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Biomedical subjects

Y Kondo

Publications and source records attributed to Y Kondo.

At least 325 records · Page 18Linked to original sources
PubMed1997

Comparison of concentrations of Cry j 1 and Cry j 2 in diploid and triploid Japanese cedar (Cryptomeria japonica) pollen extracts.

Japanese cedar (Cryptomeria japonica) possibilities has been a serious allergic disease in Japan. There are two kinds of Japanese cedar trees; the popular one is diploid, the less popular is triploid. These trees are not very different morphologically. However, the relative allergenicity of their pollens is unknown, although both major allergens, Cry j 1 and Cry j 22, have been purified and cloned from the diploid line. Triploid trees are sterile and the allergenicity of their pollen may differ. Using Japanese-cedar-allergic patient sera, we compared the concentration of these two major allergens in both kinds of pollen. Pollen collected from different years and regions was also studied. The results indicate that triploid tree pollen extract has lower concentrations of both major allergens; therefore, the pollen may be less allergenic.

Allergens↗
PubMed1997

Enhanced apoptosis in metallothionein null cells.

Metallothioneins (MTs) are major intracellular, zinc-binding proteins with antioxidant properties. Mouse embryonic cells null for MT due to loss of functional MT I and II genes (MT-/-) were more susceptible to apoptotic death after exposure to tert-butyl hydroperoxide or the anti-cancer agents cytosine arabinoside, bleomycin, melphalan, and cis-dichlorodiammineplatinum(II) compared with wild-type mouse embryonic cells (MT+/+). We measured basal levels of the tumor suppressor protein p53 and the death effector protein Bax and found the basal levels of both proteins were higher in MT null cells compared with MT+/+ cells. After treatment with the DNA-damaging agent cis-dichlorodiammineplatinum(II), p53 protein levels were induced in both MT+/+ and MT-/- cells with MT null cells always maintaining the highest p53 levels. The elevated sensitivity to apoptosis was not restricted to embryonic cells. Primary pulmonary fibroblasts were isolated from distinct litters of MT null, heterozygous, and wild-type mice, and all had undetectable basal MT levels. Zinc exposure increased MT levels in the wild-type and heterozygous fibroblasts but not in the MT null fibroblasts. Consistent with the induced MT levels, we found MT+/+ and MT+/- embryonic cells were less sensitive to cis-dichlorodiammineplatinum(II)-induced apoptosis compared with MT-/- cells. Our results implicate MT as a stress-responsive factor that can regulate apoptotic engagement.

Animals↗
PubMed1997

Mitomycin C dissolved in a reversible thermosetting gel: target tissue concentrations in the rabbit eye.

AIMS: To determine whether a new, reversible thermosetting gel enhances mitomycin C transfer to target ocular tissues in the rabbit eye. METHODS: A 0.1 ml solution of mitomycin C containing 0.22 microgram, 2.9 micrograms, or 28 micrograms of the agent dissolved in a reversible thermosetting gel consisting of methylcellulose, citric acid, and polyethylene glycol was injected subconjunctivally in 30 New Zealand albino rabbits. Scleral and conjunctival tissues were excised at 0.5, 1, 2, 4, or 24 hours after the injection and mitomycin C concentrations in these tissues were determined by high performance liquid chromatography. The concentration over time was approximated to a single exponential curve, and initial mitomycin C concentrations, time constants, and half life values were determined. Finally, the areas under the curves (AUCs) between 0.5 and 24 hours were calculated. RESULTS: The mitomycin C concentrations in the target tissues were dose dependent and decreased rapidly over 24 hours. Both the initial mitomycin C concentrations as well as AUCs in these eyes treated with mitomycin C, dissolved in a reversible thermosetting gel, were higher than those in eyes treated similarly in a previous study in which the gel was not used. CONCLUSION: Applied subconjunctivally in the rabbit eye, mitomycin C dissolved in the reversible thermosetting gel enhanced transfer of the agent to the sclera and the conjunctiva.

Animals↗
PubMed1997

Inhibition of TSH-induced hydrogen peroxide production by TNF-alpha through a sphingomyelinase signaling pathway.

