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Biomedical subjects

T Saika

Publications and source records attributed to T Saika.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Apoptosis of peripheral leukocytes in patients with myelodysplastic syndromes].

Apoptosis of peripheral leukocytes in 9 patients with myelodysplastic syndromes (MDS) was examined in vitro, using peripheral blood that had been gently incubated at 37 degrees C for 5 hours. The MDS patients included 3 with refractory anemia, 2 with refractory anemia with ringed sideroblasts, and 4 with refractory anemia with excess blasts. Peripheral blood specimens were also obtained from a control group consisting of 10 patients with iron deficiency anemia (IDA), 10 with idiopathic thrombocytopenic purpura (ITP) and 10 healthy individuals. Apoptotic granulocytes (Apo-Gs) were identified by morphological changes, including nuclear fragmentation, and expressed as a percentage of every 300 granulocytes counted. Apo-Gs were counted 1, 2, 3, 4, and 5 hours after incubation. Although the percentage of apo-Gs climbed over time in the MDS patients, a small number of apo-Gs were also observed in the healthy individuals. In the MDS patients, the proportions of apo-Gs 5 hours after incubation (37 degrees C) were significantly higher than those in the IDA and ITP patients and healthy individuals (15.7 +/- 8.0% in MDS patients vs. 2.8 +/- 1.2% in IDA patients, 2.3 +/- 1.7% in ITP patients, and 0.7 +/- 0.6% in healthy individuals; p < 0.005). No significant differences were observed in the proportions of apo-lymphocytes. DNA fragments were observed in blood lymphocyte from an MDS patient examined. Negative correlations between the percentages of granulocytes and Apo-Gs tended to be observed in the MDS patients. These results suggest that a strong susceptibility to peripheral granulocyte apoptosis is one of possible causes of granulocytopenia in MDS patients.

Agranulocytosis↗
PubMed1997

Role of the flocculus in the development of vestibular compensation: immunohistochemical studies with retrograde tracing and flocculectomy using Fos expression as a marker in the rat brainstem.

After unilateral labyrinthectomy in rats, Fos-like immunoreactive neurons appeared in the ipsilateral medial vestibular nucleus, contralateral prepositus hypoglossal nucleus and contralateral inferior olive beta subnucleus. and thereafter gradually disappeared in accordance with the development of vestibular compensation. This finding indicated that the activation of these nuclei is the initial event of vestibular compensation. In the present study, retrograde tracing experiments revealed that these Fos-like immunoreactive neurons project a proportion of their axons to the vestibulocerebellum (uvula-nodulus, flocculus). Before vestibular compensation was accomplished, right, left or bilateral flocculectomy was performed in right-labyrinthectomized rats. All these treatments caused reappearance of unilateral labyrinthectomy-induced behavioral deficits and Fos expression in the left medial vestibular nucleus and right prepositus hypoglossal nucleus. Since floccular efferents are GABAergic, these results indicate that the neurons in which Fos expression was detected by flocculectomy had been inhibited after unilateral labyrinthectomy by floccular Purkinje neurons and that disinhibition of these neurons induced by flocculectomy caused decompensation. Based on our present findings, we propose a hypothesis that the bilateral flocculus serves the restoration of balance between intervestibular nuclear activities to induce vestibular compensation after unilateral labyrinthectomy.

Animals↗
PubMed1997

A new semi-solid agar dilution method for determining amoxycillin, clarithromycin and azithromycin MICs for Helicobacter pylori isolates.

The MICs of amoxycillin, clarithromycin and azithromycin for 26 strains of Helicobacter pylori were determined using Mueller-Hinton semi-solid agar (SSA) without CO2 incubation, as in the conventional agar dilution method. The tested H. pylori strains grew satisfactorily in the SSA method within 48 h of incubation. Reasonable values of MICs of three antibiotics for these strains were obtained by this method, avoiding the inactivation of macrolides due to acidification of the medium. By this method, the MICs of the antibiotics for the reference strains were within the acceptable NCCLS ranges for quality control.

