CAP-22/NAP-22. Direct involvement of protein myristoylation in calmodulin-target protein interaction.

Various proteins in the signal transduction pathways as well as those of viral origin have been shown to be myristoylated. Although the modification is often essential for the proper functioning of the modified protein, the mechanism by which the modification exerts its effects is still largely unknown. Brain-specific protein kinase C substrate, CAP-23/NAP-22, which is involved in the synaptogenesis and neuronal plasticity, binds calmodulin, but the protein lacks any canonical calmodulin-binding domain. In the present report, we show that CAP-23/NAP-22 isolated from rat brain is myristoylated and that the modification is directly involved in its interaction with calmodulin. Myristoylated and non-myristoylated recombinant proteins were produced in Escherichia coli, and their calmodulin-binding properties were examined. Only the former bound to calmodulin. Synthetic peptides based on the N-terminal sequence showed similar binding properties to calmodulin, only when they were myristoylated. The calmodulin-binding site narrowed down to the myristoyl moiety together with a nine-amino acid N-terminal basic domain. Phosphorylation of a single serine residue in the N-terminal domain (Ser5) by protein kinase C abolished the binding. Furthermore, phosphorylation of CAP-23/NAP-22 by protein kinase C was also found myristoylation-dependent, suggesting the importance of myristoylation in protein-protein interactions.

Amino Acid Sequence↗
PubMed1999

Patterning neuronal and glia cells on light-assisted functionalised photoresists.

A common photosensitive polymeric material used in semiconductor microlithography (diazo-naphto-quinone/novolak resist) was pattern-exposed with near-UV light to create carboxylic-rich areas on the polymer surface. The patterned surfaces were further functionalised via: (1) the anchorage of peptides for specific cell-attachment or cell-detachment functions; or (2) the diffusion of silicon rich chemical species to achieve the cell detachment. Pairs of antagonistic surface characteristics controlled the cell attachment: (1) amino-rich or carboxylic-rich surfaces; and (2) hydrophilic or hydrophobic surfaces; in which the former promoted the adhesion. It was found that common microlithographic materials and techniques can be upgraded to allow an effective control of the lateral organisation of the artificial arrays of neuronal and glia cells.

Animals↗
PubMed1999

Domain organization of flagellar hook protein from Salmonella typhimurium.

Hook forms a universal joint, which mediates the torque of the flagellar motor to the outer helical filaments. Domain organization of hook protein from Salmonella typhimurium was investigated by exploring thermal denaturation properties of its proteolytic fragments. The most stable part of hook protein involves residues 148 to 355 and consists of two domains, as revealed by deconvolution analysis of the calorimetric melting profiles. Residues 72-147 and 356-370 form another domain, while the terminal regions of the molecule, residues 1-71 and 371-403, avoid a compact tertiary structure in the monomeric state. These folding domains were assigned to the morphological domains of hook subunits known from EM image reconstructions, revealing the overall folding of hook protein in its filamentous state.

Bacterial Proteins↗
PubMed1999

Endothelin antagonist treatment for successful liver transplantation from non-heart-beating donors.

BACKGROUND: With the shortage of cadaveric donors, non-heart-beating donors (NHBDs) are a potential source of liver allografts. However, warm ischemic injury in NHBDs seriously affects the viability of graft liver. Endothelin (ET)-1 has been reported to be involved in the hepatic microcirculatory disturbances after ischemia-reperfusion. METHODS: In a porcine orthotopic liver transplantation model, changes in the serum and liver tissue ET-1 concentration were measured and the effects of an ET receptor antagonist, TAK-044, were evaluated. After cardiac arrest of the donors, liver allografts were subjected to 90 min of warm ischemia, flushed, and preserved for 4 hr at 4 degrees C. The pigs were divided into two groups: a control group (no drug treatment) and a drug-treated group, in which donors and recipients were treated with TAK-044 (10 mg/kg body, drip intravenous injection). Both groups had six donor/recipient pairs. RESULTS: -The ET-1 concentration in the hepatic venous blood increased after reperfusion of the graft in the control group recipients. ET-1 in the graft liver significantly increased during the cold preservation period. TAK-044 treatment significantly increased recipient 7-day survival rate. After reperfusion of the graft, the concentrations of serum liver enzymes and arterial lactate in the drug-treated group were significantly lower than in the control group. The postoperative increase in portal venous pressure was significantly reduced in the drug-treated group. Measurements of liver enzymes in the washed-out preservation fluid at the time of graft rinsing indicated that TAK-044 treatment of the donors significantly suppressed liver enzyme release during ischemia. CONCLUSIONS: These findings indicate TAK-044 treatment has protective effects on postoperative function of hepatic allografts procured from NHBDs.

