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Biomedical subjects

J Tsuji

Publications and source records attributed to J Tsuji.

At least 37 records · Page 2Linked to original sources
PubMed1993

Efferent vestibular fibers to otolith organs in guinea pigs.

The origins of efferent vestibular fibers to the otolith organs in guinea pigs, examined with the use of retrograde transport of HRP were: i) the bilateral lateral portions of the facial genu and ii) the ipsilateral reticular nucleus at the level of the facial nucleus. These origins are almost the same as those of the efferent fibers to the three semicircular canals which we have previously identified in cats; however, they differ in certain respects.

Animals↗
PubMed1993

[Computerized database system for pure tone audiometry].

The management and storage of pure tone audiometry data creates a major problem for otolaryngological clinics. We have devised a new computerized database system to overcome this problem. The hardware involved includes multiple audiometers and computers interfaced with a glassfiber local area network (Pi-Net). The software used is database 3 plus, a popular database language and utility software package. Programs were written for data entry, data transfer, reference, entry of patient ID, and evaluation of tympanoplasty. The following benefits of the system are noted. 1) Data entry is possible at every terminal (audiometer and computer). 2) Storage capacity is sufficient for more than 10 years of operation. 3) All data can be retrieved rapidly at any terminal. Evaluations of pre- and post-tympanoplasty hearing loss are facilitated by this system. This system is very effective for follow up of hearing disorders.

Audiometry, Pure-Tone↗
PubMed1992

Production and differentiation of NK lineage cells in long-term bone marrow cultures in the absence of exogenous growth factors.

Neither lytic NK cells nor IL-2-responsive NK precursors were produced in myeloid (Dexter) long-term bone marrow cultures (LTBMC). However, when myeloid LTBMC were switched to lymphoid (Whitlock-Witte) conditions and reseeded ("recharged") with fresh bone marrow cells (BMC), nonadherent cells with NK lytic activity and NK 1.1+ phenotype were produced within 1-2 weeks without the addition of exogenous IL-2 to the cultures. NK- and T cell-depleted BMC proliferated extensively in switched cultures and in 2 weeks generated cells that lysed the NK target YAC-1 but not the LAK target P815. The presence of NK precursors in the cultures was confirmed by reculturing nonadherent cells harvested from recharged LTBMC in fresh medium containing 50 U rIL-2/ml. High levels of NK lytic activity were generated. Sequential expression of NK 1.1 and IL-2 responsiveness followed by lytic activity was demonstrated by harvesting cells early after recharge, prior to the appearance of lytic cells. Elimination of NK 1.1+ cells depleted the ability to respond to IL-2 in secondary culture. Our studies demonstrate that myeloid-to-lymphoid switched LTBMC support the proliferation and differentiation of NK lineage cells from their NK 1.1-, nonlytic progenitors in the absence of an exogenous source of growth factors.

Animals↗
PubMed1992

Phytoalexin Accumulation in Arabidopsis thaliana during the Hypersensitive Reaction to Pseudomonas syringae pv syringae.

Inoculation of leaves of Arabidopsis thaliana (L.) Heynh. with the wheat pathogen, Pseudomonas syringae pv syringae, resulted in the expression of the hypersensitive reaction and in phytoalexin accumulation. No phytoalexin accumulation was detected after infiltration of leaves with a mutant of P. s. syringae deficient in the ability to elicit a hypersensitive reaction; with the crucifer pathogen, Xanthomonas campestris pv campestris; or with 10 millimolar potassium phosphate buffer (pH 6.9). Phytoalexin accumulation was correlated with the restricted in vivo growth of P. s. syringae. A phytoalexin was purified by a combination of reverse phase flash chromatography, thin layer chromatography, followed by reverse phase high performance liquid chromatography. The Arabidopsis phytoalexin was identified as 3-thiazol-2'-yl-indole on the basis of ultraviolet, infrared, mass spectral, (1)H-nuclear magnetic resonance, and (13)C-nuclear magnetic resonance data.

Journal Article↗
PubMed1992

Effects of anti-CD11a, anti-CD11b and anti-CD18 on histamine release from human basophils primed with IL-3.

This study was carried out to investigate the possible role of adhesion molecules in the histamine release from human basophils primed with recombinant IL-3 (rIL-3). Anti-IgE monoclonal antibody (0.1 microgram/ml) did not induce apparent histamine release by itself, however, remarkable histamine release was induced from rIL-3-primed human basophils triggered by anti-IgE. Bear-1 (anti-CD11b monoclonal antibody) inhibited the histamine release enhanced by rIL-3, however SPV-L7 (anti-CD11a monoclonal antibody) or CLB-LFA1/1 (anti-CD18 monoclonal antibody) did not inhibit the histamine release enhanced by rIL-3 at all. The present study suggests that alpha-chain of Mac-1 is involved in the priming effect of IL-3 to increase histamine release from human basophils.

