Biomedical subjects
Publications and source records attributed to H Koga.
During investigations of the structural character of a mutant P-450cam where Glu-286 is replaced with lysine, we obtained evidence of a hydrogen bond network between helix K and the heme group via helix L of P-450cam. This mutant protein loses the ability to maintain the heme group in a proper position, possibly due to a break in the hydrogen bond network.
An indirect method to measure beta-glucan, a major structural component of yeast cell walls, is available, but has the disadvantage of requiring the combined use of two assays. Recent reports describe the fungal index, which measures the difference between the conventional limulus test, in which factors C and G react with endotoxin and beta-glucan, and a new endotoxin-specific test, in which only factor C reacts with endotoxin. The G test was developed as a direct method to measure beta-glucan, and contains only factor G reacting with beta-glucan alone. In this study, the G test was examined in sera of rabbits with experimental systemic candidiasis, and compared with the fungal index and mannan assay. The G test showed positive in all rabbits with systemic candidiasis faster and with higher titers than with the fungal index. Three rabbits with fulminant systemic candidiasis showed higher levels of reactivity with the G test and the fungal index than two rabbits with mild reactions. Mannan was positive by at least one serum in four of five rabbits by the latex agglutination test, and there was a good correlation between these assays. The G test is a good serodiagnostic method for the detection of candidiasis.
We report here a 75-year-old-male with a slowly progressive dementia of 5-year duration along with a rapid exacerbation of symptoms in the terminal 3 months. Neuropathological examinations revealed findings consistent with conspicuous Alzheimer's disease and mild Creutzfeldt-Jakob disease (CJD). The plaque amyloid was exclusively composed of beta-protein. The immunohistochemistry of prion protein using hydrolytic autoclaving pretreatment showed diffuse gray matter stainings in the sections of both the cerebral and cerebellar cortices. This method was thus considered useful in confirming the diagnosis of CJD for this case.
Seventy-one Japanese adult T-cell leukemia (ATL) patients and 411 Japanese asymptomatic patients from HTLV-I endemic regions of southern Japan were found to be seropositive by radioimmunoprecipitation assay (RIPA). Of these 482 positive controls, 62% of ATL patients and 67% of the asymptomatic seropositive patients were found to harbor antibodies to p40x. Additionally, 333 preselected Japanese blood donors who were identified as seropositive by particle agglutination (PA) assay were further tested for antibodies to HTLV-I/II gene encoded envelope (env) or group specific antigens (gag) by means of enzyme-linked immunosorbent assay (ELISA) and RIPA. Concordance between ELISA and RIPA was noted in 318 samples (92.5%). Discordance between ELISA and RIPA was observed in 15 sera (7.5%)--2 were seropositive by ELISA and seronegative by RIPA and 13 were seronegative by ELISA and seropositive by RIPA. Seven of these 13 samples (53.8%) contained antibodies to p40x by RIPA and may represent ELISA false negatives on the basis of both clinical and laboratory data. Current HTLV-I/II ELISA kits may yield false negative results. Additional research into the development of rapid detection cost-efficient assays that test for the full compliment of viral antigens is needed.
Picogram quantifies per ml of endotoxin showed a positive limulus test. The concentration more than ten pg/ml of curdlan ((1-3)-beta-D-glucan) was also positive to a conventional limulus test, which contains a factor G. One nanogram per ml of CM-curdlan was positive, but higher concentration of 10 pg/ml of CM-curdlan decreased its optical density of the conventional limulus test. More than one hundred ng/ml of mannan from Saccharomyces cerevisiae did not react with factor G. However, a culture supernatant of Saccharomyces cerevisiae activated factor G. This result suggested that beta-glucan activated factor G. In addition, culture supernatant of Aspergillus fumigatus, Rhodotorula rubra, Candida parapsilosis, Candida tropicalis, Candida krusei also activated factor G, but Cryptococcus neoformans did not activate it.
