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Biomedical subjects

T Okubo

Publications and source records attributed to T Okubo.

At least 325 records · Page 18Linked to original sources
PubMed1992

A correlation between IgG class antibody production and glomerulonephritis in the murine chronic graft-versus-host reaction.

A graft-versus-host reaction (GVHR) was induced in (B10 x DBA/2)F1 (BDF1) and (BALB/c x A)F1 (CAF1) murine recipients by injection of their parental or B10.D2-derived spleen cells. The incidences of glomerulonephritis and autoantibody production were then correlated. All of the BDF1 mice that received DBA/2 spleen cells (termed DBA/2----BDF1) and 33% of the CAF1 mice that received BALB/c spleen cells (BALB/c----CAF1) developed glomerulonephritis. However, in other combinations (B10.D2----BDF1, A/J----CAF1) no significant glomerular lesions were observed. An analysis of antibodies by ELISA revealed that the groups with renal disease showed a significant polyclonal elevation of IgG class antibodies, including autoantibodies (anti-DNA, anti-MRBC, and NTA) and a conventional antibody (anti-TNP-KLH). No significant IgG class antibody production was observed in the groups that did not develop glomerulonephritis. Thus, it was suggested that an IgM to IgG class switch is important in the development of glomerulonephritis in GVHR. Other factors also appear to be involved. Only 33% of BALB/c----CAF1 developed glomerulonephritis, even though a level of IgG class antibody production was comparable to that observed in DBA/2----BDF1 in which 100% showed severe glomerulonephritis.

Animals↗
PubMed1992

Comparative in-vitro activity of RP 59500 against clinical bacterial isolates.

The activity of RP 59500 against Gram-positive cocci was determined by an agar dilution method and compared with that of erythromycin, cefotaxime and ampicillin. Of the 344 clinical isolates tested, none was resistant to RP 59500; this compound was active both against methicillin-resistant Staphylococcus aureus and against macrolide-resistant Gram-positive cocci. The bactericidal activity of RP 59500 was confirmed by killing curve determinations.

Ampicillin↗
PubMed1992

Case report: fulminant hepatitis C viral infection after allogeneic bone marrow transplantation.

The authors describe two patients with acute leukemia who died of fulminant hepatitis caused by hepatitis C virus (HCV) after an allogeneic bone marrow transplant, the first such cases reported in Japan. Both had developed posttransfusion hepatitis during chemotherapy to induce remission and for consolidation. Six months after blood transfusion, the blood serum of each patient was positive for HCV antibody and HCV RNA. In each case, there was a transient improvement in liver function after the transplant. However, within 5 months of receiving the transplant and coincident with the withdrawal of cyclosporin A, each patient developed an acute exacerbation of hepatitis. The fulminant hepatitis in our patients may, therefore, have been caused by the reactivation of HCV induced by the immunosuppressive therapy followed by a reconstitution of the immune system.

Adult↗
PubMed1992

Glomerulonephritis induced by murine chronic graft-versus-host reaction.

Severe glomerulonephritis was induced successfully in (B10 x DBA/2)F1 (BDF1) mice by injection of parental DBA/2 lymphoid cells. The mice manifested typical nephrotic syndrome dying around 10 weeks post injection. Electron microscopical examination demonstrated electron dense deposits first in the mesangial matrix, then in the subepithelium compatible with immune complex glomerulonephritis. Subendothelial deposits were not observed. Immunofluorescent study revealed IgG deposition in the capillary wall and IgM in the mesangium early in the process. As the lesion progressed, both IgG and IgM were present in the mesangial area and along the capillary wall. Some glomeruli showed segmental mesangiolysis, suggesting that altered mesangial cells have a role in the development of glomerular change, which together with rise in serum anti-DNA antibody titer suggest that autoantibodies promote the glomerular lesions in this model system.

Animals↗
PubMed1992

Use of prostaglandin E1 (lipo-PGE1) to treat Raynaud's phenomenon associated with connective tissue disease: thermographic and subjective assessment.

Four patients with connective tissue disease who had been suffering from severe Raynaud's phenomenon were treated with an intravenous infusion of prostaglandin E1 (PGE1) and its effectiveness was assessed by thermography and a questionnaire approach. PGE1 in a lipid microsphere formulation (lipo-PGE1) produced a significantly greater increase in lesional skin temperature compared with treatment with PGE1 clathrated in alpha-cyclodextrin 12 months previously in the same group of patients. These results were supported by the subjective assessment obtained from the patients by questionnaire.