Amoxicillin↗
PubMed1997

[Urease-negative Helicobacter pylori isolates from gastrointestinal mucosa of patients with peptic ulcer].

It is well known that Helicobacter pylori produced a large amount of urease which plays an important role in the maintenance of infection and adhesion. Two thousand three hundred and thirty-one specimens of the gastrointestinal mucosa were obtained from patients with peptic ulcer to isolate H. pylori strains. Of these specimens, 1602 strains of H. pylori were isolated and 7 urease-negative H. pylori strains were found. Biological characteristics (except urease production) of urease-negative H. pylori were in accord with urease-positive reference strains (ATCC strains). Furthermore, these urease-negative strains were confirmed to be H. pylori strains by PCR. These results suggest that the emergence of urease-negative strains pose a new problem for H. pylori infection in patients with peptic ulcer.

Gastric Mucosa↗
PubMed1997

[Gentamicin-induced alteration in drug susceptibility and lipopolysaccharide-composition of Pseudomonas aeruginosa isolates].

Emergency of multi-drug resistance in Pseudomonas aeruginosa isolates after exposure to gentamicin was investigated with reference to their LPS-compositions. Three strains each of P. aeruginosa, different in LPS-compositions (long- and short-LPS strains, and LPS-deficient strain) were once or repeatedly incubated overnight at 35 degrees C in Mueller-Hinton broth including different concentrations of gentamicin, a poly-cationic antibiotic. LPS-compositions of the bacteria which survived and were grown after exposure to gentamicin were analyzed and the susceptibility to some of anti-pseudomonal drugs was determined. Of the test 9 strains after single exposure, No. 4 (long-LPS) and No. 41 (short-LPS) formed the LPS-deficient mutants. The resistance to ceftazidime and gentamicin was found in No. 4 strain, but not in No. 41 strain. Drug resistance in different patterns was also found in Nos. 43, 29, 45 and 52 strains without any change in their LPS-compositions. Contrary to these results, the susceptibility to norflxacin increased in Nos. 21 and 45 strains without any change in their LPS-compositions. After repeated exposures to gentamicin, the LPS-compositions of Nos. 4 and 14 (short-LPS) were altered and formed the LPS-deficient and the Intermediate-LPS (between short and long compositions) mutants, respectively. The LPS-alteration in both strains were accompanied by the development of resistance to ceftazidime and gentamicin, respectively. The drug resistance in different patterns were also found in Nos. 43, 156, 29, 41, 21, 45 and 52 strains, without any change in the LPS-compositions, whereas the increase in susceptibility to norfloxacin was simultaneously found in No. 45 strain. The ionic-binding of [3H]-gentamicin to the cell surfaces of two LPS-deficient mutants of P. aeruginosa decreased markedly, in comparison with that of the respective parents, and these results might lead to the drug resistance in the LPS-deficient mutants. However, the gentamicin-induced resistance of some strains of P. aeruginosa (but no change in the LPS-compositions) to the test drugs including gentamicin indicates a possibility that negative charges on the bacterial surface were decreased by the drug exposure. The drug resistance and LPS-compositions in the gentamicin-induced mutants of P. aeruginosa were stable during or after the 15th in vitro serial transfers.

Anti-Bacterial Agents↗
PubMed1997

[Study of diarrhea-inducing strains of Escherichia coli mainly isolated in Kanto area between June and September 1996].

A total of 21,609 faecal specimens obtained from patients with diarrhea mainly in Kanto area between June and September 1996 were investigated to identify the causative pathogens for diarrhea. One-hundred fifty-seven strains of Escherichia coli of 29 different O-serotypes were isolated as the causative pathogens, which were previously recognized to induce severe abdominal cramps and diarrhea. Of these, 114 strains, in which the possibility of enterohemorrhagic E. coli due to their O-serotypes was predicted, were examined for the producibility of Vero toxins. Twenty-six (76.5%) of the 34 strains of E. coli O157 produced the Vero toxins, and other 8 strains were the non-producers. Twenty of the 26 producers produced both VT1 and VT2, whereas the other 6 strains produced VT2 only. Furthermore, 4 strains of E. coli O26, and 1 strain each of E. coli O125 and O126 produced Vero toxins. Thirty-two of the 114 strains, isolated from the patients with diarrhea and selected as the enterohemorrhagic E. coli according to the specific O-serotypes, were actually confirmed produce Vero toxins. Thirty-four strains of E. coli O157 tested were susceptible to all antibiotics such as ampicillin, doxycylin, levofloxacin, fosfomycin, chloramphenicol and polymyxin B, and no strains resistant to levofloxacin, polymyxin B and fosfomycin were found.

