Biomedical subjects

K Asano

Publications and source records attributed to K Asano.

At least 253 records · Page 14Linked to original sources

PubMed1994

Glycosphingolipids in cultured lens epithelial cells from dog and rhesus monkey.

Vertebrate lens tissues contain several species of acidic and neutral glycosphingolipids in relatively high amounts. However, the epithelia with capsule from dog and rhesus monkey lenses had a simpler composition and lower content of glycosphingolipids than whole lenses. Gangliosides and neutral glycosphingolipids in monolayer cultures of lens epithelial cells were also different from those in whole lenses. Although alpha-galactosyl (Gal alpha 1-3Gal-R) or Lewis(x) (Gal beta 1-4[Fuc alpha 1-3]GlcNAc-R) epitopes were found in glycosphingolipids from whole lenses, they were not detected in those from monolayer cultures of dog and rhesus monkey lens cells. In addition, significant changes in ganglio-series gangliosides were induced in monolayer cultures of both cells, where GM3 and GD3 were predominant. Immunofluorescence study revealed a characteristic distribution of cell surface gangliosides in confluent monolayers. These findings suggest that glycosphingolipid synthesis in lens epithelia is intrinsically different from that in cortical and nuclear fibres, and that the expression of Lewis(x) and alpha-galactosyl epitopes in glycosphingolipids appears to be associated with the differentiation of epithelial cells to fibres.

Animals↗

PubMed1994

Protective antibodies against Taenia taeniaeformis in rats infected with eggs or injected with non-viable oncospheres or recombinant antigens of oncospheres.

Antibody responses against Taenia taeniaeformis in rats infected with eggs or injected with non-viable oncospheres or recombinant antigens of oncospheres were analysed by passive transfer of serum and Western blotting. When recipient rats were injected with 1 ml serum from donors infected with eggs (infected serum), they all showed complete resistance to oral egg challenge, whereas those injected with 1 ml serum from donors injected with either oncospheres or recombinant antigens (vaccinated serum) showed no resistance. IgG and IgG subclass responses detected by Western blotting revealed that antibody responses to oncosphere antigens in infected serum thoroughly differed from those in vaccinated serum. It is suggested that IgG2 alpha responses in infected serum should be used for screening of epitopes for candidate vaccine.

Animals↗

PubMed1994

Effect of lipopolysaccharide on mouse mast cell induction by a splenic cell culture system.

We have previously reported a method of mast cell induction by long-term culture of mouse spleen cells without using exogenous mast cell growth factor (Z.-Q. Hu, T. Yoshida, and T. Shimamura, J. Immunol. Methods 149:173, 1992). Supernatants recovered from the long-term cultures contain endogenous interleukin 3 and soluble stem cell factor. These were assessed by the capacity of the recovered supernatants to foster the growth of a mast cell growth factor-dependent cell line and by neutralizing antibodies. Besides the soluble factors, cell-to-cell contacts mediated by membrane stem cell factor on splenic stromal cells and c-Kit receptors on mast cells also affect mast cell induction. Different lots of fetal calf serum (FCS) were examined to determine a possible trigger for cytokine production. FCS can be divided into mast cell-inducible and noninducible sera by this process. However, not all FCS lots contain mast cell growth factor. The mast cell-inducible lots contain lipopolysaccharide (LPS) confirmed by a Limulus assay. Polymyxin B can neutralize the mast cell induction activity. Non-mast cell-inducible FCS can be converted to inducible FCS by adding exogenous LPS. The results indicate that LPS as a trigger of cytokine production is responsible for mast cell induction.

Animals↗

PubMed1994

Antiasthmatic activity of a macrolide antibiotic, roxithromycin: analysis of possible mechanisms in vitro and in vivo.