Adolescent↗
PubMed1992

Relationship of respiratory effort sensation to expiratory muscle fatigue during expiratory threshold loading.

We investigated whether fatigue of the expiratory muscle, that is, the abdominal muscle, may account for a change in the respiratory effort sensation in normal subjects during expiratory threshold loading. The respiratory effort sensation was scored using a modified Borg scale. Expiratory muscle fatigue was assessed both from changes in the maximal static expiratory pressure and in the centroid frequency (fc) of the abdominal muscle electromyogram (EMG). Expiratory threshold loading (magnitude of threshold; 40 to 60% of the maximal expiratory pressure at FRC, breathing frequency = 15/min, and duty cycle = 0.5) was continued until exhaustion or for 30 min. Loading was repeated following a 15-min recovery period after the end of the first expiratory loading. The maximal static expiratory pressure during loading (Pmmax) decreased initially and then remained decreased. Decreases were smaller with the 40% load (22 +/- 6%, SEM) than with the 60% load (37 +/- 3%) (p less than 0.05). The decrease during the second run of the 60% load was greater than during the first (p less than 0.01 by ANOVA). The maximal expiratory pressure at TLC before the second run of the 60% load was decreased by 9 +/- 3% compared with the control (p less than 0.02) but that with the 40% load was not. The fc with the 60% load decreased initially by 8 +/- 1% and then remained constant, although no change was observed with the 40% load.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Modulation of bronchial reactivity by angiotensin-converting enzyme in unanesthetized guinea pigs.

To investigate the role of angiotensin-converting enzyme (ACE) in the modulation of bronchial reactivity, we tested the effects of a specific ACE inhibitor, captopril (CAP), on the bronchial reactivity to substance P (SP) and methacholine (MCH) in unanesthetized guinea pigs. The relative role of ACE on the vascular endothelium and ACE in the airway tissue was examined by administering CAP as an intravenous infusion and by an inhaled aerosol. Bronchial reactivity was evaluated by a provocative dose of SP or MCH at a concentration that would double the baseline value of the specific airway resistance (PC200 or PD200). Neither pretreatment with infused CAP (10 mg/kg) nor inhaled CAP (5 mg) enhanced bronchial reactivity to inhaled SP, whereas the reactivity to infused SP (7.5 x 10(-3) to 20 nM/kg) was enhanced significantly by pretreatment with infused CAP (10 mg/kg) (p less than 0.05). The infusion of CAP (10 mg/kg) also enhanced the bronchial reactivity to both infused MCH (0.05 to 25 micrograms/kg) and inhaled MCH (0.05 to 25 mg/ml) (both p less than 0.05). However, the inhalation of CAP (5 mg) did not affect the bronchial reactivity to inhaled MCH. These observations suggest that ACE located on the vascular endothelium may modulate bronchial reactivity.

Airway Resistance↗
PubMed1992

[Multiple resistance to drugs by MRSA].

Most methicillin-resistant Staphylococcus aureus (MRSA) isolates are multiply resistant to various antimicrobial agents. Therefore, MRSA strains have become a serious problem in the clinical setting. However, it should be noted that the frequency of isolation of strains resistant to aminoglycoside and minocycline was not significantly different between low- and high-MRSA isolates and the isolation frequency of high-MRSA strains, less susceptible to not only beta-lactam antibiotics but also to macrolide antibiotics and quinolones, was significantly higher than the corresponding values for low-MRSA strains. These results suggest that high-MRSA strains were selected by antimicrobial agents for the treatment with the patients.

Aminoglycosides↗
PubMed1992

[Aminoglycosides resistance of methicillin-resistant Staphylococcus aureus].