We investigated the clinical and laboratory data of 215 hospitalized patients (mean age were 76.9 +/- 12.1) to analyze both the characteristics of senile UTI and the influence of the way of urination. UTI was present in 121 of 1897 patients (6.4%), 95 of whom (78.5%) were female. Comparison of the parameters between non-infected and infected patients were as follows: body temperature was 36.57 +/- 0.64 degrees C vs. 37.49 +/- 0.77 degree C; WBC, 5410 +/- 2040/microliters vs. 7260 +/- 3230/microliters; CRP, 1.2 +/- 2.4 mg/dl vs. 3.5 +/- 3.4 mg/dl; mean class of urinary RBC, 0-1/hpf vs. 3-5/hpf; and mean class of urinary WBC, 5-10/hpf vs. 30-50/hpf. All parameters were significantly elevated (p < 0.001) in the patients with UTI. The rate of detection of causative bacteria was 88.7%; with 14.8% Escherichia coli, 12.8% Providencia species, 9.6% Enterococci, and 8.7% Pseudomonas aeruginosa. Patients with UTI were divided into three groups according to their method of urination: normal urination, use of diapers and catheterization. Body temperature (> or = 37.5 degrees C) was 2.8%, 10.1% and 34.9%; WBC (> or = 9.000), 2.7%, 6.1%, and 14.3%; CRP, 16.9%, 36.1% and 51.1%; urine RBC (> or = 6-10/hpf), 8.4%, 7.1% and 36.1%; urine WBC (> or = 15-30/hpf), 20.4%, 44.4% and 76.9%, respectively. There was a significant difference (p < 0.05-0.001) between all parameters except for urine RBC between the normal-urination patients and diaper using patients. This investigation suggested that the use of diapers was a risk factor for UTI in elderly patients.
Life threatening mediastinitis as a complication of acute epiglottitis is very rare. A 38-year-old male in previously good health was admitted to our hospital in a state of unconsciousness. Seven days prior to admission he had complained of a sore throat, dysphagia, high fever and dyspnea. A chest X-ray on admission showed widening of the mediastinum, mediastinal emphysema, subcutaneous emphysema and left pleural effusion. Bronchoscopy showed the swelling of supraglottic structures. He was diagnosed as having acute mediastinitis and pyothorax as a complication of acute epiglottitis, but pathogens were not identified. The blood was hyperglycemic and insulin therapy was started. Though he gradually improved by massive antibiotic therapy, steroid therapy, tracheotomy and surgical drainage of both the left thoracic cavity and the mediastinum, he died suddenly of massive hemoptysis. Autopsy revealed that the acute mediastinitis had healed, but that the Aspergillus infection was present in both lungs and the pericardium. The Aspergillus infection was not lethal in the present case, and it seemed that death had resulted from arterial hemorrhage caused by erosion of the trachea. The present case suggests the need for antifungal therapy even in non-immunocompromised patients in particular when massive doses of antibiotics and steroids are administered.
Four cases of respiratory tract infections caused by Corynebacterium pseudodiphtheriticum were reported. The first two patients developed pneumonia with Corynebacterium pseudodiphtheriticum during steroid therapy used against their underlying diseases. The other two patients had acute exacerbation of chronic pulmonary diseases caused by C. pseudodiphtheriticum. These four patients improved by antibiotic therapy. Though nondiphtheria corynebacteria are regarded as "normal flora" when they are isolated from sputum, they should be recognized as potential pathogens.
The ubiquinone systems and electrophoretic comparison of enzymes were used to determine the relatedness among 64 isolates of seven Aspergillus spp. These were 31 clinical and 3 nonclinical isolates of Aspergillus fumigatus Fres., 2 isolates of A. nidulellus Samson & W. Gams, 8 isolates of A. terreus Thom, 4 isolates of A. flavus Link, 1 isolate of A. oryzae (Ahlburg) Cohn, 14 isolates of A. niger van Tieghem, and 1 isolate of A. japonicus Saito. The enzymes glucose 6-phosphate dehydrogenase, lactate dehydrogenase, glutamate dehydrogenase, fumarase, and malate dehydrogenase were examined. The relative mobilities were analyzed numerically. The results were presented as a dendrogram. Isolates from clinical and nonclinical sources within the same species had identical ubiquinone systems and identical or very similar enzyme patterns. In the dendrogram, 64 of the tested isolates were separated into seven major clusters at a 60% similarity level. Each major cluster corresponds to a single species. On the dendrogram, A. fumigatus isolates showed homogeneity, whereas A. niger isolates showed relative heterogeneity; in particular, A. niger MF-24 and the other A. niger isolates were distantly linked to each other. All A. fumigatus isolates had the Q-10 ubiquinone system and formed a single major cluster at a similarity level of 73% or greater. Glucose 6-phosphate dehydrogenase and glutamate dehydrogenase were key enzymes for differentiating all clinical and nonclinical isolates of A. fumigatus from the other Aspergillus spp. Ubiquinone systems and enzyme patterns appear to be objective and useful indicators for use in the precise identification of clinical isolates of Aspergillus spp.
