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Biomedical subjects

H Koga

Publications and source records attributed to H Koga.

At least 253 records · Page 14Linked to original sources
PubMed1994

[A case of endometrial tuberculosis diagnosed by polymerase chain reaction].

A 30-year-old female was admitted to our hospital for further investigation of infertility. The menstrual culture and polymerase chain reaction (PCR) of the endometrial tissue for detection of Mycobacterium tuberculosis were both positive. The pelvic CT scan and hysterosalpingography showed a slightly expanded uterus and irregularity of the endometrium. Barium enema and pyelography showed no abnormality. Since these data established a diagnosis of early primary endometrial tuberculosis, the combined therapy of three antituberculous agents was commenced. Menstrual smear, culture and PCR for M. tuberculosis were examined monthly throughout the therapy. The mycobacterial culture became negative soon after the start of therapy, followed by a negative PCR result 3 months later. We conclude that PCR is useful for the rapid detection of M. tuberculosis not only in pulmonary but also in endometrial tuberculosis.

Adult↗
PubMed1994

[Evaluation of (1-3)-beta-D-glucan in aspergillosis and cryptococcosis].

(1-3)-beta-D-Glucan (beta-glucan) is a major structural component of fungi. The G test is a direct method to detect beta-glucan using fractionated (1-3)-beta-D-glucan-sensitive component, factor G, eluted from the limulus lysate. Previously, we reported that the G test is a more sensitive method than the mannan detection assay for the serological diagnosis of Candida infection. In this study, we discuss beta-glucanemia in patients with pulmonary aspergillosis and cryptococcosis. The concentration of beta-glucan was less than 10 pg/ml in 9 of 10 cases of pulmonary cryptococcosis, except for one case receiving hemodialysis (16.5 pg/ml). beta-Glucan increased in 3 cases of invasive pulmonary aspergillosis (27-937 pg/ml). Galactomannan antigen was positive in all of those cases. In 8 cases of aspergilloma, which showed fungus ball on roentgenogram, the mean concentration of beta-glucan was 67.1 +/- 92.7 pg/ml. Two of 8 cases were positive for galactomannan antigen. One of three cases of PAIC (productive aspergilloma on the inner wall of a cavity) and one case of chronic necrotizing pulmonary aspergillosis showed slightly increased levels of beta-glucan and positive results of galactomannan antigen test.

Adult↗
PubMed1994

[A drug delivery system and biological response modifiers for the treatment of mycobacterial infection].

A drug delivery system (DDS) for the treatment of infectious disease has recently been developed. Since liposomal antimicrobial agents are effective on cytozoic bacteria, we applied liposomal streptomycin and amikacin for the treatment of systemic mycobacterial tuberculosis in mice. Liposomal aminoglycosides showed excellent efficacy compared to free aminoglycosides or empty liposome. This therapeutic strategy should be developed for clinical application. Although the human defense mechanism against microbial infection is very complicated, biological response modifiers (BRM) such as vaccination or cytokine therapy have been investigated. One of the most useful and protective vaccines for prevention of tuberculosis is the Mycobacterium vaccae vaccine, developed by Stanford et al. As for the cytokines, interleukin-2, granulocyte macrophage-colony stimulating factor, and tumor necrosis factor have very strong antimycobacterial activity. Interferon alone, however, has weak efficacy, and should be combined with other effective cytokines. These BRM constitute an excellent strategy for antimycobacterial chemotherapy.

Amikacin↗
PubMed1993

p53 gene mutations in pontine gliomas of juvenile onset.

Using polymerase chain reaction-single strand polymorphism(PCR-SSCP) and nucleotide analyses, p53 gene mutation was examined in 13 pontine gliomas many of which were of juvenile onset. A total of 15 mutations were detected in 8 cases, of which 5 revealed multiple or tandem mutations. The mutations included 6 G:C-A:T and 4 A:T-G:C transitions and 4 G:C-T:A and 1 A:T-T:A transversions. There was only 1 transition at the CpG site. Normal tissues of the same patients revealed no mutation, suggesting that these mutations were somatic, but not of germ line, in nature. The pattern of mutation characterized by frequent multiple or tandem occurrence, predominancy of transition at non-CpG sites and relatively frequent transversions suggested that pontine glioma might be related with some mutagenic or carcinogenic agents.

