Biomedical subjects

H Yamaguchi

Publications and source records attributed to H Yamaguchi.

At least 433 records · Page 24Linked to original sources

PubMed1998

Immunohistochemical expression of ABH/Lewis-related antigens in primary breast carcinomas and metastatic lymph node lesions.

The expression of blood group antigens A, B, and H, as well as sialylated and nonsialylated forms of Lewis(a) and Lewis(x), was studied using immunohistochemical methods in normal and tumor tissues in the following cohort of patients: 51 patients with primary breast carcinoma, 13 with metastatic lymph node lesions, and 16 with benign tumors of the breast. As a control, normal tissue was obtained from a similar group of 22 patients with breast cancer. The noncancerous tissues expressed the same A/B/H antigens as the patients' red blood cells and also usually expressed Lewis-related antigens. Seventy-six percent of primary carcinomas failed to express the appropriate A/B/H antigens, and in one blood group A patient the tumor tissue expressed B antigen. In the metastatic lesions, Lewis(a)/sialyl Lewis(a) expression was reduced when compared with the primary tumors, but Lewis(x)/sialyl Lewis(x) antigens were still expressed. These results suggest a possible relationship between the metastatic behavior of the tumor and expression of the blood group antigens.

Antigens, Tumor-Associated, Carbohydrate↗

PubMed1998

Decreasing profile of residual sulphaquinoxaline in eggs.

1. Sulphaquinoxaline (SQ) was added to the diet of laying hens at 200 mg/kg for 7 successive days. Contents (mg/kg) of SQ in albumen and egg yolk of eggs laid after drug withdrawal were determined by high pressure liquid chromatography (HPLC). The contents in the whole egg were calculated taking into consideration the respective weights of albumen and egg yolk. 2. A time-lag in the initiation of decrease of SQ from eggs after the withdrawal of dietary SQ was observed. 3. The decreasing pattern from whole egg could be well described by the following equation with a time-lag of 1.0 d, y = 2.07 e-0.5620(t-1.0), where y is the SQ content in whole egg, t is time (d) after the withdrawal of dietary SQ and a constant of 2.07 is the SQ content in whole egg laid at the withdrawal. 4. Biological half-life of SQ in the whole egg was estimated to be 1.23 d. 5. From the above equation, SQ residue of whole egg laid at 9th d after withdrawal will be below the detection limit of 0.01 mg/kg.

Animal Feed↗

PubMed1998

Anastomotic recurrence of oesophageal squamous cell carcinoma after transthoracic oesophagectomy.

OBJECTIVE: To assess the incidence of anastomotic recurrence of oesophageal carcinoma and its relationship with proximal surgical margin invaded by tumour. DESIGN: Retrospective study. SETTING: National Cancer Center, Tokyo. SUBJECTS: 463 patients with thoracic oesophageal squamous carcinoma who underwent transthoracic oesophagectomy with a minimal follow-up of three years. MAIN OUTCOME MEASURES: Proximal surgical margin, anastomotic recurrence rate, prognosis. RESULTS: Anastomotic recurrence developed in 12 of the 463 patients (3%), 10 of whom had histologically clear surgical margins. Sixteen patients had histologically invaded surgical margins, 13 of whom developed recurrent disease, 2 (13%) at the anastomosis. These 2 patients died of other diseases after treatment for their recurrent tumours. Two patients with anastomotic recurrence lived for over 5 years without signs of disease after excision of the recurrent tumour. Necropsy of 47 patients with recurrent tumors showed that only one (2%) was at the anastomosis. CONCLUSIONS: Anastomotic recurrence was not inevitable and was rarely fatal in patients with invaded proximal surgical margins at transthoracic oesophagectomy. However, although infrequent, it did occur, even in patients with a cancer-free surgical margin. Resection may be indicated for patients with anastomotic recurrence and no other signs of metastases.

