Biomedical subjects

Y Aikawa

Publications and source records attributed to Y Aikawa.

At least 37 records · Page 2Linked to original sources

PubMed1997

Competitive PCR quantification of pro- and anti-inflammatory cytokine mRNA in the central nervous system during autoimmune encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory disease of the central nervous system that can be induced by immunization with myelin basic protein (MBP)/complete Freund's adjuvant and serves as a model for multiple sclerosis. Recent studies have suggested that cytokines play a crucial role in the clinical course of EAE. To clarify the roles of cytokines in EAE, we examined levels of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta1 (TGF-beta1) and interleukin-10 (IL-10) mRNA in isolates from infiltrating inflammatory cells in EAE lesions induced in Lewis rats. The non-radioactive and sensitive competitive PCR method was employed to quantify the relative amounts of cytokine mRNA. Levels of both IFN-gamma and TNF-alpha mRNA were increased at the early stage of EAE and rapidly decreased at the peak stage. On the other hand, TGF-beta1 mRNA was demonstrated throughout the course of EAE as well as under normal conditions and its amount paralleled the severity of EAE. IL-10 mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR) under normal conditions, but was below the level of detection of competitive PCR. IL-10 mRNA expression peaked at the early stage of EAE and declined gradually thereafter. Taken together, these results suggest that IFN-gamma and TNF-alpha might play a crucial role in the development of EAE. Furthermore, it appears that the peak expression of IL-10 mRNA at the early stage and the following marked TGF-beta1 expression at the peak stage might represent an important endogenous mechanism to limit the extent of inflammation and to prevent relapse in the course of acute monophasic EAE.

Animals↗

PubMed1997

Further studies on thermal denaturation of pyruvate dehydrogenase complex from Bacillus stearothermophilus.

Thermally induced changes in pyruvate dehydrogenase complex (PDC) from B. stearothermophilus were examined mainly at temperatures from 60 degrees to 70 degrees C. Accompanied by inactivation of pyruvate decarboxylase, light scattering decreased, and ANS fluorescence increased. These changes including the inactivation were approximately first-order reactions, and the values of rate constants were greatly dependent on temperature. Chromatographic studies showed that any polypeptides were in associated forms and that final products were aggregates (> 230S) and an assembly (48S) smaller than PDC. The aggregates and assembly were rich in decarboxylase and lipoate acetyltransferase, respectively. It was suggested that, during the thermal denaturation, a decarboxylase was dissociated from PDC and immediately involved in aggregates.

Chromatography, Gel↗

PubMed1995

Late rectal complication following high dose rate intracavitary brachytherapy in cancer of the cervix.

PURPOSE: To examine the incidence of radiation-induced late rectal complications using a rectal reference point in patients with cancer of the uterine cervix. METHODS AND MATERIALS: The subjects were 253 patients with cancer of the cervix who underwent high dose rate intracavitary brachytherapy (HDR-ICR). The rectal point (RP) was defined according to the criteria recommended in the ICRU Report 38. The time-dose factor (TDF) and the biologically effective dose (BED) were calculated as components of the cumulative reference rectal dose using the rectal reference point dose in intracavitary brachytherapy combined with the external whole pelvis dose. RESULTS: Statistical comparison of factors affecting the incidence of late rectal complication was conducted using data for 161 patients. The incidence of late rectal complications in the 161 patients was 9 patients (5.6%) for grade 1, 51 patients (31.7%) for grade 2, 11 patients (6.8%) for grade 3, and 13 patients (8.1%) for grade 4. The TDF and BED values were significantly correlated with the incidence of late rectal complication, and also showed strong correlation (r = 0.976) with each other. Grade 4 rectal complication was not observed in any patients with TDF below 130 or BED below 147. The calculated incidence of complications ranged from 5 to 10% at TDF values from 104 to 124 and at BED values from 119 to 146. CONCLUSION: These data regarding the incidence of rectal complication may be useful in reducing the incidence of late rectal complications arising after HDR-ICR treatment of cervical uterine cancer by adjusting the dose per fraction and number of fractions of HDR-ICR in individual patients and by improving the technique of inserting the intracavitary radiation apparatus.

Female↗

PubMed1995

Homogeneity of the pyruvate dehydrogenase multienzyme complex from Bacillus stearothermophilus.