Amino Acid Sequence↗
PubMed1993

Essential role of the Arg112 residue of cytochrome P450cam for electron transfer from reduced putidaredoxin.

Cytochrome P450cam (CYP101) of Pseudomonas putida PpG1 in which Arg112 is substituted by Cys was isolated by in vitro random mutagenesis of the camC gene DNA coding for P450cam. The absorption spectra of the purified mutant enzyme were similar to those of the wild type enzyme, but its substrate-dependent NADH oxidation activity in the presence of putidaredoxin (Pd) and putidaredoxin reductase (PdR) was extremely low. The rate constant of electron transfer from reduced Pd to the heme of the mutant P450cam, measured on an anaerobic stopped flow apparatus, was 1/400 of that of the wild type enzyme and the dissociation constant of the mutant P450cam for oxidized Pd was several fold higher than that of the wild type enzyme. A considerable decrease in mid-point potential of the mutant enzyme was also noted. We conclude that Arg112, which is located on the surface of the P450cam molecule and hydrogen-bonded to one of the heme propionate chains, plays an essential role in the electron transfer from Pd.

Arginine↗
PubMed1993

Complete nucleotide sequence of the 5-exo-hydroxycamphor dehydrogenase gene on the CAM plasmid of Pseudomonas putida (ATCC 17453).

We determined the complete nucleotide sequence of the first gene of Pseudomonas putida cytochrome P-450cam hydroxylase operon, camD, which encodes 5-exo-hydroxycamphor dehydrogenase. This dehydrogenase apparently consists of 361 amino acids and has a molecular mass of 38.4 kDa. Structural relationships to other zinc-containing alcohol dehydrogenases also became evident.

Alcohol Dehydrogenase↗
PubMed1993

High detection rates of cryptococcal antigen in pulmonary cryptococcosis by Eiken latex agglutination test with pronase pretreatment.

Two different kits for the detection of serum cryptococcal antigen in patients with pulmonary cryptococcosis were evaluated. The Eiken test (the Eiken Co., Tokyo), which uses pronase for pretreatment of serum, was compared with the Crypto-LA test (International Biological Laboratories, Cranbury, NJ), which did not use pronase prior to testing. Cryptococcal antigen was detected in 21 of 23 patients (91%) with the Eiken test and in only 10 of 23 patients (43%) with the Crypto-LA test (p < 0.01 by McNemar test). However, the sensitivity of two tests was identical without use of pronase, as both tests could detect as little as 10(4) cells/ml of Cryptococcus neoformans and 10 ng/ml of capsular polysaccharide of C. neoformans. In those serum specimens for which both tests were positive, titers were much higher for the Eiken test, but there was a statistically significant correlation between the two tests (coefficient correlation 0.79, p < 0.01). Cryptococcal antigen titer levels measured by the Eiken test correlated well with clinical courses. There was one false-positive reaction among 82 sera of non-cryptococcal patients. Pronase enhanced the sensitivity of the Eiken test, which appeared to be useful in patients with pulmonary cryptococcal disease, and its use may prevent unneeded lung biopsies.

Adult↗
PubMed1993

An evaluation of serodiagnostic tests in patients with candidemia: beta-glucan, mannan, candida antigen by Cand-Tec and D-arabinitol.

The serodiagnostic tests, beta-glucan, mannan, candida antigen by Cand-Tec, and D-arabinitol were evaluated in 10 patients with candidemia, 14 patients with suspected fungemia, and 10 healthy persons. By blood culture or lysis centrifugation, C. albicans was isolated from 5 patients, C. parapsilosis from 4, and C. tropicalis from 1 patient; no organisms were isolated from the 14 patients with suspected fungemia or the 10 healthy subjects. Beta-glucan was measured by the difference between two chromogenic limulus tests (Endotoxin test-D and Endospecy), which was more than 60 pg/ml in 7 of 9 (78%) candidemic patients and 1 of 12 (8%) patients with suspected fungemia. Mannan was positive in 6 of 10 (60%) candidemic patients and 1 of 13 (8%) patients with suspected fungemia. Both antigens were very sensitive and highly specific for candidemia. However, the Cand-Tec assay was less specific, because titers of more than 4 were observed in 5 of 14 (34%) patients with suspected fungemia. D-Arabinitol was the least sensitive, because a D-arabinitol/creatinine ratio greater than 2.0 mumol/mg was observed in only 2 of 7 (29%) candidemic patients. The titers of serodiagnostic tests decreased after successful treatment with an anti-fungal agent. Our results show that the combined use of the assays in necessary for accurate serological diagnosis of candidemia.