Anastomosis, Surgical↗

PubMed1998

Oxidative refolding of bovine pancreatic RNases A and B promoted by Asn-glycans.

It was previously revealed [Yamaguchi, H. and Uchida, M. (1996) J. Biochem. 120, 474-477] that both intra- and extramolecular high-mannose type Asn-glycans promote the renaturation of reductively denatured bovine pancreatic RNases A and B under oxidation conditions. To characterize the conformational changes of the polypeptides during the renaturation promoted by the intramolecular Asn-glycans, RNase B was compared with its nonglycosylated form, RNase A, as to the features of the regeneration from their reductively denatured species under Cu2+-catalyzed oxidation conditions. The refolding intermediates of RNase B, as compared with those of RNase A, seemed to contain much less impaired disulfide linkages. In agreement with this finding, the proper refolding of RNase B was much faster than that of RNase A, as revealed by the intrinsic fluorescence and 1-anilino-8-naphthalenesulfonate binding of the refolding intermediates. Such a promoting effect was also observed for extramolecular Asn-glycans of the complex as well as of the high-mannose type. In contrast, common mono-, oligo-, and polysaccharides, but not yeast mannan, exhibited much lower stimulatory effects on the oxidative refolding of RNase A.

Anilino Naphthalenesulfonates↗

PubMed1998

Promotion of polypeptide folding by interactions with Asn-Glycans.

We have recently revealed that the intramolecular Asn-glycans promote the refolding of reductively denatured bovine pancreatic RNase B, and that extramolecular Asn-glycans of both high-mannose and complex types also markedly stimulate the oxidative refolding of RNase B and its nonglycosylated form, RNase A [Yamaguchi, H. and Uchida, M. (1996) J. Biochem. 120, 474-477; Nishimura et al. (1998) J. Biochem. 123, 516-520]. The present investigation was undertaken to see whether this function of Asn-glycans is specific to the refolding of pancreatic RNases; i.e., extramolecular Asn-glycans were examined for their effects on the oxidative refolding of hen egg white lysozyme and bovine alpha-lactalbumin by monitoring changes in activity, dynamic volume, intrinsic fluorescence, and affinity for a fluorescent probe, 1-anilino-8-naphthalenesulfonate. Asn-glycans of both high-mannose and complex types markedly stimulated the oxidative refolding of these proteins, giving similar results to those previously obtained with RNases, though differences attributable to the characteristics of individual proteins were observed in the promotive effects. Thus it seems probable that Asn-glycans generally promote the proper folding of denatured polypeptides.

Anilino Naphthalenesulfonates↗

PubMed1998

A virulence factor of Helicobacter pylori: role of heat shock protein in mucosal inflammation after H. pylori infection.

Among the various virulence factors of Helicobacter pylori the role of its heat shock protein 60 (HSP60, HspB) in mucosal inflammation after H. pylori infection was examined. In flow cytometric analysis, the expression of HSP60 on the cell surface was different, depending on the H. pylori strain used. The HSP60 epitope was also detected on the surface of both human gastric cancer cells (MKN45, KATOIII, and MKN28) and human gastric biopsy specimens. The intensity of the expression of HSP60 on the cell surface correlated significantly with the adhesion of H. pylori to MKN45 cells, but not with urease activity and production of vacuolating cytotoxin. A monoclonal antibody to H. pylori HSP60 inhibited the adhesion of H. pylori to MKN45 cells. These results suggest that HSP60 of H. pylori might act as an important virulence factor after H. pylori infection.

Antibodies, Monoclonal↗

PubMed1998

Establishment and characterisation of a monoclonal antibody to inhibit adhesion of Helicobacter pylori to gastric epithelial cells.

