Biomedical subjects

A Kato

Publications and source records attributed to A Kato.

At least 271 records · Page 15Linked to original sources

PubMed1998

Immunotherapy decreases seasonal rise in serum-soluble CD23 in seasonal allergic rhinitis.

There is increasing in vitro evidence that soluble CD23 (sCD23) is capable of potentiating IgE synthesis, but the in vivo physiologic significance remains to be established. This study investigated the seasonal changes in sCD23 in patients with seasonal allergic rhinitis. It included 112 adult patients with seasonal allergic rhinitis due to Japanese cedar pollens and 20 nonatopic healthy volunteers. The 64 patients of the pharmacotherapy group were treated with nonsedating antihistamine tablets alone throughout the pollen season and the remaining 48 patients of the immunotherapy group continued to be treated with immunotherapy. Serum concentrations of sCD23 were measured in each patient, before and during the pollen season of 1996, by a sandwich enzyme-linked immunosorbent assay. The serum levels of sCD23 in the pharmacotherapy group before the pollen season were significantly higher than those in the nonatopic group (P = .0130) and those in the immunotherapy group (P = .0316). Seasonal increase in sCD23 was significant in the pharmacotherapy group, irrespective of the clinical response (P < .0001). By contrast, sCD23 was not significantly increased in the good responders to immunotherapy (P = .1826), but was significantly increased in the poor responders to immunotherapy (P = .0052). A significant correlation between seasonal increase in rate in specific IgE and seasonal increase in rate in sCD23 was confirmed in both the pharmacotherapy group (rs = 0.321, P = .0107) and the immunotherapy group (rs = 0.474, P = .0012). In conclusion, seasonal rise in sCD23 is associated with and is probably involved in seasonal rise in specific IgE in patients with seasonal allergic rhinitis, and successful immunotherapy is capable of blunting seasonal increase in sCD23, thus resulting in attenuation of seasonal increase in specific IgE and clinical benefits during the pollen season.

Adult↗

PubMed1998

Four geographically distinct genotypes of JC virus are prevalent in China and Mongolia: implications for the racial composition of modern China.

JC polyomavirus (JCV) is ubiquitous in humans, persisting in renal tissue and excreting progeny in urine. It has been shown that the genotyping of urinary JCV offers a novel means of tracing human migrations. This approach was used to elucidate the racial composition of modern China. JCV isolates in the Old World were previously classified into nine distinct genotypes. One of them (B1) has a wide domain, encompassing part of Europe and the entirety of Asia. By constructing a neighbour-joining phylogenetic tree, all B1 isolates detected so far were classified into four distinct groups (B1-a to -d), each occupying unique domains in the world. According to this revised classification system of JCV DNAs, four genotypes (CY, SC, B1-a and -b) were found to be prevalent in China and Mongolia (Mongolia was studied instead of Inner Mongolia, which is part of China). There was a remarkable variation in the incidence of genotypes among the sites of sample collection. CY was more frequently detected in Northern China, SC was predominant in Southern China and B1-b was detected only in Mongolia. B1-a was spread throughout China. These data were statistically analysed and the observed regional differences in the incidence of genotypes were found to be significant. It is likely that these differences in JCV distribution in China reflect the intermingling of different population groups that constitute modern China.

Base Sequence↗

PubMed1998

The Fas system is not significantly involved in apoptosis in human hepatocellular carcinoma.

We investigated the role of apoptosis in relation to proliferative activity in hepatocellular carcinoma (HCC) using in situ DNA nick end labeling (ISNEL) and immunostaining for the Ki-67 antigen in 35 patients with HCC. We also performed immunostaining for Fas and Fas ligand (Fas L) to determine the relationship between the Fas system and apoptosis. The ratio of the ISNEL labeling index (LI) to the Ki-67 LI was significantly lower in HCC than in surrounding nontumorous liver tissue (p<0.0001), suggesting that a decrease in apoptosis relative to cell proliferation is important in the pathogenesis of HCC. Fas and Fas L were expressed in both HCC and nontumorous tissue, but Fas and Fas L LIs were significantly lower in HCC (p<0.0001). Fas expression by cells near ISNEL-positive cells tended to be increased in nontumorous tissue in mirror-image sections, suggesting that apoptosis is related to Fas expression. However, this pattern was rarely observed in HCC. These findings indicate that the Fas system may not play a major role in apoptosis in HCC.

