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Biomedical subjects

Y Hirakata

Publications and source records attributed to Y Hirakata.

At least 91 records · Page 5Linked to original sources
PubMed1996

Enolase antigen, mannan antigen, Cand-Tec antigen, and beta-glucan in patients with candidemia.

We compared the specificities and sensitivities of four tests used for the serodiagnosis of candidemia in 39 patients with candidemia, including 10 patients with superficial Candida colonization, 10 patients with deep mycosis, and 20 healthy subjects. The results obtained by the dot immunoblotting assay for detecting the enolase antigen (48 kDa) were compared with those of assays for detecting mannan antigen, heat-labile antigen (a threshold titer of four times), and beta-glucan (> or = 60 pg/ml). Enolase antigen was detected in 28 (71.8%) patients with candidemia, while 30 (76.9%), 10 (25.6%), and 27 (84.4%) patients were positive for the heat-labile antigen by the Cand-Tec assay, the mannan antigen by the Pastorex Candida assay, and beta-glucan by the limulus test, respectively. Ten patients with superficial Candida colonization, 5 patients with invasive pulmonary aspergillosis, 5 patients with cryptococcosis, and 20 healthy subjects were negative for both enolase antigen and mannan antigen. Two patients with superficial Candida colonization, one patient with invasive pulmonary aspergillosis, and two patients with cryptococcosis were positive by the Cand-Tec assay. The beta-glucan concentration was more than 60 pg/ml in all patients with invasive pulmonary aspergillosis; however, it was less than 10 pg/ml in all patients with cryptococcosis. The specificity of enolase antigen in the serodiagnosis of candidemia was 100%, but the sensitivity was 71.8%. The specificity and sensitivity of Cand-Tec, the assay for mannan antigen, and the assay for beta-glucan were 76.9 and 87.5%, 25.6 and 100%, and 84.4 and 87.5%, respectively. Our results demonstrated that antigen detection tests are useful for the diagnosis of candidemia; however, none is satisfactory for the serodiagnosis of candidemia. We suggest that a combination of two assays may increase the accuracy of diagnosis of candidiasis.

Adult↗
PubMed1996

CD5-expressing B-cell lymphomas/leukemias: relatively high frequency of CD5+ B-cell lymphomas with an overall poor prognosis in Nagasaki Japan.

To characterize CD5+ B-cell neoplasms in Japan, where chronic lymphocytic leukemia (CLL) is rare and of different subtypes in comparison with Western countries, we collected 58 cases of CD5+ B-cell lymphomas/leukemias and analyzed their clinicopathologic features. According to the French-American-British (FAB) and standard histologic classification, the cases corresponded to small lymphocytic lymphoma (SLL, group I; n = 22, consisting of CLL, n = 10, CLL/PL, n = 3, and CLLmixed, n = 7); intermediate differentiated lymphoma/mantle cell lymphoma (IDL/MCL, group II, n = 18); and others with CD5-positive lymphomas (group III, n = 18). The CD5+ B-cell lymphomas showed morphologic and prognostic variability among the three groups. The clinical and immunophenotypic features were remarkably consistent in leukemic disease being seen in 73% of all cases, splenomegaly in 63%, and intense CD19, CD20, surface membrane immunogobulin M (SmIgM) or SmIgM and SmIgD, light-chain expression, and no CD10 expression. The median survival time of groups I, II, and III was 7.8, 3.3, and 0.8 years, respectively. These findings suggest that CD5 antigens may serve as valid markers for the prognosis and clinical features of B-cell lymphomas and that CD5+ B-cell lymphomas with an overall poor prognosis occurs at a relatively high frequency in Japan. This also suggests that a combination of immunophenotypic and morphologic features is of value for characterizing CD5+ B-cell neoplasms.

Adult↗
PubMed1996

[Contralateral lung contusion].