Alanine Transaminase↗
PubMed1999

Using the spleen for time-delay correction of the input function in measuring hepatic blood flow with oxygen-15 water by dynamic PET.

By the spleen, we calculated a time-delay correction of the input function for quantitation of hepatic blood flow with oxygen-15 water and dynamic positron emission tomography. The time delay (deltat) between the sample site and the spleen was calculated based on nonlinear multiple regression analysis when splenic blood flow was determined. Then hepatic blood flow was quantified by a method using the input function and incorporating deltat, which was assumed to be equal to the time delay between the sample site and the liver. Then hepatic arterial and portal blood flows were estimated separately as well as the delay time for passage within the organs of the portal circulation. The mean coefficient of variation and the mean sum of squares of errors decreased to about 70% when total hepatic blood flow was calculated from the results for regions of interest in three slices of the same liver segment. We concluded that using the spleen for time-delay correction of the input function for measuring hepatic blood flow by this method gave satisfactory results.

Adult↗
PubMed1999

Evidence for a contribution of store-operated Ca2+ channels to NO-mediated endothelium-dependent relaxation of guinea-pig aorta in response to a Ca2+ ionophore, A23187.

A23187 (6S-[6alpha,8beta,9beta,11alpha]-5-(methylamino) -2-[[3,9,11-trimethyl-8-[1-methyl-2-oxo-2-(1H-pyrrol-2-yl)ethyl]-1,7- dioxaspiro[5.5]undec-2-yl]methyl]-4-benzoxazolecarboxylic acid, calcimycin), an antibiotic Ca2+ ionophore, produces an endothelium-dependent vascular relaxation. In the present study, pharmacological features were functionally characterized of endothelium-dependent relaxant response of guinea-pig aorta to A23187, especially focusing on the possible Ca2+ source and Ca2+ mobilization mechanisms in endothelial cells responsible for the vasorelaxant response to the Ca2+ ionophore. A23187-induced endothelium-dependent relaxation was suppressed profoundly by N(G)-nitro-L-arginine (L-NNA; 3 x 10(-4) M) or calmidazolium (3 x 10(-5) M), suggesting that nitric oxide (NO) produced by the enhanced activation of Ca2+/calmodulin-dependent endothelial NO synthase (eNOS) is largely responsible for the relaxant response of this artery to A23187. In the Ca2+-free solution without EGTA, NO-mediated endothelium-dependent relaxation induced by A23187 was almost abolished, which suggests that Ca2+ entry from extracellular space into endothelial cells plays the key role in the A23187-induced functional vasorelaxation. On the other hand, SK&F96365 (1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole; 5 x 10(-5) M) and Ni2+ (3 x 10(-4) M), both of which inhibit capacitative Ca2+ influx through store-operated Ca2+ channels (SOCCs), attenuated significantly NO-mediated endothelium-dependent relaxation by A23187. Furthermore, A23187-induced endothelium-dependent relaxation was suppressed more strongly than endothelium-independent relaxation induced by SIN-1 (3-morpholino-sydnonimine), an NO donor, when aortic preparation was preconstricted with high KCl instead of agonistic stimulation (prostaglandin F2alpha). These findings suggest that NO-mediated endothelium-dependent relaxant response of guinea-pig aorta to A23187 is preceded by the increase in endothelial cytosolic free Ca2+ concentration ([Ca2+]cyt) due to the enhanced Ca2+ influx from extracellular space. In the enhanced Ca2+ entry leading to the stimulation of eNOS and NO-mediated functional relaxant response of guinea-pig aorta to A23187, activation of SOCCs but not the Ca2+ entry through plasma membrane Ca2+-specific routes made by A23187 seems to play the predominant role. It is most likely that A23187 acts primarily at the Ca2+ store sites in endothelial cells, which subsequently depletes stored Ca2+ to activate SOCCs via unidentified mechanisms.

