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Biomedical subjects

K Kojima

Publications and source records attributed to K Kojima.

At least 163 records · Page 9Linked to original sources

Interaction of a lectin from Psathyrella velutina mushroom with N-acetylneuraminic acid.

A lectin from the fruiting body of Psathyrella velutina has been used as a specific probe for non-reducing terminal N-acetylglucosamine residues. We reveal in this report that P. velutina lectin recognizes a non-reducing terminal N-acetylneuraminic acid residue in glycoproteins and oligosaccharides. Binding of biotinyl P. velutina lectin to N-acetylneuraminic acid residues was prevented by desialylation of glycoconjugates and was distinguished from the binding to N-acetylglucosamine. Sialooligosaccharides were retarded or bound and eluted with N-acetylglucosamine on a P. velutina lectin column, being differentiated from each other and also from the oligosaccharides with non-reducing terminal N-acetylglucosamine which bound more strongly to the column.

Basidiomycota↗

The significance of p53 mutations as an indicator of the biological behavior of recurrent hepatocellular carcinomas.

The significance of p53 mutations in the primary lesion for recurrent hepatocellular carcinoma (HCC) was evaluated. Mutations of p53 were examined using nonradioisotopic (nonRI)-polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) in 98 resected HCCs. Of the 98 cases, 25 (26%) had a p53 mutation. In 83 patients who survived surgery, the presence of a p53 mutation was associated with a shortened overall survival (P < 0.001) and a shortened cancer-free survival (P < 0.05). In 43 patients who developed recurrence, there was no statistically significant correlation between the status of p53 in the primary lesion and the clinical features of recurrent HCCs examined, i.e., extrahepatic metastasis, the number of recurrent tumors, extent of recurrent tumors, and treatment for recurrent tumors. However, postrecurrence survival was significantly lower in patients in whom a p53 mutation had been detected in the primary lesion (P < 0.01). A multivariate analysis for prognostic value after recurrence revealed that the p53 mutation was a useful independent prognostic factor affecting survival after recurrence (P < 0.01). In conclusion, our findings suggest that HCCs with p53 mutations have a high malignant potential based on their poor prognosis. Therefore, a p53 mutation in the primary lesion is useful as an indicator of the biological behavior of recurrent HCCs.

Carcinoma, Hepatocellular↗

Intrathoracic retroesophageal goiter causing tracheal stenosis.

A 65-year-old woman presented with stridor revealed a mass on a chest X-ray on physical examination. A huge goiter arising in the left lobe of the thyroid had extended retroesophageally and across the midline to the right side of the posterior mediastinum far caudally down to the level of the carina. The trachea was remarkably compressed. Surgery was performed via a combined thoracic and cervical approach, and the tumor was completely removed with resultant relief from stridor. The patient is presently doing well at 1 year after the operation.

Aged↗

Serum levels of parathyroid hormone-related protein are not elevated in patients with T-cell prolymphocytic leukemia.

T-cell prolymphocytic leukemia (T-PLL) is a rare post-thymic T-cell neoplasm which shares most clinical features with adult T-cell leukemia (ATL). We measured serum level of C-terminal parathyroid hormone-related protein (C-PTHrP) in patients with T-PLL and ATL. Serum C-PTHrP levels of eight patients with T-PLL (median 36.8 pmol/l; range 27.0-50.2 pmol/l) did not differ from those of 30 human T-lymphotropic virus type I (HTLV-I)-seronegative blood donors (median 37.0 pmol/l; range 22.6-54.0 pmol/l). The C-PTHrP levels in ten ATL patients (median 69.6 pmol/l; range 42.5-899.4 pmol/l) were significantly higher than those in healthy controls (p<0.0001) or T-PLL patients (p=0.001). We suggest that the serum level of PTHrP can provide useful information for differentiating between T-PLL and ATL.

Adult↗

Epstein-Barr virus infection resembling autoimmune hepatitis with lactate dehydrogenase and alkaline phosphatase anomaly.

A 73-year-old man had fever, lymphadenopathy, granulocytopenia, thrombocytopenia, ascites, pleural effusion, liver injury, and an allergic-like skin rash. Autoantibodies, such as anti-nuclear antibody, were shown, and there were lactate dehydrogenase and alkaline phosphatase anomalies and platelet-associated IgG. His liver injury resembled that in autoimmune hepatitis. He was diagnosed with Epstein-Barr virus (EBV) infection associated with autoimmunization because of his clinical course, fluctuation of anti EBV antibodies and positive EBV genome in circulating lymphocytes and serum. This case suggests a close relationship between EBV infection and autoimmunization or autoimmune-like hepatitis.