A 47-year-old man was admitted to the emergency room in November 1994 with left-sided chest pain. Two days before admission, he had fallen two meters and hit the left side of his chest. A chest roentgenogram showed patchy infiltrative shadows and a pleural effusion confined to the right lung field. Bloody fluid was obtained from the right B3b by bronchoalveolar lavage. Specimens obtained from the right lung by transbronchial lung biopsy revealed deposition of hemosiderin and precipitation of fibrin, which were consistent with lung contusion. The abnormal shadows on the chest roentgenogram disappeared spontaneously within one week. Review of the literature suggests that contra coup pulmonary contusion is rare, and that the mechanism might involve injury of small vessels by high-speed vibration of the contralateral part of the mediastinum.

Accidents, Occupational↗
PubMed1996

[Differential diagnosis of tuberculous pleurisy by the measurement of cytokine concentration in pleural effusion].

Pleural fluids obtained from 26 patients with tuberculous pleurisy (T-group), 11 with parapneumonic pleurisy (B-group) and 21 with malignant pleurisy (M-group) were tested for their biologic parameters and cytokine concentrations. 1) The average age of T-group was over 10 years lower than that of M-group with a statistically significant difference. 2) The average CRP value of B-group and the positivity on PPD skin test of T-group were higher than those of the other groups, respectively. 3) Yellowish pleural fluids were mainly observed in T- and B-group, while bloody pleural fluids were mostly seen in M-group with a statistically significant difference. The average total protein amount and adenosine deaminase value in pleural fluid significantly increased in T-group. The percentage of polymorphonuclear leukocytes showed a significant increase in B-group, while lymphocytes significantly increased in T-group with a statistically significant difference. 4) Although no significant difference in concentrations of IL-1 beta, IL-2, IFN-gamma and TNF-alpha in serum was noticed among the three groups, the average concentrations of IFN-gamma and TNF-alpha in pleural fluid in T-group were significantly higher than those in the other groups. 5) TNF-alpha-mRNA of mononuclear cells in pleural fluid was strongly expressed in 3 out of 11 patients of T-group, while no expression was observed in 6 patients of M-group. In conclusion, the measurement of concentrations of two kinds of cytokines in pleural fluid, IFN-gamma and TNF-alpha, may be clinically useful for the differential diagnosis of tuberculous pleurisy from parapneumonic pleurisy and malignant pleurisy.

Adult↗
PubMed1996

[Clinical evaluation of sulbactam/cefoperazone for lower respiratory tract infections. Correlation between the efficacy of sulbactam/cefoperazone and beta-lactamase].

The efficacy and safety of sulbactam/cefoperazone (SBT/CPZ) were evaluated in 42 patients with respiratory tract infections, including pneumonia (29 patients) and lower respiratory tract infections (5 patients). Overall clinical efficacy rates (excellent + good) were 79% in pneumonia and 80% in respiratory tract infections in 34 patients evaluated for clinical efficacy. It was excellent that the clinical efficacy rate was 92% in mild and moderate pneumonia. Pathogens isolated from sputa were 31 strains, including 8 strains of Pseudomonas aeruginosa, 7 of Streptococcus pneumoniae, 3 of Staphylococcus aureus and 3 of Haemophilus influenzae. Since the isolates were eradicated in 18 strains, replaced in 3, unchanged in 2 and unknown in 8, the overall eradication rate was 91%. The eradication rates were 89% in beta-lactamase producing strains and 100% in beta-lactamase positive sputum, and excellent or good in 19 (83%) of 23 patients with beta-lactamase negative sputum. The eradication rate was 88% in 5 patients with beta-lactamase positive sputum. One patient experienced a moderate rash. Abnormal laboratory test values were observed in 10 patients (26.3%), but these abnormalities were mild and transient. These results suggested that SBT/CPZ was effective and safe for the treatment of respiratory tract infections caused by beta-lactamase producing as well as beta-lactamase non-producing bacteria.