Tumor necrosis factor-alpha (TNF-alpha) has been suggested to be related to the pathogenesis of autoimmune thyroid diseases, nonthyroid illness, and other thyroid dysfunctions induced by infectious diseases. In relation to these, in vitro studies demonstrated that TNF-alpha influences growth and/or differentiated functions mediated by thyroid-stimulating hormone (TSH), including 125I organification. In the present study, we found that TNF-alpha inhibits TSH-induced H2O2 production, which is an inevitable process for iodide organification, and hence thyroid hormone synthesis, in FRTL-5 thyroid cells. In the cells, TNF-alpha induced ceramide production and the addition of exogenous ceramide or sphingomyelinase treatment of the cells simulated TNF-alpha actions. Although TSH stimulation of H2O2 production is mediated by the phospholipase C (PLC)-Ca2+ pathway, TNF-alpha and exogenous and endogenous ceramide affected neither TSH-dependent PLC activation and Ca2+ mobilization nor TSH-induced cAMP accumulation but attenuated Ca(2+)-induced H2O2 production. We conclude that TNF-alpha, through a sphingomyelinase-ceramide pathway, regulates TSH-induced H2O2 production at steps beyond the Ca2+ mobilization step in the PLC-Ca2+ signaling pathway coupled to TSH. This suggests participation of TNF-alpha in thyroid disorder in hormone synthesis induced by thyroid disease associated with the activation of immune systems.

Animals↗
PubMed1997

Characterization of sphingosine 1-phosphate-induced actions and its signaling pathways in rat hepatocytes.

Sphingosine 1-phosphate (S-1-P) and lysophosphatidic acid (LPA) stimulated glycogen phosphorylase, a rate-limiting enzyme responsible for glycogenolysis, in association with Ca2+ mobilization and phospholipase C (PLC) activation in rat hepatocytes. S-1-P, but not LPA, also inhibited adenosine 3',5'-cyclic monophosphate accumulation reflecting adenylyl cyclase inhibition. S-1-P-induced PLC activation, Ca2+ mobilization, and phosphorylase activation were markedly enhanced by primary culture of the cells for 24 h, whereas the inhibitory adenosine 3',5'-cyclic monophosphate response was unchanged by increasing culture time. Activation of the PLC-Ca2+ system during primary culture was specific to the lysosphingolipid; PLC and Ca2+ responses to LPA and NaF were unchanged or slightly attenuated by increasing culture time. Pertussis toxin treatment almost completely suppressed the S-1-P-induced inhibition of adenylyl cyclase but hardly influenced the lipid-induced activation of PLC and its cascade reactions. We conclude that S-1-P, through an LPA receptor-independent mechanism, stimulates two signaling pathways, i.e., activation of the PLC-Ca2+ system and inhibition of adenylyl cyclase, through distinct S-1-P receptor-transducer systems, resulting in the modulation of glycogenolysis in rat hepatocytes.

Animals↗
PubMed1997

Reevaluation of anionic sites in the rat glomerular basement membrane.

We reevaluated the distribution of anionic sites in the glomerular basement membrane with ruthenium red, alcian blue, cationic ferritin, polyethyleneimine, and cationic colloidal gold. Without the accentuation by the metal staining with uranyl acetate and lead citrate, we observed the existence of anionic sites throughout all the layers of the glomerular basement membrane with a similar reticular pattern and the structural difference between the lamina rara and lamina densa, indicating that the lamina rara is an actual structural element.

Alcian Blue↗
PubMed1997

Sphingosine 1-phosphate stimulates hydrogen peroxide generation through activation of phospholipase C-Ca2+ system in FRTL-5 thyroid cells: possible involvement of guanosine triphosphate-binding proteins in the lipid signaling.

Exogenous sphingosine 1-phosphate (S1P) stimulated hydrogen peroxide (H2O2) generation in association with an increase in intracellular Ca2+ concentration in FRTL-5 thyroid cells. S1P also induced inositol phosphate production, reflecting activation of phospholipase C (PLC) in the cells. These three S1P-induced events were inhibited partially by pertussis toxin (PTX) and markedly by U73122, a PLC inhibitor, and were conversely potentiated by N6-(L-2-phenylisopropyl)adenosine, an A1-adenosine receptor agonist. In FRTL-5 cell membranes, S1P also activated PLC in the presence of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S), but not in its absence. Guanosine 5'-O-(2-thiodiphosphate) inhibited the S1P-induced GTP gamma S-dependent activation of the enzyme. To characterize the signaling pathways, especially receptors and G proteins involved in the S1P-induced responses, cross-desensitization experiments were performed. Under the conditions where homologous desensitization occurred in S1P-, lysophosphatidic acid (LPA)-, and bradykinin-induced induction of Ca2+ mobilization, no detectable cross-desensitization of S1P and bradykinin was observed. This suggests that the primary action of S1P in its activation of the PLC-Ca2+ system was not the activation of G proteins common to S1P and bradykinin, but the activation of a putative S1P receptor. On the other hand, there was a significant cross-desensitization of S1P and LPA; however, a still significant response to S1P (50-80% of the response in the nontreated control cells) was observed depending on the lipid dose employed after a prior LPA challenge. S1P also inhibited cAMP accumulation in a PTX-sensitive manner. We conclude that S1P stimulates H2O2 generation through a PLC-Ca2+ system and also inhibits adenylyl cyclase in FRTL-5 thyroid cells. The S1P-induced responses may be mediated partly through a putative lipid receptor that is coupled to both PTX-sensitive and insensitive G proteins.