This study was designed to examine the possible mechanisms by which macrolide antibiotics favorably influence the clinical course of asthmatic patients. In the first set of experiments, we investigated the effect of roxithromycin (RXM), a newly synthesized macrolide antibiotic, on in vitro cytokine secretion by mitogen-activated human peripheral blood leukocytes. RXM suppressed the secretion of T cell cytokine interleukins (IL) 2-4 and monocyte cytokine tumor necrosis factor alpha. This inhibitory effects on cytokine secretion was dose dependent and firstly noted at a concentration of as little as 0.5 microgram/ml which is much lower than therapeutic blood levels. In the second part of experiments, we examined the influence of RXM on cytokine appearance in mouse lung extract induced by lipopolysaccharide (LPS) inhalation and on bronchial responsiveness to methacholine in LPS-treated mice. As compared with mice pretreated with phosphate-buffered saline, RXM administered orally at a single dose of 5 mg/kg once a day for 21 days inhibited the appearance of IL-3, IL-4, IL-5, and tumor necrosis factor alpha in aqueous lung extracts. Pretreatment with RXM also decreased the bronchial responsiveness to methacholine induced by intratracheal injection of LPS. We conclude that the attenuating effect of macrolide antibiotics on asthmatic syndromes might be explained partially by their inhibitory effects on cytokine secretion from leukocytes.

Animals↗

PubMed1994

Influence of propagermanium (SK-818) on chemically induced renal lesions in rats.

A histopathological study was performed to examine the influence of propagermanium and germanium dioxide (GeO2) on chemically induced renal lesions in rats. Animals were treated with adriamycin or mercuric chloride to induce glomerular or proximal tubular damage, and then given drinking water containing propagermanium (480 or 2,400 ppm solution) or GeO2 (300 or 1,500 ppm solution: equivalent to propagermanium in terms of germanium contents). The distal tubular epithelium after 8 weeks dosage with the 1,500 ppm solution of GeO2 was characterized by vacuolization and deposits of PAS-positive material not only in adriamycin-treated rats, but also in normal rats. In contrast, propagermanium administration was not associated with any alternation in the changes induced by adriamycin or mercuric chloride. We previously clarified that propagermanium had no biochemical influence on the renal function of these renal injured rats. The histological demonstration that this compound does not exert renal toxicity, even when given at a high dosage to renal injured rats, further indicates that it would not exacerbate renal dysfunction already present. This confirms that propagermanium may be a safe compound for use in individuals with compromised kidneys.

Animals↗

PubMed1994

[High oxygen breathing improves inhomogeneities of ventilation-perfusion distributions in acutely injured lungs].

Using twenty-five mongrel dogs either with or without alveolar flooding induced by oleic acid administration, the effects of high oxygen breathing (60% O2) on ventilation--perfusion (VA/Q) distributions in the lungs were systematically investigated. VA/Q distributions were examined by multiple inert gas elimination technique, from which the VA/Q values describing mean positions of perfusion (Q) and ventilation (VA) distributions against the VA/Q axis were calculated (mean Q and mean VA). As the first measure of dispersion for VA/Q distribution, the log standard deviation was estimated (log SD (Q) and logSD (VA)). As the second measure of dispersion, the area under the curve, constructed by plotting inert gas arterial-to-alveolar partial pressure differences as a function of blood-gas partition coefficient, was calculated (aAD area). High oxygen breathing slightly enhanced the dispersion of VA/Q distributions in the normal dogs but decreased that in the dogs injured with oleic acid. Therefore, we concluded that high oxygen breathing worsened the inhomogenieties of VA/Q distributions in normal lungs but did improve those in acutely injured lungs.

Acute Disease↗

PubMed1994

Partial splenic embolization for Felty's syndrome: a 10-year followup.

Partial splenic embolization was performed in a case of Felty's syndrome in 1980. The granulocyte count has since remained normal without serious infections for the 10 years after the procedure. This is the first report of partial splenic embolization in this syndrome. This treatment may have an advantage over splenectomy because the defense mechanisms of the spleen are preserved and overwhelming infections may occur less frequently.

Blood Cell Count↗

PubMed1994

[Mycobacterium kansasii lung infection associated with myelofibrosis--a case refractory to treatment with antitubercular agents].