Aged↗

Interleukin 1 beta, interleukin 6, beta 2-microglobulin, and transforming growth factor-alpha in gingival crevicular fluid from human periodontal disease.

Inflammatory mediators are central to the pathogenesis of periodontal diseases and may be used as markers in diagnosis. The aim of this study was to identify and quantify the various growth factors, apoptosis-related modifiers [soluble form of Fas (sFas) and bcl-2] and cytokines in the gingival crevicular fluid (GCF) of patients with different severities of periodontitis as compared with those of controls. GCF samples were taken from patients with periodontal disease and from controls. The concentrations of epidermal growth factor, transforming growth factor (TGF)-alpha, interleukin (IL)-1 beta, IL-6, interferon-gamma, beta 2-microglobulin (beta 2-MG), and apoptosis-related modifiers sFas and bcl-2 in the samples were determined by enzyme-linked immunosorbent assay. TGF-alpha was significantly lower in patients with periodontal disease than in the controls. In contrast, the concentrations of IL-1 beta, IL-6; and beta 2-MG were significantly higher in the group with severe periodontal disease than in the controls. The amount of total protein in the GCF was considerably higher in the disease group than the controls (p < 0.05). TGF-alpha, IL-1 beta, and beta 2-MG concentrations were associated (Spearman rank correlation, r < 0.05 for all) with clinical measures of disease severity (pocket depth) and inflammation (bleeding when probed). Apoptosis-related modifiers (sFas and bcl-2) could not be detected in any samples. These results suggest that the growth factor TGF-alpha and certain cytokines are associated with the presence of periodontal disease.

Adult↗

A study on the adsorption structure of an adhesive monomer for precious metals by surface-enhanced Raman scattering spectroscopy.

In order to clarify the role of a primer on the adhesion between dental precious metals and resin, surface-enhanced Raman scattering (SERS) technique has been applied to the structural analysis of the adhesive monomer, 6-(N-(4-vinylbenzyl)propylamino)-1,3,5-triazine-2, 4-dithione (VBATDT) adsorbed on colloidal Au surfaces. VBATDT is one of the major components of commercial primers. A mixture of a methanol solution of VBATDT and aqueous Au colloid was illuminated by the 647.1 nm line from a Kr ion laser to obtain the SERS. The most intense peak at 458 cm-1 due to C = S stretching in the Raman spectrum of solid VBATDT disappears completely in the SERS, while all the other peaks due to vinylbenzyl group vibrations remain unchanged. It suggests that some structural change occurs in VBATDT upon adsorption on Au which involves the C = S bonds and that the molecule undergoes thione-thiol-type tautomerization in the adsorption process. The SERS spectrum of a commercial primer containing VBATDT exhibits a similar spectral pattern. The present results lead us to conclude that some specific interactions exist between the sulfur atoms of VBATDT and Au surface to form chemical bond likes, which are effective to improve the bond strength between dental precious metals and resin. The ambivalent properties of the primer, chemical stability in storage and chemical affinity to Au, are also explained by the thione-thiol-type tautomerization of VBATDT on the basis of the spectroscopic evidence.

Adhesives↗

Reproduction of occult metastasis of head and neck cancer in nude mice.

The presence of occult metastasis is the most important factor that influences the prognosis in patients with head and neck cancer. To reproduce occult metastasis of oral cancer cells, we serially resected the primary focus in an orthotopic implantation model to examine when metastasis of cancer cells occurs. Human squamous cell carcinoma was implanted into the tongue of nude mice divided into two groups, non-surgery and surgery groups. Mice in the non-surgery group were sacrificed, and the tongue cancer and cervical lymph nodes were resected simultaneously. In the surgery-group, resection of the tongue cancer was performed, and the cervical lymph nodes were resected on day 28. For the non-surgery-group, the incidences of metastasis were 0%, 9%, 36%, 91% and 100% on days 3, 7, 14, 21 and 28, respectively. For the surgery-group, resection of the tongue cancer was performed on days 3, 7 and 14, and the incidence of metastasis on day 28 was 0%, 82% and 91%, respectively. The occult metastasis was reproduced using resected primary cancer on day 7. This time-based model may be useful to clarify the mechanism of metastasis and to develop new treatments.