Adenylyl Cyclase Inhibitors↗
PubMed1997

Potentiation of ejaculatory activity by median raphe nucleus lesions in male rats: effect of p-chlorophenylalanine.

The effect of radiofrequency lesions in the median or dorsal raphe nucleus (MRL or DRL) on copulatory behavior was examined in sexually inexperienced male rats. Three weeks after castration and the brain surgery, all males were subcutaneously implanted with Silastic capsules containing testosterone. In the first behavioral test, the frequency of ejaculation in the MRL group was significantly higher than that in sham and DRL males, but mount and intromission were not. Seven days after the first test, the second test was carried out after treatments with 100 mg/kg p-chlorophenylalanine (PCPA), a serotonin synthesis inhibitor, or saline daily for 4 days in MRL and DRL males. The frequencies of male sexual behavior in PCPA treated DRL males were higher than those in saline treated DRL males. In contrast, even after treatments with PCPA, male sexual activity in MRL males was comparable to those in saline treated MRL males. These results suggest that serotonergic neurons in the median raphe nucleus play an inhibitory role in the regulation of male sexual activity, especially ejaculation. Furthermore, it can be thought that PCPA acts on the median raphe neurons and facilitates ejaculatory behavior.

Analysis of Variance↗
PubMed1997

Interactive communication in high-technology home care: videophones for pediatric ventilatory care.

OBJECTIVE: To develop and to assess the clinical impact of a near-television quality home digital videophone system (Integrated Services Digital Network [ISDN] 64, 320 x 200 resolutions, 10 to 12 frames per second), which would provide respiratory care specialists' resources to primary care physicians and their pediatric patients receiving home respiratory care. METHOD: A prospective study comparing the preceding 6 months and following 6 months of implementation of a videophone system on seven pediatric home respiratory care patients (group I) and a prospective analytical study of three patients (group II) being introduced to home ventilatory care were carried out. Clinical effectiveness and time-saving benefits were studied. RESULTS: There were large reductions in the number of house calls by the physicians (from 5 to 0), unscheduled hospital visits by patients (from 24 to 5), and hospital admission days (from 22 to 10), with a fivefold increase in phone calls (from 11 to 58) in group I. This reduced the net number of hours spent by both patients and physicians in unscheduled medical care by 95 hours for the patients and 51.2 hours for the physicians. A total of 45 videophone calls, of which 27 were related to mechanical concerns and 18 to medical concerns, were made in group II. There were 7 mechanical and 10 medical problems of clinical significance, but all were directly handled by physicians by videophone. The majority (35 of 45) of videophone calls were made in the first 3-month period, indicating a decrease in nonspecific concerns after this period. The specifications of the system we used were found acceptable by both patients and health care professionals. The system seemed to be useful in effectively using the time of specialists and in relieving the anxieties of families. No deleterious effects were noted. The current initial cost is substantial but rapidly falling. The running cost is similar to a regular telephone bill when one ISDN 64 line is used. CONCLUSIONS: The videophone system using ISDN 64 can now be considered a practical and effective tool to recruit specialist resources into home care and to improve the quality of pediatric home ventilatory care. This study encourages the use of videophones to help establish designated home care support systems that may extend beyond national borders and time zones.

Adolescent↗
PubMed1997

Stage-dependent distribution of calreticulin in oocytes of the frog, Rana rugosa.