The pyruvate dehydrogenase multienzyme complex was purified from Bacillus stearothermophilus by means of six gel-filtration column chromatographies; once on Cellulofine GCL-2000, twice on Sepharose CL-2B, and three times on Sephacryl S-500HR. The molecular size distribution of the complex was examined in detail by gel-filtration chromatography, analytical and sucrose-density ultracentrifugations, and dynamic light scattering. The complex was found to be homogeneous; a dimeric complex was undetectable even with a high concentration of protein (below 6.8 mg/ml).

Centrifugation, Density Gradient↗

PubMed1995

T-614, a novel antirheumatic drug, inhibits both the activity and induction of cyclooxygenase-2 (COX-2) in cultured fibroblasts.

To elucidate the mechanism for the selective inhibition of prostaglandin E2 (PGE2) production in inflammatory tissue by T-614 (3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-o ne), its effects on both the activity and the induction of cyclooxygenase (COX)-2 were investigated in vitro. T-614 inhibited the activity of purified COX-2 enzyme (IC50: 7.7 micrograms/ml), but was inactive against both COX-1 activities of microsomal and purified enzymes (IC50: > 300 micrograms/ml). On the other hand, when the inhibition of PGE2 production by T-614 was examined in the cultured fibroblasts stimulated with bradykinin, T-614 at 1 microgram/ml or less inhibited PGE2 release more effectively than that in the above cell-free system. Therefore, we examined which of the COX enzymes was expressed in bradykinin-stimulated fibroblasts by using both the reverse transcriptase-polymerase chain reaction (RT-PCR) and Northern blot analyses. As a result, COX-1 mRNA was constitutively expressed in the cells, whereas COX-2 mRNA was not detected without stimulation with bradykinin, but was expressed within 30 min when stimulated. Furthermore, it was found that the addition of T-614 reduced the COX-2 mRNA levels in 30 min after stimulation. These studies suggest that at least some of inhibitory effects of T-614 on prostanoids production are mediated by the synergy of the inhibition of COX-2 activity and the inhibition of induction, and such an action of T-614 may explain the pharmacological properties of this drug.

3T3 Cells↗

PubMed1995

[General pharmacology of T-3761, a new oral quinolone antibacterial agent (1). Effect on the central nervous system].

General pharmacological effects of T-3761, a new oral quinolone antibacterial agent, on the central nervous system were investigated in laboratory animals. The results obtained are summarized as follows. 1. T-3761 exerted no significant effects on spontaneous motor activity, motor coordination, pentobarbital-induced hypnosis, electroshock-, pentetrazole- or strychnine-induced convulsion, acetic acid-induced writhing responses, reserpine-induced hypothermia and ptosis in mice at oral doses of 100, 300 and 1,000 mg/kg. The same oral doses of T-3761 exerted no significant effects on body temperature and passive avoidance response in rats. 2. T-3761 had no effects on EEG in cats and spinal reflex in rats at intravenous doses of 10, 30 and 100 mg/kg. 3. Convulsions were not observed in mice after any oral combinations of T-3761 at a dose of 200 or 1,000 mg/kg with 14 different nonsteroidal anti-inflammatory drugs (NSAIDs) including fenbufen. 4. An oral combination of T-3761 even at a higher doses of 3,000 mg/kg with 4-biphenylacetic acid (BPAA) which is a principally active metabolite of fenbufen also did not induce convulsions in mice. 5. T-3761 did not inhibit GABA receptor binding in rat brain synaptic membranes at 10(-4) M in either the absence or presence of BPAA. These results suggest that T-3761 is an antibacterial agent which would be unlikely to produce any side effects on the central nervous system and to produce convulsion when combined with NSAIDs in clinical use.

Animals↗

PubMed1994

Detection of bacteria in phagocyte-smears from septicemia-suspected blood by in situ hybridization using biotinylated probes.

