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Biomedical subjects

K Yasui

Publications and source records attributed to K Yasui.

At least 163 records · Page 9Linked to original sources
PubMed1997

Distribution pattern of HNF-3beta proteins in developing embryos of two mammalian species, the house shrew and the mouse.

The pattern of expression of HNF-3beta in organizing centers and axial structures during early vertebrate development suggests an important role for this protein in the establishment of the vertebrate body plan. To establish whether the pattern of expression during embryogenesis is species specific, a comparative immunohistochemical study of two mammalian species, the house shrew, insectivore, and the mouse was carried out; it is difficult to obtain accurate morphological differences from the study of remotely related animals. The earliest expression of HNF-3beta appeared in the node and hypoblast (or endoderm) in both species, where the presumptive foregut endoderm showed intense immunoreactivity prior to the formation of the axial mesoderm, suggesting a role different from that in axial formation. The anterior extension of immunopositive axial mesoderm and the median band of the neural plate varied between the two species, and was delayed in the house shrew. HNF-3beta in the anterior end of the foregut disappeared transiently in the house shrew but persisted in the mouse embryo. An asymmetric pattern of distribution in the primitive streak was also observed in the mouse but not in the house shrew. The present immunohistochemical study elucidated that the distribution of HNF-3beta is conserved initially but soon manifests species specificities in development even between mammalian species.

Animals↗
PubMed1997

A new macroscopic classification predicts prognosis for patient with liver metastases from colorectal cancer.

OBJECTIVE: The authors defined a new macroscopic classification of liver metastases from colorectal cancer. SUMMARY BACKGROUND DATA: There were different prognostic results after the same operative procedure for liver metastases with similar background factors. METHODS: Eighty-one resected liver metastases were classified into simple nodular (SN) or confluent nodular (CN) types according to the characteristics of the cut surface of the tumor. RESULTS: The 5-year survival rates after hepatectomy were 41.7% for the SN lesions (n = 39) and 23.1% for the CN lesions (n = 42). The difference between the survival curves was statistically significant (p = 0.0307). Multivariate analysis using Cox's proportional hazards model revealed that the macroscopic type (p = 0.023), the tumor diameter (p = 0.0001), and the presence of lymph node metastases (p = 0.0016) were statistically significant independent prognostic factors. CONCLUSION: The new macroscopic classification may be valuable as a prognostic factor reflecting the biologic behavior of liver metastases.

Colorectal Neoplasms↗
PubMed1997

Surgical treatment of early cancer of the proximal third of the stomach.

A retrospective study was conducted in search of an optimal surgical procedure for early cancer of the proximal stomach. The clinicopathological findings and survival data of 128 patients operated on during a recent period of 16 years were analyzed. Nodal metastasis was found in 12% of the patients and had a significant influence on the survival. It was more frequently observed in the undifferentiated type, regardless of the tumor size. Most metastases were found in the proximal paragastric nodes, and no metastasis was observed in the pyloric region or at the splenic hilum. These facts suggest that while the resection of paragastric nodes is advocated, neither total gastrectomy nor splenectomy is required simply for the purpose of lymphadenectomy.

Humans↗
PubMed1997

Involvement of thromboxane A2 in antigen-induced nasal blockage in guinea pigs.

To estimate the involvement of thromboxane (Tx) A2 in the onset of nasal blockage, we examined the effect of the selective TxA2 receptor antagonist, S-1452, as well as an H1-antihistamine, diphenhydramine, on the antigen-induced increase in intranasal pressure, as an index of nasal blockage, in anesthetized guinea pigs actively sensitized by inhalation of aerosolized ovalbumin (OA). Oral administration of S-1452 or intravenous administration of diphenhydramine significantly but incompletely reduced the increase in intranasal pressure following exposure of the nasal cavity of guinea pigs to aerosolized OA. In combination, the two agents were more effective than either alone, but there was no significant difference between them. The TxB2 level was significantly elevated in nasal lavage fluid 15 and 30 min after antigen challenge. Exposure of the nasal cavity of guinea pigs to aerosolized U-46619, a TxA2 mimetic, also resulted in a marked increase in intranasal pressure, and this could be almost completely suppressed by S-1452. These findings suggest that TxA2 contributes to antigen-induced nasal blockage in guinea pigs.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1997

Successful blade atrial septostomy in a patient with severe primary pulmonary hypertension--a case report.