Animals↗

Hematopoietic progenitor cells from allogeneic bone marrow transplant donors circulate in the very early post-transplant period.

Despite the therapeutic efficacy of allogeneic bone marrow transplantation (allo-BMT), circulating hematopoietic progenitor cells after bone marrow transplantation have not been well characterized. In the present study, we focused on these 'post-transplant circulating progenitor cells (PTCPC)' which may be on their way to bone marrow. We analyzed the number of myeloid progenitor cells (CFU-GM) per 10 ml of peripheral blood (PB) on days 0 (just before transplantation), 1 (8-15 h after the completion of transplantation), 2, 3, 5, 7, 10, 14, 17, 21, 28 and 35 after allo-BMT in five transplant patients using a standard methylcellulose assay. In addition, high proliferative potential colony-forming cells (HPP-CFC) of the harvested donor bone marrow (BM) and day 1 PB of recipients were assayed in five patients. The origin of HPP-CFC from day 1 PB was analyzed by polymerase chain reaction of a DNA region containing a variable number of tandem repeats. The replating potential of these HPP-CFC was evaluated by a secondary colony assay. The proportion of CD38negative cells among CD34+ cells in the harvested BM and day 1 PB was evaluated by two-color flow cytometric analysis. The number of CFU-GM on day 1 ranged from 6 to 73/10 ml PB, and became undetectable on day 5. The reappearance of PTCPC was observed on day 14, along with hematopoietic recovery. The proportion of HPP-CFC among myeloid colonies from day 1 PB was significantly higher than that from harvested BM (44.3+/-10.4% vs 11.3+/-2.1%, respectively, n=5, P=0.0030). These HPP-CFC from day 1 PB were confirmed to be of donor origin. More than 90% of these HPP-CFC had replating potential. Two-color flow cytometric analysis revealed that the proportion of CD34+CD38negative cells was significantly higher in day 1 PB than in the harvested BM (61.0+/-16.5% vs 9.3+/-3.5%, respectively, n=7, P=0.0002). These observations suggest that both primitive and committed transplanted myeloid progenitor cells may circulate in the very early period following allo-BMT.

ADP-ribosyl Cyclase↗

Additional translocation (8;21)(q22;q22) in a patient with Philadelphia-positive chronic myelogenous leukaemia in the blastic phase.

We report a case of Philadelphia-positive chronic myelogenous leukaemia in blastic phase with the additional translocation (8;21)(q22;q22), which is frequent in acute myeloid leukaemia but not in chronic myelogenous leukaemia. The t(8;21) was not detected in the chronic phase, and was the only additional chromosomal anomaly in the blastic clone. Reverse transcription-polymerase chain reaction revealed the AML1/ETO fusion transcript in the cells of blastic phase but not in those of chronic phase. Regarding t(9;22), the breakpoint on chromosome 22 occurred in the mu-BCR region of the BCR gene, resulting in hybrid BCR/ABL mRNA with an e19a2 junction. Our findings provided molecular evidence that t(8;21) can occur as an additional genetic change in Philadelphia-positive chronic myelogenous leukaemia.

Adult↗

Comparison of sedative effects of medetomidine-midazolam, acepromazine-butorphanol and midazolam-butorphanol in dogs.

Sedative effects of medetomidine at 20 micrograms/kg and midazolam at 0.3 mg/kg (MM), acepromazine at 0.05 mg/kg and butorphanol at 0.2 mg/kg (AB), and midazolam at 0.1 mg/kg and butorphanol at 0.2 mg/kg (MB) were compared in dogs. All dogs given MM were laterally recumbent within 11 min of the administration of the drugs, and this combination also induced deep sedation accompanied by analgesia and muscle relaxation, and strongly depressed arousal reactions to external stimuli. However, undesirable effects such as bradycardia and decreased respiration were also observed in dogs given MM. Six of seven dogs given AB were laterally recumbent within 16 min of the administration of the drugs, and this combination induced relatively deep sedation but only a mild depression of arousal reactions to external stimuli. MB induced mild or moderate sedation with relatively large differences in effects among individuals. The recovery from sedation in each group was smooth and total recovery times were not significantly different.

Acepromazine↗

Comparison of cardiopulmonary effects of medetomidine-midazolam, acepromazine-butorphanol and midazolam-butorphanol in dogs.