Aged↗
PubMed1995

Influence of various immunosuppressive agents on the occurrence of endogenous bacteraemia in mice.

The influence of six immunosuppressive agents on the occurrence of endogenous bacteraemia in mice was evaluated. The mortality rates in conventional ddY mice given cyclophosphamide (CY), fluorouracil (5-FU), methotrexate (MTX), cisplatin (CDDP) or FK-506 intraperitoneally, or dexamethasone (DXM) subcutaneously were 70, 100, 100, 100, 0 and 0%, respectively. Pseudomonas aeruginosa was isolated from 70% of mice treated with CY but from only 10% of mice treated with 5-FU and 30% treated with MTX. Enterobacteria were isolated from 90% of mice treated with 5-FU. Specific-pathogen-free (SPF) mice fed P. aeruginosa were also treated with these agents. All mice in the CY, 5-FU, MTX and CDDP groups died whereas mice treated with DXM and FK-506 showed 20% and 0% mortality, respectively. Pure cultures of P. aeruginosa were obtained from all of the mice treated with CY. Polymicrobial bacteraemia with P. aeruginosa and enterobacteria occurred in 5, 25, 5 and 5% of mice treated with 5-FU, MTX, CDDP and DXM, respectively. Enterobacterial bacteraemia was observed in 70% of mice treated with CDDP and in 5% of the DXM group. Different types of bacteraemia were induced by different immunosuppressive agents. The mechanism of immunosuppression may affect the frequency of bacteraemia and the causative organism.

Animals↗
PubMed1995

A protective role for lymphocytes in cyclophosphamide-induced endogenous bacteraemia in mice.

Cyclophosphamide (CY) is used in many animal studies, including models of bacteraemia, to deplete peripheral neutrophils and induce a compromised state. Although CY also influences lymphocyte function, the protective role of lymphocytes in bacteraemia is unclear. Therefore, CY (200 mg/kg) was administered to ddY mice and its influence on the number, cellular composition, and function of lymphocytes in the spleen and Peyer's patches was examined. A single dose of CY reduced the number of lymphocytes in a time-dependent fashion. Flow cytometry showed that B cells carrying B220 antigen decreased significantly. The production of IgA in Peyer's patches, as measured by enzyme-linked immunosorbent assay, was also suppressed in a time-dependent fashion. Blastogenic responses of splenic lymphocytes to Concanavalin-A, lipopolysaccharide and heat-killed Pseudomonas aeruginosa were suppressed 48 h after CY administration. The results suggest that CY suppresses the number and function of lymphocytes, especially B cells. This may lead to bacterial overgrowth in the gut and result in bacteraemia. Intravenous transfusion of normal lymphocytes or oral inoculation of IgA to mice with P. aeruginosa D4 endogenous bacteraemia significantly increased survival rates, indicating that lymphocytes and their products have a protective role in bacteraemia in mice.

Administration, Oral↗
PubMed1995

The influence of exo-enzyme S and proteases on endogenous Pseudomonas aeruginosa bacteraemia in mice.

The role of Pseudomonas aeruginosa exo-enzymes was evaluated in a murine model of endogenous bacteraemia in which the bacteria invaded the bloodstream after oral dosing. Although an elastase mutant PAO-E64 was as virulent as its parent strain PAO1, an exo-enzyme S-deficient mutant, DG1-ExS5 and alkaline protease mutants PAKS-16, PAKS-17, PAKS-19, were less virulent than their parent strains, DG1 and PAKS-1, respectively (p < 0.01). Thus exo-enzyme S and alkaline protease, but not elastase, appear to contribute to the pathogenicity of P. aeruginosa in this model.

Animals↗
PubMed1995

A salivary gland-type monomorphic adenoma with trabecular proliferation in the lung.

