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Biomedical subjects

S Ando

Publications and source records attributed to S Ando.

At least 217 records · Page 12Linked to original sources

Epitopes on Cry j I and Cry j II for the human IgE antibodies cross-reactive between Cupressus sempervirens and Cryptomeria japonica pollen.

Forty sea from French patients allergic to Cupressus sempervirens pollen were tested for cross-reactivities against Cry j I, Cry j II (major allergens of Cryptomeria japonica pollen) and other pollen allergens from botanically related plants. Seventy-three per cent of the sera reacted with either Cry j I or Cry j II, or with both of them. These IgE cross-reactions were blocked effectively by mAb 046 (anti-Cry j I) or N26, T27 (anti-Cry j II), and weakly by mAbs 052, 027 and 026 (anti-Cry j I). Furthermore, the IgE antibodies in two sera, #40 and #11, bound to peptide fractions obtained from enzyme-digested Cry j I, and mAb 027 could also bind to the fractions. Analyses of the amino acid sequences of the peptides revealed that reactive peptides contained "NGNATPQLTKNAGVLTCSLSKR" sequence and the third residue N3 was glycosylated, however, when the N3 was not glycosylated, the IgE antibodies did not react, but mAb 027 could. The glycosylation of the N3 might be required for IgE-binding to the peptides. Sugar component on the N3 residue was found to be 0.4 mol galactose, 1.3 mol mannose, 0.8 mol fucose and 2.0 mol N-acetyl-glucosamine. Cross-reactivities against other pollen allergens from botanically related plants were found in most of the sera. However, many of these reactivities were detected by sandwich ELISA but not by an ELISA using allergen-coated plates, indicating that it is important to select an appropriate ELISA procedure in order to detect an allergen or an IgE antibody to an allergen.

Allergens↗

Effects of patterns of sympathetic nerve stimulation on vasoconstricting responses in the hindquarter of rabbits.

It is now well known that sympathetic nerve discharges (SND) of animals as well as humans oscillate at low frequencies. To determine effects of the oscillation or burst on vasoconstriction, we applied two different kinds of electrical stimulation of the lumbar sympathetic nerve, and examined the magnitude and rate of vasoconstriction in the autoperfused hindquarter of alpha-chloralose anesthetized rabbits (n = 6). In the first protocol, we obtained power spectra of lumbar SND of rabbits with sinoaortic denervation and vagotomy. The power resided over the frequency range of 0.5-5 Hz with a broad peak at 1 Hz. In the second protocol, we modulated the basal stimulus trains 5 Hz on an average with slower rhythms of 0.5, 1.0 and 2.0 Hz (frequency modulation). This experiment revealed that, compared with the results with constant stimulation, the frequency modulation of stimulation did not affect the magnitude of the maximal vasoconstriction but augmented the rate of vasoconstriction at 0.5 and 1.0 Hz (P < 0.01). In the third protocol, we examined effects of stimulation on vasoconstriction while changing the intra-burst frequency at a fixed inter-burst interval. Since the power spectra of lumbar SND showed a peak at 1 Hz in the first protocol, we fixed the inter-burst interval at 1 Hz and varied the intra-burst frequency at 10, 20, and 40 Hz while the total number of stimuli were kept constant at 5 impulses per second. This experiment showed that the 10 Hz burst was most effective in augmenting the rate of vasoconstriction, though the magnitude of maximal vasoconstriction was not affected by any of them.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effects of anesthesia on sympathetic nerve rhythm: power spectral analysis.

It has been shown that central transduction of the input from arterial baroreceptors shows bandpass characteristics. Previous studies have demonstrated that anesthesia may affect the gain of arterial baroreflex control of sympathetic nerve activity, but whether anesthesia affects the frequency response of central transduction of the arterial baroreflex system is not known. We examined cardiac cycle-related oscillation of renal sympathetic nerve activity (RNA) in conscious (n = 5) and alpha-chloralose-anesthetized (n = 10) rabbits. Power spectra of arterial pressure and RNA were obtained at rest, after i.v. propranolol and after i.v. isoproterenol. At rest with a cardiac cycle at about 5 Hz, cardiac cycle-related oscillation of RNA was observed in conscious rabbits, but it was not present or markedly attenuated in anesthetized rabbits. As the cardiac cycle was slowed by propranolol in anesthetized rabbits, cardiac cycle-related oscillation of RNA gradually appeared. These results suggest that alpha-chloralose anesthesia in rabbits narrowed the bandpass region of the central baroreflex system so that the baroreceptor input at a high frequency (above 5 Hz) was no longer transduced into RNA.