We report herein the detection of intracellular bacteria in phagocyte-smears obtained from septicemia-suspected blood samples by in situ hybridization. This was obtained by using nick-translated biotin-11-dUTP-labeled DNA probes and streptavidin-alkaline phosphatase conjugates for visualization of the hybridized signals. The probes were made from random genomic DNA clones of bacteria which are frequently the causative agents of bacteremia, such as Staphylococcus spp., Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli, Klebsiella spp. and Enterobacter spp. When our in situ hybridization method was compared with conventional culture protocols for the ability to detect bacteria from the blood of patients suspected of having septicemia, 30 positive results were obtained in 50 specimens by in situ hybridization methods. In contrast, only 7 positive results were obtained by blood cultures. Thus, even if bacteria cannot be detected by conventional blood cultures and histology, our in situ hybridization method allows for direct observation of bacterial foci in circulating phagocytes and identification of the bacteria. Our investigations suggest that in septicemia, circulating polymorphonuclear neutrophils carry some surviving bacteria as well as metabolized bacterial DNA and RNA for a considerable period of time. Thus, our in situ hybridization method using the phagocyte-smears have diagnostic value for detecting most bacteria which cause septicemia.

Bacteremia↗

PubMed1994

Transconjunctival and transantral approaches are combined with antral wall bone graft to repair orbital floor blow-out fractures.

Orbital floor blow-out fractures in two patients were surgically repaired. The transconjunctival approach alone was unsuccessful in freeing the entrapped orbital contents, so the transantral approach with the use of antral wall bone graft was also used. The combined approaches produced good results. The transconjunctival approach supplemented with the transantral approach and bone graft may be a useful technique in the repair of orbital floor blow-out fractures.

Adolescent↗

PubMed1994

Detection of Staphylococci in mouse phagocytic cells by in situ hybridization using biotinylated DNA probes.

In situ hybridization was used to detect intracellular Staphylococcus aureus and S. epidermidis in mouse phagocytic cells after experimental infection of C3H mice with Staphylococci via abdominal or intravenous injection. Isolated ascites or whole blood were tested by the phagocyte smear technique, using bacteriolytic enzymes to preserve phagocytic cell morphology. The exposed bacterial DNA was visualized as intracellular hybridized signals by use of biotinylated DNA probes and by immunocytochemistry using streptavidin-alkaline phosphatase conjugates as detector molecules. These DNA probes, prepared from randomly cloned genomic DNA fragments of S. aureus and S. epidermidis, were strain-specific and did not cross-hybridize either in situ or on dot-blot hybridization. This technique of in situ hybridization with phagocyte smears is useful for detection and diagnosis of intracellular bacteria regardless of viability.

Animals↗

PubMed1993

Skin barrier defect in atopic dermatitis: increased permeability of the stratum corneum using dimethyl sulfoxide and theophylline.

The existence of a defect in the skin barrier of patients with atopic dermatitis (AD) was demonstrated and its importance in the pathogenesis of AD was emphasized. In order to evaluate the penetration properties of the stratum corneum of AD patients, the in vivo skin response to the penetration of dimethyl sulfoxide (DMSO) and in vitro response to the penetration of theophylline utilizing a diffusion chamber were studied. Both methods demonstrated an increasing level of penetration through the epidermal stratum corneum, with greatest penetration being evident with lesional skin, followed by AD non-lesional and then the normal control. However, statistical significances existed only between non-lesional and lesional skins in the case of the DMSO test, and between the normal control and non-lesional skin in the case of the diffusion chamber analysis using theophylline. Increased penetration of a non-specific nature is important in the pathogenesis of AD.

Adolescent↗

PubMed1993

A proposed guideline for psoralen photochemotherapy (PUVA) with atopic dermatitis: successful therapeutic effect on severe and intractable cases.

Psoralen photochemotherapy with UVA (PUVA) has been reported to be successfully substitutional for, or an adjunct to, conventional treatments in patients with atopic dermatitis (AD). Against the considerable advantages of utilizing PUVA for AD patients, however, it must also be balanced against the possible hazards for individual patients. We attempted herein to formulate a guideline for the selection of AD patients assigned to PUVA. According to this guideline, 114 patients were selected for PUVA treatment. Forty-five percent of the patients did not respond adequately to other conventional forms of treatment. Side effects from former treatments, particularly steroids, appeared in 39% of the patients. Subsequent to the treatments, the skin lesions significantly decreased in 81% of the inpatients and 67% of the outpatients, while some patient's lesions disappeared, despite that other forms of treatment had been unsuccessful in many cases.