Aged↗

PubMed1998

Measles virus attenuation associated with transcriptional impediment and a few amino acid changes in the polymerase and accessory proteins.

Measles virus (MV) isolated in B95a cells, a marmoset B-cell line, retains full pathogenicity for cynomolgus monkeys, while its derivative obtained by adaptation to the growth in Vero cells, a monkey kidney cell line, loses the pathogenic potential (F. Kobune, H. Sakata, and A. Sugiura, J. Virol. 64:700-705, 1990). Here, we show with a pair of strains, a fresh isolate (9301B) in B95a cells and its Vero cell-adapted form (9301V), that the in vivo attenuation parallels the decrease of replication and syncytium-inducing capabilities in the original B95a cells and that these in vitro phenotypes are attributable to impediment of transcription, which is already obvious at the level of primary transcription catalyzed by the virion-associated RNA polymerase. On the other hand, cell fusion assays detected no functional difference between the glycoproteins of the two viruses. Essentially the same transcriptional impediment with reduced syncytium induction following Vero cell adaptation was found with two other pairs of strains that had been similarly prepared. Nucleotide sequence comparison between the 9301B and 9301V viruses revealed that a few (at most five) amino acid changes, which sporadically took place in the polymerase (L and P proteins) and/or accessory V and C proteins, were responsible for the in vitro and in vivo attenuation through adaptation to growth in Vero cells.

Adaptation, Physiological↗

PubMed1998

Activation of the Ras/mitogen-activated protein kinase pathway by kinase-defective epidermal growth factor receptors results in cell survival but not proliferation.

Signalling by the epidermal growth factor (EGF) receptor (EGFR) has been studied intensively, but for most cell types the analysis is complicated by the fact that EGFR not only homodimerizes but can also form heterodimers with other EGFR family members. Heterodimerization is a particular problem in the study of EGFR mutants, where the true phenotype of the mutants is confounded by the contribution of the heterodimer partner to signal transduction. We have made use of the murine hemopoietic cell line BaF/3, which does not express EGFR family members, to express wild-type (WT) EGFR, three kinase-defective EGFR mutants (V741G, Y740F, and K721R), or a C-terminally truncated EGFR (CT957) and have measured their responses to EGF. We found that under the appropriate conditions EGF can stimulate cell proliferation of BaF/3 cells expressing WT or CT957 EGFRs but not that of cells expressing the kinase-defective mutants. However, EGF promotes the survival of BaF/3 cells expressing either of the kinase-defective receptors (V741G and Y740F), indicating that these receptors can still transmit a survival signal. Analysis of the early signalling events by the WT, V741G, and Y740F mutant EGF receptors indicated that EGF stimulates comparable levels of Shc phosphorylation, Shc-GRB-2 association, and activation of Ras, B-Raf, and Erk-1. Blocking the mitogen-activated protein kinase (MAPK) signalling pathway with the specific inhibitor PD98059 abrogates completely the EGF-dependent survival of cells expressing the kinase-defective EGFR mutants but has no effect on the EGF-dependent proliferation mediated by WT and CT957 EGFRs. Similarly, the Src family kinase inhibitor PP1 abrogates EGF-dependent survival without affecting proliferation. However blocking phosphatidylinositol-3-kinase or JAK-2 kinase with specific inhibitors does arrest growth factor-dependent cell proliferation. Thus, EGFR-mediated mitogenic signalling in BaF/3 cells requires an intact EGFR tyrosine kinase activity and appears to depend on the activation of both the JAK-2 and PI-3 kinase pathways. Activation of the Src family of kinases or of the Ras/MAPK pathway can, however, be initiated by a kinase-impaired EGFR and is linked to survival.

