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H Ohno

Publications and source records attributed to H Ohno.

At least 217 records · Page 12Linked to original sources
PubMed1997

A rapid drug susceptibility test for Mycobacterium tuberculosis using the hybridization protection assay.

The conventional drug susceptibility tests for Mycobacterium tuberculosis are time-consuming and the results are available only after 2-4 weeks. We have recently reported a new, simple and fast M. tuberculosis drug susceptibility test, using the hybridization protection assay (HPA), that allows the detection of isoniazid- or rifampicin-resistant strains of M. tuberculosis within 24 h of incubation. In the present study, the scope of application of our new test was extended to another two first-line antimycobacterial agents, namely ethambutol and streptomycin, and a quinolone antimicrobial agent, ciprofloxacin. The ethambutol-, streptomycin- and ciprofloxacin-resistance characteristics of M. tuberculosis were also delineated within 72 h of incubation with or without the drug. The results of our novel and rapid drug susceptibility test for M. tuberculosis were not only comparable to those determined by the conventional method, but became available within a few days of incubation. Our results also suggest that the drug susceptibility test using HPA might also be useful for detecting organisms resistant to antimicrobial agents other than antimycobacterials.

Anti-Infective Agents↗
PubMed1997

Effects of endurance training on superoxide dismutase activity, content and mRNA expression in rat muscle.

1. The purpose of the present study was to investigate the changes in superoxide dismutase (SOD) isoenzyme (Mn(2+)-SOD and Cu2+, Zn(2+)-SOD) activities, contents and mRNA expressions in rat skeletal muscle during endurance training and a single bout of exercise. 2. Thirty-eight male Wistar rats were divided into untrained (U) and trained (T) groups. The T group rats were treadmill-trained for 9 weeks. The activity, content and mRNA expression of Mn(2+)-SOD and Cu2+, Zn(2+)-SOD were determined in the soleus muscle of each rat. 3. Mn(2+)-SOD activity and content in the T group were significantly higher than in the U group, both at rest (22 and 21%, respectively) and after exercise (24 and 46%, respectively), while a single bout of exercise affected neither the activity nor content of Mn(2+)-SOD in either group. 4. The content of Cu2+,Zn(2+)-SOD in both groups was not different at rest and after exercise, although its activity at rest was significantly higher in the T group than in the U group (by 29%). 5. After exercise, the expression of Mn(2+)-SOD mRNA was markedly attenuated only in the U group (49%); the expression of Cu2+,Zn(2+)-SOD mRNA was not influenced by exercise. 6. Our results suggest that adequate endurance training increases both the activity and content of Mn(2+)-SOD and that untrained rats are rather susceptible to oxidative stress during physical exercise. It thus appears that Mn(2+)-SOD provides a reliable index of physical training. 7. The results obtained in the present study also suggest that muscle has the capacity of responding to training in such a manner as to reduce the potential harm arising from the accumulation of oxygen free radicals resulting from enhanced metabolic activity.

Animals↗
PubMed1997

Three approaches for laparoscopic unroofing of simple and complicated renal cysts.

We report 2 cases of simple renal cysts which were marsupialized with 2 laparoscopic approaches involving either transperitoneal, with reflection of the colon medially or dissection through the mesocolon, and a case of a multilocular renal cyst which was treated by the retroperitoneal approach. Although laparoscopic unroofing of a renal cyst is a safe and effective alternative to open surgical techniques, the transperitoneal approach should only be used for simple renal cysts. The retroperitoneal approach for complicated renal cysts may be indicated if preoperative examinations exclude the possibility of malignancy.

Aged↗
PubMed1997

[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↗
PubMed1997

[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↗
PubMed1997

Relationship between cold tolerance and generation of suppressor macrophages during acute cold stress.

Acute cold stress induces suppressor macrophages expressing large numbers of receptors to the crystallizable fragment (Fc) portion of immunoglobulin G (MAC-1+ FcgammaRII/IIIbright cells), resulting in the immunosuppression of splenocyte mitogenesis. The generation of MAC-1+ FcgammaRII/IIIbright cells is mediated by the action of glucocorticoids (GCs) through the GC-receptor. In the present study, the generation of MAC-1+ FcgammaRII/IIIbright cells in peritoneal exudate cells was closely related to the decrease of rectal temperature during 3-day exposure to 5 degrees C. We next investigated the effects of improved cold tolerance on the generation of MAC-1+ FcgammaRII/IIIbright cells during acute cold stress. Mice were adapted to cold by exposure to 5 degrees C for 3 wk (cold-acclimated mice) and then reexposed to 5 degrees C for 3 h (acute cold stress) after living at 25 degrees C for 24 h. The rectal temperature of cold-acclimated mice was not decreased by the acute cold stress. In addition, the proportion of MAC-1+ FcgammaRII/IIIbright cells in peritoneal exudate cell population from cold-acclimated mice was unaffected by the acute cold stress. The cold acclimation significantly attenuated the increases in serum corticosterone levels and the expression of the GC-receptor mRNA on peritoneal exudate cells in response to acute cold stress. These results suggest that the altered GC response to acute cold stress by the improvement of cold tolerance inhibits the generation of suppressor macrophages during acute cold stress.