We studied immunohistologically the distribution of a Ca2(+)-binding protein, calreticulin (CLT), at different stages of growing oocytes in the frog, Rana rugosa. Northern blot analysis showed that the CLT gene expression in gonads of metamorphosing tadpoles was low, but was extremely strong in the ovary, but not in the testis, of 2-month post-metamorphosis frogs, followed by decline to a lower level in adult frogs. On the contrary, the beta-actin gene expression did not increase in the same ovary. As for the distribution of CLT protein, a weak immunostaining was observed in indifferent gonads of tadpoles at stage I. The CLT distribution in oocytes from stage A to F was stage-dependent. In addition, Western blot analysis revealed that the CLT level was low in gonads of tadpoles at stage I, but increased at stage XVI. It still increased in the ovary of frogs 2 months after metamorphosis, and then dropped to a lower level in adult frogs. The results indicate that CLT gene expression occurs in the early stage of growing oocytes, and that CLT is synthesized actively in oocytes in the ovary of frogs after metamorphosis. Based on these findings, the role of CLT is discussed.

Actins↗
PubMed1997

[Clinical efficacy of imipenem/cilastatin sodium for respiratory infections in patients with lung cancer].

Imipenem/cilastatin sodium (IPM/CS) was administered to 102 patients with respiratory tract infections and lung cancer. Patients with other serious diseases were excluded and a total of 73 patients were enrolled. They were divided into 12 patients who underwent surgery (operated group) and 61 who did not (non-operated group); the latter group included 28 patients treated with anticancer agents or radiation therapy (treated group) and 33 untreated patients (untreated group). IPM/CS was effective in 75% of the patients, both with and without surgery. The drug was effective in 81% of the treated group, although many of the patients had Stage III or more advanced cancer, as well as bronchial occlusion. IPM/CS was also effective in 69% of the untreated group, although many of the patients have serious infections and a PS (Performance Status) of 3 or greater. Thus, IPM/CS treatment achieved good results. Bacteriological studies showed that 3 out of 4 strains in the operated group and 16 out of 18 in the non-operated group were eliminated. Safety was evaluated in all patients. Two patients (2%) experienced side effects and two others (2%) showed abnormal clinical findings, but the symptoms were mild and resolved after discontinuation or completion of therapy. In conclusion, IPM/CS was very effective for treating respiratory infections in patients with lung cancer.

Adenocarcinoma↗
PubMed1997

In situ observation of bovine serum albumin-adsorbed stearic acid monolayer by Brewster angle microscopy.

The morphology of protein-adsorbed stearic acid monolayers containing a fluorescent probe (rhodamine B octadecylester perchloride: RBO) was observed by using fluorescence spectroscopy, fluorescence microscopy, and Brewster angle microscopy (BAM). The quenching of fluorescence of RBO was observed at the limiting area of the stearic acid monolayer. Thus, the fluorescence of RBO could be a good marker for packing of the matrix monolayer. On the other hand, the BAM image showed the morphology of not the matrix monolayer, but the adsorbed protein monolayer. Thus, the packing processes of the two could be distinguished. The present method is available for a protein that does not have visible absorption, such as bovine serum albumin (BSA). It is suggested that electrostatic interaction between matrix and protein molecules greatly affects the change in the morphology of the protein-adsorbed monolayer.

Adsorption↗
PubMed1997

Necrotizing alveolar capillaritis in autopsy cases of microscopic polyangiitis. Incidence, histopathogenesis, and relationship with systemic vasculitis.

OBJECTIVES: To determine the incidence of necrotizing alveolar capillaritis, to elucidate its histopathogenesis and the most reliable histopathologic features for its detection, and to explore its relationship with systemic vasculitis in microscopic polyangiitis. METHODS: Twenty-five autopsy cases of microscopic polyangiitis were examined. Double staining with periodic acid-silver methenamine and trichrome was used. RESULTS: Periodic acid-silver methenamine and trichrome staining proved to be a useful and convenient method for the detection of necrotizing alveolar capillaritis. Capillaritis was detected in 10 (40%) of the 25 cases studied. Of 18 cases that exhibited the early degenerative stage of systemic vasculitis, capillaritis was seen in 10 (56%). Fibrinoid necrosis of the alveolar wall was the most reliable histopathologic feature for detecting necrotizing alveolar capillaritis in microscopic polyangiitis. The early stage of capillaritis displayed very little neutrophil exudation, and conspicuous accumulation of neutrophils developed after fibrinoid necrosis. Statistical analysis revealed that alveolar capillaritis had a statistically significant correlation (P < .05) with necrotizing vasculitis of the pulmonary circulatory system. Capillaritis tended to occur when systemic vasculitis of microscopic polyangiitis was in its early degenerative stage. CONCLUSION: Necrotizing alveolar capillaritis was detected in about half of the microscopic polyangiitis autopsy cases that exhibited the early degenerative stage of systemic vasculitis, and results based on earlier reports of clinical observations may have been too conservative.