Bacterial Toxins↗
PubMed1997

[Apoptosis in infectious mononucleosis].

Apoptosis of lymphocytes in infectious mononucleosis (IM) was studied. Apoptotic cells (APCs) were defined by morphological characteristics, such as nuclear fragmentation, undergoing apoptosis. Among 10 of 27 IM patients (37.0%) APCs > or = 3 per 500 peripheral white blood cells were observed on admission, but not in normal individuals. Sequential changes of proportions of both APCs and atypical lymphocytes (examined in 2 cases) showed a similar pattern, although APCs began to appear somewhat later and peak level of APCs were lower in comparison with those of atypical lymphocytes. APCs were positive for both anti-T cell and anti-Fas antigen monoclonal antibodies. Fas-positive cells were frequent in the early stage of IM, and returned to the normal range with the decrease of atypical lymphocytes. Sequential analyses of DNA fragmentation, done in one case, revealed that DNA fragmentation appeared with increase of APCs and disappeared with the decrease of APCs. These results suggest that apoptosis of T-cells in IM participates in the reconstitution of a proportion of lymphocytes disturbed by EB virus.

Apoptosis↗
PubMed1996

[Development of multi-drug resistant mutants of clinical isolates of Pseudomonas aeruginosa after exposure to fluoroquinolone].

Eight multi-drug resistant mutants (4.94%) were found in 162 clinical isolates of P. aeruginosa after exposure to norfloxacin at different concentrations (1/4, 1/2, 1, 2 and 4 MICs) and were investigated for the mechanisms of drug resistance. All the mutants were eight-times more resistant to norfloxacin than the respective parents, and showed the cross-resistance to the other fluoroquinolones. However, these mutants differed in the drug-resistant patterns; the 94-74 mutant was resistant to carbenicillin, ceftazidime and chloramphenicol, TA-15 mutant was resistant to imipenem, and the 93-183 was resistant to carbenicillin, ceftazidime and gentamicin. TA-16 mutant only showed a marked decrease in the bacterial uptake of norfloxacin. Profiles of the outer membrane proteins of the mutants were analyzed by SDS-PAGE method. The six mutants, except for TA-52 and 93-183 mutants, increased the intensity of bands in the 46 KD region. Three mutants (TA-15, TA-16 and 93-183) decreased the intensity of 44 KD (OMPE) and also the former two decreased the intensity of 22 KD (OMP G). The gryA mutations associated with fluoroquinolone-resistance were investigated for the eight mutants, and the 93-183 mutant showed to have the gyrA mutation caused by the alteration in the amino acid sequence of gyrA; Thr-83 (ACC) to Ile (ATC). The result of the present study indicate that multi-drug resistance of clinical isolates of P. aeruginosa develops through different types of mechanisms, and is not easily explained fully by the present results, and suggest that many factors attributed to the development of the resistances in those mutants remains to be clarified.

Anti-Infective Agents↗
PubMed1996

[Drug-resistance patterns and biological properties of MRSA isolated from different geographical areas of Japan].