A case of Mycobacterium kanasasii lung infection associated with myelofibrosis is reported. A 32-year-old woman was admitted to Keio University Hospital because of fever. One year before admission, a diagnosis of myelofibrosis was made at another hospital. The initial chest X-ray film showed bilateral diffuse infiltrative shadows and right hilar enlargement. Sputum cultures yielded Mycobacterium kansasii on 3 occasions. A fever of 38 degrees C or higher persisted for about 4 months despite the use of antitubercular agents, including INH, RFP, SM, and PZA. During the course of treatment, the hilar and mediastinal lymph node enlargement became more severe, and this was followed by calcification of the nodes. The fever and chest X-ray findings improved in response to the addition of treatment with EB, Ofloxacin, TH, and an increase in the doses of INH (from 300 to 500 mg/day) and RFP (from 450 to 600 mg/day). The patient was discharged 14 months after admission. It is rare especially in Japan for a Mycobacterium kansasii lung infection (not disseminated) to persist in spite of treatment with antitubercular drugs, including RFP or TH. The response to treatment may have been impaired by an immunological disorder associated with the myelofibrosis.

Adult↗

PubMed1994

[Effects of vasoactive cyclooxygenase products on shunt flow and extravascular lung water in acute lung injuries].

Using 50 mongrel dogs with alveolar flooding produced by oleic acid administration, the possible roles of vasoactive cyclooxygenase products on intrapulmonary shunt flow (QS/QT) and extravascular lung water (ETVI) in acutely injured lungs were assessed. Suppressing cyclooxygenase activity with indomethacin administration diminished the concentrations of thromboxane (TX) B2 and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) in arterial blood, resulting in a significant reduction in QS/QT. Furthermore, indomethacin completely suppressed the increase in ETVI. Inhibition of TXA2 generation by OKY-046 (thromboxane A2 synthase blocker) diminished the concentration of TXB2 while increasing that of 6-keto-PGF1 alpha in blood. Administration of either OKY-046 or synthetic prostacyclin (PGI2) markedly enhanced QS/QT, in association with an increase in ETVI. In conclusion, the potent vasodilator prostacyclin was considered to enhance shunt flow, leading to the augmentation of edema formation.

Acute Disease↗

PubMed1994

[A patient with Legionella pneumonia diagnosed early by the PCR method].

A 72-year-old man was admitted to our hospital because of acute respiratory failure. Initially he had been diagnosed as having pneumonia in the lower left lung field and treated with cephem antibiotics by a local physician. Chest X-ray photograph revealed wide-spread infiltrates throughout both lungs, and chest CT scan revealed pleural effusions. The partial pressure of oxygen in arterial blood was 45.8 Torr. In the bronchoalveolar lavage fluid (BALF) specimen, legionella DNA was detected by the polymerase chain reaction (PCR) method. Thus, we were able to diagnose Legionella pneumonia immediately, and to treat the patient successfully.

Aged↗

PubMed1994

Effects of exercise training at 1,500 m on arterial oxygen saturation and pulse rate.

We compared the effects of exercise training at a low (610 m) altitude with those at moderate (1,500 m) altitude on arterial oxygen saturation (SaO2) and pulse rate (PR) between two groups of men: five subjects in the low altitude group (LG), and five other subjects in the moderate-altitude group (MG), after giving them a series of bicycle training in a hypobaric chamber. Training intensity was 75% HRmax for 60 min/day, 3 times per week for 5 weeks. Before and after the training, Sao2 and PR were measured with a pulse oximeter during step-tests under various air pressures, corresponding to 610 m, 2,000 m, and 4,000 m, respectively, in the chamber. We found that: 1) Sao2 during the step-test carried out at 2,000 m and 4,000 m in the hypobaric chamber was significantly increased in MG compared with that in LG; and 2) PR during the step-tests at 610 m, 2,000 m, and 4,000 m was significantly decreased in MG compared with that in LG. Thus, we conclude that exercise training at a moderate altitude is a useful method for increasing Sao2 and decreasing PR and may prevent mountain sickness.

Adult↗

PubMed1993

Determination of aspoxicillin in broncho-alveolar lavage fluid by high-performance liquid chromatography with photolysis and electrochemical detection.

A determination method for the penicillin antibiotic aspoxicillin in broncho-alveolar lavage fluid has been developed, involving high-performance liquid chromatography and post-column photolysis. The method enabled the determination of aspoxicillin at concentrations below 100 ng/ml, with a linear calibration curve at concentrations of 1-1000 ng/ml for 100 microliters of lavage fluid. The detection limit was 1 ng/ml at a signal-to-noise ratio of 3:1.