Animals↗
PubMed1999

An endothelin receptor antagonist ameliorates injuries of sinusoid lining cells in porcine liver transplantation.

BACKGROUND: TAK-044 is an endothelin receptor antagonist. Whether the agent has protective effects on liver graft injuries from non-heart-beating donors is unknown. METHODS: In donor pigs, cardiac arrest was induced by stopping the respirator. Forty-five minutes after cessation of the respirator, the liver was flushed with University of Wisconsin (UW) solution, preserved for 8 hours at 4 degrees C, and transplanted orthotopically. The pigs were divided into two groups: a control group and a drug-treated group in which TAK-044 was given in the UW solutions (10 mg/L) and was administered to recipients (10 mg/kg body weight). RESULTS: TAK-044 treatment significantly increased recipient survival rate. After reperfusion of the graft, portal venous pressure and 15-minute retention rate of indocyanine green were significantly reduced in the drug-treated group. Electron microscopic findings indicated that TAK-044 attenuated endothelial cell injuries. CONCLUSION: TAK-044 treatment improves the viability of livers harvested from non-heart-beating donors. The main effect of the agent is protection of endothelial cells from ischemia/reperfusion injuries.

Animals↗
PubMed1999

Examination of the relationship between parameters to determine electropermeability of Saccharomyces cerevisiae.

A rectangular electric pulse was applied to Saccharomyces cerevisiae suspensions in NaCl solutions. The relationship between field strength, pulse width and conductivity of extracellular media of key--factors to determine the yield of electropermeability--was examined at the time when the same permeability occurred. The results showed that the dependence of the yield of permeability upon the width of applied pulse was mutually related with the conductivity of extracellular media. Namely at one field strength, the value of pulse width is inversely proportional to that of conductivity of media and its relationship holds true for any field strength. Further, the relationship between parameters considered bears a close resemblance to that recognized between stress amplitude and the number of cycles to failure in the fatigue fracture of materials.

Cell Membrane Permeability↗
PubMed1999

A case of reflex sympathetic dystrophy (complex regional pain syndrome, type I) resolved by cerebral contusion.

We present a case of refractory reflex sympathetic dystrophy (RSD) (complex regional pain syndrome, type I) whose symptoms (ongoing pain, allodynia, hyperhydrosis and temperature abnormalities) were resolved after the patient suffered a traumatic cerebral contusion in the left temporal lobe, which caused no neurological deficit. This case suggests that symptoms of some RSD patients may largely sustained by a complex network involving the brain.

Brain Concussion↗
PubMed1999

Apoptosis of the hyaloid artery in the rat eye.