Animals↗

Production of chronic congestive heart failure by rapid ventricular pacing in the rabbit.

OBJECTIVE: The aim was to produce a model of low output congestive heart failure by rapid pacing in rabbits. METHODS: To perform rapid pacing in rabbits, a custom made pacemaker was developed which is light (about 80 g) and can pace at up to 400 beats.min-1 for more than two weeks. A thoracotomy was done and two electrodes were sutured onto the left ventricle. A central venous pressure line was chronically implanted. With the use of this pacemaker, rabbits were paced at 350-400 beats.min-1 for several weeks. RESULTS: Central venous pressure increased from 1.4(SEM 0.2) to 6.4(0.5) mm Hg (p < 0.01, n = 14). After pacing for 16.1(1.6) d, haemodynamic studies were performed under anaesthesia with thiamylal sodium. Left ventricular end diastolic pressure was higher in the paced rabbits (n = 10) than in the control rabbits which underwent sham operation but were not paced (n = 6), at -0.6(0.6) v 19.3(2.0) mm Hg (p < 0.01). Cardiac output [673(56) v 536(45) ml.min-1, p < 0.10] and +dP/dt [1433(97) v 722(51) mm Hg.s-1, p < 0.01] were lower in the paced rabbits (n = 7-8) than in the control rabbits (n = 6). The paced rabbits had more ascites [1.9(1.0) v 45.9(18.9) ml, p < 0.05] and pleural effusion [0.4(0.3) v 12.9(6.7) ml, p < 0.10] than control rabbits. Plasma noradrenaline was higher in the paced rabbits (n = 11) than in the control rabbits (n = 7), at 1.59(0.43) v 0.60(0.05) ng.ml-1 (p < 0.05). The ratio of wet heart weight or lung weight to body weight was higher (p < 0.01) in the paced rabbits than in the control rabbits. CONCLUSIONS: Chronic biventricular congestive heart failure can be produced in rabbits by rapid pacing.

Animals↗

Isolation and characterization of a trisialyllactosylceramide, GT3, containing an O-acetylated sialic acid in cod fish brain.

An O-acetylated ganglioside that generated a trisialyllactosylceramide or GT3 by base treatment was found for the first time in cod fish brain. This ganglioside was isolated by high-performance liquid chromatography, and characterized by fast atom bombardment mass spectrometry, and proton nuclear magnetic resonance spectroscopy in addition to chemical analysis. The structure was identified as a modified GT3 in which the external sialic acid is O-acetylated at the C-9 position. The chemical structure is as follows: II3(9-O-Ac-NeuAc2-8NeuAc2-8NeuAc2-3)Lac Cer.

Acetylation↗

A new O-acetylated trisialoganglioside, 9-O-acetyl GT2, in cod brain.

An O-acetylated trisialoganglioside that is converted to GT2 on mild base treatment was found in cod brain. This alkali-labile ganglioside was isolated using high-performance liquid chromatography, and its chemical structure was characterized. This novel ganglioside was identified as a GT2 derivative having an acetyl group at the C-9 position of the external sialic acid. Its chemical structure is as follows.

Acetylation↗

Neutralization of Chlamydia psittaci with monoclonal antibodies.

Neutralization of Chlamydia (C.) psittaci avian strain P-1041 was examined in vitro using monoclonal antibodies (MAbs). Of the 10 MAbs used, 6 were found to exhibit neutralizing capability. These include 3 against major outer membrane protein (MOMP), 1 against lipopolysaccharide (LPS) and 2 against other protein molecules [90 kilodalton (kDa) and 90/50 kDa]. Most neutralizing MAbs were dependent on complement for efficient neutralization, while a strain-specific MAb (2B5) against the 90 kDa protein displayed a different requirement for complement and neutralized the infectivity of the P-1041 at high concentrations without complement. By competitive inhibition enzyme-linked immunosorbent assay (competitive inhibition ELISA), all 3 neutralizing anti-MOMP MAbs were demonstrated to recognize different epitopes found in very close proximity to each other on the outer membrane.