Cardiopulmonary effects of intramuscular administration of medetomidine-midazolam at 20 micrograms/kg and 0.3 mg/kg, respectively (MM), acepromazine-butorphanol at 0.05 and 0.2 mg/kg, respectively (AB), and midazolam-butorphanol at 0.1 and 0.2 mg/kg, respectively (MB), were compared in dogs. MM produced relatively large cardiovascular changes such as bradycardia, hypertension, a decrease in cardiac output and vasoconstriction. AB produced moderate cardiovascular changes. Hypotension was observed within 5 min after administration and the mean arterial blood pressure decreased by 30% at 20 min after administration. MB produced decreases in arterial blood pressure and cardiac output, but these changes were small and, of the combinations evaluated in this study, MB had the mildest cardiovascular effects.

Acepromazine↗

Efficacy of an implanted drug delivery system for advanced hepatocellular carcinoma using 5-fluorouracil, epirubicin and mitomycin C.

BACKGROUND: In order to assess the efficacy of repeated hepatic arterial infusion (HAI) therapy for advanced hepatocellular carcinoma, we administered HAI therapy using 5-fluorouracil, epirubicin and mitomycin C, with an implanted drug delivery system. METHODS AND RESULTS: Thirty-seven patients received HAI therapy with a response rate of 21.6%. The 6-month and 1-year survival rates were 67.6 and 29.7%, respectively. Responders to HAI therapy showed significantly longer survival than non-responders, while patients with mild liver dysfunction tended to survive longer than those with severe dysfunction. Neither tumour thrombosis of the main trunk of the portal vein nor extrahepatic metastases were considered to constitute contraindications for HAI therapy. Catheter-related trouble occurred in eight patients and biloma in one patient, but other side effects were transient and tolerable. These patients received HAI therapy as outpatients for an average of 79.6% of the entire course of therapy. CONCLUSIONS: Hepatic arterial infusion therapy proved effective for patients with advanced hepatocellular carcinoma in terms of improving survival and outpatient rates.

Adult↗

Multi-specificity of a Psathyrella velutina mushroom lectin: heparin/pectin binding occurs at a site different from the N-acetylglucosamine/N-acetylneuraminic acid-specific site.

An N-acetylglucosamine (GlcNAc)/N-acetylneuraminic acid-specific lectin from the fruiting body of Psathyrella velutina (PVL) is a useful probe for the detection and fractionation of specific carbohydrates. In this study, PVL was found to exhibit multispecificity to acidic polysaccharides and sulfatides. Purified PVL and a counterpart lectin to PVL in the mycelium interact with heparin neoproteoglycans, as detected by both membrane analysis and solid phase assay. The pH-dependencies of the binding to heparin and GlcNAc5-6 differ. The heparin binding of PVL is inhibited best by pectin, polygalacturonic acid, and highly sulfated polysaccharides, but not by GlcNAc, colominic acid, or other glycosaminoglycans. Sandwich affinity chromatography indicated that PVL can simultaneously interact with heparin- and GlcNAc-containing macromolecules. Extensive biotinylation was found to suppress the binding activity to heparin while the GlcNAc binding activity is retained. On the other hand, biotinyl PVL binds to sulfatide and the binding is not inhibited by GlcNAc, N-acetylneuraminic acid, or heparin. These results indicate that PVL is a multi-ligand adhesive lectin that can interact with various glycoconjugates. This multispecificity needs to be recognized when using PVL as a sugar-specific probe to avoid misleading information about the nature of glycoforms.

Acetylglucosamine↗

Engineering a chimeric pyrroloquinoline quinone glucose dehydrogenase: improvement of EDTA tolerance, thermal stability and substrate specificity.