Monoclonal antibodies (MAbs) that inhibit adhesion of Helicobacter pylori to human gastric cancer (MKN45) cells were established to clarify the mechanism of adhesion of H. pylori. Of 53 hybridoma clones screened by the primary inhibition assay for adhesion, MAb A20 of IgM class was selected on the basis of both its reactivity to whole cells of H. pylori by ELISA and its inhibitory effect on adhesion of H. pylori. The adhesion of H. pylori strain TK1029 to MKN45 cells was inhibited by MAb A20, depending on the concentration of the MAb. The MAb recognised the surface antigen, lipopolysaccharide (LPS) of H. pylori, suggesting that LPS is associated with adhesion of H. pylori to human gastric epithelial cells.

Antibodies, Bacterial↗

PubMed1998

Development of reference procedures for broth microdilution antifungal susceptibility testing of yeasts with standardized endpoint determination.

Standard guidelines for the broth microdilution antifungal susceptibility testing of amphotericin B, flucytosine, fluconazole, miconazole and itraconazole are reported. These are a modification of the method developed by the National Committee for Clinical Laboratory Standards (NCCLS) on the following two points: standardization of the means of endpoint determination and the inclusion of miconazole and itraconazole in the testing. MIC was determined to be when the positive control had a turbidity of 0.2 at the 630 nm wavelength. The endpoint was 80% inhibition for azoles and 100% inhibition for other drugs. The method provided good reproducibility, and a wide range of MIC distribution was observed in all antifungal agents except amphotericin B.

Antifungal Agents↗

PubMed1998

Morphological alterations of Saccharomyces cerevisiae induced by benanomicin A, an antifungal antibiotic with mannan affinity.

The effects of benanomicin A, a mannose-binding antifungal antibiotic, on yeast cells of Saccharomyces cerevisiae were studied by electron microscopy. Cytological studies using vital stain with methylene blue demonstrated that benanomicin A at 20 and 80 microg/ml killed buds in preference to parent cells. In confirmation, examination by TEM revealed that benanomicin A at 80 microg/ml damaged buds more severely than parent cells. The major effect on the ultrastructure was characterized by severe damage to the cell membrane. In addition, it caused expansion and vacuolation of the endoplasmic reticulum (ER), and partial fragmentation and disappearance of nuclear membranes. The membrane-disruptive activity of benanomicin A may be closely associated with its membrane affinity.

Anthracyclines↗

PubMed1998

Anti-Candida activity of calprotectin in combination with neutrophils or lactoferrin.

The effect of an anti-microbial protein, calprotectin, in combination with neutrophils on the growth of Candida albicans was investigated. The growth inhibition of C. albicans by murine neutrophils was augmented by the addition of a low concentration of calprotectin prepared from rat peritoneal exudate cells. The concentrations of calprotectin causing 50% inhibition of growth of C. albicans in the absence or presence of neutrophils at an effector-to-target (E/T) ratio of 30 and 60 were estimated to be 0.45, 0.34 and 0.28 U/ml, respectively. The anti-Candida activity of calprotectin was completely inhibited by 2 microM of zinc ion, while it only partially lowered the activity of the combination of calprotectin and neutrophils. Lactoferrin, which is an anti-microbial protein released from neutrophils, strongly inhibited the growth of C. albicans in combination with calprotectin. These results suggest that calprotectin and lactoferrin released from neutrophils may cooperate to inhibit the growth of C. albicans at a local lesion of the infection where there is an accumulation of neutrophils.

Animals↗

PubMed1998

Assay for detecting IgE and IgG antibodies against Candida albicans cell-wall mannan.