Acclimatization↗
PubMed1997

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↗
PubMed1997

Endurance training improves the resistance of rat diaphragm to exercise-induced oxidative stress.

The current study was designed to test the hypothesis that endurance training improves the ability of the diaphragm muscle to resist exercise-induced oxidative stress. Twenty-eight male Wistar rats were assigned to either untrained or trained groups. Trained rats were treadmill-trained for 9 wk. Each group was subdivided into acutely exercised or nonexercised groups. Diaphragm muscle from each rat was analyzed to determine the levels of certain antioxidant enzymes: Mn-superoxide dismutase (Mn-SOD), Cu,Zn-superoxide dismutase (Cu,Zn-SOD), glutathione peroxidase, and catalase. In addition, interleukin-1 and myeloperoxidase levels were determined. Endurance training upregulated all of the antioxidant enzymes. Conversely, acute exercise increased glutathione peroxidase and catalase in untrained rats, while it had no overt effect on any antioxidant enzymes in trained rats. Both Mn-SOD and Cu,Zn-SOD contents and activities were increased with endurance training. However, the mRNA expressions of both forms of SOD did not show any significant change with endurance training. Acute exercise also increased the levels of interleukin-1 and myeloperoxidase in untrained rats but not in trained rats. Moreover, acute exercise significantly increased the ability of neutrophils to produce superoxide, especially in untrained rats. The results from this study demonstrate that endurance training can upregulate certain antioxidant enzyme activities in rat diaphragm muscle, indicating the potential for improvement of the resistance to intracellular reactive oxygen species. The results of this study also suggest that acute exercise may cause oxidative damage in rat diaphragm through the activation of the inflammatory pathway and that endurance training may minimize such an extracellular oxidative stress by acute exercise.

Animals↗
PubMed1997

Effects of a specific cysteinyl leukotriene antagonist, pranlukast, on antigen-induced cysteinyl leukotriene-mediated rhinitis in guinea pigs.

To examine the effects of a specific cysteinyl leukotriene (cysLT) antagonist, pranlukast, on allergic rhinitis, antigen-induced rhinitis in guinea pigs was modified by pretreatment with an cyclooxygenase inhibitor (indomethacin) followed by an H1-blocker (pyrilamine). Intranasal ovalbumin (OVA) administration in actively sensitized guinea pigs resulted in concentration-dependent increases in nasal permeability and nasal airway resistance (NAR). Although pyrilamine (1 mg/kg, i.v.) abolished these antigen-induced changes, pretreatment with indomethacin (5 mg/kg, i.v.) followed by pyrilamine enhanced these responses to a degree similar to that observed with OVA challenge alone. Analyses of nasal perfusate in indomethacin/pyrilamine-pretreated animals showed that cysLTs increased by 270.8%, whereas thromboxane B2 decreased by 88.3% as compared with those on challenged with OVA alone. Oral administration of pranlukast (1-10 mg/kg) dose-dependently prevented increases in nasal permeability and NAR of indomethacin/pyrilamine-pretreated animals. However, an anti-allergic agent, azelastine, did not affect these responses. These results indicate that pranlukast suppresses antigen-induced cysLT-mediated responses of allergic rhinitis in actively sensitized guinea pigs. A cysLT antagonist, pranlukast, may thus prevent cysLT-mediated symptoms of allergic rhinitis.

Airway Resistance↗
PubMed1997

Cysteinyl leukotrienes induce nasal symptoms of allergic rhinitis via a receptor-mediated mechanism in guinea pigs.

To examine whether cysteinyl leukotrienes (cysLTs: LTC4, LTD4 and LTE4) induce symptoms of allergic rhinitis via their receptors, we studied the following: i) the specific binding of radiolabeled cysLTs to guinea pig nasal mucosa membrane and ii) effects of nasal LTD4 challenge in normal guinea pigs. The binding study indicated that there was a single population of binding sites for LTC4, LTD4 and LTE4 with Kd and Bmax values of 34.9+/-2.0, 0.252+/-0.015 and 0.589+/-0.039 nM and 10, 140+/-490, 122+/-11 and 306+/-23 fmol/mg protein, respectively. The in vivo study showed that topical nasal challenge of LTD4 (0.1-30 microg/nose) increased nasal secretion, nasal airway resistance and nasal eosinophil infiltration without inducing sneezing. While the increases in nasal secretion and nasal airway resistance were transient, peaking 10 to 20 min after LTD4 challenge, nasal eosinophil infiltration persisted at least until 24 hr post-challenge. These nasal symptoms were dose-dependently suppressed by oral administrations of pranlukast (0.3-3 mg/kg). The results suggest that cysLTs cause not only early-phase symptoms but also nasal eosinophil migration, a characteristic associated with the late-phase symptom of allergic rhinitis, via a receptor-mediated mechanism. Cysteinyl leukotrienes, thus, may be important mediators in allergic rhinitis.