In the last decade, there has been a dramatic increase in the isolation frequency of methicillin-resistant Staphylococcus aureus (MRSA) in Japan. Especially, a high incidence of multiple resistant MRSA strains has been reported. These strains are resistant not only to beta-lactams but to aminoglycosides and macrolides. About 90% of MRSA strains were resistant to gentamicin (GM) and/or tobramycin (TOB), producing an aminoglycoside modifying enzyme, mainly, APH (2")/AAC (6) and/or AAD (4',4"). Based on these modifying enzymes produced, MRSA strains were classified into three groups; group 1 produced APH (2")/AAC (6), belonging to phage group I and coagulase IV, group 2 produced AAD (4',4"), belonging to phage group III and coagulase II, and group 3 produced APH (2")/AAC (6) and AAD (4',4"), belonging to phage group III and coagulase II. The epidemiological results suggest that MRSA strains changed from group 1 to group 2, and then to group 3. Recently, arbekacin (ABK), a new anti-MRSA aminoglycoside, has been introduced into clinical practice. ABK shows a potent activity to GM-resistant strains, due to poorly modification by APH (2")/AAC (6'). However, there were few ABK- and GM-resistant strains in clinical isolates. These strains produced a higher amount of the enzyme than ABK-susceptible and GM-resistant strains. This observation suggests that ABK-resistant strains might be derived from GM-resistant strains by mutation of the gene coding APH (2")/AAC (6').

Acetyltransferases↗
PubMed1992

[Lymphoid infiltration of colon cancer and clinical significance of the skin test].

It was reported that lymphoid infiltration (LI) of colon cancer tended to be found more commonly in patients with colonic cancer in an early stage than in an advanced stage. This time, the correlation among LI of colon cancer, cell-mediated immunity and the cumulative 5-year survival rate was studied in 124 patients with resected colon cancer. The results were as follows: 1) The cumulative 5-year survival rate in patients with positive LI was higher than that in the patients with negative LI. 2) There was correlation between the degree of LI of the cancer and Su-PS skin reaction. 3) Postoperative cell-mediated immunity was reduced in the cases of poor prognosis. Therefore we insist on paying attention to immunochemotherapy for 24 months after surgery.

Colonic Neoplasms↗
PubMed1992

[Early diagnosis and management against perioperative fungus infection].

Candida spp. is frequently detected from perioperative patients, especially from those requiring central venous catheter (CVC) management. CAND-TEC could detect the blood fungus infection easily and quickly. We analyzed 438 specimens from 57 patients requiring perioperative CVC management for more than three weeks, and investigated usefulness of CAND-TEC comparing with other serological methods. The dilution rate of CAND-TEC showed a positive correlation with amount of beta-D-glucan which was measured by Toxicolor test and Endotoxin-specific assay. It also showed a positive correlation with amount of D-arabinitol. When blood samples diluted more than four times were positive with CAND-TEC, the patients were considered to be infected, and accumulative infection rate was up to 84.2% three weeks after introduction of CVC management. CAND-TEC would be useful in detecting Candida infection compared with conventional methods, and the fungus infection was much more frequent incidence than ever expected. It is important to detect fungus infection early and respond immediately to avoid nosocomial infection.

Candidiasis↗
PubMed1992

[Reactive histiocytosis during initial remission induction therapy for acute myeloblastic leukemia].

Six of 14 patients with acute myeloblastic leukemia (AML) complicated reactive histiocytosis during initial remission induction therapy. All six patients had a high fever without signs of infection during initial chemotherapy, and periods of myelosuppression were prolonged. Histiocytes with a mature appearance, some of which phagocyted erythrocytes, thrombocytes or neutrophils, increased in the bone marrow. All of 3 patients tested showed high serum levels of ferritin. Two of 3 patients treated with 125 mg/day methylprednisolone achieved complete remission. In the remaining 3 patients, one patient achieved complete remission, but the others died of fungal pneumonia or sepsis. Thus, reactive histiocytosis is one of the severe complications in patients with AML undergoing chemotherapy.

Adult↗
PubMed1992

[Burkitt's lymphoma diagnosed by molecular analysis of DNA from malignant cells in ascites].

A 73-year-old man was admitted with severe abdominal fullness. Physical examination suggested much ascites. Laboratory data revealed that BUN was 39 mg/dl, Cr was 2.2 mg/dl, UA was 19.7 mg/dl, and LDH was 1,569 U/l. In ascites, there were many cells with large nuclei and many vacuoles. Immunocytological characterization indicated that most of these cells were B lineage. And diagnosis of malignant lymphoma, the patient was treated with VEPA therapy. However, he soon died with acute renal failure. We examined the possibility of gene rearrangements between the c-myc and immunoglobulin genes and found that c-myc gene was rearranged at the first intron, and joined with immunoglobulin JH locus as head to head. These results suggested that the patient carried Burkitt's lymphoma of the American type.

Aged↗
PubMed1992

[Polycythemia vera terminating in chronic neutrophilic leukemia: studies on in vitro growth of hematopoietic progenitor cells].