Blade atrial septostomy (BAS) for pulmonary hypertension has increased long-term survival and is an effective and palliative preliminary to heart and/or lung transplantation. We treated an 18-year-old woman with severe pulmonary primary hypertension whose symptoms had worsened as a resulted low cardiac output. The patient's right ventricular pressure was 150/23 mmHg, cardiac index (CI) 1.0 L/min per m2, and she showed signs and symptoms of severe primary pulmonary hypertension. We performed BAS successfully, paying particular attention to the following points. To maintain pulmonary blood flow after creating an atrial right-to-left shunt, the patient was infused intravenously with packed red blood cells and volume expander. Oxygen delivery was also increased by the transfusion of packed red blood cells. To avoid unacceptable hypoxemia immediately after the procedure, the atrial septum was initially incised with a very small-blade catheter. Nine months after the BAS, catheterization revealed a decrease in mean pulmonary arterial pressure to 73 mmHg and an increase in CI to 2.5 L/min per m2. Thirteen months after the BAS, the patient died as a result of progressive worsening of right-sided heart failure. We concluded that BAS could be successful in patients with severe pulmonary hypertension providing attention is paid to the patient's condition and that BAS is an effective therapy for prolonging survival.

Adolescent↗
PubMed1997

Plasma concentration of matrix metalloproteinase 9 in gastric cancer.

BACKGROUND: The clinical significance of plasma concentration of matrix metalloproteinase 9 (MMP-9) was investigated in patients with gastric cancer. METHODS: Plasma was obtained from 138 healthy individuals and 70 patients who underwent gastrectomy for gastric cancer at Aichi Cancer Centre between August 1994 and July 1995. Plasma concentrations of MMP-9 were measured using a one-step sandwich enzyme immunoassay employing monoclonal antibodies. RESULTS: Patients with gastric cancer had plasma higher concentrations of MMP-9 than normal subjects. Postoperative concentrations of MMP-9 were lower than preoperative levels. In addition to patients with advanced cancer, those with early gastric cancer also exhibited higher mean values of and positivity rates for MMP-9 than healthy individuals. Preoperative plasma MMP-9 concentration correlated closely with Union Internacional Contra la Cancrum tumour node metastasis (pTNM) stage, severity of T, N and M classification, and tumour size. CONCLUSION: Plasma MMP-9 concentration can be used for detection of primary or recurrent gastric cancer, and for estimation of tumour extent.

Adult↗
PubMed1997

Assembly of JC virus-like particles in COS7 cells.

JC virus lacks an appropriate cell line to support virus replication. The establishment of a JC pseudovirus assembly system could play an alternative role for a virus culture system. COS7 cells and a transfer vector, pcDL-SR alpha 296, were used to express JC viral structural genes. VP231-SR alpha, which encodes VP2/VP3 and VP1, but lacks 137 bp of the 5'-terminus of agnogene, showed both efficient nuclear migration and quantitative expression of the major capsid protein VP1. JC pseudovirus assembly was observed in the nucleus of VP231-SR alpha transfected cells. Evidence of JC pseudovirus assembly is presented. The further utilization of this system, which includes a study for the viral morphogenesis, serological diagnosis, as well as the potential application for gene transfer vector, is discussed.

Animals↗
PubMed1997

[Acute viral infection].

Expression of neuronal diseases by acute viral infection concerns itself with the mechanisms of the virus-host neuronal cell interactions. The neuropathogenecity of a virus can be determined by the availability of specific host macromolecules in the neuronal cells for such virus and ability of virus-coded molecules to interact with those host macromolecules. Factors concerned with the neuropathogenecity may be a receptor, transcription or replication factor, or translation initiation factor and virus structural and non-structural proteins.

Acute Disease↗
PubMed1997

[A comparison of ultrasonography and cerebral angiography for the evaluation of extracranial carotid stenosis].

To investigate the usefulness of extracranial carotid ultrasonography for atherosclerotic plaque, we performed carotid ultrasonography and cerebral angiography (CAG) and classified the severity of the stenosis into 6 scores. We filmed 2-4 images (anterior, lateral, right anterior oblique and left anterior oblique views) for each vessel on CAG. There were 104 cases (169 vessels) with suspected or definite cerebrovascular disease. Both scores agreed in 67.5% of cases. In cases with over 50% stenosis on CAG, the scores agreed in 19 of 20 cases. But in cases with 50% or less stenosis on CAG, the scores agreed in only 95 of 149 cases. In most cases where scores were different, scores for ultrasonography were higher than those for angiography. The inconsistency of scores was attributed to eccentric plaque of early carotid atherosclerosis, uniform thickening of the intima-media complex and remodeling of the vessels. We filmed 4 images for 39 vessels to elevate CAG sensitivity for carotid stenosis. The results based on 4 images did not differ significantly from those based on 2 images. Carotid remodeling, or vessel enlargement in relation to the plaque area, was seen in 2 cases. Ultrasonography, which provided real-time information about both lumen and vessel wall characteristics, was necessary to make the diagnosis of carotid remodeling.