Diffuse panbronchiolitis (DPB) is a disease of adults characterized by chronic inflammation of the respiratory bronchioles and the infiltration of chronic inflammatory cells. The clinical efficacy of erythromycin therapy has been demonstrated in DPB patients, but the mechanism of action of this drug is unknown. We investigated the localization of neutrophils in lung biopsy specimens, as well as the cell population and elastolytic-like and chemotactic activity of bronchoalveolar lavage (BAL) fluid, before and after treatment with erythromycin or ampicillin in 11 DPB patients (six biopsy-proven and five clinically diagnosed) and one follicular bronchiolitis patient. These bronchiolitis patients had a high percentage of neutrophil and a high neutrophil-derived elastolytic-like activity in BAL fluid compared with chronic bronchitis patients and normal control subjects. The number of neutrophils and the neutrophil-derived elastolytic-like activity in BAL fluid decreased significantly after treatment with erythromycin along with a significant improvement in pulmonary function studies, although there was no significant change in the chemotactic activity of BAL fluid. No significant reduction in BAL fluid neutrophilia was found in the ampicillin-treated patients. These results suggest an important role for the neutrophil in the pathogenesis or development of bronchiolitis, and also suggest that erythromycin may be useful for the treatment of bronchiolitis through its direct action upon host phagocytic cells.
A series of substituted 1,3-dioxolo[4,5-f]-1,2-benzisoxazole-6-carboxylic acids 13 and 1,3-dioxolo[4,5-g]-1,2-benzisoxazole-7-carboxylic acids 14 were synthesized and evaluated for diuretic and uricosuric activities in rats. Most of the benzisoxazole derivatives 13 and 14 showed potent diuretic activities. Moderate uricosuric activities were also found in 14a, 14b, and 14f.
Employing soluble denatured protein substrates and their derivatives, the proteolytic activity of rat cathepsin H was investigated. The enzyme showed aminopeptidase activity which sequentially released amino acid from the N-terminal of the substrate. The aminopeptidase activity did not act on N alpha-acetylated peptides and showed moderate ionic-strength dependence when methionyl-methylcoumarylamide was employed as a substrate. These results indicate that the activity essentially requires an N-terminal free amino group of the substrate and recognizes it electrostatically to some extent. On the other hand, the enzyme was also indicated to exhibit endopeptidase activity by employing appropriate N alpha-acetylated peptide substrates. In contrast to the aminopeptidase activity, the endopeptidase activity showed rather strict specificity, preferring hydrophobic residues at P2 and P3 sites. Because of the broad specificity and high efficiency of the aminopeptidase activity, it was difficult to directly observe endopeptidase activity in the digestion of large peptide substrates with a free alpha-amino terminal. Thus, this is the first experimental evidence that indicates endopeptidase activity by assigning internal peptide bonds cleaved by this activity. From this data, we proposed a model of the binding site of this enzyme.
The efficacy of ofloxacin, rifampicin and isoniazid was prospectively compared with the regimen of ethambutol, rifampicin and isoniazid for the primary treatment of pulmonary tuberculosis in 124 patients. All drugs were given orally daily for nine months. Culture conversion rates three months after starting treatment were 98 percent in the ofloxacin group and 94 percent in the ethambutol group; by six months all patients in both groups were culture-negative. Significant radiological improvement of pulmonary infiltrates was observed in 83 percent of the ofloxacin group and 85 percent of the ethambutol group one year after starting treatment. No relapse in either group was observed during a two-year follow-up period after the cessation of chemotherapy. Ofloxacin appears to be as useful as ethambutol in the treatment of pulmonary tuberculosis when either drug is combined with isoniazid and rifampicin.