Administration, Oral↗
PubMed1997

Significance of rearrangement of the BCL6 gene in B-cell lymphoid neoplasms.

Chromosomal translocations involving 3q27 are among the most common recurring translocations in non-Hodgkin's lymphoma (NHL) of B-cell phenotype. Molecular cloning of junctional areas of the translocations resulted in isolation of the BCL6 gene adjacent to the breakpoint cluster on 3q27. The gene encodes a zinc-finger transcription factor which is expressed in nuclei of germinal center B-cells. Rearrangement of BCL6 was observed in 6.4 to 14.3% of follicular lymphomas and 28.6 to 35.5% of diffuse large cell lymphomas; regarding the latter, a Japanese series showed a lower incidence. Survival curves suggested that NHL carrying rearrangement of BCL6 and lacking that of BCL2 is curable by chemotherapy. Detailed analysis of the vicinity of translocations showed that the 5' untranslated region of BCL6 was replaced by heterogeneous promoters not only from immunoglobulin genes but also from many previously uncharacterized loci. Bcl-6 protein is expressed in NHL of follicular center B-cell origin, independently of the presence or absence of BCL6 rearrangement. At present, limited information is available about the functional consequences of the rearrangements and, in particular, about their ultimate implications for lymphomagenesis.

Chromosomes, Human, Pair 3↗
PubMed1997

[Localization of 8q24 break-point of Burkitt lymphoma in Japan : relationship to EBV status].

It has been reported that the break point of 8q24 in t (8; 14) (q24; q32) is located far up-stream from c-myc gene locus in endemic EBV (Epstein-Barr virus)-positive BL, while the break-point is located close to the 1st intron of c-myc gene in sporadic EBV-negative BL. Considering that no statistical analysis is available regarding BL in Japan, the break-point of chromosome No.8 was investigated in 13 BL/L3 cell lines (having t(8; 14)) and 4 fresh samples derived from Japanese patients, including 3 EBV-positive BL cell lines, by using long-distance PCR. In this PCR, one primer was set in the 2nd intron of the c-myc gene, and the other primer in Ig constant region gene, mu, gamma, alpha and epsilon. This long distance PCR can cover up to 30 kb. Thus, this PCR does'nt generate product, if the 8q24 break-point is located far up-stream (more than 50 kb) fom c-myc gene. In 2 of the 3 t (8; 14) EBV-positive BL lines, no product was generated in two lines(N831 and Middle 91), while a product was synthesized in one line(Akata), indicating that the 8q24 break-point is near the c-myc gene in Akata. In all the other BL/L3 lines, a product was synthesized. A larger number of BL cases are necessary to investigate in order to know which 8q24 break-point pattern is exhibited by EBV-positive BL in Japan, while this method is suitable for testing a large number of case materials.

Burkitt Lymphoma↗
PubMed1997

Effects of swimming training on brown-adipose-tissue activity in obese ob/ob mice: GDP binding and UCP m-RNA expression.

Brown adipose tissue (BAT) of obese animals is generally in a relatively atrophied and thermogenically quiescent state. The aim of the current study was to investigate the effect of swimming training on BAT activity in lean and obese (ob/ob) mice. The trained mice underwent a 6-week endurance swimming training (1 h/day, 5 days/week) in water at 35-36 degrees C. The swimming training significantly increased BAT mass and its protein content in both the lean and obese mice, suggesting hypertrophy. After swimming training, the amounts of protein and guanosine 5'-diphosphate binding in the mitochondria recovered from BAT of both mice increased significantly as compared with the respective sedentary groups, whereas the uncoupling protein (UCP) content increased significantly only in lean mice. After swimming training, the level of UCP mRNA expression did not change substantially in lean mice but appeared to increase in obese mice. The results obtained here suggest that swimming training leads to an increase in the nonshivering thermogenesis of obese mice in addition to lean mice.

Adipose Tissue, Brown↗
PubMed1997

Effect of swimming training on antioxidant enzymes in kidney of young and old mice.

