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H Koga

Publications and source records attributed to H Koga.

At least 145 records · Page 8Linked to original sources

[Genetic evaluation for rifampicin-susceptibility of Mycobacterium tuberculosis].

We evaluated the relationship between rifampicin (RFP)-susceptibility and genetic alterations in rpoB gene of clinically isolated Mycobacterium tuberculosis strains, collected from different geographic locations within Japan. Alterations in rpoB gene were detected by PCR-direct sequencing analysis, and the minimum inhibitory concentrations (MICs) of RFP were determined by broth microdilution method using Middlebrook 7H9 broth. One hundred and sixty six epidemiologically unrelated M. tuberculosis strains were examined. A total of 99 genetic alterations in the 69 bp core region of rpoB gene were detected in 95 out of 166 strains. Among them, 96 out of 166 strains showed RFP-resistant phenotypes with MICs > or = 2 micrograms/ml. Examination of the correlation between the MICs of RFP and amino acid substitutions in 69 bp core region of rpoB gene revealed that 58 out of 59 strains containing amino acid substitution in codon 531 showed highly RFP-resistant phenotypes with MICs > or = 64 micrograms/ml. In contrast, a variable level of RFP-susceptibility was observed among strains containing amino acid substitutions in either codon 516 or 526. On the other hand, the MICs of three strains with a point mutation in either codon 515 or 533 were all < or = 1 microgram/ml. Our results suggest that rpoB gene sequencing is useful for not only the detection of RFP-resistant M. tuberculosis strains, but also the prediction of RFP-susceptibility of the strains.

Antibiotics, Antitubercular↗

[Efficacy of erythromycin inhalation in chronic respiratory infection caused by Pseudomonas aeruginosa].

The prognosis of chronic respiratory tract infection with Pseudomonas aeruginosad considered to be poor. However, low-dose and long-term 14 membered macrolide, such as erythromycin or clarithromycin, treatment has been reported as effective clinically in chronic lower respiratory tract disease. There was no report to investigate the effect of macrolide on chronic biofilm related Pseudomonas aeruginosa respiratory tract infection in vivo. In a newly established murine model of chronic Pseudomonas aeruginosa respiratory infection mimicking diffuse panbronchiolitis (DPB), we investigated the effect of erythromcin inhalation on viable bacteria in the lungs. Infection was produced by placement of a plastic tube in the bronchus with inoculating. Pseudomonas aeruginosa suspended in saline was also inoculated in bronchus after intubation of the tube. Viable bacteria were constantly isolated at 10(4) 10(6) cfu-specimen from the lungs for more than 30 days. Treatment with erythromycin inhalation for four days reduced the number of viable bacteria in the lungs with statistically significant. Our result indicated that our new model of chronic respiratory tract infection is simple and provides a useful tool to study the pathogenic process and treatment of such infection. Our results also suggest that the erythromycin inhalation is effective on chronic Pseudomons aeruginosa respiratory infection.

Administration, Inhalation↗

Role of coagulase in a murine model of hematogenous pulmonary infection induced by intravenous injection of Staphylococcus aureus enmeshed in agar beads.

We describe a novel mouse model of acute staphylococcal pneumonia induced by intravenous injection of Staphylococcus aureus enmeshed in agar beads. For comparison, we also used various strains of bacteria, including three strains of S. aureus, two strains of Staphylococcus epidermidis, one strain of Streptococcus pyogenes, three strains of Pseudomonas aeruginosa, and one strain of Klebsiella pneumoniae. All except two strains of S. aureus were cleared rapidly from the lungs. When S. aureus NUMR1 enmeshed in agar beads was injected intravenously, the organisms concentrated and remained in the lung for a period longer than several weeks. Multiple lung abscesses were evident macroscopically, and histological examination of the infected lung showed multiple lung abscesses around the pulmonary arterioles, consisting of bacterial colonies encircled with fibrin filaments and surrounded by inflammatory cells of neutrophils and macrophages. When 14 strains of clinically isolated S. aureus were injected intravenously, the number of bacteria recovered from the lung tissue 7 days after infection correlated with the titer of staphylocoagulase (P < 0.01) but not with the titer of clumping factor. Injection of coagulase-deficient mutant strain DU5843 was associated with a markedly reduced number of viable bacteria isolated from the lung, compared with its coagulase-positive parental strain DU5789. Our results suggest that coagulase may play a role in the development of blood-borne staphylococcal pneumonia in our model. Our animal model is simple and reproducible and resembles blood-borne staphylococcal pneumonia in humans, and it could be useful for investigating the pathogenicity or treatment of staphylococcal pulmonary infection, including infections with methicillin-resistant S. aureus.