Adaptor Proteins, Signal Transducing↗

PubMed1998

Vasopressin-elicited water and urea permeabilities are altered in IMCD in hypercalcemic rats.

To investigate how hypercalcemia blunts renal concentrating ability, alterations in basal and arginine vasopressin (AVP)-elicited osmotic water (Pf) and urea (Purea) permeabilities were measured in isolated perfused terminal inner medullary collecting ducts (IMCD) from control and chronically hypercalcemic rats after dihydrotachysterol (DHT) (M. Levi, L. Peterson, and T. Berl. Kidney Int. 23: 489-497, 1983) treatment. The IMCD Pf of DHT-treated rats did not increase significantly after AVP and was accompanied by a significant 87 +/- 4% reduction in aquaporin-2 (AQP-2) protein but not mRNA. In contrast, both basal and AVP-elicited IMCD Purea from DHT rats were significantly increased and accompanied by a significant 41 +/- 11% increase in AVP-regulated urea transporter protein content. Immunoblotting with anti-calcium/polyvalent cation-sensing receptor protein (CaR) antiserum revealed specific alterations in CaR bands in endosomes purified from the apical membranes of inner medulla of DHT rats. These data are the first detailed analyses of hypercalcemia-induced alterations in AVP-regulated permeabilities and membrane transporters in IMCD. We conclude that selective alterations in IMCD transport occur in hypercalcemia, permitting the body to dispose of excess calcium without forming calcium-containing renal stones.

Animals↗

PubMed1998

Role of daunorubicin in the induction therapy for adult acute myeloid leukemia.

PURPOSE: To evaluate the relationship of total-dose of daunorubicin (DNR) to the induction therapy and treatment outcome, we have administered individualized doses of DNR during induction treatment to patients with acute myelogenous leukemia (AML). PATIENTS AND METHODS: Ninety-two previously untreated adult patients with AML who entered our hospital were analyzed for the dose of DNR required to achieve complete remission (CR), the CR rate, disease-free survival (DFS), and overall survival (OS). Induction therapy consisted of DNR 40 mg/m2 daily intravenously from day 1 until the marrow was hypoplastic, cytarabine (Ara-C), prednisolone (PRD), and/or 6-thioguanine (6-TG). RESULTS: Eighty-three of 92 patients with adult AML were assessable for this study. Sixty-three (76%) patients achieved CR. Fifty-two of 63 CR patients achieved the CR in the first course of induction therapy, and 11 patients required the second course of induction therapy. The 5-year and 10-year DFS rates were 31.2% and 5-year and 10-year OS rates were 45.1% and 42.3%, respectively. The median total dose of DNR in the induction therapy was 280 mg/m2 (120 to 480 mg/m2). DNR dose did not influence the response to therapy and was not influenced by the initial WBC count or French-American-British (FAB) system classification. CONCLUSION: These results indicated that when the dose was linked to observed tumor response, the optimal dose of DNR in the induction therapy was approximately 280 mg/m2 (40 mg/m2 for 7 days), which is greater than the conventional dose of 40 to 60 mg/m2 for 3 days.

Adolescent↗

PubMed1998

Long-term regulation of inner medullary collecting duct urea transport in rat.

