[Management of infections under the new Infection Control Law: discussion].
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Biomedical subjects
Publications and source records attributed to S Ichiyama.
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Serum interleukin 15 (IL-15) levels were measured in 77 patients who were consecutively admitted to our intensive care unit. Postoperative enterocolitis occurred in four patients and Methicillin-resistant Staphylococcus aureus (MRSA), but not Clostridium difficile, was identified in the faecal specimens from these patients. The IL-15 levels in the patients with MRSA enterocolitis were significantly elevated compared with those of other MRSA infections without enterocolitis including pneumonia (n=6) and cholangitis (n=1), and other MRSA non-colonized patients (n=66) (21.2+/-5.2 pg/ml vs 4.3+/-0.2, 4.3+/-0.5). Notably, an increase in serum IL-15 was observed just before clinical manifestation of severe diarrhoea. Our findings suggest that IL-15 may be associated in the pathogenesis of postoperative enterocolitis and its serum level may be a severity indicator of the disease.
We previously reported that immunization with a synthetic peptide of human thyrotropin receptor (TSH-R) expanded humoral autoimmunity to TSH-R (Sugawa H, Ueda Y, Ueda M, Kosugi S, Ichiyama S, Mori T. Immunization with the 'immunogenic Peptide' of TSH receptor induces oligoclonal antibodies with various biological activities. Peptide 1998;19:1303-7.). In the present study, we examined this phenomenon at the T-cell level. Balb/c mice were immunized with a synthetic peptide corresponding to the C-terminal-specific insert of human TSH-R. Spleen cells were collected and subjected to antigen-specific ELISPOT assay. The number of interleukin 4-secreting cells specific to P354-367 increased within 3 weeks. Cells responding to the other peptides increased 7 weeks after immunization. This phenomenon was not observed in mice immunized with bovine serum albumin alone. During immunization, numbers of interferon-gamma-secreting lymphocytes were not changed significantly. These results indicated that immunization with C-terminal TSH-R-specific insert peptide causes fluctuation in the type 2 helper T-cell population but not type 1 Th cells against the TSH-R, and the recognition repertoire of type 2 helper T cell was expanded by the peptide.
Constrictive bronchiolitis obliterans is rare, and the pathogenesis of the disease often remains unknown. This study reports on the case of a 38 yr-old female with constrictive bronchiolitis obliterans and paraneoplastic pemphigus associated with malignant lymphoma. The patient developed progressive obstructive lung disease. The chest radiograph showed almost normal lungs. Paraneoplastic pemphigus is a newly described syndrome in which patients have autoantibodies binding to some epithelia, including in the respiratory tract. The disease develops in association with non-Hodgkin's lymphomas or other malignant neoplasms. The case presented here suggests that constrictive bronchiolitis obliterans associated with paraneoplastic pemphigus may be one of the facets of autoimmune responses in this context.
Antimicrobial susceptibility of 996 isolates of Streptococcus pneumoniae from clinical specimens was investigated in 11 Asian countries from September 1996 to June 1997. Korea had the greatest frequency of nonsusceptible strains to penicillin with 79.7%, followed by Japan (65.3%), Vietnam (60.8%), Thailand (57.9%), Sri Lanka (41.2%), Taiwan (38.7%), Singapore (23.1%), Indonesia (21.0%), China (9.8%), Malaysia (9.0%), and India (3.8%). Serotypes 23F and 19F were the most common. Pulsed-field gel electrophoresis (PFGE) of 154 isolates from Asian countries showed several major PFGE patterns. The serotype 23F Spanish clone shared the same PFGE pattern with strains from Korea, Japan, Singapore, Taiwan, Thailand, and Malaysia. Fingerprinting analysis of pbp1a, pbp2x, and pbp2b genes of 12 strains from six countries also showed identical fingerprints of penicillin-binding protein genes in most strains. These data suggest the possible introduction and spread of international epidemic clones into Asian countries and the increasing problems of pneumococcal drug resistance in Asian countries for the first time.
CD40-CD40 ligand (CD40L) interaction was originally defined as important molecules for the development of humoral immunity. Thereafter, some investigations have focused on its essential roles for the induction of cell-mediated immunity in host defenses. Here we investigated the antitumor activity of murine alveolar macrophages through CD40-CD40L interaction. The CD40L gene was transfected into murine lung cancer cells (3LLSA), and CD40L-expressing clones (3LLSA-CD40L) were established. Stimulation of CD40 molecules on the surface of alveolar macrophages with 3LLSA-CD40L cells induced the production of nitric oxide, tumor necrosis factor-alpha, and interleukin-12 and the tumoricidal activity of alveolar macrophages in the presence of interferon-gamma, which increased the surface expression of CD40 molecules on alveolar macrophages. These findings were not observed when alveolar macrophages were obtained from CD40-deficient mice. On the other hand, interleukin-6 production by alveolar macrophages did not depend on CD40-CD40L interaction. We also established a murine melanoma cell line expressing CD40L (B16 4A5-CD40L) that could induce tumoricidal activity of alveolar macrophages. Furthermore, when spleen cells were cocultivated with 3LLSA-CD40L cells, specific cytotoxic T lymphocytes for wild-type 3LLSA cells could be induced. These results suggest that CD40L gene transfer into tumor cells may induce antitumor immunity in a tumor-bearing host and may offer a new strategy for cancer gene therapy.