Agar↗

A 77-kilodalton protein of Cryptococcus neoformans, a member of the heat shock protein 70 family, is a major antigen detected in the sera of mice with pulmonary cryptococcosis.

Heat shock proteins (HSPs) from several pathogenic microbes have been shown to be target molecules of humoral responses as well as cellular immune responses. However, little is known about target molecules in pulmonary cryptococcosis. Western blotting analysis revealed that experimentally induced pulmonary cryptococcosis in (BALB/c x DBA/2)F1 mice was associated with the appearance of serum antibodies to a 77-kDa protein derived from Cryptococcus neoformans as well as to 18-, 22-, 25-, 36-, and 94-kDa proteins. Since the 77-kDa band also reacted with rabbit polyclonal antibodies against 70-kDa HSP (HSP70) family members, the protein was predicted to be a member of the HSP70 family. We also purified HSP70 directly from a C. neoformans cell extract by Mono Q fast protein liquid chromatography and ATP-agarose affinity column chromatography and showed that it was positive in immunoblot analysis using either serum from C. neoformans-infected mice or rabbit anti-HSP70 antibodies. N-terminal amino acid sequencing of this purified protein confirmed that the 77-kDa protein was a member of the HSP70 protein family. A 66-kDa protein, which coincidentally purified with the HSP70 protein and was identified as a member of the HSP60 family by N-terminal amino acid sequencing, was not reactive with sera from C. neoformans-infected mice. Thus, a protein associated with the HSP70 family and derived from C. neoformans was a major target molecule of the humoral response in murine pulmonary cryptococcosis.

Amino Acid Sequence↗

A flow cytometric analysis of the expression of adhesion molecules on human renal cell carcinoma cells with different metastatic potentials.

OBJECTIVES: We investigated the relationship between the metastatic potential and the surface expression of adhesion molecules on human renal cell carcinoma (HRCC) cells. METHODS: The metastatic potential was studied by the intravenous injection of cells from an HRCC cell line SN12C parent and its variants, SN12C-MM3, SN12C-clone2 and SN12C-clone8 into athymic Balb/c nude mice. The surface expression of adhesion molecules on these four HRCC cell lines was studied by a flow cytometric analysis. RESULTS: Of the four cell lines, SN12C-MM3 had the highest ability to produce pulmonary metastatic nodules. In contrast, the SN12C parent, SN12C-clone2 and SN12C-clone8 produced either few or no pulmonary metastatic nodules. A flow cytometric analysis revealed that SN12C-MM3 showed a strong expression of sialyl Lewis X (sialyl Le(x)) carbohydrate antigen and a slightly stronger expression of CD11a (LFA-1 alpha-chain) and CD54 (ICAM-1) compared with the other three cell lines. All cell lines expressed CD29 (beta 1-integrin) and CD44 to the same extent. CONCLUSION: Sialyl Le(x) is thought to be a ligand for the adhesion molecule called ELAM-1 (endothelial-leukocyte adhesion molecule-1, E-selectin) and mediates the interaction of leukocytes or tumor cells to endothelial cells, followed by the integrin-mediated adhesion. These data suggest that SN12C-MM3 cells may have more of a chance to adhere to endothelial cells in blood vessels and consequently shows a higher metastatic potential when injected intravenously in comparison to the other three lines.

Animals↗

Effect of clarithromycin on lymphocytes in chronic respiratory Pseudomonas aeruginosa infection.