In the present study, we assayed mannan-specific IgE and IgG antibodies in samples of serum isolated from blood collected from adult patients with bronchial asthma, using a liquid-phase method with a polysaccharide, mannan (Mn), purified from Candida albicans (C. alb), and investigated the relationships of allergenicity among a crude extract of C. alb, purified Mn, and acid protease (AP), The correlations between the titers of anti-Mn A and anti-Mn B IgE and IgG were very strong, and the levels of inhibition of anti-Mn A IgE and IgG reactions by Mn A and Mn B were almost identical. Although no common allergenicity was observed between Mn A and AP because there was no correlation between the titers of anti-Mn A and anti-AP IgE, and no inhibition of the anti-Mn A IgE reaction by AP, both antigens were found to exist in crude C. alb. The level of inhibition of anti-crude C. alb IgG reaction by Mn A or Mn B was about 60%. Approximately 70% inhibition of the anti-Mn A IgE reaction was observed for eight different fungal allergen extracts, but no inhibition was observed for 11 of the other fungal allergen extracts tested. The above results indicate that common antigenicity was observed between Mn A and Mn B in the human IgE and IgG antibody production system, and the cross-allergenicity observed among some fungi was considered to be the result of the common antigenicity of Mn isoforms.

Allergens↗

PubMed1998

Transferring profile of dietary sulphaquinoxaline into eggs.

Sulphaquinoxaline (SQ) was fed to laying hens at the dietary levels of 25, 50, 100 and 200 ppm, respectively, for 7 successive days. The increasing amount of SQ transferred into the whole egg during SQ feeding could be well described by the following equation: [equation: see text] where y is the SQ content (ppm) in the whole egg, x is the dietary SQ level (ppm), T is days on SQ feeding (T < or = 4). After 4 days of SQ feeding, the SQ content in the homogenized eggs reached a plateau at 0.0292.x (= 0.007318.4x) ppm. This equation permits to predict SQ content in the eggs.

Administration, Oral↗

PubMed1998

Antisporulating and respiration-inhibitory effects of essential oils on filamentous fungi.

Sporulation of four species of filamentous fungi, namely Aspergillus fumigatus, Fusarium solani, Penicillium expansum and Rhizopus oryzae, was suppressed by gaseous contact with citron, lavender and thyme oils and, to a lesser extent, by that of perilla and tea tree oils. Lemongrass and cinnamon bark oils were scarcely active. The antisporulating effect of the essential oils was not observed when they were applied as a solution, indicating that their vapours were the active form. Moreover, exposure of fungal cultures to vapours of the active essential oils caused curling of the tips of aerial hyphae (R. oryzae) or incomplete development of conidiophores (A. fumigatus). These antisporulating effects of the vapourizing essential oils seemed to be correlated with their respiration-inhibitory activity, rather than with their growth-inhibitory activity.

Fungi↗

PubMed1998

Morphological effects of itraconazole on murine macrophage.

Morphological effects of itraconazole (ITCZ) on murine macrophages were examined by light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and compared with the effects of other antifungal agents. Thioglycolate-induced peritoneal macrophages were prepared from C3H/He J mice and cultured for 20 h in the presence of the antifungal azoles econazole, fluconazole, miconazole, ketoconazole, ITCZ, hydroxy-itraconazole (ITCZ-OH), and a polyene antibiotic amphotericin B (AMPH). Among these reagents, only ITCZ and its derivative ITCZ-OH were effective in causing morphological changes of murine macrophage as determined by LM and SEM. Macrophages treated with 2 microg/ml ITCZ or ITCZ-OH were stretched out bidirectionally, their surface was smooth and their 'ruffles' decreased. TEM observation showed that the bundles of the filamentous structure existed along the cell shape in the cytoplasm. These findings suggest that ITCZ and ITCZ-OH affect the morphology of macrophages.

Animals↗

PubMed1998

Suppression of macrophage activation by peritoneal fluid from patients with endometriosis.

To investigate the effects of peritoneal fluid from patients with endometriosis on mouse peritoneal macrophages (Mphi), peritoneal fluid from endometriosis patients (n = 15) were added to a monolayer of C3H/HeJ mouse peritoneal Mphi. Tumor necrosis factor-producing activity was measured by the L929 assay activated with FK-23 (a preparation of heat-killed Enterococcus faecalis). Tumor necrosis factor-producing activity of C3H/HeJ mouse peritoneal Mphi incubated with peritoneal fluid was suppressed in 14 endometriosis patients. Interestingly, in nine endometriosis patients, tumor necrosis factor-producing activity was much lower than seen with mouse peritoneal Mphi incubated with corticosterone. Peritoneal fluid contains suppressive properties for the activation of peritoneal Mphi, which might allow the implantation of free endometrial cells or the metaplastic phenomena stimulated by retrograde menstruation.