A retrospective study was done to determine the prevalence of anti-HTLV-I antibodies in patients with pulmonary cryptococcosis. None of the 19 patients with pulmonary cryptococcosis had underlying immunodeficiency. Anti-HTLV-I antibody was present in 6 (32%) of 19 patients with pulmonary cryptococcosis, a significantly higher prevalence than found in patients with bronchial asthma (4 (7%) of 58) (p less than 0.01, chi-square test). No statistical difference was noted when anti-HTLV-I antibody seropositivity was compared to that of patients with pulmonary tuberculosis (16% (17/105)), lung cancer (17% (22/129)) and pneumonia (9% (6/64)). A reduced cellular immunity as shown by lymphopenia, the CD4/CD8 ratio, and purified protein derivative skin test was found in only 1 (5%) of 19, 2 (12%) of 17, and 6 (33%) of 18 patients, respectively. These results do not explain the susceptibility to pulmonary cryptococcosis in HTLV-I carriers. This is the first report of high prevalence of pulmonary cryptococcosis in HTLV-I carriers and it raises the question whether HTLV-I carriers are more susceptible to opportunistic infections and other malignancies probably due to subtle immunological abnormalities.
Factor G, the coagulation enzyme from limulus amebocytes, is activated by (1-->3)-beta-D-glucan but not by endotoxin. The endotoxin-specific limulus test, which is devoid of factor G, reacts only with endotoxin. However, the conventional limulus test which includes factors G and C, reacts with not only endotoxin but also with (1-->3)-beta-D-glucan. In this study, the culture supernatant of Candida albicans in RPMI medium activated the conventional limulus test, but not the endotoxin-specific limulus test. All five rabbits inoculated intravenously with Candida albicans (1.0 x 10(7) CFU/rabbit) showed increased levels of reactivity with the conventional limulus test, whereas no elevation in the levels of the endotoxin-specific limulus test was observed in the sera of any infected rabbits. Only one serum sample from rabbit No. 5 on day 8 showed a positive Cand-tectest. The difference in the titers of the two limulus tests was suggestive of a diagnosis of Candida infection.
A 23-year-old man with persisting high fever developed hepatosplenomegaly, lymphadenopathy and massive pericardial effusion. Immunological examination revealed a marked elevation of anti-Epstein-Barr virus antibodies (anti-viral capsid antigens IgG-antibody 1:10,240, anti-early antigens-DR IgG-antibody 1:5,120), decreased activities of Epstein-Barr virus specific cytotoxic T lymphocytes, natural killer cells and lymphokine activated killer cells. A liver biopsy showed moderate sinusoidal lymphocytosis with punched-out lesions. These findings suggested severe chronic active Epstein-Barr virus infection syndrome. The patient was treated with recombinant human interleukin-2, but it was discontinued because of an adverse reaction. Twelve months later, he died of suspected pulmonary infection.
An outbreak of Legionnaires' pneumonia occurred at a nursing home in December 1990. A 79-year-old female and a 73-year-old male clerk who were staying at the nursing home developed pneumonia with only a 5-day interval. Legionella pneumophila serogroup I was isolated from transtracheal aspirate of the former and sputum of the latter. After treatment with a combination of erythromycin and rifampicin both patients improved. Serological surveillance of inpatients and staff of the nursing home was performed in February 1991. Seven out of 51 samples (14.0%) showed a titer higher than 1:128 of anti-Legionella pneumophila serogroup I antibody determined by indirect immunofluorescence; two of these seven complained of respiratory symptoms. Molecular epidemiology analyzed by restriction endonuclease digestion of isolated L. pneumophila showed an identical pattern which suggested a common origin.
A 63-year-old woman with chronic necrotizing pulmonary aspergillosis complicated by active pulmonary tuberculosis is reported. A small infiltrative shadow appeared, but no definite diagnosis was made. Six years later the shadow was found to have increased in size; chest CT revealed a fungus ball, while a transbronchial lung biopsy revealed aspergillus hyphae. The intrabronchial inoculation of amphotericin B proved ineffective, and a lobectomy was performed. Histopathologic findings showed necrotic granulomas containing aspergillus and some acid-fast bacilli. While the superinfection of healed tuberculous lesions by Mycobacteria or Aspergillus species is well documented, their coexistence is rare.