Adolescent↗
PubMed1993

[Treatment of experimental invasive pulmonary aspergillosis in rats with liposomal amphotericin B].

Liposomal amphotericin B was evaluated for toxicity, pharmacokinetic properties and therapeutic efficacy in invasive pulmonary aspergillosis in Sprague-Dawley rats. The protective effect of liposomes against the toxicity induced by repeated amphotericin B infusions was observed in a survival study of rats, thereby allowing higher dosages to be administered. Pharmacokinetic studies showed that liposomes led to high levels of amphotericin B in the spleen and liver. Drug levels in the lung were higher at ten minutes after intravenous injection of liposomal amphotericin B at 20 mg/kg than of free amphotericin B at 1.5 mg/kg. Efficacy was assessed in rats treated with cortisone acetate, fed a low-protein diet and infected transtracheally with 8 x 10(4) Aspergillus fumigatus spores to cause fetal pneumonia and pulmonary bleeding. Dosages of 20 or 4 mg/kg of liposomal amphotericin B, or 1.5 mg/kg of free amphotericin B were administered intravenously to rats once daily for 8 days. Control rats received saline. Twenty mg/kg of liposomal amphotericin B was as effective on survival rate as 1.5 mg/kg of free amphotericin B. However, 4 mg/kg of liposomal amphotericin B was less effective than 1.5 mg/kg of free amphotericin B, prolonging the mean survival time of rats treated with saline, which showed elevation of galactomannan antigen titers of Aspergillus fumigatus in sera and invasive proliferation or mycelia with bleeding in histopathological sections of the lung. We conclude that liposomal amphotericin B reduces toxicity of the drug, thereby increasing the concentration of the drug in the lung by high-dose administration, but decreases the efficacy of the drug in experimental pulmonary aspergillosis.

Amphotericin B↗
PubMed1993

[A study of respiratory infection and sepsis caused by MRSA at Hokusho Central Hospital].

At Hokusho Central Hospital, we studied the isolation rate of methicillin-resistant Staphylococcus aureus (MRSA) from 1985 to 1989; respiratory infection with MRSA, in 1989; and sepsis of MRSA, from 1988 to 1989. The isolation rate of MRSA from sputum increased from 0% in 1985 to 65.4% in 1989. MRSA was isolated mainly from elderly patients in a geriatric ward, with 55 of 67 strains (82%) being isolated from these patients in 1989. MIC80 of isolated MRSA strains was 0.01 microgram/ml to rifampicin, 0.02 microgram/ml to mynomycine, 3.13 micrograms/ml to vancomycin, 12.5 micrograms/ml to ofloxacin and 100 micrograms/ml to imipenem in 1989. One-third of the 60 isolated cases showed respiratory infections including 10 cases of pneumonia and 10 sepsis patients and 11 blood samples in 1988 and 1989, especially 92.9% of S. aureus isolated in 1989 was MRSA. Four of the 6 patients with respiratory infections of MRSA and 1 of the 3 patients with MRSA sepsis were treated successfully by a combination therapy of imipenem/cilastatin and cefazolin.

Aged↗
PubMed1993

[Detection of mecA gene of methicillin resistant staphylococci from oral swabs by polymerase chain reaction].

We evaluated the polymerase chain reaction method (PCR) for the rapid detection of methicillin resistant Staphylococcus aureus (MRSA), and compared it with the conventional culture method. Primers for amplification of mecA gene were synthesized by DNA synthesizer according to the published sequences of mecA gene. The results were as follows: Specificity of PCR was excellent, as there was no cross-reaction with any organism other than MRSA. Fifty colony forming units of MRSA were detected, indicating good sensitivity. We examined oral swabs from 13 bed-ridden patients (age range: 65-82 yrs) by PCR and the conventional culture method. The PCR elicited positive results in 6 out of 13 cases. MRSA or coagulase negative Staphylococci (CNS) in Mueller-Hinton agar containing 12.5 micrograms/ml methicillin were obtained from all of these PCR-positive specimens. Two of 7 PCR-negative specimens raised MRSA or CNS colonies, but the number of colonies from these specimens was below the sensitivity threshold of the PCR. The good specificity and sensitivity of the PCR method for the detection of mecA gene obtained in this study suggest the possibility of application of this method for detection of MRSA in clinical specimens.