Age and sex dependent differences in the clinical reference values for white blood cell(WBC) count, WBC differential including segmented neutrophils(SEG), band neutrophils(BAND), lymphocytes (LYMPH), monocytes(MONO), eosinophils(EOSINO), basophils(BASO), platelet count(PLT) and mean platelet volume(MPV) were calculated by the iterative truncation method with correction(Usui's method) using the result from tests on 6,300 patient specimens obtained at Kyoto University Hospital. WBC counts exhibited log-normal distribution in all age either in male and female. PLT counts and MPV showed normal or log-normal distribution. WBC differential (SEG, BAND, LYMPH, MONO, EOSINO, BASO) usually showed log-normal distribution. As to the reference value for WBC, high limit values gradually decreased in the age range of 5-14 year old in males and females. After 15 year old, it gradually increased and reached adult's level. Low limit values for WBC gradually decreased with age both in males and females. The reference value for SEG showed similar change to WBC. The reference value for LYMPH gradually decreased age both in males and females. The reference values for BAND, MONO, EOSINO, BASO were generated by the percentile method instead of the iterative truncation method because of the strong deviation in the distribution pattern. BAND, MONO and BASO values were very stable for all ages in males and females. High limit values for EOSINO in the age range of 5-10 year old in males and females remained constant, and gradually decreased in 10-20 year old, and were stable at ages above 20 year old. PLT counts gradually decreased with age, and the MPV remained constant in all age populations both in male and female.
COBAS CORE Anti-HIV-1/HIV-2 EIA DAGS (CORE HIV-1/2) for the detection of antibodies to HIV-1 and HIV-2 was evaluated by a fully automated immunoassay system, COBAS CORE II (Roche Diagnostics K.K.). The sensitivity of CORE HIV-1/2 was assessed in comparison with PA1/2, Enzygnost, VIDAS and AxSYM by testing serial two-fold dilutions of HIV-1 and HIV-2 sera. CORE HIV-1/2 showed the highest sensitivity than other methods. The agreements of the results of anti-HIV antibodies determinations between the CORE HIV-1/2 and other methods, PA1/2, Enzygnost, VIDAS, and AxSYM, were 99.4%, 100%, 100%, and 99.7%, respectively in the tests for anti-HIV-1 antibody. In the tests for anti-HIV-2, all results were agreed at 100%. Discrepant samples which showed a negative by CORE HIV-1/2 and a positive by PA1/2 and AxSYM were clearly negative of anti-HIV-1 antibody by p24 ACA, PCR, Western blot, and continuous clinical studies. This assay showed excellent coefficients of variation for both within-run and day to day precision. The determination of anti-HIV antibodies was not interfered with hemoglobin, bilirubin, and chylemia. We conclude that the excellent specificity and sensitivity of the CORE HIV-1/2 make the CORE HIV-1/2 a suitable method for diagnosis of HIV-1 and HIV-2 infections in clinical laboratories.
A newly developed microdilution antimycobacterial susceptibility test, BrothMIC MTB (Kyokuto Pharmaceutical Industrial Co., Ltd., Tokyo, Japan) to determine minimum inhibitory concentrations (MICs) was evaluated at multisites. The test method utilizes air-dried microplates containing serially diluted antimicrobial agents and the modified Middlebrook 7H9 broth. The eight antimycobacterial agents tested were rifampicin, isoniazid, ethambutol, streptomycin, kanamycin, levofloxacin, sparfloxacin and ciprofloxacin. The test plates were reconstituted by inoculation of 0.2 ml of cell suspensions (6 x 10(5) cells/ml) and were incubated at 36 degrees C in 5% to 10% CO2. The growth endpoints were visually read after 7-day and 10-day incubations. The reproducibility was evaluated with the four reference strains of Mycobacterium tuberculosis, and were compared with the agar proportion method described in the National Committee for Clinical Laboratory Standards (NCCLS) M24-T. Of the 1,022 testings of the reference strains, 1,020 (99.8%) of the MICs read after 7-day incubation fell within 3 log2 dilutions. The growth endpoints read after 7-day and 10-day incubations gave equal MIC ranges for the respective agents. The results obtained by the BrothMIC MTB for 93 clinical isolates of M. tuberculosis compared well with those determined by the NCCLS method with 98% to 99% agreements, except for ethambutol. According to the comparative analysis with the agar proportion method, the interpretive MIC breakpoints to discriminate between the isolates susceptible and resistant against the respective agents were proposed. In conclusion, this newly developed microdilution test for M. tuberculosis is a practical, rapid, quantitative, nonradiometric alternative for the determination of MICs in clinical mycobacteriology laboratories.