Adult↗
PubMed1997

Minimum inhibitory concentration of various single agents and the effect of their combinations against Helicobacter pylori, as estimated by a fast and simple in vitro assay method.

OBJECTIVES: Fast and simple in vitro methods of accurately assaying anti-Helicobacter pylori (H. pylori) activity are needed to facilitate the selection of optimal drugs for the eradication of H. pylori. With that purpose in mind, we developed a broth microdilution technique that uses a 96-well flat-bottom microplate. METHODS: Clinical isolates of H. pylori were placed in 25-cm2 tissue culture flasks and were grown in an atmosphere of 5% CO2 in air at 37 degrees C and 100% humidity. Then they were inoculated in 96-well flat-bottom microplates. After 24 h, the bacterial growth was assessed by automatic measurement at A450 with a microplate reader. Minimum inhibitory concentrations (MICs) of 11 drugs against H. pylori and the effect of two-drug combinations were respectively evaluated by the broth microdilution technique and by calculating the fractional inhibitory concentration index according to the checkerboard titration method. RESULTS: The MICs of all drugs tested with this system roughly agreed with those of previous reports in which the agar dilution method was used. The MIC of lansoprazole, a proton pump inhibitor, was low (0.88 microg/ml) and surpassed that of metronidazole (3.15 microg/ml). The effect of the combination of macrolide antibiotics with tetracycline was favorable. The proton pump inhibitor demonstrated a strong additive effect with macrolide antibiotics and fostered the activity of ecabet sodium (mucosal protective agent). CONCLUSION: This system could estimate the MIC of individual drugs quickly and simply, and could accurately measure the efficacy of two-drug combinations in vitro.

Anti-Bacterial Agents↗
PubMed1997

Prevalence and molecular epidemiology of GB virus C/hepatitis G virus infection in Mongolia.

We studied the prevalence of GB virus C/hepatitis G virus (GBV-C/HGV) infection among 112 patients with liver disease and 121 blood donors in Ulaanbaatar, Mongolia. Reverse transcription and polymerase chain reaction were employed to detect GBV-C/HGV RNA using the specific primers derived from the 5'-untranslated region (5'-UTR) of the GBV-C/HGV genome. Nucleotide sequences of all positive samples for GBV-C/HGV RNA were determined. The sequences were analyzed by a molecular evolutionary method. Twenty-five (10.7%) of 233 people were positive for GBV-C/HGV RNA. Eight (6.6%), 11 (9.1%), and 30 (24.8%) blood donors were positive for GBV-C/HGV RNA, HBsAg, and anti-HCV, respectively, although 17 (15.2%), 65 (58.0%), and 64 (54.5%) patients with liver disease were positive for each viral marker. The prevalences of GBV-C/HGV RNA, HBV, and HCV in the patients were significantly higher than those in blood donors (P < 0.05). There was no significant difference in the prevalence of anti-HCV among people with and without GBV-C/HGV RNA, while the prevalence of HBsAg among people with GBV-C/HGV RNA was significantly higher than among those without GBV-C/HGV RNA (P < 0.05). The molecular evolutionary tree showed that GBV-C/HGV was a heterogeneous virus and all strains could be divided into 2 types. One is the same phylogenetic type as HGV, and the other is a new type that is different from GBV-C and HGV.

Adult↗
PubMed1997

Signal averaged electrocardiogram after exercise in patients with mitral valve prolapse.

While late potentials are correlated with an increased incidence of ventricular tachycardia, they are not necessarily a good predictor of ventricular electrical instability in patients with mitral valve prolapse (MVP). Our objective was to determine whether the signal averaged electrocardiogram (SAECG) after exercise can discriminate groups with a higher frequency of ventricular arrhythmia from those without. The SAECG was recorded before and after treadmill exercise in 20 normal subjects (N group), 20 patients with MVP (MVP group) and 10 patients with old myocardial infarction (MI group). Five patients (25%) in the MVP group and two patients (33%) in the MI group had late potentials before exercise. Late potentials in the MI group did not disappear with exercise, whereas they disappeared with exercise in two patients in the MVP group. The results suggest that the late potentials observed in patients with MVP differ in nature from those with old myocardial infarction and are not always related to lethal arrhythmia.

Adult↗