An engineered Escherichia coli PQQ glucose dehydrogenase (PQQGDH) with improved enzymatic characteristics was constructed by substituting and combining the gene-encoding protein regions responsible for EDTA tolerance, thermal stability and substrate specificity. The protein region responsible for complete EDTA tolerance in Acinetobacter calcoaceticus, which is recognized as the indicator of high stability in co-factor binding, was elucidated. The region is located between 32 and 59% from the N-terminus of A. calcoaceticus PQQGDH(A27 region) and also corresponds to the same position from 32 to 59% from the N-terminus in E. coli PQQGDH, though E. coli PQQGDH is EDTA sensitive. We previously reported that the C-terminal 3% region of A. calcoaceticus (A3 region) played an important role in the increase of thermal stability, and that His775Asn substitution in E. coli PQQGDH resulted in an increase in the substrate specificity of E. coli PQQGDH towards glucose. Based on these findings, chimeric and/or mutated PQQGDHs, E97A3 H775N, E32A27E41 H782N, E32A27E38A3 and E32A27E38A3 H782N were constructed to investigate the compatibility of two protein regions and one amino acid substitution. His775 substitution to Asn corresponded to His782 substitution to Asn (H782N) in chimeric enzymes harbouring the A27 region. Since all the chimeric PQQGDHs harbouring the A27 region were EDTA tolerant, the A27 region was found to be compatible with the other region and substituted amino acid responsible for the improvement of enzymatic properties. The contribution of the A3 region to thermal stability complemented the decrease in the thermal stability due to the His775 or His782 substitution to Asn. E32A27E38A3 H782N, which harbours all the above mentioned three regions, showed improved EDTA tolerance, thermal stability and substrate specificity. These results suggested a strategy for the construction of a semi-artificial enzyme by substituting and combining the gene-encoding protein regions responsible for the improvement of enzyme characteristics. The characteristics of constructed chimeric PQQGDH are discussed based on the predicted model, beta-propeller structure.

Acinetobacter↗

Immunolocalisation of PIVKA-II in paraffin-embedded specimens of hepatocellular carcinoma.

AIMS/BACKGROUND: Although serum PIVKA-II has been widely used as a tumor marker for hepatocellular carcinoma (HCC), little information is available concerning tissue PIVKA-II, and detection of tissue PIVKA-II in paraffin-embedded tissue specimens of HCC is also considered difficult. METHODS: Paraffin-embedded HCC tissues obtained at autopsy from 22 patients were subjected to immunohistochemical staining using the antibody MU-3 (Eisai Co., Ltd.) after microwave antigen retrieval. RESULTS: PIVKA-II was mainly detected in the cytoplasm of HCC cells. The intensity of tissue PIVKA-II staining was not correlated with serum PIVKA-II levels or with the histotogical differentiation of HCC. However PIVKA-II staining tended to be more intense in tissue from patients with portal tumor thrombus, distant metastases, or a longer duration of HCC. CONCLUSION: This method of immunohistochemical staining is easy and simple to use and may be helpful for detecting tissue PIVKA-II in paraffin-embedded HCC specimens.

Adult↗

Antineutrophil cytoplasmic antibodies in Japanese patients with inflammatory bowel disease: prevalence and recognition of putative antigens.

OBJECTIVE: Our aim was to investigate the prevalence of antineutrophil cytoplasmic antibodies (ANCA) in Japanese patients with ulcerative colitis (UC) and Crohn's disease (CD), and the putative antigens recognized by perinuclear staining pattern ANCA (p-ANCA)-positive sera. METHODS: Sera from UC (n = 52) and CD (n = 43) patients, and from healthy controls (n = 74) were studied. The indirect immunofluorescence (IIF) method was used for the detection of ANCA and its binding pattern. p-ANCA-positive sera were studied further for putative antigens. ELISAs using lactoferrin (Lf), myeloperoxidase (MPO), and cathepsin G (Cat G) as antigens were performed. RESULTS: ANCA was positive in 40 of the 52 (76.9%) UC (p-ANCA in 33) and in 32 of the 43 (74.4%) CD (p-ANCA in 31) patients. UC and CD patients showed significantly higher titers of p-ANCA than controls; however, no significant difference was observed between UC and CD. In UC, 23, 17, and nine of the 33 patients with p-ANCA-positive sera showed reactivity with Lf, MPO, and Cat-G, respectively. In CD, 21, 20, and 11 of the 31 patients with p-ANCA-positive sera showed reactivity with Lf, MPO, and Cat-G, respectively. Fourteen of the UC and six of the CD patients showed reactivity with two different antigens, and seven of the UC and 11 of the CD patients showed reactivity with all three antigens. The presence of anti-Lf and anti-MPO antibodies was further confirmed by Western blotting. CONCLUSIONS: ANCA is useful in distinguishing patients with IBD from normal subjects but is not sufficient for the differential diagnosis of CD and UC. p-ANCA reactivity might be derived from the recognition of heterogeneous neutrophil-associated antigens.

Adult↗