Amoxicillin↗

PubMed1993

Immunisation of cattle with a recombinant vaccinia vector expressing the haemagglutinin gene of rinderpest virus.

The efficacy of a recombinant rinderpest vaccine, constructed by inserting the rinderpest virus haemagglutinin gene into attenuated vaccinia virus, LC16mO strain, was tested in cattle. After subcutaneous inoculation of 10(8) plaque-forming units (pfu) of the recombinant vaccine, neither palpable skin lesions nor increases in body temperature were observed, indicating the absence of detectable clinical reactions. All the vaccinated cattle were completely protected from challenge with the Saudi 1/81 strain of virulent rinderpest virus. Contact control cattle housed in the same pen with the vaccinated animals did not develop antibodies to rinderpest or vaccinia viruses, and developed typical clinical signs of rinderpest after challenge with virulent rinderpest virus, indicating that there was no contact transmission of the recombinant virus. The 50 per cent protective doses of the vaccine, estimated by the mortality and morbidity rates respectively. were 10(4) and 10(5) pfu. To observe the effect of pre-existing immunity to vaccinia virus on the efficacy of the vaccine, cattle inoculated with the Lister strain of vaccinia virus three weeks earlier, were vaccinated with the recombinant virus. These animals developed antibodies to rinderpest virus and were protected from challenge with virulent rinderpest virus, showing that the vaccine was effective in animals already immune to vaccinia virus. The effectiveness and safety of the vaccine demonstrated in this study suggest that it has potential as a new vaccine against rinderpest.

Animals↗

PubMed1993

Structures of mucin-type sugar chains on human erythropoietins purified from urine and the culture medium of recombinant Chinese hamster ovary cells.

Less is known about the mucin-type sugar chains attached to human erythropoietin as compared with N-linked sugar chains which structures and function have been well studied. In this study, we purified urinary human erythropoietin from three independent groups of aplastic anemia patients, and analyzed the structures of mucin-type sugar chains as well as that obtained from recombinant human erythropoietin produced by Chinese hamster ovary cells. Unlike the N-linked sugar chains, the mucin-type sugar chains are totally different between the urinary and the recombinant erythropoietins. All of the three independent samples of urinary erythropoietin contained oligosaccharides with the structures of +/- Neu5Ac alpha 2-->6GalNAc, while recombinant human erythropoietin contained those with the structures of Neu5Ac alpha 2-->3Gal beta 1-->3(Neu5Ac alpha 2-->6)GalNAc, Neu5Ac alpha 2-->3Gal beta 1-->3GalNAc, and Gal beta 1-->3(Neu5Ac alpha 2-->6)GalNAc.

Anemia, Aplastic↗

PubMed1993

Assessment of exercise-induced alterations in body composition of patients with coronary heart disease.

The purpose of this study was to determine the effects of exercise habituation on body composition and anthropometric characteristics in cardiac patients. The subjects, comprising 20 patients with coronary heart disease, aged 43-69, participated in our supervised exercise programme for 38.0 (SD 12.5) weeks while in hospital. The intensity of most exercise was set at the lactate threshold. Analyses of the data indicated that small but significant reductions were observed in body mass (mb) [-1.4 (SD 1.8) kg], abdominal girth [-1.4 (SD 2.6) cm], chest girth [-1.3 (SD 1.8) cm], body mass index [-0.6 (SD 0.7)], and skinfold thicknesses at all the sites measured. As expected, fat-free mass, derived from either bio-electrical impedance (BI) or a skinfold technique with commonly used regression equations, remained essentially unchanged, while there were significant decreases in body fat (BF) and %BF. The absolute amount of change in mb (i.e. delta mb) was significantly associated with delta abdominal girth (r = 0.506), delta BF estimated by the BI technique (r = 0.476), and delta BF estimated by the skinfold technique (r = 0.451). Although the period of the exercise programme [38.0 (SD 12.5) weeks] varied greatly among subjects, it was found not to be associated with delta mb and alterations in body composition. We concluded that aerobic exercise induced significant decreases in BF and many anthropometric variables, independent of the duration of exercise, and that a combination of abdominal girth, BI and/or skinfold measurements would be advantageous in estimating primarily exercise-induced alterations in BF in cardiac patients.