Aged↗
PubMed1996

90-kDa S6 kinase is insufficient or not involved in the activation of glycogen synthase induced by insulin.

Insulin and growth factors increase glycogen synthesis via complex pathways including protein phosphorylation/dephosphorylation processes. We investigated the involvement of 90-kDa S6 kinase in the control of insulin- or epidermal growth factor (EGF)-stimulated glycogen synthase activation using newly synthesized compounds which selectively inhibit 90-kDa S6 kinase. HH-5709 (1-(5-hydroxynaphthalenesulfonyl)-1H-hexahydro-1,4-diazepine) inhibited 90-kDa S6 kinase at lower concentrations than observed for protein kinases A or C. The inhibition by HH-5709 was competitive with respect to ATP with a Ki value of 1.3 microM. H-7, an inhibitor of protein kinases A and C, and HA-1077 (1-(5-isoquinolinesulfonyl)-homopiperazine), where the naphthalene ring of HH-5709 was replaced with isoquinoline, also inhibited 90-kDa S6 kinase to a similar extent as HH-5709. In 3Y1 fibroblasts, H-7 and HA-1077 attenuated the activation of glycogen synthase. HH-5709, however, failed to affect the glycogen synthase activation by either insulin or EGF. These findings suggest that 90-kDa S6 kinase is unrelated or insufficient to mediate activation of glycogen synthase and that unidentified pathway(s) sensitive to H-7 or HA-1077 would be involved in the activation of glycogen synthase by insulin or EGF in 3Y1 fibroblasts.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1996

Gastric stump carcinoma after partial gastrectomy for benign gastric lesion: what is feasible as standard surgical treatment?

METHOD: Clinicopathological features and prognostic factors were evaluated in 26 cases of stump carcinoma, operated on in the recent 20 years, in search of the standard surgical treatment. BACKGROUND: Stump carcinoma usually emerges more than 20 years after the initial gastrectomy and is often not diagnosed in the early clinical stage, resulting in a significantly low incidence of curative resection compared with primary gastric carcinoma. RESULTS: No improvement in the survival curves for stump carcinoma was observed between the past two decades. Nodal metastases were frequently found within the first tier nodes, and no 5-year survivor was found among the patients with nodal metastasis beyond pN1. CONCLUSIONS: Subtotal gastrectomy might suffice for the treatment of stomal cancer, and most patients might not benefit from extensive lymphadenectomy.

Carcinoma↗
PubMed1996

Developmental pattern of axonal pathways in the house shrew maxillary nerve.

The topographic patterns of peripheral receptors and effectors seem to contribute to the construction of the neuronal circuit in the central nervous system (CNS) in mammals. Many patterns replicating those of the periphery have been found in the CNS, and fasciculation has been regarded as having a central role in the pattern replication. The house shrew, Suncus murinus, is an excellent species in which to study this topic because it has a vibrissae system arranged in a single ordered fashion and extraordinarily well-developed trigeminal spinal tracts. Using immunostaining and retrograde-tracing techniques, we examined the developmental pattern of the maxillary nervous system in the house shrew. The results indicate that the basic pattern of axonal extension reiterates with a parallel arrangement throughout the course of development except at a site in the brainstem where the central processes bifurcate into ascending and descending branches. Dorsoventral inversion of the peripheral pattern in the spinal tract occurs with this dual-leveled bifurcation in association with the mediolaterally ordered entry of the central processes into the brainstem. The basic pattern of the central processes is established prior to the appearance of the vibrissae, indicating that the basic topographic pattern of the maxillary nerve is not related to the vibrissae system. The fasciculation pattern does not correspond to the overall layout of the arrays of vibrissae, and there are frequent exchanges of axons between fascicles both in the periphery and centrally. The parallel organization of the majority of the processes, together with the free exchange of processes between fascicles, suggests that these processes have an important role in the formation of the fasciculation and somatotopic patterns.