In a newly established murine model of chronic Pseudomonas aeruginosa respiratory infection mimicking diffuse panbronchiolitis (DPB), we investigated the effect of oral administration of clarithromycin on lymphocyte accumulation in the lung. Infection was produced by placement of a plastic tube precoated with P. aeruginosa in the bronchus. The number of bacteria on the tube was 6.25 +/- 0.22 log10 colony-forming units (cfu)/ml. Viable bacteria were constantly isolated at 10(5) to 10(6) cfu/specimen from the lungs for more than 1 yr. The histopathologic features resembled those of DPB consisting of massive accumulation of lymphocytes in the lung. The total number of pulmonary lymphocytes started to increase on Day 7, reaching a peak level within 12 d of intratracheal challenge. The number remained steady at that level for up to 120 d. There was also a steady fall in the CD4+/CD8+ ratio in the lungs, commencing on Day 7 and persisting to Day 120. A 10-d course of oral clarithromycin (10 mg/kg/d) from Day 7 resulted in a reduction of lymphocyte numbers to baseline level, although the dose did not influence the number of bacteria in the lungs. Treatment also increased the CD4+/CD8+ ratio to the baseline level from Day 7 to 17. Our results were similar to those detected in bronchoalveolar lavage fluid of patients with DPB and suggest that the therapeutic benefits of clarithromycin are due to its anti-inflammatory properties rather than antimicrobial effect.

Animals↗

Rapid prediction of rifampin susceptibility of Mycobacterium tuberculosis.

We evaluated the relationship between rifampin (RIF) susceptiblility and amino acid substitution in rpoB gene of Mycobacterium tuberculosis and the usefulness of rpoB gene sequencing in the rapid prediction of RIF susceptibility of M. tuberculosis in clinical specimens. A total of 76 genetic alterations in the 69 bp core region of rpoB gene were detected in 74 of 130 M. tuberculosis strains. Examination of the correlation between the minimum inhibitory concentrations (MICs) of RIF and amino acid substitutions in the 69 bp core region of rpoB gene revealed that all 43 strains containing amino acid substitution with Leu or Trp in codon 531 showed RIF-resistant phenotypes, with MICs > or = 64 microg/ml. In contrast, a variable level of RIF susceptibility was observed among strains containing amino acid substitutions in either codon 516 or codon 526. In the clinical study, we tested 26 sputum samples, two gastric lavages, and one synovial fluid sample obtained from patients with tuberculosis. The RIF susceptibility predicted by direct rpoB sequencing was satisfactorily compatible with the results of the RIF-susceptibility test and the MICs of RIF against isolated organisms. Our results suggest that rpoB gene sequencing is useful for the detection of M. tuberculosis in clinical samples as well as the rapid prediction of RIF susceptibility of these strains.

Amino Acid Sequence↗

[Lymphocytic infundibulo-hypophysitis with diabetes insipidus as a new clinical entity: a case report and review of the literature].

In 1992, we reported a lymphocytic adenohypophysitis (LIH) (Neurol Med Chir). We considered this case unusual in that the case was that of a menopausal female and that it was accompanied with diabetes insipidus as classical lymphocytic adenohypohysitis (LAH). Subsequently, Ahmed reported two cases which presented a similar pathological manifestation, except for necrosis, as did our case and named them "necrotizing infundibulo-hypophysitis." Recently we encountered another similar case, which is reported hereunder. A female, 34 years of age, had suffered from headache, polyuria, and amenorrhea. CT scan showed a pituitary mass, and pituitary tumor was surgically removed transcranially at a local hospital. The pathological examination revealed the findings of chronic inflammation and necrosis. One month after the operation, however, she was an in-patient again under the suspicion of meningitis for fever and, when antibiotic therapy at the local hospital resulted in no improvement, she was referred to our hospital. Endocrinological studies showed low FSH, LH, ACTH and plasma cortisol level. Antibodies of serum to RNP, Sm, mitochondria, nucleus, AChR, and DNA were all negative. Because of an intrasellar mass with suprasellar extension on MRI, transsphenoidal operation was conducted four months after the initial operation. The pathological examination revealed the infiltration of lymphocytes, plasma cells, and foamy macrophages, and necrosis. After this operation, the headache was cured and the patient was discharged. Two months subsequent to the second operation, headache recurred and temporal upper quadrantic anopsia was noted. An enlarged tumor was found, but prednisolone worked to cure the pain and the visual field defect was found to have been remedied. The patient's diabetes insipidus is presently persisting, and she still relies on the use of desmopressin acetate and is still in need of cortisol replacement therapy. Including our cases, ten cases of lymphocytic hypophysitis, not related to pregnancy or delivery but with diabetes insipidus, have been reported. Several clinical and anatomical features distinguish these 10 cases from classical LAH. The classical LAH was predominantly related to pregnancy or delivery. However 6 of 10 cases were male in LIH. LAH related to pregnancy or delivery does not accompany diabetes insipidus, but all reported cases of LIH had a diabetes insipidus. Visual field and/or ocular movement disturbance are LAH's chief complaints (15 out of 25 cases) but visual field disturbance seldom occurs in LIH (1 out of 10 cases). Hypopituitarism is more serious in LAH, and 4 cases became fatal from an adrenal crisis. Anatomically, inflammatory change of LIH is located anterior and posterior to the pituitary gland and extends to the pituitary stalk and, at times, hypothalamus. On the other hand, LAH relates to pregnancy or delivery, the inflammatory change localizes to the adenohypophysis. Ahmed emphasized necrosis, while necrosis was not a prominent histological finding in LIH. Necrosis was noted only in 3 of 10 cases. To be stressed, rather, are the inflammatory changes seen on the neurohypophysis and the pituitary stalk, together with the characteristic diabetes insipidus. We believe, in view of the above, that what Ahmed named necrotizing infundibulo-hypophysitis should be named "LIH with diabetes insipidus." Whereas differential diagnosis is necessary between this said new disorder and the conventional LAH, we advocate that the latter, which is related to pregnancy or parturition but is free from neurohypophysitis be identified as "LAH related to pregnancy or delivery." With respect to treatment, steroid therapy is essential. If the symptoms do not improve, a transsphenoidal operation for diagnosis (LIH and LAH) and decompression (the case of LAH with visual or external ocular movement disturbance) is advisable. However, extensive surgery is not recommended, because per