Aged↗
PubMed1993

[A case of Campylobacter fetus subspecies fetus meningitis].

A 40-year-old male with no history of underlying disease was admitted to Hokusho Central Hospital on May 25, 1991, complaining of high fever and headache. Physical examination on admission revealed a temperature of 38.5 degrees C, a pulse rate of 84 beat/min (relative bradycardia) and no abnormal findings for the chest or abdomen. Slight neck stiffness without Kernig's sign was observed at neurological examination. Laboratory data were: ESR 11 mm/lh, WBC 12000/mm3, C-reactive protein positive. Lumbar puncture showed an initial pressure of 230 mmH2O; CSF revealed a cell count of 2633/3 mm3 with mononuclear pleocytosis, total protein of 76 mg/dl and sugar of 54 mg/dl (CSF:blood glucose ratio 0.47). We initially suspected tuberculous or cryptococcal meningitis, but Campylobacter fetus subsp. fetus (C. fetus) was isolated from the CSF and venous blood on the 27th hospital day. IPM/CS 1 g/day, MINO 200 mg/day and FOM 4 g/day were intravenously administered. This antibiotic therapy was very effective: the patient was soon afebrile, and gradually all signs and symptoms were resolved. C. fetus was sensitive to IMP/CS, MINO, KM, GM, EM, OFLX, CP. The patient was discharged with no complication. He has eaten raw beef frequently before admission, but stool culture for C. fetus was negative.

Adult↗
PubMed1993

Efficacy of intravenous itraconazole against experimental pulmonary aspergillosis.

The efficacy of intravenous itraconazole solubilized in hydroxypropyl-beta-cyclodextrin was assessed in a rat model of Aspergillus fumigatus pneumonia. Immunosuppressed rats were infected by intratracheal inoculation of A. fumigatus conidia. Intravenous administration of various doses of itraconazole was started immediately after infection and continued once a day for 7 days. A 10-mg dose of intravenous itraconazole per kg was as effective on survival as 1 mg of amphotericin B per kg daily (a survival rate of 100% in 28 days), while treatment with 1 mg/kg did not increase the survival rate. The 50% lethal dose of intravenous itraconazole given to immunosuppressed and uninfected rats for 7 days was 24.5 mg/kg/day. A microbiological assay to estimate accumulation in tissue after five daily intravenous administrations of itraconazole at 10 mg/kg showed that itraconazole and its active metabolites were present in the lungs for at least 6 h, reaching the MIC as previously described (B. Dupont and E. Drouchet, Rev. Infect. Dis. 9(Suppl. 1):71-76, 1987; A. Espinel-Ingroff, S. Shadomy, and R. J. Gebhart, Antimicrob. Agents Chemother. 26:5-9, 1984). Intravenous itraconazole was considered to be worth evaluating in clinical trials of aspergillosis.

Animals↗
PubMed1993

Accumulation of a newly developed fluoroquinolone, OPC-17116, by human polymorphonuclear leukocytes.

The accumulation of OPC-17116 by human polymorphonuclear leukocytes was studied by comparison with three other new quinolones, ofloxacin, levofloxacin, and DR-3354. The intracellular/extracellular concentration ratio was the highest for OPC-17116, being 66.2, followed by 9.8 for levofloxacin, 7.6 for ofloxacin, and 5.8 for DR-3354. Furthermore, it was suggested that the accumulation of these new quinolones was partially related to their active transport system. The elution of OPC-17116 and ofloxacin from cells was rapid, but the elution of OPC-17116 decreased at a high extracellular pH and increased at a low extracellular pH. The accumulation of OPC-17116 as well as that of the other new quinolones was satisfactorily high, thus indicating that they are expected to be useful for the treatment of various kinds of infections, particularly infections caused by cytozoic bacteria.

Adult↗