Antibodies, Monoclonal↗
PubMed1991

Responses and anatomical connections of peripheral vestibular neurons innervating otolith organs.

The response patterns of the Scarpa's neurons and lateral vestibular nucleus (LVN) neurons that respond to lateral and antero-posterior tilting were investigated using cats. The following observations were made: 1) The Scarpa's neurons that respond to lateral tilting have directional sensitivity physiologically and may innervate the utricular macula; 2) The LVN neurons that respond to lateral tilting are found mostly in the ventral part of the LVN and also have directional sensitivity. They project toward the spinal cord into the lateral vestibulo-spinal tract.

Acoustic Maculae↗
PubMed1991

Salmonellosis in laboratory-housed iguanid lizards (Sceloporus spp.).

Fifteen wild-caught iguanid lizards (14 Sceloporus variabilis and one S. malachiticus) were used in a 3 mo study on thermal acclimation. Over a 2 mo period, five of the lizards showed decreased activity, anorexia and enlarged joints, and were either found moribund or were euthanatized due to their poor condition. Specimens taken from lesions in four of the five lizards were cultured and were infected with Salmonella spp. Salmonella spp. was cultured from cloacal swabs in six of the 10 surviving lizards. Standard metabolic rates of those that were infected did not differ significantly from those that were not infected. We postulate that the lizards were inapparent carriers of Salmonella spp. at the time of capture and, as a result of stress, five developed active overwhelming systemic infections.

Animals↗
PubMed1991

A synthetic pseudosubstrate peptide of protein kinase C inhibits the phorbol-12,13-dibutyrate effect on permeabilized coronary artery smooth muscle.

We have studied the effects of a synthetic peptide that is based on the autoinhibitory domain of protein kinase C on tension development in detergent-permeabilized coronary artery smooth muscle. This peptide inhibited two forms of protein kinase C that were isolated from the coronary artery media layer by hydroxylapatite chromatography, with apparent Ki values in the 5-8 microM range. Contractions induced by calcium in the permeabilized arteries were not affected by the peptide (30 microM). Potentiation of calcium-induced contractions by 1 microM phorbol-12,13-dibutyrate was partially inhibited by 10 microM peptide and was completely abolished by 30 microM peptide. These results indicate that phorbol-12,13-dibutyrate potentiates calcium-induced contractions of permeabilized coronary arteries by activation of protein kinase C, but activated protein kinase C is not a requirement for the induction of contractions by calcium alone.

Animals↗
PubMed1990

The influence of caloric stimulation on the otolith organs in the cat.

The influence of caloric stimulation on the otolith organs was investigated in cats by recording the firing rate of the single vestibular nerve fiber originating from each otolith organ. Sixty-six percent of the vestibular nerve fibers originating from the otolith organs responded to the caloric stimulation. The caloric nystagmus occurred not only by the activities of the semicircular canal system but also by those of the otolith system.

Action Potentials↗
PubMed1990

Pharmacokinetics in chimpanzees of recombinant human tissue-type plasminogen activator produced in mouse C127 and Chinese hamster ovary cells.

Pharmacokinetics of recombinant tissue-type plasminogen activator (rt-PA) produced in mouse C127 cells (t-PA(C127] and Chinese hamster ovary cells (t-PA(CHO] was investigated in chimpanzees. rt-PA was administered via a constant rate i.v. infusion for 60 min, and t-PA concentration and activity in plasma were measured during and after infusion. The noncompartmental parameters were calculated according to the moment analysis method, and a population pharmacokinetic analysis was performed to obtain the mean and interindividual variability of the pharmacokinetic parameters. The mean residence time of t-PA(C127) was significantly longer and the total body clearance was significantly less than that of t-PA(CHO). t-PA(C127) has an alpha-galactosyl moiety in its carbohydrate chains, whereas such a structure is not found in t-PA(CHO). These results demonstrate that two preparations of rt-PA's with different carbohydrate structures show different pharmacokinetics, and suggest that the carbohydrate structure can affect the efficiency of hepatic uptake of t-PA. A possible mechanism is an interaction of t-PA(C127) with the natural anti-alpha-galactosyl antibody. The anti-alpha-galactosyl antibody level in plasma decreased in association with the plasma levels of t-PA(C127) but was unaffected by t-PA(CHO) levels.