Adult↗

[Relationship between streptomycin susceptibility and rpsL mutations of Mycobacterium tuberculosis strains].

The relationship between streptomycin (SM) susceptibility and rpsL mutations of Mycobacterium tuberculosis strains was studied. Of 18 clinically isolated SM-resistant M.tuberculosis strains, mutation was suspected in 9 strains (50%) with SM MICs of > or = 256 micrograms/ml by PCR-single strand conformation polymorphism targeting rpsL gene. On the other hand, using PCR-direct sequence method, amino acid substitution caused by single nucleotide point mutation in rpsL gene was demonstrated in 11 out of 18 strains (61%). The same amino acid substitution at codon 43 (Lys-->Arg) was observed in all 11 strains with SM MICs of > or = 256 micrograms/ml. In addition, PCR products obtained from these 11 strains could not be cut by a restriction enzyme, Mbo II, while H37Rv strain and the other 32 strains with SM MICs of < 256 micrograms/ml were cut into 2 fragments. In conclusion, our results suggest that highly SM-resistant M.tuberculosis strains with MICs of > or = 256 micrograms/ml could be rapidly and easily detected by the restriction enzymatic method.

Antibiotics, Antitubercular↗

[An observation on tuberculosis associated with HIV infection in Japan].

OBJECTIVE: To observe the reported cases of tuberculosis (TB) with HIV infection in Japan, in terms of their main clinical features and related factors. METHODS: A voluntary reporting network has been organized by the authors who are specialists of TB or respiratory medicine in tuberculosis institutions located roughly all over the country. The members have been encouraged to report not only their own cases but cases seen by their friends or in other institutions. RESULTS: By the end of 1996, a total of 71 cases have been reported of which 59 were TB and 12 NTM cases. Nationality of the cases were; Japan 48, Other Asian countries 16, Others 7. All of the NTM cases were Japanese. 30% of the cases were aged less than 30 years, 24% were thirties, 24% forties, 17% fifties and 6% were those aged 60 years or older. The cases were clearly younger than the TB cases in the national TB registry, and older than HIV-infected persons as known from the HIV surveillance system. 97% of the TB cases were bacteriologically confirmed cases. Eight of NTM cases were positive for MAC, others for M.kansasii. 42% of the cases had extra-pulmonary disease, including disseminated infections seen among 19%. Of TB cases 25% were excreting bacilli resistant to any of the anti-TB drugs which was higher than in the case of general TB population (10-15%). 11% of TB cases had past history of TB treatment. The cases had severe immunological impairment, 79% of the cases having CD4+ cell count less than 100. The route of HIV infection were; 51% heterosexual, 13% homosexual, 13% through blood preparations, etc. DISCUSSION: Although there may be many cases not included in this observation, it is considered to well reflect the real situation of the problem of Japan. More attention should be paid to HIV infection of the patients in the clinical practice of TB in Japan.