One hundred isolates of methicillin-resistant Staphylococcus aureus (MRSA) collected from hospitals located in different geographical areas of Japan were used in the present study. The susceptibilities of the strains to gentamicin (GM), erythromycin (EM), tetracycline (TC) and ofloxacin (OFLX) were determined and classified into twelve groups according to their differences in the patterns of the resistance to the four drugs. Of the 100 strains tested, 75 belonging to the main four groups were investigated for the relationships between their patterns of the drug-resistance and biological properties such as coagulase, enterotoxin and phage types, TSST-1 and beta-lactamase producibilities, and percentages of the strains carrying plasmids of large size (> or = 20,000 bp). The main four patterns of drug resistance of the 75 strains were as follows: the first group (33 strains resistant to GM, EM, TC and OFLX), the second group (15 strains resistant to EM, TC and OFLX), the third group (11 strains resistant to GM, EM and OFLX) and the fourth group (16 strains resistant to EM and OFLX) and the remaining 25 strains were divided into further groups. A considerable number of the strains in the third group differed markedly in some biological properties from those in the other groups; coagulase typing (III type-50%: the other groups-II type), enterotoxin typing (64%-non-production: the other groups-C type), TSST-1 producibility (36%-production: the other groups-76 to 88%-production) and phage typing (55%-non-typable: the other groups-80 to 97%-non-typable). In beta-lactamase and plasmids of large size, the first group consisted of the strains with beta-lactamase producibility at the ratio of 50:50, but the other groups consisted of most of the strains with the beta-lactamase producibility. Most of the strains belonging to the second and fourth groups carried large size of plasmids, but 36 and 46% of those belonging to the first and third groups did not carry them. On the other hand, our results of the susceptibility test for the 100 strains showed that a considerable number of strains were susceptible to GM (35%) and TC (42%) at therapeutically significant concentrations.

Anti-Bacterial Agents↗
PubMed1996

[Drug-resistance patterns of clinical isolates of Pseudomonas aeruginosa in regard to their lipopolysaccharide-chain sizes].

Pseudomonas aeruginosa strains isolated from patients with different types of the infections each consisted of LPSs different in chain sizes. The drug-susceptibility patterns of these strains of P. aeruginosa were investigated to clarify the relationship between the LPS-compositions and susceptibility to some kinds of anti-pseudomonal drugs. The susceptibilities of nineteen strains (seven long-LPS strains, four short-LPS strains and eight LPS-deficient strains) to piperacillin, ceftazidime, gentamicin, norfloxacin and polymyxin-B were determined and these strains were classified into six types (Types I-VI) according to their drug-resistance patterns. Six of the eight LPS-deficient strains were found to be highly resistant to gentamicin alone (Type IV). Four of the seven strains with the long-LPS and one strain with the short-LPS were resistant to three drugs such as piperacillin, ceftazidime and norfloxacin, and classified into Type I. These results indicated that the major part of the LPS-deficient strains and the considerable part of the long-chain LPS strains of P. aeruginosa tested had each characteristic profile in the drug resistance. The outer membrane proteins of thirteen strains, consisting of different types of LPS compositions, were analyzed by SDS-PAGE. The strains belonging to the same types of the drug-resistance patterns were found to have similar OMP-profiles, although a few exceptions were found. beta-lactamase and gentamicin-inactivating activities were determined for piperacillin-resistant and gentamicin-resistant strains, respectively. Of the piperacillin-resistant strains tested, the activity of beta-lactamase was high in one (No. 8) only, low in four and not found in four. The results showed that degrees of resistance of P. aeruginosa strains tested to piperacillin did not correlate to their producibility of beta-lactamase except one strain. Of the nine gentamicin-resistant strains tested, the gentamicin inactivating activity was high in one (No. 30) only, moderate in six and low in two. These results suggested that the significant levels of piperacillin- or gentamicin-resistance of P. aeruginosa isolated tested might be expressed each due to their decreased abilities for drug-permeabilities in addition to drug-inactivating activities such as beta-lactamase or gentamicin-modifying enzyme. In the case of some resistant strains, the resistance to piperacillin or gentamicin was not explained by the results of the present study. Therefore, we must investigate the possibility that other mechanisms participate in the resistance of these strains.

Drug Resistance, Microbial↗
PubMed1996

[Relationship of intracellular concentration and duration of contamination of pirarubicin and adriamycin in human bladder cancer cell lines and human bladder normal mucosa cell line].