Salivary gland-type adenoma, especially monomorphic adenoma in the lung is very rare. We report a 66-year-old previously healthy woman who developed cough, hemosputum, and fever. Bronchoscopy revealed an endobronchial mass in the proximal portion of the left lower lobe bronchus. Following left lower lobectomy, the pathological diagnosis was an unusual monomorphic adenoma of the salivary gland-type with trabecular proliferation.

Adenoma↗
PubMed1995

Elevation of tumour markers in serum and bronchoalveolar lavage fluid in pulmonary alveolar proteinosis.

It is unclear whether tumour markers are generally increased in the serum and bronchoalveolar lavage fluid (BALF) of patients with pulmonary alveolar proteinosis (PAP). To clarify this point, levels of tumour markers were measured in the serum and BALF of patients with PAP. Squamous cell carcinoma (SCC) antigen, carcinoembryonic antigen (CEA), and carbohydrate antigens sialyl Lewis (CA 19-9) and sialyl SSEA-1 (SLX) were assayed with radioimmunoassay kits. Cytokeratin 19 fragments (CYFRA) were measured by enzyme-linked immunosorbent assay. Values for the tumour markers in serum, except for SCC, exceeded cut-off values in some PAP patients. Levels of the markers were higher in BALF compared with those in serum, and were significantly elevated in PAP patients compared with control subjects. There was a significant inverse correlation between CA19-9 level in BALF and arterial oxygen tension (PaO2) in PAP patients. A gradual elevation of CA19-9 and SLX was observed in a patient who showed a decrease in PaO2 level during the study period. In the light of these findings, it is possible that levels of tumour markers in BALF, especially levels of CA19-9 and SLX, may reflect the severity of the disease in PAP patients.

Adult↗
PubMed1995

[Pulmonary hypertrophic osteoarthropathy and clubbing of fingers in patients with lung cancer].

We examined clinical characteristics of patients with primary lung cancer associated with clubbing of the fingers or pulmonary hypertrophic osteoarthropathy. Clubbing was observed in 12.5% of patients with lung cancer. Squamous cell carcinoma was frequently associated with clubbing. Clubbing was found in all clinical stages. PaO2 and PaCO2 were normal in patients with lung cancer, which suggests that neither hypoxemia nor hypercapnia caused the clubbing in these patients. Pulmonary hypertrophic osteoarthropathy was found in three patients with lung cancer (two men and one woman, mean age 49 years). The incidence was 2.9% among lung cancer patients with clubbing, 0.22% in all lung cancer patients, and was apparently lower than those in reports from outside Japan. One of these patients has stage IIIA squamous cell carcinoma, one had stage IV large cell carcinoma, and one had stage IV adenocarcinoma. In all cases bone scans were useful for diagnosis and for following the clinical course.

Adenocarcinoma↗
PubMed1994

Profiles of outer membrane proteins and lipopolysaccharide of Pseudomonas aeruginosa grown in the presence of sub-MICs of macrolide antibiotics and their relation to enhanced serum sensitivity.

We have previously reported that erythromycin at sub-inhibitory concentrations enhanced the serum sensitivity of some Pseudomonas aeruginosa strains. To explore the mechanism of this effect, we have now examined the influence of macrolide antibiotics on outer membrane proteins and lipopolysaccharide (LPS) of P. aeruginosa. The strains S-6 and PAO-1 of P. aeruginosa were used as susceptible and resistant strains respectively to assess enhancement of serum sensitivity by erythromycin. The strain S-6 became more serum-sensitive when grown on agar with sub-MICs of erythromycin or azithromycin, but not of josamycin, whereas no change was observed in the serum sensitivity of the strain PAO-1 after growth with any of these antibiotics. The analysis of outer membrane proteins showed that erythromycin treatment resulted in a reduction in the amount of the 38 kDa protein (OprF) and in a prominent increase of 41 kDa protein band in the strain S-6, but not in the strain PAO-1. By an immunoblotting assay, this 41 kDa protein was shown to be highly reactive to the immune serum against untreated P. aeruginosa. LPS of the strain S-6 were examined by SDS acrylamide gel electrophoresis. The treatment with erythromycin or azithromycin, but not with josamycin, reduced the amounts of LPS species with lower molecular weights although the levels of LPS species with high molecular weights were similar to those of untreated bacteria. These results suggest that the enhanced serum sensitivity of P. aeruginosa by erythromycin is associated with changes in bacterial surface components, such as outer membrane proteins and LPS.