Facilitated urea transport is regulated acutely by arginine vasopressin (AVP) and hyperosmolality in rat terminal inner medullary collecting duct (IMCD). This study tested whether chronic diuresis or antidiuresis regulates facilitated urea transport. Basal and AVP-stimulated urea permeabilities (Purea) were measured in perfused IMCD subsegments. Rats were made: (1) diuretic by giving them sugar water (with or without food) or furosemide; or (2) antidiuretic by water deprivation. They were then compared with untreated rats given food and water ad libitum. Terminal IMCD from untreated rats had a high basal Purea that was significantly increased by AVP. Diuresis significantly increased basal Purea in terminal IMCD in all five diuresis protocols. Water deprivation for 1 or 3 d had no effect on basal or AVP-stimulated Purea in the IMCD2 subsegment of the terminal IMCD. In contrast, 3 d of water deprivation significantly increased both basal and AVP-stimulated Purea in the IMCD3 subsegment; 1 d of water deprivation had no effect on basal or AVP-stimulated Purea. Next, initial IMCD (IMCD1) were studied. Initial IMCD from untreated rats had a low basal Purea that was not increased by AVP (10 nM). Water diuresis (with or without food) for 3 to 5 d had no effect on basal Purea but significantly increased AVP-stimulated Purea. Furosemide diuresis and water diuresis for 1 or 7 d had no effect on either basal or AVP-stimulated Purea in initial IMCD. Water deprivation for 2 to 3 d, but not for 1 d, significantly increased basal Purea in initial IMCD, whereas water deprivation for 1 d increased AVP-stimulated Purea. It is concluded that chronic changes in hydration cause heterogeneous changes in facilitated urea transport in rat IMCD subsegments.

Animal Feed↗

PubMed1998

Diversity of the limited-host range iaaH gene of Agrobacterium vitis strain Ag162.

The indole-3-acetamide hydrolase gene (iaaH) of the limited-host range strain AG162, a biotype III strain of Agrobacterium tumefaciens has been the subject of several studies and reviews, but its primary structure has not been previously reported. In the course of our own work we found that this gene hybridizes only weakly to a nucleic acid probe corresponding to the iaaH gene from a biotype I strain of A. tumefaciens. Analysis of the primary structure of the Ag162 iaaH gene revealed that it is diverse from biotype I iaaH genes and, surprisingly, also from the iaaH genes of previously characterized biotype III Agrobacterium strains.

Amidohydrolases↗

PubMed1998

Intravascular large cell lymphoma associated with hypoalbuminemia.

We report here a 71-yr-old Japanese woman who presented with severe anasarca and hypoalbuminemia. She had a postmortem diagnosis of intravascular large B-cell lymphoma, which is a rare type of lymphoma characterized by an intravascular proliferation of lymphoma cells. Severe generalized edema was thought to be attributed to vascular and/or lymphatic obstruction due to proliferation of lymphoma cells within the lumina and/or an increase in catabolism induced by tumor proliferation.

Aged↗

PubMed1998

Hematoxylin procedure for staining mature pollen grains in maize with dimethylsulfoxide as a clearing agent.

Observing nuclei of mature pollen grains in maize is extremely difficult because the starch granules surrounding the nuclei are deeply stained. The cytoplasm of hematoxylin stained pollen grains becomes clear when DMSO and gentle heating are used. By separating the staining and clearing processes, uniformly stained pollen grains were consistently obtained. Using this method, 2,000 pollen grains were examined and it was determined that 99.5% were in the normal tricellular state, while pentacellular pollen, bicellular pollen and pollen grains with two vegetative nuclei were observed in the remaining 0.5%.

Coloring Agents↗

PubMed1998

[Neck Dissection for salivary gland carcinoma].

Between 1986 and 1997, 18 patients with high-grade salivary gland malignancies were treated at our institution. Histologically, 7 of the 18 malignant tumors were adenoid cystic carcinomas. 4 were carcinoma in pleomorphic adenoma, 3 were undifferentiated carcinomas and 4 were others. For treatment of the neck, 11 patients underwent neck dissection, 1 received supraomohyoid neck dissection (SOMH) and 7 received no neck treatment. In our study, there was no difference according to local-regional control as to whether to use neck dissection or not. The result do not suggest that prophylactic total neck dissection for salivary gland carcinoma show an impressive degree of improvement in local-regional control. Total neck dissection should be performed when the neck is clinically positive for a tumor. Based on the above findings, we concluded that SOMH is feasible for submandibullar gland cancer without positive lymph nodes.

Adenocarcinoma↗

PubMed1998

A new anti-MRSA antibiotic complex, WAP-8294A. I. Taxonomy, isolation and biological activities.