Animals↗
PubMed1990

Specificity of human natural antibody to recombinant tissue-type plasminogen activator (t-PA) expressed in mouse C127 cells.

A natural antibody with binding specificity for recombinant tissue-type plasminogen activator (t-PA) expressed in mouse C127 cells was present in almost all disease-free humans and patients with thrombotic disease examined. This antibody was specific for a carbohydrate, alpha 1-3-linked galactose residue, and was isolated by affinity chromatography using Synsorb 90 coupled with the glycosidic epitope Gal alpha 1-3Gal beta 1-4Glc-R as an immunoadsorbent. The evaluation of various glycoproteins for ability to bind the purified antibody in ELISA demonstrated that not only recombinant t-PA from C127 cells but also recombinant erythropoietin (EPO) and recombinant protein C produced in C127 cells have alpha 1-3-linked galactose residues on their sugar side chains. This anti-alpha-galactosyl antibody also interacted with natural t-PA from human vascular trees (vascular t-PA) and placenta (placenta t-PA), but not to melanoma t-PA, recombinant t-PA, EPO or protein C expressed in Chinese hamster ovary (CHO) cells.

Animals↗
PubMed1988

The influence of middle ear pressure on the otolith system in cats.

The influence of varying middle ear pressure on the otolith system was investigated in anesthetized cats. Extra-axonal recordings of action potentials were performed in the vestibular nerve fibers and in the neurons in the lateral vestibular nucleus that responded to lateral or anteroposterior steady-state tilt. Positive or negative pressure was applied to the ipsilateral middle ear during the recordings. Seventy-three percent of the fibers and 63% of the neurons responded to changes in the middle ear pressure. These response rates were higher than those previously reported on the units innervating semicircular canals. Findings suggest that the otolith organs are more sensitive to changes in the middle ear pressure than are the semicircular canals. The units responding to lateral tilt were more sensitive to middle ear pressure than those that responded to anteroposterior tilt. Displacement of endolymph caused by pressure changes in the middle ear was considered to have affected the activities of hair cells in otolith organs.

Animals↗
PubMed1985

Studies on antigenicity of the polyethylene glycol (PEG)-modified uricase.

The purified uricase (urate: oxygen oxidoreductase, EC 1.7.3.3) from Candida utilis was modified to varying degrees with monomethoxypolyethylene glycol (PEG) of different molecular weights using cyanuric chloride as the coupling reagent. The PEG-uricase conjugates were examined on their immunological properties by means of ring test and passive cutaneous anaphylaxis (PCA). As increasing amounts of PEG were attached to uricase, it showed decreasing ability to elicit antibody production in rabbits. When sufficient polymers were attached, the modified uricase was devoid of the capacity to combine in vivo and in vitro with antibodies from guinea pigs injected with the unmodified uricase, however, were still able to react with antibodies to PEG-uricase conjugate. Antibodies against PEG-uricase conjugates also reacted with PEG modified superoxide dismutase (superoxide: superoxide oxidoreductase, EC 1.15.1.1). These results indicate that the coupling of PEG to uricase resulted in the loss of original antigenicity and immunogenicity, but in the appearance of new antigenicity and immunogenicity which never showed any cross-reactions against the native uricase.

Animals↗
PubMed1982

Enzyme immunoassay for cytidine 3',5'-cyclic monophosphate (cyclic CMP).

An enzyme immunoassay for cytidine 3',5'-cyclic monophosphate (cyclic CMP) is presented. This assay is based upon the principles of competitive reaction and the double antibody solid phase method. Succinyl cyclic CMP-human serum albumin conjugate was injected into rabbits. Specific anti-cyclic CMP antibodies were incubated with a mixture of succinyl cyclic CMP labeled with beta-D-galactosidase and standard or sample cyclic CMP that had been succinylated prior to assay. The antibody-bound beta-D-galactosidase-cyclic CMP conjugate was separated from that of free with a second antibody, anti-rabbit immunoglobulin G, that was immobilized to a polystyrene ball. Then, activity of the enzyme on the solid phase was fluorometrically determined. When cyclic CMP contents in biological materials were estimated, acid extracts were partially purified by Dowex 1 x 8 formate column chromatography. The present immunoassay allows the detection of as little as 0.5 fmol of cyclic CMP with practically no interference from other cyclic nucleotides and cytidine analogs. By use of the enzyme immunoassay technique, we determined the amounts of cyclic CMP in various tissues of rats. They were found to be as little as 0.24-0.51 pmol/g wet weight, which was roughly 3000 to 20,000 and 100 to 500 times less than those of cyclic AMP and cyclic GMP, respectively.

Animals↗