Dermatitis, Atopic↗

PubMed1993

Completely thrombosed giant fusiform aneurysm in a young patient--case report.

A completely thrombosed giant fusiform aneurysm of the peripheral anterior cerebral artery occurred in a 16-year-old female, with a familial and personal history of vascular headache for 4 or 5 years. She was admitted in a drowsy state with severe headache. Computed tomography revealed subarachnoid hemorrhage and intracerebral hemorrhage as a mottled and ring-like high-density area in the left paramedian frontal lobe not enhanced postcontrast. Left carotid angiography demonstrated an avascular mass and a 5 cm defect in the A3 portion of the anterior cerebral artery. The rupture of the giant fusiform aneurysm was confirmed intraoperatively.

Adolescent↗

PubMed1992

Pharmacological studies on 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-one (T-614), a novel antiinflammatory agent. 4th communication: inhibitory effect on the production of interleukin-1 and interleukin-6.

In vitro effects of 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-on e (T-614), a novel antiinflammatory compound, on the production of interleukin-1 (IL-1) and/or interleukin-6 (IL-6) by human monocytes and the THP-1 cells of a human monocytic cell line, were examined. T-614 inhibited the release of immunoreactive IL-1 beta from these cells stimulated with lipopolysaccharides (LPS) in a dose-dependent manner (0.3-30 micrograms/ml). The release of IL-6 from THP-1 cells, as determined by the assays for its hepatocyte-stimulating activities and immunoreactivities, was inhibited by T-614 with the IC50 values of 2.0 and 6.6 micrograms/ml, respectively. Northern blotting analysis using LPS-stimulated THP-1 cells indicated that the inhibitory effect of T-614 on IL-1 beta production is caused by the suppression of IL-1 beta mRNA expression. The inhibition of cytokine production by T-614 may provide an important insight into the additional mechanisms contributing to its antiinflammatory activities.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1992

Pharmacological studies of the new antiinflammatory agent 3-formylamino-7-methylsulfonylamino-6-phenoxy-4'-1-benzopyran-4-o ne. 2nd communication: effect on the arachidonic acid cascades.

The in vitro and in vivo effects of 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-on e (T-614, CAS 123663-49-0), a new antiinflammatory agent, on arachidonic acid metabolism were investigated in comparison with those of reference drugs. Although the inhibitory effect of T-614 on the synthesis of prostaglandins by rabbit renal microsomes was very weak (IC50 of 58 micrograms/ml), T-614 effectively inhibited the prostaglandin E2 (PGE2) generation by mouse fibroblasts stimulated with bradykinin with an IC50 value of 0.47 micrograms/ml. The suppressive effect of T-614 on the PGE2 generation in fibroblasts was also found when cells were stimulated with Ca ionophore A23187, but not when induced with arachidonic acid. T-614 suppressed the A23187-induced PGE2 generation by rat macrophages, but not the leukotriene B4 production. In addition, 5-lipoxygenase activities in guinea-pig peritoneal exudated cells were not inhibited. In in vivo experiments, at doses of more than 1 mg/kg, T-614 reduced the PGE2 contents in inflammatory exudate of rat carrageenin-sponge type inflammation, but it was almost inactive in inhibiting gastric prostaglandins production up to 100 mg/kg. T-614 also did not affect the urinary PGE2 excretion in rats, and slightly inhibited the thromboxane synthesis in rat blood. Furthermore, the convulsion-induced increase of PGE2 in mouse brain was inhibited by T-614. These data suggest that T-614 inhibits the production of cyclooxgenase-mediated products with apparently different mode from classical non-steroidal antiinflammatory drugs, and may partly explain the discrepancy in pharmacological properties between this compound and other drugs.

Animals↗

PubMed1992

Pharmacological studies of the new antiinflammatory agent 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-o ne. 1st communication: antiinflammatory, analgesic and other related properties.