The current study was undertaken to investigate the effect of swimming training on the antioxidant enzyme system in kidney of young and old mice. Both young and old mice, aged 2 and 26 months old, respectively, were divided into the sedentary and swimming-trained groups. The trained mice underwent a 6-week swimming program (1 h/day, 5 days/week) in water at 35-36 degrees C. Cu,Zn-superoxide dismutase (Cu,Zn-SOD) activity was significantly decreased with aging but was not influenced by swimming training, such changes being similar to those noted for catalase activity rather than for glutathione peroxidase activity. After swimming training Mn-SOD activity increased significantly only in old mice but was unaffected by aging. Although neither aging nor swimming training had overt effect on the expression of Cu,Zn-SOD mRNA, the immunoreactive Cu,Zn-SOD content in young mice decreased significantly after the training. Meanwhile, Mn-SOD mRNA expression in old mice was reduced by half after swimming training, accompanied by a significant decrease in its immunoreactive content; unexpectedly, however, Mn-SOD content in young mice did not parallel its mRNA expression. These findings suggest that the antioxidant enzyme system in mouse kidney trends to be down-regulated with aging, and that swimming training fails to attenuate such reduced levels of the antioxidant enzymes.

Aging↗
PubMed1997

Long distance polymerase chain reaction for detection of chromosome translocations in B-cell lymphoma/leukemia.

To establish a rapid and sensitive method to detect neoplastic cells carrying a specific chromosomal translocation in B-cell lymphoma/leukemia, we have developed a novel strategy based on long distance polymerase chain reaction (LD-PCR) amplification. Genomic DNA were extracted from tumor cells carrying a t(14;19)(q32;q13), a t(8;14)(q24;q32), a t(3;22)(q27;q11), a t(2;3)(p12;q27), and a t(3;14)(q27;q32). Oligonucleotide primer pairs were designed to be complementary to exons or flanking sequences of the BCL3, c-MYC and BCL6 oncogenes, and to constant region genes of the IG genes. LD-PCR with a newly available Taq polymerase for longer product synthesis successfully amplified fragments representing BCL3/C alpha junctional sequences for t(14;19); c-MYC/C mu, c-MYC/C gamma and c-MYC/C alpha for t(8;14); BCL6/C lambda for t(3;22); BCL6/C kappa for t(2;3); 5'-BCL6/C mu and 5'-BCL6/C gamma for t(3;14), respectively. The sizes of the amplified fragments were varied from 1.8 kb to 12 kb, which were specific to each material. Present study provides a useful tool for diagnosis and subsequent management of B-cell lymphoma/leukemia characterized with specific chromosomal translocation.

B-Cell Lymphoma 3 Protein↗
PubMed1997

Rearrangement of the BCL6 gene in B-cell lymphoid neoplasms.

We report here a large series of B-cell neoplasms with regard to rearrangement of the BCL6 gene on chromosome band 3q27. Southern blot analysis using probes from the major translocation cluster (MTC) region of the BCL6 revealed rearrangement in 32 of a total of 222 patients with various subtypes of B-cell neoplasm. In non-Hodgkin's lymphoma (NHL), rearrangements of the BCL6 gene were not closely associated with a specific histopathologic subtype but distributed in subcategories in the Working Formulation. A comparative study between NHL associated either with BCL2 or BCL6 rearrangement showed that advanced disease and bone marrow involvement were more frequent in BCL2(+) NHL. In contrast, extranodal involvement was more frequently observed in the BCL6(+) NHL. The survival curve of BCL6(+) NHL was characterized by a rapid decline followed by a plateau. Of the total of 32 BCL6(+) patients, 6 carried both BCL2 and BCL6 rearrangements, and showed clinicopathological properties of follicular lymphoma. This study suggests that BCL6 rearrangement is primarily associated with large cell lymphoma, and that BCL2(-)BCL6(+) NHL could potentially be curable with modern combination chemotherapy.

Bone Marrow↗
PubMed1997

BCL3 rearrangements and t(14;19) in chronic lymphocytic leukemia and other B-cell malignancies: a molecular and cytogenetic study.

The t(14;19)(q32.3;q13.1) is a recurring translocation found in the neoplastic cells of some patients with chronic lymphocytic leukemia (CLL) or other B-lymphocytic neoplasms. We previously cloned the translocation breakpoint junctions present in the leukemic cells from three such patients and identified a gene, BCL3, whose transcription is increased as a result of the translocation. In the present paper, we describe three additional patients with the t(14;19), one with lymphoma and two with CLL, and report the cloning and sequencing of the breakpoint junction in one of these patients as well as in a previously reported patient. We and others have found that the breakpoints on chromosome 14, with one exception, fall within the switch region upstream of the immunoglobulin heavy chain C alpha 1 or C alpha 2 sequences. Several of the breaks within chromosome 19 fall immediately upstream of the BCL3 gene, but several others are more than 16 kb 5' of the gene. Most patients with CLL and the t(14;19) also show trisomy 12.

Adult↗