Adipose Tissue↗

PubMed1993

Long-term results of the intracardiac repair of tetralogy of Fallot: a follow-up study conducted over more than 20 years on 100 consecutive operative survivors.

A long-term retrospective and follow-up study was conducted on patients with tetralogy of Fallot to evaluate survival rates and quality of life following surgery. Intracardiac repairs were performed on 132 patients at our institute between January, 1965, and July, 1971, among whom 100 consecutive operative survivors, being 54 males and 46 females, were followed for 20-25 years. Late deaths were confirmed in eight patients (8%) six of which (6%) were considered cardiac deaths. The 20- and 25-year survival rates were 93.7 +/- 2.5% and 90.9 +/- 3.6%, respectively. Reoperations were performed on six patients for residuae or sequelae without mortality or morbidity, and 90.4% +/- 3.1% of the patients were free from late death or reoperation at 20 years and 83.9 +/- 5.3% at 25 years. Thirty-one of the 46 female patients were married and 28 had children. Forty-three live births were confirmed without any association of a congenital heart anomaly. Employment status was satisfactory in most of the patients, and 81%-89% of the patients in this series were considered to have a good quality of life. Less than half the patients had late symptoms, and all were related to cardiac arrhythmias. Late ventricular arrhythmias remain the major concern of the future, and therefore, the establishment of effective pre- and intraoperative management to prevent postoperative arrhythmias is essential.

Adolescent↗

PubMed1993

Effects of high altitudes on finger cooling test in Japanese and Tibetans at Qinghai Plateau.

The influences of both hypobaric hypoxia and cold on peripheral circulation were studied using the finger cooling test (measurement of the decrease in finger temperature, measured at the dorsal surface of the finger, during immersion of the hand in 0 degrees C water for 20 min) at Qinghai Plateau. The same test was carried out at simulated altitudes in a 25 degrees C climatic chamber to separate the hypobaric hypoxia influence from that of cold. In Japanese subjects at Qinghai Plateau there was a significant difference between finger skin temperatures (FSTs) during 20 min of 0 degrees C water immersion at altitudes of 2260 m and 4860 m by ANOVA. Mean finger skin temperature during the 20-min immersion (5-20 min, MST) measured at 4860 m was significantly lower than that at 2260 m. In Tibetan subjects, there was also a significant difference between FSTs at 2260 m and at 4860 m by ANOVA. MST at 4860 m tended to be lower than that at 2260 m. In the 25 degrees C climatic chamber, there was a significant difference between FSTs of Japanese expedition members at 2000 m and at 4000 m by ANOVA. MST was higher at 4000 m than at 2000 m, contrary to the data obtained in Qinghai. In conclusion, the higher skin temperature in response to local cold immersion, which would have been caused by stronger hypobaric hypoxia, must have been masked by the lower ambient temperature.

Acclimatization↗

PubMed1993

Lymphokine production by mesenteric lymph node cells from BALB/C mice during Hymenolepis nana infection.

Mesenteric lymph node cells (MLNC) prepared from BALB/c mice during infection with Hymenolepis nana proliferated extensively when cultured in the presence of soluble egg antigen, as assessed by measuring 3H-thymidine incorporation. Analysis of Hymenolepis-specific proliferative cells in MLNC by using monoclonal antibody specific for mouse T lymphocyte surface antigens revealed that the proliferative response of MLNC was mediated by Thy-1.2+, L3T4+ cells, that is, helper T cells. Supernatant of MLNC cultured with egg antigen contained large amounts of interleukin-2 and interferon-gamma, but only low levels of interleukin-5. The titer of these cytokines did not correlate with the interval between oral infection and collection of MLNC. These results strongly indicate that the Th1 subtype of helper T lymphocytes respond well to stimulation of H. nana egg antigen and suggest that acute inflammatory responses are involved in host-protective immunity to H. nana.

Animals↗