A 57-year-old man, diagnosed as Polycythemia vera (PV), had been treated with administrations of Busulfan since 1984. Three years later, the number of neutrophils in peripheral blood increased to 50,000/microliters with progression of splenomegaly, and the case was diagnosed as Chronic neutrophilic leukemia (CNL) based on the criteria by Miura et al, in November, 1989. In spite of 6MP and Busulfan therapy, marked neutrophilia and splenomegaly progressed, and the patient died due to liver dysfunction in June of 1991. To clarify the pathophysiology of PV and CNL, we studied the in vitro growth kinetics of hematopoietic progenitor cells in bone marrow of this unique case and made a comparison with those of 4 cases of PV and 4 normal volunteers employing methylcellulose culture. As in other cases of PV, erythroid colonies were formed in culture of bone marrow from this patient without addition of erythropoietin. Furthermore, spontaneous colonies derived from CFU-GM and CFU-Mix increased remarkably in this case only. The results suggest that the hematopoietic abnormalities in this case involve the multipotent stem cells as well as erythroid and granuloid-macrophage progenitors.

Colony-Forming Units Assay↗
PubMed1992

[Involuntary smoking in a workplace situation--discomfort of nonsmokers and interpersonal awareness of smokers].

A questionnaire survey was conducted to examine the socio-behavioral interaction between smokers and nonsmokers in a workplace situation. A socio-behavioral interaction is hypothesized to be centered around the subjective discomfort such as 'bothered feelings' towards involuntary smoking among nonsmokers. Study subjects were 1,134 nonsmokers and 1,457 smokers working in 21 small-scale production companies in Japan. Among nonsmokers, a combined 93.3% reported 'perceived exposure to smoking', 'always', 'often', or 'sometimes' compared to 6.6% reporting 'never'. Similarly, 74.6% experienced 'bothered feelings' 'sometimes', 'always', or 'often' compared to 25.3% reporting 'never'. A combined total of 39.4% expressed their discomfort to smokers 'sometimes', 'often', and 'always' compared to 60.6% who 'never' did. In contrast, 59.1% of smokers responded that they smoked with consideration of nonsmokers' presence (interpersonal awareness) 'sometimes', 'often', and 'always' compared to 41.0% for 'never'. 'Bothered feelings' among nonsmokers was significantly lower among those with past smoking history and correlated positively with 'perceived exposure to smoking' (rs = 0.22, p less than 0.001) and with 'expression of discomfort among both male (rs = 0.32, p less than 0.001) and female nonsmokers (rs = 0.34, p less than 0.001). Among male smokers 'interpersonal awareness' was significantly higher for those with less cigarette consumption and with past history of smoking cessation. A regression analysis was performed using mean scores calculated for smokers and nonsmokers of each workplace. Lower 'bothered feelings' of nonsmokers significantly correlated with higher 'interpersonal awareness' of smokers (r = -0.59, p less than 0.005). These finding imply the presence of socio-behavioral interactions between smokers and nonsmokers and thus suggest the significance of workplace education on involuntary smoking.

Adult↗
PubMed1992

[Identification and antibiotic prophylaxis of high-risk patients in biliary tract surgery].

A prospective randomized trial has compared 3 policies of antibiotic prophylaxis in biliary surgery. Patients considered to be high-risked against postoperative infection were randomly allocated to 2 groups: in group CTM-H, patients were given cefotiam; in group CMX-H, patients were given cefmenoxime. Patients free of risk factors (group CTM-L) were all given cefotiam. The high-risk factors adopted in this trial were; emergency surgery, presence of jaundice or cirrhosis, malignant disease, diabetes mellitus, age over 70, recent biliary tract infection, choledocholithiasis, and previous biliary surgery. Postoperative infection occurred in 2.1% (4/190) in the CTM-L group, which was lower compared to 15.5% (11/71) of the CMT-H group (p less than 0.01), and 11.3% (8/71) of the CTM-H group (p less than 0.01). The rates of bacterial isolation from intraoperative bile culture and wound swab were significantly high in the two high-risk groups compared to the low-risk group, but is was not different within the two high-risk groups. These findings suggest that while cefotiam is appropriate for prophylaxis for the low-risk patients, the utmost care should be taken in the high-risk patients to prevent intraoperative contamination along with prophylactic antibiotic therapy which covers the bacteria isolated from the bile.

Adolescent↗