WAP-8294A, produced by Lysobacter sp., is a complex consisting of water soluble depsipeptide antibiotics. It was further purified by column chromatographies and HPLC, and 19 components were obtained. WAP-8294A2, a major component, and minor components A1, A4, Ax8, Ax9 and Ax13 were active against gram-positive bacteria, in particular, methicillin-resistant Staphylococcus aureus (MRSA) in vitro. WAP-8294A2 was highly active in vivo in mice against the systemic infection of MRSA.

Animals↗

PubMed1998

Aggressive surgical approaches to hilar cholangiocarcinoma: hepatic or local resection?

BACKGROUND: It has been reported that surgical excision of hilar cholangiocarcinoma rather than palliative surgical therapy, chemotherapy, or radiotherapy caused prolonged survival in some patients, However, excision is associated with high operative morbidity and mortality rates, particularly when hepatic resection is also performed. The aim of this study was to evaluate the clinical implications of hepatic resection in hilar cholangiocarcinoma. METHODS: The study involved 76 patients with hilar cholangiocarcinoma who were undergoing surgical resections. Twenty-one patients (28%) underwent a combined resection, with reconstruction of the portal vein in 20 patients and reconstruction of the hepatic artery in 7 patients. Sixty-five patients undergoing seven different types of hepatic resection with extrahepatic bile duct resection (BDR) and 11 patients undergoing BDR only were retrospectively compared for background, operative morbidity and mortality, and survival. RESULTS: Curative resection was obtained in 5 of 11 (45%) patients undergoing local resection and in 49 of 65 (75%) patients undergoing hepatic resection (p < 0.05). The surgical morbidity rates were 34% and 27% for hepatic and local resection, respectively. The 30-day mortality and hospital mortality rates were 4.6% and 15% for hepatic resection and 0% and 0% for local resection, respectively. The 5-year survival rate was 26% for all resected patients (76 patients); it was 40% versus 0% for curative versus noncurative resections (p < 0.05). No significant difference in surgical resection rates was revealed between hepatic and local resection among resected and curative resected patients. CONCLUSIONS: Aggressive surgical approaches to obtain curative resections could bring about a better prognosis in hilar cholangiocarcinoma independently of whether hepatic resection or local resection is performed.

Adult↗

PubMed1998

[EPOCH therapy for relapsed/refractory lymphoid malignancies].

Patients with refractory or relapsed non-Hodgkin's lymphoma (NHL), acute T-cell leukemia (ATL), ATL lymphoma and acute lymphocytic leukemia (ALL) received EPOCH therapy. All were previously treated with doxorubicin (DOX), vincristine (VCR) and other drugs. The EPOCH treatment schedule is consisted with DOX (10 mg/M2/day, 5 days c.i.v.), VCR (0.4 mg/M2/day, 4 days c.i.v.), etoposide (50 mg/M2/day, 4 days c.i.v.), cyclophosphamide (750 mg/M2/day, day 6 i.v.) and prednisolone (60 mg/M2/day, 5 days p.o.). Twenty-one patients (ALL:10, NHL:8, ATLL:2, ATL:1) were assessable for response and toxicity. Two patients with ALL and NHL, respectively, achieved a complete remission and 3 patients obtained partial remission (NHL:2, ATLL:1). The hematological toxicity (grade > 1) included neutoropenia, anemia and thrombocytopenia, which were observed in 83.3%, 76.7% and 76.7% respectively, of total 30 EPOCH courses. The major non-hematological toxicities were nausea/vomiting, constipation and infection, but most of the toxicity were tolerable with sufficient clinical supportive care. These results indicate that continuous infusion of DOX, VCR and ETP might be effective in patients who were treated with, and presumed to be resistant to the same drugs administrated by bolus infusion.

Adolescent↗

PubMed1998

[Primary cardiac non-Hodgkin's lymphoma].