The antiinflammatory, analgesic and antipyretic activities of 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-on e (T-614, CAS 123663-49-0) were investigated in various animal models and compared with those of nimesulide, indomethacin and ibuprofen. The antiinflammatory potency of T-614 on carrageenin-induced paw edema, paper disk granuloma and established adjuvant arthritis was greater than that of ibuprofen, but slightly lower than those of nimesulide and indomethacin. In acute inflammatory models, unlike indomethacin, T-614 suppressed the edemas provoked by dextran and bromelain in rats, but its inhibitory action on ultraviolet erythema in guinea-pigs was weak. Although the analgesic activity of T-614 was hardly demonstrated in writhing tests in mice, its potency against the inflammatory pain such as Randall-Selitto test, adjuvant-induced hyperalgesia and antigen-induced arthritic pain in rats was superior to that of ibuprofen. Moreover, it had a potent analgesic effect on urate-induced synovitis in dogs. T-614 exerted a prompt and strong antipyretic effect in both yeast-induced febrile rats and lipopolysaccharide-induced febrile rabbits. T-614 had virtually no gastrointestinal ulcerogenic action and did not affect water and sodium excretion in rats. T-614 is a novel antiinflammatory compound with different pharmacological properties from that of the reference drugs.

Animals↗

PubMed1991

Antikeratin 14 monoclonal antibody staining in psoriasis and seborrhoeic keratosis: immunofluorescence and two colour FACS studies.

A monoclonal antibody (ES3A) was raised against a mouse graft-versus-host reaction (GVHR) model. This antibody was against basal cell cytoplasm and reacted with an acidic (pI 6.2) 50 kDa keratin of human epidermis. However, ES3A reacted with several lower layers of epidermal cells in psoriasis and seborrhoeic keratosis. Acanthotic seborrhoeic keratosis showed varying patterns even in a single lesion. If combined with FACS analysis, ES3A-positive cells could be quantified. Normal skin showed 28%, while psoriasis and seborrhoeic keratosis showed 44% and 51%, respectively. ES3A-positive compartments of the acanthotic type of seborrhoeic keratosis were larger than those of the hyperkeratotic type. ES3A may be suitable for quantification of germinative or proliferative cells.

Animals↗

PubMed1991

Topical psoralen photochemotherapy for atopic dermatitis: evaluation of two therapeutic regimens for inpatients and outpatients.

Forty-seven adolescent and adult patients suffering from long-standing atopic dermatitis (AD) too severe to respond to conventional therapies were treated with topical psoralen photochemotherapy (PUVA) and relatively low doses of ultraviolet (UV) irradiation. For practicality and convenience, two different therapeutic regimens were implemented; short-term hospitalization with almost daily irradiation (inpatient group, n = 23) and weekly irradiation combined with topical corticosteroids which had failed to manage symptoms before initiating the treatment (outpatient group, n = 25). Excellent therapeutic effects were achieved in 72% of the inpatients after 5-38 (mean 18.2) times of irradiation (mean cumulative dose; 44.7 J/cm2). In addition, 56% of outpatients responded excellently to the treatment after 6-22 (mean 13.0) times (mean cumulative dose; 25.8 J/cm2). In fact, 16 of the inpatients and 10 of the outpatients achieved almost complete remission. The duration of remission in these patients was 1-25 months (mean 6.3 months) in the inpatients and 1-6 months (mean 3.0 months) in the outpatients. Peripheral blood eosinophils significantly decreased after the treatments. A follow-up study showed a delayed decrease in serum IgE levels. In contrast, the specific IgE to house dust antigens and the water holding capacity of stratum corneum did not vary after treatment.

Adolescent↗

PubMed1991

HLA-DR antigen expression on peripheral T cell subsets in pityriasis rosea and herpes zoster.

Using 2-color fluorescein-activated cytometric analysis, HLA-DR antigen expression on peripheral blood T cell subsets was studied in patients with herpes zoster (HZ), pityriasis rosea (PR) and psoriasis. In HZ and PR, HLA-DR was found to be significantly expressed on T cell surfaces (CD3+ cells), when compared to that of the normal control (HZ: p less than 0.001, PR: p less than 0.05). Among T cell subsets, such HLA-DR antigen was predominantly expressed on suppressor/cytotoxic cells (CD8+) in HZ (vs. normal control, p less than 0.01). However, in the case of PR, it was predominantly expressed on helper cells (CD4+; vs. control, p less than 0.05). On the other hand, activated T cell antigen (CD25+) was not significantly expressed on T cells (CD3+) in either HZ or PR. In the T cell subsets, HLA-DR antigen expression returned to normal levels during the recovery phases of HZ and PR.

Adult↗