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Fluoroacetate dehalogenase (EC 3.8.1.3) catalyzes the dehalogenation of fluoroacetate and other haloacetates. The amino acid sequence of fluoroacetate dehalogenase from Moraxella sp. B is similar to that of haloalkane dehalogenase (EC 3.8.1.5) from Xanthobacter autotrophicus GJ10 in the regions around Asp-105 and His-272, which correspond to the active site nucleophile Asp-124 and the base catalyst His-289 of the haloalkane dehalogenase, respectively (Krooshof, G. H., Kwant, E. M., Damborský, J., Koca, J., and Janssen, D. B. (1997) Biochemistry 36, 9571-9580). After multiple turnovers of the fluoroacetate dehalogenase reaction in H218O, the enzyme was digested with trypsin, and the molecular masses of the peptide fragments formed were measured by ion-spray mass spectrometry. Two 18O atoms were shown to be incorporated into the octapeptide, Phe-99-Arg-106. Tandem mass spectrometric analysis of this peptide revealed that Asp-105 was labeled with two 18O atoms. These results indicate that Asp-105 acts as a nucleophile to attack the alpha-carbon of the substrate, leading to the formation of an ester intermediate, which is subsequently hydrolyzed by the nucleophilic attack of a water molecule on the carbonyl carbon atom. A His-272 --> Asn mutant (H272N) showed no activity with either fluoroacetate or chloroacetate. However, ion-spray mass spectrometry revealed that the H272N mutant enzyme was covalently alkylated with the substrate. The reaction of the H272N mutant enzyme with [14C]chloroacetate also showed the incorporation of radioactivity into the enzyme. These results suggest that His-272 probably acts as a base catalyst for the hydrolysis of the covalent ester intermediate.
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Balb/c mice were immunized with a synthetic peptide (P354-14) corresponding to "the immunogenic peptide" of human thyrotropin receptor (hTSH-R). Through screening for binding to the peptide, we obtained several monoclonal antibodies with various biological activities: thyroid stimulation (SAb), inhibition of TSH stimulation (BAb) and no significant effect on cAMP production. One of the stimulatory clones was further studied. This clone enhanced cAMP production in Cos-7 cells transformed with the truncated TSH-R cDNA deleting the immunogenic peptide. These results indicated that the immunogenic peptide of the TSH-R induces oligoclonal anti-TSH-R antibodies, although the region is not essential for the functional epitope.
Campylobacter fetus subspecies fetus rarely causes celluitis associated with bacteremia in debilitated hosts. We have identified this infection in two patients with systemic lupus erythematosus and in one with liver cirrhosis. All three patients had eaten raw beef, liver, or improperly cooked pork before the manifestations of the illness. C. fetus subspecies fetus was recovered from blood and feces from the three patients. This organism was also isolated from a subcutaneous aspirate of the cellulitis lesion in one patient. DNA macrorestriction endonuclease profiles analyzed by pulsed field gel electrophoresis differed for the isolates from the three patients but were identical for the blood and fecal isolates or the aspirate and fecal isolates from each patient. These findings suggest that cellulitis associated with bacteremia arises from ingestion of C. fetus subspecies fetus organisms and that clinicians and microbiologists should be aware of this infection in debilitated hosts.
One hundred clinical isolates, including Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris and Proteus mirabilis, were exposed to carbapenems (imipenem, panipenem, meropenem and biapenem) at 0.5 x MIC for 3 h, then their morphology was examined and endotoxin release determined. Ceftazidime, which induces filament formation, was used as a control. Scanning electron microscopy showed that these carbapenems induced formation of spherical or ovoid cells, except for P. aeruginosa treated with meropenem and biapenem; these latter cells had a 'bulge' midway along them and we have termed them 'oval-centred'. There was a relationship between morphology and the amount of endotoxin released following exposure to carbapenems or ceftazidime. Of all the species investigated, P. aeruginosa showed the most variable morphological changes. P. aeruginosa exposed to biapenem were longer oval-centred in shape, and released significantly more endotoxin than those exposed to imipenem, panipenem (spherical) or meropenem (shorter oval-centred cells) (P=0.030, 0.017 and 0.002, respectively). In all strains except P. aeruginosa, carbapenems induced significantly less endotoxin release than ceftazidime (P < 0.05).
We examined the relationship between the levels of macrophage inflammatory protein 1alpha (MIP-1alpha) and interleukin-8 (IL-8) in organ cultures of antral mucosal tissues, background gastroduodenal diseases, and grades of histologic gastritis. Significantly higher levels of MIP-1alpha and IL-8 were detected in patients with H. pylori infection than in those without infection. In H. pylori-positive patients, mucosal specimens from patients with peptic ulcer disease showed higher levels of MIP-1alpha and IL-8 than the specimens obtained from patients with erosive gastritis or those from endoscopically normal mucosa, and this was particularly pronounced in patients with duodenal ulcer. There were positive correlations between MIP-1alpha and IL-8 levels and histologic grades of activity, inflammation, and H. pylori density as defined by the Sydney system. However, the degree of association with the inflammatory cell count was different between these two chemokines. MIP-1alpha levels had a stronger association with mononuclear cells than with neutrophils, whereas IL-8 levels showed an association with neutrophils and mononuclear cells to an almost equal degree. These results suggest that MIP-1alpha and IL-8 may play important roles as inflammatory mediators in the pathogenesis of histologically proven H. pylori-associated gastritis.