The hyaloid artery is a vestigial vessel situated on the optic nerve extending to the posterior surface of the lens in the vitreous cavity of the eye. We studied the nature and pattern of cell death during regression of the hyaloid artery. The cells comprising the hyaloid artery appear to be alive for 20 days after birth in the rat, and cell death during regression of the hyaloid artery has the characteristics of apoptosis. We observed apoptotic bodies containing condensed chromatin and identified the hyaloid vessels as targets of macrophage-mediated remodelling. Using the "TUNEL method" for labeling fragmented DNA in vascular cells, we assessed the pattern of apoptotic cell death during hyaloid artery regression. Our study demonstrated the appearance of apoptosis in pericytes as well as endothelial cells during regression in the vasculature. In pericytes, apoptosis appeared to begin or to occur more frequently than in endothelial cells. Both morphological and TUNEL analyses indicated that capillary apoptosis occurs mainly from day 10 to day 20 after birth rather than from the 1st day. Macrophages were present near the hyaloid artery and these may influence apoptosis.

Aging↗
PubMed1999

Overexpression of CD44 on alveolar eosinophils with high concentrations of soluble CD44 in bronchoalveolar lavage fluid in patients with eosinophilic pneumonia.

BACKGROUND: High levels of interleukin-5 (IL-5) are found in the alveolar space of patients with eosinophilic pneumonia (EP). IL-5 promotes the growth and differentiation of eosinophils, as well as activating these cells. IL-5 also induces the expression of CD44 on eosinophils in vitro. To evaluate the contribution of CD44 to the pathogenesis of EP, we examined the expression of CD44 on eosinophils in bronchoalveolar lavage fluid (BALF) and measured the concentration of soluble CD44 (sCD44) in BALF from patients with EP. METHODS: The concentrations of IL-5, sCD44, and hyaluronic acid (HA) were measured in BALF. The expression levels of CD44 on eosinophils in BALF and peripheral blood in patients with EP were compared. RESULTS: The expression of CD44 on alveolar eosinophils and the concentration of sCD44 were increased in BALF of patients with EP. There was a significant correlation between IL-5 and sCD44 in BALF. A high concentration of HA was observed in BALF of EP patients. CONCLUSIONS: Our results suggest that the high expression of CD44 on eosinophils probably results from upregulation by IL-5 and could be important in the pathogenesis of EP.

Adult↗
PubMed1999

Activation of lymphocytes and increased interleukin-5 levels in bronchoalveolar lavage fluid in acute eosinophilic pneumonia.

Acute eosinophilic pneumonia (AEP) is a recently described illness and the number of case reports has increased during the last few years. However, the role of interleukin (IL)-5 and activated lymphocytes in the pathogenesis or activity of AEP is still not clear. The clinical features, lymphocyte surface analysis and IL-5 concentrations in bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) of a young female patient with AEP are described before and at 2 weeks, 4 weeks and 6 months after a 3-day course of i.v. methylprednisolone. Serum and BALF concentrations of IL-5 before treatment were 5,200 and 8,400 pg x mL(-1), respectively. Activated CD4 lymphocytes bearing CD25 and human leukocyte antigen (HLA)-DR in BALF were higher than in PB. Treatment caused a rapid fall in these cells and levels of IL-5 in BALF returned to normal levels in parallel with clinical improvement. There was no evidence of recurrence after cessation of steroid therapy. In contrast, eosinophilia in BALF persisted for 4 weeks after steroid therapy in spite of normalization of the chest radiograph and arterial blood gases. The number of CD8+CD11b- (suppressor/cytotoxic) T-cells subsequently increased while the number of CD8+CD11b+ cells decreased. These results suggest that activated CD4 cells and interleukin-5 elevation contribute to the development of acute eosinophilic pneumonia rather than persistent eosinophilia in the lung and that a short course of steroid therapy may effectively control acute eosinophilic pneumonia.

Acute Disease↗
PubMed1999

Chromosomal aberrations in human hepatocellular carcinomas associated with hepatitis C virus infection detected by comparative genomic hybridization.