To establish a method for reasonable clinical use of adriamycin (ADM) and pirarubicin (THP) in the intravesical chemotherapy for superficial bladder cancer, intracellular concentrations of these drugs were examined in culture cell lines (T-24, T-24/ADM and FHS736b1) with variable durations of contamination. The intracellular concentration of THP showed a plateau at 15-30 min. contamination in T-24, and in T-24/ADM, and showed the time dependence of contamination in FHS736b1, human normal bladder mucosa cell line. The intracellular concentration of ADM showed the time dependence of contamination in T-24, T-24/ADM and FHS736b1. And these concentrations of THP were 20 times higher than those of ADM. In conclusion, it seems better that THP was retained for 5-15 min. in the bladder in the intravesical chemotherapy, from the point of view of drug efficacy and preventing side effects. And it seems good that ADM was retained for more than 30 min. in the case with drug sensitive tumors.

Antibiotics, Antineoplastic↗
PubMed1996

[Unclassified chronic myeloproliferative disorder (Ph negative/bcr rearrangement negative CML) with late appearing Philadelphia like chromosome].

A 48-year-old male was diagnosed to be unclassified chronic myeloproliferative disorder (UCMPD)/Ph negative bcr rearrangement negative (Ph-/bcr-) CML by hematological, cytogenetical and DNA analyses (Jpn. J. Clin. Hematol. 33(4): 525-531, 1992). Three years and a half after the diagnosis of UCMPD/Ph-bcr- CML, Ph chromosome was observed in 17 of 20 examined cells. Hematological findings showed a transformation into blast crisis. The late appearing of Ph in a case of UCMPD/Ph1-bcr- CML described here is rare. Southern blot analysis using 3' and 5' bcr probe showed no bcr rearrangement. Analyses of BCR/ABL chimeric RNA by RT-PCR method were negative in both of Major- and Minor BCR/ABL chimeric RNA. In the present case it is speculated that Ph is developed as the result of multistep progression and also speculated that the breakpoint at BCR gene differs from Major- and Minor-bcr in usual Ph+CML and de nove Ph+ ALL. Therefore, it may be reasonable that the present case is understood to be a case with late appearing Ph-like chromosome.

Base Sequence↗
PubMed1995

Effects of MK801 on Fos expression in the rat brainstem after unilateral labyrinthectomy.

Unilateral labyrinthectomy (UL) causes ocular and postural asymmetries, which disappear over time in the processes of equilibrium recovery known as vestibular compensation. It has been reported that N-methyl-D-aspartate (NMDA) receptors are involved in vestibular compensation. In the present study, in order to elucidate the NMDA receptor-mediated neural circuit responsible for the development of vestibular compensation, we used Fos expression as a marker of neural activation and examined the effects of MK801, a specific antagonist of NMDA receptors, on UL-induced Fos expression in the rat brainstem. After UL, Fos-like immunoreactive (-LIR) neurons were observed in the ipsilateral medial vestibular nucleus (ipsi-MVe), the contralateral prepositus hypoglossal nucleus (contra-PrH) and the contralateral inferior olive beta subnucleus (contra-IOb). Fos-LIR neurons gradually disappeared in the processes of vestibular compensation. It is suggested that the activation of the ipsi-MVe, the contra-PrH and the contra-IOb neurons after UL are the initial event of vestibular compensation. Intraperitoneal injection of MK801 in the processes of vestibular compensation caused reappearance of UL-induced behavioral deficits. During the decompensation induced by MK801, Fos-LIR neurons appeared in the contra-MVe, the ipsi-PrH and the bilateral-IOB. It is suggested that the contra-MVe, the ipsi-PrH and the bilateral-IOb neurons are inhibited by glutamatergic synapses driving inhibitory neurons via NMDA receptors in the processes of vestibular compensation and that disinhibition of these nuclei induced by MK801 causes decompensation. However, MK801 caused neither Fos expression nor behavioral decompensation after vestibular compensation is accomplished. All these findings that the NMDA receptor-mediated inhibitory modulation in the central vestibular system plays an important role for the initial processes of the development of vestibular compensation.