Antibodies, Bacterial↗

Contribution of wall mechanics to the dynamic properties of aortic baroreceptors.

To examine the contribution of wall mechanics to dynamic properties of baroreceptors, we subdivided the transfer function of baroreceptors into two subsystems [aortic pressure to diameter and diameter to aortic depressor nerve activity (ANA)]. In six alpha-chloralose-anesthetized rabbits, we measured pressure, diameter, and ANA while randomly perturbing pressure. We obtained transfer functions (pressure to ANA, diameter to ANA, and pressure to diameter) by taking the ratio of crosspower spectrum to the input power spectrum (0.005-5 Hz). Below 3 Hz, the transfer function from pressure to ANA was nearly identical to that from diameter to ANA, whereas that from pressure to diameter was flat. Using transfer functions we could reproduce adaptation and hysteresis that were quantitatively similar between pressure-ANA transduction and diameter-ANA transduction. The pressure-diameter relationship was almost instantaneous and thus showed no hysteresis. In a second group of rabbits, the ratio of the shift of the hysteresis loop was unchanged by ouabain (40 micrograms/kg iv, n = 7). We conclude that the dynamic properties of baroreceptors may not be related to the wall mechanics or the Na(+)-K(+)-adenosinetriphosphatase activity.

Animals↗

Suppression of murine IgE responses with ovalbumin-pullulan conjugates: comparison of the suppressive effect of different conjugation methods and different molecular weights of pullulan.

Ovalbumin (OVA)-pullulan conjugates were made using four different conjugation methods and eight different molecular weights of pullulan ranging from 4,200 to 600,000. Pretreatment of mice by the administration of conjugates made by using cyanulic chloride or cyanogen bromide and pullulan of molecular weight 40,000 or more, anti-OVA IgE antibody response was suppressed completely and anti-OVA IgM and IgG antibody response was enhanced. In contrast, by the administration of conjugates made by using an oxidation or thiol activation method, only partial suppression of anti-OVA IgE antibody response was achieved and no enhancement of anti-OVA IgM and IgG antibody production was observed.

Animals↗

Vasodilatory effect of arginine vasopressin is mediated by nitric oxide in human forearm vessels.

Arginine vasopressin (AVP) causes biphasic changes in vascular resistance in human forearms; vasoconstriction at lower doses and vasodilation at higher doses. Vasoconstriction is mediated by the V1 receptor. However, the mechanism of AVP-induced vasodilation is not known. We investigated whether AVP-induced vasodilation is mediated by nitric oxide (NO) in human forearms by examining the effects of L-arginine (a precursor of NO) and NG-monomethyl-L-arginine (L-NMMA, a blocker of NO synthase) on AVP-induced vasodilation. AVP was infused intraarterially at doses of 0.05, 0.1, 0.2, 0.5, and 1.0 ng/kg per min (n = 8). The lower doses of AVP (< or = 0.1 ng/kg per min) increased, whereas the higher doses of AVP (> or = 0.5 ng/kg per min) decreased forearm vascular resistance (FVR) (P < 0.01). Intraarterially infused L-arginine at 10 mg/min did not alter arterial pressure, baseline FVR, or heart rate. L-arginine did not alter the magnitude of AVP-induced vasoconstriction at the lower doses, but L-arginine augmented the magnitude of AVP-induced vasodilation at doses of 0.2 (P < 0.05), 0.5 (P < 0.01), and 1.0 (P < 0.05) ng/kg per min. In another group (n = 6), intraarterially infused L-NMMA (4 mumol/min for 5 min) increased baseline FVR without systemic effects, and inhibited acetylcholine-induced vasodilation (P < 0.01). L-NMMA at this dose inhibited AVP-induced vasodilation (P < 0.01) but did not affect vasoconstriction. L-arginine reversed the inhibitory effect of L-NMMA. Our results suggest that the vasodilatory effect of AVP may be mediated by NO in human forearms.