Thirty-five hepatocellular carcinomas (HCCs) associated with hepatitis C virus (HCV) were analysed by comparative genomic hybridization (CGH), to screen for changes in copy-number of DNA sequences. Chromosomal losses were noted in 1p34-36 (37%), 4q12-21 (48%), 5q13-21 (35%), 6q13-16 (23%), 8p21-23 (28%), 13q (20%), 16q (33%) and 17p13 (37%). Gains were noted in 1q (46%), 6p (20%), 8q21-24 (31%) and 17q (43%). High level gains indicative of gene amplifications were found in 7q31 (3%), 11q13 (3%), 14q12 (6%) and 17q12 (3%); amplification at 14q12 may be characteristic for HCCs. No significant difference in chromosomal aberrations was noted between carcinomas associated with HCV-infection in our study and those reported earlier in HCCs infected with hepatitis B virus (HBV), indicating that both HBV- and HCV-related carcinomas may progress through a similar cascade of molecular events.

Carcinoma, Hepatocellular↗
PubMed1999

No survival benefit from combined pancreaticosplenectomy and total gastrectomy for gastric cancer.

BACKGROUND: It remains unknown whether extended surgery improves the survival rate of patients with gastric cancer. This study was a review of combined pancreaticosplenectomy with total gastrectomy for gastric cancer. METHODS: The clinicopathological details of 190 patients who underwent combined pancreaticosplenectomy with total gastrectomy between 1969 and 1996 were compared retrospectively with those of 206 patients who underwent total gastrectomy with splenectomy alone. RESULTS: There was no statistical difference in the survival rate when pancreaticosplenectomy was added to total gastrectomy. The mortality rate was similar, but the morbidity rate was higher in patients who had pancreaticosplenectomy. Six patients who had direct pancreatic invasion and two thought to have involved lymph nodes along the splenic artery survived for more than 5 years after operation. In the latter group, the metastatic lymph nodes along the splenic artery could have been resected without pancreatectomy. CONCLUSION: Since a combined pancreaticosplenectomy adds no survival advantage to total gastrectomy for gastric cancer, this procedure should no longer be regarded as routine.

Female↗
PubMed1999

Conradi-Hünermann syndrome with ocular anomalies.

We report a Japanese girl with the Conradi-Hünermann form of chondrodysplasia punctata and anterior segment malformations characteristic of Axenfeld-Rieger syndrome. The patient also had cataracts and unilateral optic atrophy. A possible role for homeobox-containing genes in the etiology of this type of chondrodysplasia punctata is suggested as an explanation for the coincidence of these two syndromes.

Anterior Eye Segment↗
PubMed1999

Number and anatomical extent of lymph node metastases in gastric cancer: analysis using intra-lymph node injection of activated carbon particles (CH40).

BACKGROUND: The long-term survival of 200 patients with gastric cancer who underwent radical gastrectomy was analyzed with respect to the number and anatomical extent of lymph node metastasis. All of the patients received intra-lymph node injection of fine activated carbon particle solution (CH40) during surgery. METHODS: The average number of resected lymph nodes increased in line with the anatomical level of lymph node dissection; 32.5 per patient in D1, 42.3 in D2, 3 and 66.3 in D4. The percentage of blackened lymph nodes without metastasis (42.4%) was slightly higher than that of lymph nodes containing metastasis (37.2%), but the difference was not statistically significant. Of the 200 patients, 61 (30.5%) had microscopic evidence of metastatic lymph node involvement. Twenty-two patients had between one and three metastatic lymph nodes, 19 had between four and nine and 20 patients had more than nine. The 5-year survival rate was 93.1% in patients without lymph node metastasis, 71.9% in patients with 1-8 metastatic nodes, 36.1% in patients with 4-9 nodes and 19.2% in patients with > 9 nodes. RESULTS: The 5-year survival rate according to the anatomical extent of metastatic lymph nodes was 93.1% in n0, 63.1% in n1, 37.9% in n2, 27.8% in n3 and 0% in n4. The number of metastatic lymph nodes and also their anatomical extent were identified as independent prognostic factors for survival by multivariate analysis. CONCLUSION: The number and anatomical extent of metastatic lymph nodes have similar impacts on prognosis in gastric cancer.

Adult↗