Amino Acid Sequence↗
PubMed1995

Epidemiological investigation of insulin resistance syndrome (syndrome X) in a city in Japan.

1. In order to study the prevalence of insulin resistance syndrome (syndrome X) in Japanese subjects, inhabitants aged above 40 years living in Osaka-Sayama city from September 1992 through December 1993 were investigated. The population-based study was performed on 2498 subjects (661 males and 1837 females) constituting 10.9% of the total population aged above 40 years. 2. The prevalence of glucose intolerance was 8.7% (n = 218) in 2498 subjects. The prevalence of hypertension was 36.9% (n = 923) and that of hypertriglyceridaemia was 19.0% (n = 475). The prevalence of syndrome X as characterized by an association of glucose intolerance, hypertension and hypertriglyceridaemia was 1.6% (n = 39) in all subjects examined and 17.4% in subjects showing glucose intolerance. 3. Fasting serum insulin levels were significantly higher in patients with syndrome X than in normal subjects. Furthermore, the levels were significantly correlated with blood levels of frucutosamine, fasting glucose and triglyceride, and with body mass index as well. 4. In conclusion, insulin resistance syndrome (syndrome X) is also found among the larger Japanese population, and fasting serum insulin levels can be a useful marker of this metabolic disorder.

Adult↗
PubMed1995

[Heterogeneity of lipopolysaccharide chain size of Pseudomonas aeruginosa isolated from different clinical sources--with reference to gentamicin-susceptibility and serotype].

Lipopolysaccharide (LPS) compositions of P. aeruginosa isolated from from clinical sources such as blood, urine, pus, sputum, and feces were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and aminoglycoside-susceptibility and serotype of these isolates were investigated in this study. Fifty-nine isolates tested were divided into three groups according to the difference in their LPS compositions; 35 strains with the long-LPS chain (B-band LPS), 14 strains with the short chain (A-band LPS) and 10 LPS-deficient strains. The relationship between the LPS compositions and their sources of 59 strains were investigated. The majority of clinical isolates (12 of the 13 strains) from the blood samples possessed the long-LPS chain (B-band LPS) and the remaining possessed the short-LPS chain (A-band LPS). About 67% each of the isolates from urine and feces possessed the long-LPS chain, and the minor part of both groups possessed the short-LPS chain. In isolates from both sputum and pus samples, the long- and short-LPS chains were found at almost the same rate, and the LPS-deficient isolates were found in the sputum samples at a considerably high rate of 42%. The 19 of the 35 isolates with the long-LPS chain were susceptible to gentamicin (54%) and 12 isolates were resistant (34%). On the other hand, the 14 isolates with the short chain were divided roughly into three groups, gentamicin-resistant, and -susceptible groups and intermediate groups. It was also notable that 7 of the 10 LPS-deficient isolates were resistant to gentamicin.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug Resistance, Microbial↗
PubMed1995

Changes in Fos and Jun expression in the rat brainstem in the process of vestibular compensation.

By means of immunohistochemical technique, we examined the changes in Fos and Jun expression after unilateral labyrinthectomy (UL) in the rat brainstem. We observed Fos-like immunoreactivity (-LIR) in the ipsilateral medial vestibular nucleus (ipsi-MVe), the contralateral prepositus hypoglossal nucleus (contra-PrH) and the contralateral inferior olive beta subnucleus (contra-IOb) 1 h after UL. Then, Fos expression in the contra-PrH and the contra-IOb disappeared 3 days after surgery. However, we still found the residual expression in the ipsi-MVe, which disappeared within 7 days. On the other hand, no Jun-LIR was detected in the vestibular or vestibular-related nuclei before or after the operation. Fos expression in the MVe, PrH and IOb was induced immediately after UL. Then, the Fos expression disappeared in accordance with the development of the vestibular compensation. These findings suggest that the transient Fos expression in the vestibular and vestibular related nuclei is a trigger of vestibular compensation.

Animals↗