Adult↗

Relaxing effect of vesnarinone (OPC-8212) on the tracheal muscle strips isolated from guinea pigs.

The effect of vesnarinone (OPC-8212), an orally active positive inotropic agent was studied in tracheal muscle isolated from guinea pigs, and the mechanism of its action was analyzed. Vesnarinone (10(-6)-10(-4) M) caused a concentration-dependent relaxation of tracheal muscle pre-contracted by 10(-4) M histamine. The potency of the relaxing effect of vesnarinone was greater than that of theophylline; the pD2 values for vesnarinone and theophylline were 4.9 and 4.5, respectively. Vesnarinone reduced the high-K(+)-induced contracture of depolarized tracheal muscle non-competitively (pD'2 = 3.7). Vesnarinone at the low concentration of 3 x 10(-6) M shifted the concentration-response curve for isoproterenol in a parallel fashion to the left. Vesnarinone additively acted on the relaxing effect of isobutyl methyl xanthine. Propranolol (10(-5) M) and reserpine pre-treatment (5 mg/kg, i.p., 24 hr) had no effect on the relaxing effect of vesnarinone. These results suggested that vesnarinone elevated the intracellular cyclic AMP level via phosphodiesterase inhibition, resulting in the tracheal muscle relaxation.

1-Methyl-3-isobutylxanthine↗

Safety and accuracy of dipyridamole thallium myocardial scintigraphy in elderly patients.

This study examined mainly the adverse effects of 201Tl myocardial scintigraphy with dipyridamole (D-Tl) in 73 elderly patients over 70 years old in comparison with those in 65 younger patients. Fifty-five of 73 elderly patients (75%) and 49 of 65 younger patients (75%) had a persistent or dipyridamole-induced perfusion defect on D-Tl. The hemodynamic changes induced by dipyridamole as well as the incidence of cardiac and noncardiac adverse effects were similar in both groups and no serious adverse effect occurred in either group. Secondly, we examined the procedure's usefulness for detecting ischemic heart disease in elderly and younger patients. Dipyridamole induced perfusion defect was noted in 21 elderly patients and in 24 younger patients (N.S.). Among the patients in whom coronary angiography was performed, significant coronary artery stenosis was found in 5 of 8 elderly patients and 17 of 20 young patients (N.S.). In patients with one or two-vessel disease, the area with dipyridamole induced ischemia was concordant with the stenotic area seen on coronary angiography in 3 of 3 elderly patients and 12 of 13 younger patients (N.S.). Thus, the safety and usefulness of D-Tl for detecting myocardial ischemia were comparable in elderly and young patients.

Age Factors↗

Morphological changes of unmyelinated nerves in the cerebral arteries after removal of the pterygopalatine ganglion--an electron microscopic study.

To investigate the participation of the pterygopalatine ganglion in the parasympathetic innervation of the cerebral arteries, Wallerian degeneration was evaluated in the unmyelinated nerves of the major cerebral arteries following the removal of the bilateral pterygopalatine ganglia in dogs. Several days after removal, transmission electron microscopy demonstrated typical features of degeneration in about one-third of the unmyelinated nerves, which are generally considered to be mostly autonomic, i.e., sympathetic and/or parasympathetic. Accordingly, removal of the pterygopalatine ganglion causes Wallerian degeneration of the sympathetic and/or parasympathetic nerves innervating the cerebral arteries. A supplementary study using monoamine fluorescence histochemistry demonstrated that there was no degeneration of the sympathetic nerves innervating the cerebral arteries. Therefore, the degenerated unmyelinated nerves are almost all parasympathetic. These experimental results support the concept that most parasympathetic nerves innervating the cerebral arteries originate in the pterygopalatine ganglion.

Animals↗

Analysis of the site on a TNF-alpha molecule which affects type II TNF receptor binding in human cells.