Anti-Bacterial Agents↗
PubMed1994

Detection of antibody-coated bacteria in expectorated sputum for diagnosis of lower respiratory infections.

We evaluated antibody-coated bacteria (ACB) in expectorated sputum to discriminate contaminating or colonizing organisms from true pathogens. We examined 60 expectorated sputum samples from 51 patients with lower respiratory infections (chronic obstructive pulmonary disease 25, pneumonia 20, purulent tracheobronchitis 6). All samples were examined with quantitative culture and immunofluorescent demonstration of ACB. From the results of quantitative culture, we divided specimens into pathogen-isolated and pathogen-free samples. Among pathogen-isolated samples, in which we isolated accepted pathogenic organisms at > or = 10(7) colony-forming units per ml, 16 of 23 samples were ACB-positive (69.5%). In contrast, among pathogen-free samples, in which we isolated accepted pathogens at < 10(7) colony forming units per ml or only upper respiratory flora, only 3 of 37 samples were ACB-positive (8.1%). The ACB-positive rate was significantly higher in pathogen-isolated than in pathogen-free samples (P < 0.001). Consequently, detecting ACB in expectorated sputum shows good potential as another criterion for distinguishing contaminating or colonizing organisms from true pathogens.

Adult↗
PubMed1994

Comparative in vitro exoenzyme-suppressing activities of azithromycin and other macrolide antibiotics against Pseudomonas aeruginosa.

The inhibitory effects of azithromycin (AZM), a new 15-membered macrolide antibiotic, on the production of exotoxin A, total protease, elastase, and phospholipase C by Pseudomonas aeruginosa were determined, and the virulence-suppressing effects of AZM were compared with those of erythromycin (EM), roxithromycin (RXM), and rokitamycin (RKM). The effect of exposure of P. aeruginosa PA103 or B16 in cultures to sub-MICs of these macrolide antibiotics on the production of exoenzymes was determined. AZM suppressed the in vitro production of extracellular and intracellular exotoxin A by P. aeruginosa PA103 more than did EM, even at a concentration of only 2 micrograms/ml. At concentrations of between 4 and 32 micrograms/ml, AZM also inhibited total protease, elastase, and phospholipase C production by P. aeruginosa B16 more than did EM, RXM, and RKM. AZM was effective in suppressing exotoxin A and total protease production through 24 h of incubation in the presence of drug at sub-MICs, but it had no significant effect on either the growth of P. aeruginosa or its total protein production. Moreover, at a concentration of 4 micrograms/ml, AZM suppressed exoenzyme production by other strains of P. aeruginosa more than did EM. These findings indicate that AZM, EM, RXM, and RKM each has an inhibitory effect on exoenzyme production separate from the antimicrobial effect and that, of these macrolides, AZM has the strongest virulence-suppressing effect.

ADP Ribose Transferases↗
PubMed1993

Effect of clearance of bacteria from the blood on the development of systemic bacteraemia in mice.