Adult↗

PubMed1998

[Survey of fungemia cases during the past seventeen years at Teikyo University Hospital].

Fungi were isolated from 642 cases (3.5%) of 18,403 blood samples at Teikyo University Hospital during the 17-years period between 1979 and 1995. The number of fungemia cases began to increase around 1985, reached a peak in 1988, and since then, it has been gradually decreasing. The fungal species of isolates were: (1) Candida albicans in 224 cases (34.9%), (2) C. parapsilosis in 149 cases (23.2%), (3) C. tropicalis in 87 cases (13.6%), (4) C. glabrata in 65 cases (10.1%), (5) Hansenula anomala in 58 cases (9.0%), (6) C. guilliermondii in 24 cases (3.7%), (7) C. famata in 14 cases (2.1%), (8) Trichosporon beigelii in 11 cases (1.7%), (9) C. inconspicua in 5 cases (0.8%) and C. lusitaniae in 5 cases (0.8%), and other yeasts in 33 causes (5.1%). The number of isolates of C. albicans has been decreasing since 1989, concomitant with the clinical introduction of fluconazole in this hospital. However, the number of fluconazole-insusceptible fungi such as non-albicans Candida and Trichosporon spp. has increased. Fungemia cases infected concomitantly or sequentially with two or more different fungal species have been found occasionally since 1983 and have shown a high mortality rate. The spectrum of the causative organisms of fungemia appears to be, at least, partly influenced, by the usage of antifungal agents, particularly fluconazole.

Candida↗

PubMed1998

[Current status of acute respiratory infections in children under five years of age in Nairobi, Kenya].

Two hundreds and twenty-six children under five years of age with pneumonia were recruited from an urban poor area in Nairobi, Kenya, and examined for pathogens for 1 year from February 1997. One hundred and twenty-eight of the 226 patients were pathogen-positive cases. The patients under 1-year-old were 61.8% of the pathogen-positive cases. A total 192 organisms were isolated from 128 pathogen-positive patients. Streptococcus pneumoniae had the highest prevalence rate of 31.3%, followed by respiratory syncytial virus with 10.4%, Candida albicans with 9.9%, Moraxella (B) catarrhalis with 7.8%. In S. pneumoniae, 66.7% of the organism was resistant to oxacillin. It was also shown that 51.1% and 65.1% of the S. pneumoniae strains were resistant to gentamicin and trimethoprim/sulfam, respectively. From these results, it is clear that a lot of multi-drug resistant S. pneumoniae strains including penicillin-resistant S. pneumoniae were frequently detected in an urban poor area.

Acute Disease↗

PubMed1998

[The role of heat shock protein 60 (HSP60) of Helicobacter pylori in adhesion of H. pylori to human gastric epithelial cell].

Adhesion of Helicobacter pylori to both human gastric carcinoma cell lines (MKN45, MKN28 and KATO III) and prepared primary human gastric epithelial cells were analyzed with flow-cytometry. All strains adhered to human gastric carcinoma cells. Especially, these strains strongly adhered to MKN45 cells. Adhesion of H. pylori strains to prepared primary human gastric epithelial cells was also observed. However, the adherence rates of H. pylori to these cells were different among the cells used. These results suggested that the host factor might be important for adhesion of the bacteria to human gasgric cells. In addition, H20 monoclonal antibody directed to H. pylori HSP60 inhibited the adhesion of H. pylori to both cells. These results indicate that H. pylori HSP60 might be associated with the adhesion of the bacteria to human gastric epithelial cells.

Bacterial Adhesion↗