A 69-year-old man who initially presented with lumbago developed heart failure during an MRI scan on the day of admission. A chest X-ray showed cardiomegaly and bilateral pleural effusion. Echocardiogram and computed tomography (CT) scan of the chest revealed a large tumor mass encompassing the heart with much pericardial effusion was demonstrated. The cytology of the effusion obtained by pericardiocentesis was consistent with non-Hodgkin's lymphoma, diffuse large B cell type. As CT scans of the abdomen and pelvis were negative, he was considered to have primary cardiac lymphoma. Although he responded remarkably to therapy with vincristine, cyclophosphamide and prednisolone and, he developed acute respiratory failure on the seventh month after admission. Although incidence of primary cardiac lymphoma is very low, it is necessary to investigate the mechanism of this disease in order to establish appropriate diagnostic and therapeutic approaches.

Aged↗

PubMed1998

[Discrepancy between surgeon's binocular parallax perception and manipulation in the neurosurgical operation].

The application of virtual reality (VR) to the neurosurgical field has been increasing recently, however, the relation between the surgeon and the VR environment is rarely studied. We examined the trajectory of a surgical instrument during manipulation of a virtual object using a video-see-through microscope and a neurosurgical navigator (CANS Navigator) to find better surgeon-microscope interface. A resin cylindrical phantom was produced representing the surgical field, which included two 3 dimensionally arranged small spheres and a virtual 'gate'. The phantom was fixed and set under the microscope with a skull clamp mimicking conditions in an ordinary craniotomy. Firstly, the binocular parallax perception under microscope was examined. Experienced and inexperienced neurosurgeons were asked to learn the position of the virtual 'gate' for 3 minutes. Then, after 5 minutes to point with the navigator probe (suction tube), under various conditions; under the naked eyes, under the microscope, under the navigator without observing the phantom, and under the microscope with picture in picture (PIP) display of the navigational image. The positions of the suction tube were recorded at real time into the navigator for later analysis. Secondly, the task performance in this VR environment was studied by analyzing the trajectory of the suction tube from one sphere to the other sphere passing the virtual 'gate' under various conditions. A significant difference in pointing precision between experienced and inexperienced neurosurgeons was able to be observed only under microscope. This difference was mainly derived from overestimation of the depth of the virtual 'gate' by the inexperienced neurosurgeons. Among the above conditions, pointing under the microscope with PIP was able to be performed the most precisely and the most promptly. This study disclosed the presence of stereoscopic distortion in the microscope. The PIP display of the navigational image in the microscopic view remarkably improved the task performance, which could be accounted for by the correction of the somewhat distorted binocular parallax perception under the neurosurgical microscope by the provision of another visual key.

Brain↗

PubMed1998

[Prognostic significance of CD7 expression in adult acute myeloid leukemia].

To evaluate the prognostic significance of CD7 expression in de novo acute myeloid leukemia (AML), we studied 63 patients with AML who had been admitted to our hospital between September 1989 and January 1996. Even of the patients were later eliminated from the study (9 due to insufficient surface marker analyses, and 2 due to early death). The remaining 52 patients (median age: 42.5 years) were evaluated for morphologic subtype, immunophenotypic classification, complete remission (CR), disease-free survival (DFS) and overall survival (OS). All 52 patients were grouped by the French-American-British classification system: 10 as M1, 16 as M2, 11 as M3, 8 as M4, 5 as M5, and 2 as M6. Ten of the patients expressed CD7 on their leukemia cells (positive rate > or = 25) and were classified as CD7(+)AML, with morphological subtypes as follows: 3 as M1, 6 as M2, and 1 as M3. Thirty-three of the 42 patients with CD7 + AML (78.6%) and 6 of the 10 patients with CD7 + AML (40%) achieved CR. DFS and OS rates for the patients with CD7(+)AML were 22.1% and 35.4%, respectively; those for the CD7(+)AML patients were 53.3% and 44.4%, respectively. No significant differences in gender hematological findings, clinical manifestations such as hepatosplenomegaly, lymphadenopathy, or incidence of central nervous system involvement, CR rate, and DFS distinguished patients with CD7(+)AML from those with CD7(+)AML. These suggest that CD7 expression is unlikely to be a prognostic factor in AML.

Adolescent↗