Clearance of various bacteria isolated from portal and systemic blood of mice was evaluated and compared. All portal blood strains, including Escherichia coli and enterococci were eliminated more rapidly from the circulation than were strains isolated from systemic blood, including Pseudomonas aeruginosa. With mannose-type lectin, mannose or fucose residues that mediated lectinophagocytosis were detected on the surfaces of most portal strains by agglutination tests. Blood clearance of Esch. coli H21 was inhibited by prior injection of mannose into mice, suggesting that the clearance of this strain was mediated by mannose-type lectin on the surface of tissue macrophages. However, no inhibition of clearance of any other strains was observed by the injection of mannose, galactose, or fucose into mice, nor by pre-incubation of bacteria with mannose. Blood clearance of some portal strains was significantly faster in CBA/J mice than in CBA/N mice with B cell immune deficiency, indicating that immunoglobulin was involved in their clearance. Among portal strains only enterococci showed high cell-surface hydrophobicity. These data suggest that initial bacteria blood clearance may be critical in determining whether latent portal bacteraemia progresses to systemic bacteraemia and that the rapid clearance of most strains is multifactorial.

Agglutination Tests↗
PubMed1993

Mortality rates amongst mice with endogenous septicaemia caused by Pseudomonas aeruginosa isolates from various clinical sources.

Mice that had been treated with cyclophosphamide and ampicillin were fed with Pseudomonas aeruginosa. These procedures induced an endogenous septicaemia under conditions mimicking the pathophysiology of the disease in man. This model was used to compare the mortality rates in mice infected with P. aeruginosa isolates from various clinical sources. Mortality rates in mice given isolates from blood cultures had a broad range (0-100%), but the mean rate was significantly higher than with isolates from other infection sites. Moreover, blood isolates persisted in the intestines of mice after oral inoculation, whereas most isolates from other sources were gradually eliminated. Most P. aeruginosa isolates from blood culture produced significantly higher levels of exotoxin A and total proteases than isolates from other infection sites. Amongst the blood isolates, all but one of the lethal strains produced large quantities of exotoxin A or total proteases or both. Taken together, the results suggest that the ability of P. aeruginosa to adhere to the intestinal tract and to produce high levels of exo-enzymes may contribute to the development of fatal septicaemia.

ADP Ribose Transferases↗
PubMed1993

Effects of sub-MICs of erythromycin and other macrolide antibiotics on serum sensitivity of Pseudomonas aeruginosa.

We examined the effects of sub-MICs of erythromycin (EM) and other macrolide antibiotics on the serum sensitivity of Pseudomonas aeruginosa. P. aeruginosa S-6 grown for 36 and 48 h on agar with 10 micrograms of EM per ml (1/10th the MIC) showed significantly increased sensitivity to human serum bactericidal activity compared with those of bacteria grown on agar without EM (P < 0.05). No changes in serum sensitivity were observed in bacteria grown for less than 24 h. This increased sensitivity was apparent even at a concentration of 1.5 micrograms of EM per ml (1/67th the MIC) in bacteria grown for 48 h (P < 0.01). Among the other macrolide antibiotics tested, clarithromycin also enhanced sensitivity to serum, but there were no changes in the sensitivities of bacteria grown on agar with kitasamycin, josamycin, rokitamycin, or oleandomycin even at a concentration of 12 micrograms/ml (1/16th, 1/16th, 1/8th, and 1/33rd the MICs, respectively). P. aeruginosa S-6 grown on agar with subinhibitory concentrations of EM showed decreased cell surface hydrophobicity in a dose-dependent manner, whereas oleandomycin and rokitamycin, even at a concentration of 12 micrograms/ml, induced a slight decrease in hydrophobicity which was approximately equivalent to that of 1.5 micrograms of EM per ml. Among six other strains of the nonmucoid phenotype, three strains became more sensitive to serum by exposure to 10 micrograms of EM per ml for 48 h. In contrast, no evident correlation between EM treatment and a change in serum sensitivity was observed in six strains of the mucoid phenotype, as judged by the results of experiments with both 2 and 0.4% serum. These results show that EM at subinhibitory concentrations enhances the serum sensitivity of some P. aeruginosa strains. Since induced serum sensitivity was accompanied by a decrease in bacterial cell surface hydrophobicity, EM may render P. aeruginosa more serum sensitive by changing the cell surface structure(s) of this organism.

Anti-Bacterial Agents↗