Age Factors↗
PubMed1996

Identification of peptides mimicking the antigenicity and immunogenicity of conformational epitopes on Japanese encephalitis virus protein using synthetic peptide libraries.

Monoclonal antibodies (mAbs) N.03 and N.08 that recognize conformational epitopes on the prM protein of Japanese encephalitis virus (JEV) were analyzed to identify their peptide ligands by using a novel approach that combined two different synthetic peptide libraries. Immunoscreening of a library containing 20(5) sequences of pentapeptides revealed that the ligands for N.03 and N.08 had motif sequences, (Y/W/F)GG(I/L/M) and (N/Q)WY(D/E), respectively. To select higher-affinity ligands, we synthesized and screened another type of library with 20 peptide mixtures that were based on the identified motif, where only one amino acid position was defined; and the process was reiterated for the remaining undefined positions. Consequently, the peptides YGGIYMNG and QWYDDR were identified as peptide ligands of N.03 and N.08, respectively. These peptides bound specifically to the antigen-combining sites of the mAbs as confirmed by competitive binding assays. Mouse antisera directed against the peptide YGGIYMNG specifically recognized JEV, while those against QWYDDR did not. These data demonstrated that peptide ligands which reproduce or mimic the immunogenicity as well as the antigenicity of conformational epitopes can be at least partly identified using this approach. This approach may be useful for analyzing conformational epitopes, which are generally difficult to characterize, and might provide a step toward vaccine development when applied to protective mAbs.

Antigens, Viral↗
PubMed1996

Side effects of high-dose interferon therapy for chronic hepatitis C.

BACKGROUND/AIMS: Various side effects have been reported in patients treated with alpha interferon, but their incidence and prognosis remain unknown. METHODS: Nine hundred and eighty-seven patients with chronic active hepatitis C received 6 to 10 MU of alpha interferon per day for 2 weeks and 3 times per week for 22 weeks. Autoantibodies, thyroid function tests, and fasting plasma glucose concentrations were evaluated prior to alpha interferon therapy. RESULTS: Of the 987 patients, 310 were required reduction in the dose of alpha interferon to 3 MU/day or cessation of alpha interferon therapy because of adverse reactions such as flu-like symptoms, leukopenia, and thrombocytopenia. Of the remaining 677, five developed diabetes mellitus, 12 had hyperthyroidism, and six acquired hypothyroidism. Of the 18 with thyroid disorders, five demonstrated antimicrosomal antibodies before therapy. Forty-four patients revealed high or low concentrations of thyroid stimulating hormone at the end of alpha interferon therapy. Three patients developed interstitial pneumonia, one acquired systemic lupus erythematosus-like syndrome, two had autoimmune hepatitis, two developed rheumatoid arthritis, and one developed autoimmune thrombocytopenic purpura. No patients had a history of an autoimmune disorder. One patient experienced sudden hearing impairment and one had retinal detachment. Melena was seen in three patients; two of these cases were compatible with ischemic colitis. Symptoms of depression were seen in 23 patients, and one patient manifested memory loss. CONCLUSION: High-dose alpha interferon therapy induces various adverse effects. Most of the side effects cannot be predicted, but are reversible.

Adult↗
PubMed1996

Regulation of neutrophil O2- production by neutrophil-endothelial cell interaction via CD11b: its modulation by tumor necrosis factor-alpha (TNF-alpha) and lipopolysaccharide (LPS).

Polymorphonuclear leukocyte-endothelial cell (PMN-EC) adhesion and the O2- production by subsequently triggered polymorphonuclear leukocytes (PMN) must be involved in the development of multiple organ failure at septic inflammatory sites. In this study, the adhesion and O2- production of PMN treated with LPS and serum, were markedly enhanced on the EC monolayer by treatment with TNF-alpha or LPS. However, in the intact EC monolayer, neither adhesion nor O2- production was increased. Monoclonal antibodies (mAb) against CD18, CD11b, and ICAM-1 inhibited PMN-EC adhesion. All antibodies except for anti-CD11b mAb had no effect on O2- production by adhered PMN. Anti-CD11b mAb stimulated O2- production in a PMN cell suspension. The pertussis toxin, an inhibitor of some G-proteins, inhibited this reaction. These findings indicate that the adhesion mediated by CD11b provides the signal for O2- production by PMN. This O2- production may involve a signal transduction mechanism mediated by pertussis toxin-sensitive G-proteins.

Cell Communication↗