AIDS-Related Opportunistic Infections↗

[Expiration-like movement and spino-bulbo-spinal reflex in a patient with apneic coma caused by anoxic encephalopathy].

A 72-year-old female patient, hospitalized for parkinsonism, suffered cardiopulmonary arrest without any certain causes. The patient was successfully resuscitated and her life was sustained by artificial ventilator for 100 days. All brainstem reflexes were absent, and flat electroencephalogram and no response of brainstem auditory evoked potentials were confirmed twice with an interval of over 6 hours. Flexion of the arm induced reflex rectus abdominis muscle contraction, resembling expiratory movement. Muscle stretch reflexes on rectus abdominis were hyperactive. The expiration-like movement appeared in an apnea test seven minutes after a cessation of artificial ventilation. Electrical stimuli on femoral nerve induced complex action potentials with a 70.2 +/- 6.9 msec latency and 300 msec duration in rectus abdominis muscle, which were similar to the spino-bulbo-spinal reflex. Single photon emission tomography showed only slight cerebral cortical blood flow. The expiration-like movements observed in this case suggest a relationship not only with the spinal cord reflex but also with polysynaptic reflexes to reticular formation in the medulla oblongata.

Aged↗

The C-terminal SH3 domain of p67phox binds its natural ligand in a reverse orientation.

Src-homology 3 (SH3) domains are small protein modules that bind to proline-rich motifs and mediate the formation of signalling complexes. SH3 domains have been implicated in the assembly of the phagocyte NADPH oxidase complex, a multicomponent enzyme responsible for the production of antimicrobial oxidants. Two components of the NADPH oxidase, p67phox and p47phox, each contain two SH3 domains and we have previously shown that the SH3 domain near the carboxyl terminus of p67phox interacts with a proline-rich region of p47phox. In order to gain an insight into the specificity of this interaction, a structural model of the p67phox SH3 domain has been produced using the known structure of the c-abl SH3 domain as a template. The model suggests that the proline-rich ligand of p47phox can bind to the SH3 domain in either of two orientations. In each orientation, the key residues of the SH3 domain that contact the ligand have been identified and altered by site-directed mutagenesis. The ability of the mutated SH3 domains to associate with p47phox from cell lysates was tested and the results provide the first evidence for the binding of a full-length protein to an SH3 domain in a reversed orientation.

Amino Acid Sequence↗

Restriction fragment length polymorphism of genes of the alpha 2(XI) collagen, bone morphogenetic protein-2, alkaline phosphatase, and tumor necrosis factor-alpha among patients with ossification of posterior longitudinal ligament and controls from the Japanese population.

STUDY DESIGN: The present study analyzed the restriction fragment length polymorphism patterns of alpha 2(XI) collagen, bone morphogenetic protein-2, alkaline phosphatase, and tumor necrosis factor-alpha genes in patients with ossification of the posterior longitudinal ligament. This study investigates the genetic polymorphism of bone-induced factors in patients with ossification of the posterior longitudinal ligament and compares it with healthy control subjects. OBJECTIVES: To clarify the genetic markers linked to ossification of the posterior longitudinal ligament. SUMMARY OF BACKGROUND DATA: Ossification of the posterior longitudinal ligament is a genetic disease associated with abnormal calcium metabolism involving the posterior longitudinal ligament. Previous genetic studies have not identified the pathologic mechanism of ossification of the posterior longitudinal ligament. Histopathologic studies of ossification of the posterior longitudinal ligament and the animal model, the spinal hyperostotic mouse, have revealed an increase in Type XI collagen and bone morphogenetic protein-2 expression. METHODS: Eighteen Japanese patients with ossification of the posterior longitudinal ligament and 51 healthy, unrelated control subjects were investigated for the restriction fragment length polymorphism patterns of COL11A2, bone morphogenetic protein-2, alkaline phosphatase, and tumor necrosis factor-alpha, genes with various restriction endonucleases. RESULTS: The gene frequencies of COL11A2 obtained with BamHl (10.0 kb fragment) and HindIII (19.0 kb fragment) observed in patients with ossification of the posterior longitudinal ligament were higher compared with control subjects (0.43 and 0.14, respectively). These differences were statistically significant (BamHl P = 0.018; Hindlll P = 0.046). Two new restriction fragment length polymorphism patterns were detected of the bone morphogenetic protein-2 gene with Mspl and Taql and one already known restriction fragment length polymorphism pattern of the tumor necrosis factor-alpha gene with Ncol. However, they were not significantly different from the control subjects. CONCLUSIONS: Seven restriction fragment length polymorphisms of COL11A2 gene were identified. Two of them (BamHl, 10.0/10.0 kb genotype; HindIII, 19.0/19.0 kb genotype) were significantly different in patients with ossification of the posterior longitudinal ligament.