The epitope region on the TNF-alpha molecule recognized by monoclonal antibody (mAb) 3-D-6, which neutralizes the cytotoxic activity on murine LM cells, has been determined as Gly24-Gln-Leu-Gln-Trp-Leu-Asn-Arg31. To examine whether this region participates in TNF receptor binding in human cell lines, four kinds of TNF-alpha mutants (Gln25 --> Glu, Gln27 --> Glu, Leu29 --> Val, and Arg31 --> Ser) were prepared using site-directed mutagenesis. One mutant, mRS31, which has a nonconserative mutation at position 31 (Arg --> Ser), showed markedly reduced binding in U-937 cells and in HL-60 cells compared with the wild-type recombinant TNF-alpha (rTNF-alpha). These two cell lines have been reported to have both type I and type II TNF receptors. mRS31 also showed reduced cytotoxicity on U-937 cells. Another mutant, mLV29, which has a conservative mutation at position 29 (Leu --> Val), showed, to a lesser extent, reduced binding in U-937 cells and HL-60 cells and reduced cytotoxic activity in U-937 cells. However, all four TNF-alpha mutants showed a similar binding in HEp-2 cells and in HeLa cells, which have been reported to have only the type I TNF receptor. These results suggest that Leu29 may be involved in direct contact with the type II receptor and that the nonconservative mutation at position 31 may induce a local conformational change in the site involved in type II TNF receptor binding.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

[Immunological and physicochemical properties of Cry j II, the second major allergen of Japanese cedar pollen (Cryptomeria japonica)].

Cry j II, the second major allergen of Japanese cedar (sugi, Cryptomeria japonica) pollen was examined for the allergenicity by intradermal test and RAST. Nineteen of the 25 allergic patients examined, showed positive reaction to the Cry j II. Contents of Cry j II in the extracts of the pollen collected in various regions from 1977 to 1991 showed yearly variation ranging from 2.9 to 14 mg/100 g pollen, whereas the amount of Cry j I in the extract was comparatively stable at about 35 mg/100 g pollen. Physicochemical treatments of Cry j I and Cry j II suggested that specific human IgE antibodies and some mAbs bind to conformational epitopes which are denatured and destroyed by certain treatments.

Allergens↗

[A case of B-chronic lymphocytic leukemia/prolymphocytic leukemia (CLL/PL)].

A 59-year-old man was admitted to our hospital on May 17, 1991 because of dizziness and a sense of abdominal fullness. Physical examination on admission showed splenomegaly without hepatomegaly or lymphadenopathy, and blood examination revealed normocytic anemia, thrombocytopenia and marked leukocytosis of 16,800/microliters with 87% lymphoid cells. Prolymphocytoid cells formed 28% of the lymphoid cells. Bone marrow aspiration revealed massive infiltration of lymphoid cells. Surface marker analysis showed that the lymphoid cells were positive for anti-HLA-DR, CD 5, CD19, CD20, CD21, SmIgM and SmIgD. The patient was diagnosed as having B-CLL/PL, according to the classification advocated by Melo in 1986, and initially treated with vindesine + prednisolone + pirarubicin (VP-THP). However, the prolymphocyte count increased, so we changed to VP-THP + cyclophosphamide (VEP-THP), and remission was obtained. CLL/PL is a rare disease in Japan but we obtained a good response to chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

Tyrosinase gene transcription and its control by melanogenic inhibitors.

The levels of tyrosinase mRNA and tyrosinase activity were analyzed in two amelanotic melanoma cell lines, D1(178) (hamster) and G-361 (human). Neither tyrosinase mRNA nor tyrosinase activity were detected in D1(178) cells. On the other hand, both tyrosinase mRNA and weak tyrosinase activity were detected in G-361 cells. Assuming that the different types of melanogenic inhibitors affected melanogenesis in these two amelanotic melanoma cells in different manners, we performed a screening of melanogenic inhibitors in these two cell lines. As an isolated tyrosinase suppressive melanogenic inhibitor, ascorbic acid and glutathione were identified from D1(178) cells and G-361 cells, respectively. Furthermore, lactic acid was identified from D1(178) cells as an isolated tyrosinase non-suppressive melanogenic inhibitor. B-16 mouse melanotic melanoma cells were depigmented by treatment with lactic acid. The melanogenesis suppression by lactic acid in B-16 cells was found to be due to inhibition of tyrosinase gene expression.

Animals↗