Alkaline Phosphatase↗

Rapid detection and identification of mycobacteria by combined method of polymerase chain reaction and hybridization protection assay.

A new method for the rapid detection and identification of mycobacteria, combining polymerase chain reaction (PCR) with DNA probe, was developed. The mycobacterial 16S rRNA encoding gene was amplified by nested PCR, and the PCR product was identified by hybridization protection assay using acridinium ester labelled DNA probe. The optimum temperature for hybridization of PCR product and DNA probe was estimated as 55 degrees C. The specificity of the combined method was excellent in the detection and identification of Mycobacterium tuberculosis and Mycobacterium avium-intracellulare complex (MAC). The detection limit was 10 fg DNA for M. tuberculosis, and 100 fg DNA for MAC. Results of preliminary clinical investigation of this method using 207 clinical specimens demonstrated an efficient detection and identification of M. tuberculosis and MAC. These results indicate that the new combined method may be a useful test for the rapid detection and identification of M. tuberculosis and MAC in clinical specimens.

Humans↗

Antimicrobial activity of superoxidized water.

We tested the antimicrobial activity of superoxidized water against methicillin-sensitive Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Serratia marcescens, Escherichia coli, Pseudomonas aeruginosa and Burkholderia cepacia. The number of bacteria was reduced below detection limit following incubation in superoxidized water for 10 s. The bactericidal activity of superoxidized water was similar to that of 80% ethanol, but superior to that of 0.1% chlorhexidine and 0.02% povidone iodine. We conclude that superoxidized water is a low cost but powerful disinfectant.

Burkholderia cepacia↗

Increased delivery of a new cisplatin analogue (254-S) in a rat brain tumor by an intracarotid infusion of bradykinin.

The intracarotid infusion of bradykinin has been shown to selectively increase capillary permeability in a brain tumor without affecting either normal brain capillary permeability or the systemic blood pressure. We examined whether the intracarotid infusion of bradykinin could selectively increase the delivery of a new watersoluble antitumor agent, cis-diammine glycolato-platinum (254-S, 303.2 mol. wt.), to transplanted RG2 glioma in rats. The platinum contents in the brain, tumor tissues and plasma were measured using an atomic absorption spectrophotometer. The transfer ratio of 254-S from plasma to the tissues was calculated and expressed as the volume of plasma containing platinum per g tissue (Dp, microliter g-1). Intracarotid bradykinin infusion at a rate of 20 micrograms kg-1 min-1 increased the delivery of 254-S in the tumor tissue by 1.3-fold when compared with intracarotid infusion of 0.9% saline (48.78 +/- 18.11 vs. 37.12 +/- 12.53; p < 0.05). In normal brain tissue including the ipsilateral cortex, the contralateral basal ganglia and the contralateral cortex, bradykinin did not significantly increase the delivery of 254-S in comparison with 0.9% saline (12.28 +/- 9.53 vs. 10.70 +/- 5.05, 4.96 +/- 3.54 vs 4.96 +/- 4.80, 7.64 +/- 4.10 vs. 13.07 +/- 11.38, respectively). These results indicate that the intracarotid infusion of bradykinin selectively increases the delivery of 254-S to the brain tumor without affecting the normal brain. This method may, therefore, enhance the antitumor effect of 254-S for the treatment of brain tumors and also reduce neurotoxicity in the normal brain.

Animals↗