Search PubMed⌕ Search

Biomedical subjects

T Marui

Publications and source records attributed to T Marui.

At least 37 records · Page 2Linked to original sources
PubMed1997

Quinine suppression of single facial taste fiber responses in the channel catfish.

Two groups of single facial taste fibers that were responsive to quinine hydrochloride (QHCl) and amino acids were identified in the channel catfish, Ictalurus punctatus. Group I fibers were significantly more excited by quinine hydrochloride (QHCl) than were group II fibers. QHCl (10(-3) M), as one component in a binary mixture, suppressed taste responses of group II fibers to 10(-4) M amino acids (other component) by 61%, but did not inhibit significantly the responses to L-alanine of group I fibers. QHCl (10(-2) M) suppressed the response to 10(-4) M L-alanine of group I fibers by 58% and group II fibers to 10(-4) M L-alanine, L-arginine and L-proline by 89-100%. The suppression of amino acid responses of both groups of fibers by QHCl was reversible in subsequent testing of stimuli in the absence of QHCl. QHCl also suppressed the taste responses to other bitter stimuli [10(-3) M caffeine and 10(-2) M denatonium benzoate(DB)]; however, neither caffeine nor DB suppressed amino acid taste responses. Possible mechanisms for the suppressive effect of QHCl on taste nerve activity are discussed.

Amino Acids↗
PubMed1997

Effect of growth factors on matrix synthesis by ligament fibroblasts.

Although it has been reported that several growth factors modulate soft-tissue healing, the specific effects of growth factors on protein synthesis during ligament healing have not been widely investigated. In this study, we examined the effects of basic and acidic fibroblast growth factors, transforming growth factor beta 1, and epidermal growth factor on collagen and noncollagenous protein synthesis by cultured fibroblasts from medial collateral ligament and anterior cruciate ligament in vitro. Uptake of tritiated proline was used to measure synthesis of collagen and noncollagenous protein, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to analyze the type of collagens synthesized. Our data showed that transforming growth factor beta 1 increased both collagen and noncollagenous protein synthesis by medial collateral and anterior cruciate ligament fibroblasts on a dose-dependent basis. Collagen synthesis by cultured fibroblasts from the medial collateral and anterior cruciate ligaments was increased by treatment with transforming growth factor beta 1 by as much as approximately 1.5 times that of untreated controls. Although the response to transforming growth factor beta 1 by anterior cruciate ligament fibroblasts was equal to that by medial collateral ligament fibroblasts, the amounts of matrix proteins synthesized by anterior cruciate ligament fibroblasts were approximately half of that by medial collateral ligament fibroblasts. The increase was mostly in type-I collagen. Treatment of anterior cruciate ligament fibroblasts with epidermal growth factor increased collagen synthesis by approximately 25% but had little effect on medial collateral ligament fibroblasts. Neither basic nor acidic fibroblast growth factor increased either collagen or noncollagenous protein synthesis. These findings suggest that topical application of transforming growth factor beta 1, alone or in combination with epidermal growth factor, may have the potential to strengthen the ligament by increasing matrix synthesis during its remodeling and healing processes.

Analysis of Variance↗
PubMed1997

The effects of age on rabbit MCL fibroblast matrix synthesis in response to TGF-beta 1 or EGF.

In this study, we examined the effects of age on collagen and total protein synthesis by ligament fibroblasts in response to growth factors. Three different doses of transforming growth factor-beta 1 (TGF-beta 1) or epidermal growth factor (EGF) were individually added to in vitro fibroblast cultures from the medial collateral ligament (MCL) of skeletally immature (age 3 months), mature (age 12 months) and senescent (age 48-51 months) rabbits. Analysis of the effects of age revealed that fibroblasts from senescent rabbits produced significantly less collagen in response to TGF-beta 1 or EGF stimulation when compared to fibroblasts from immature rabbits. Furthermore, increased age was found to result in significant reductions in the baseline levels of collagen synthesis but not total protein synthesis. Additionally, collagen and total protein synthesis by MCL fibroblasts were significantly affected by the TFG-beta 1 dose, but not by the EGF dose. When fibroblasts were normalized to their own controls, the increase in collagen and total protein synthesis due to TGF-beta 1 and EGF for the senescent group were found to be greater than those for the skeletally immature rabbits at all doses. This demonstrates that MCL fibroblasts from senescent rabbits are responsive to growth factors.

Aging↗
PubMed1997

Bimodal (taste/tactile) fibers innervate the maxillary barbel in the channel catfish.

Analysis of single fibers isolated from a branch of the facial/trigeminal complex innervating the maxillary barbel of the channel catfish, Ictalurus punctatus, indicated the existence of bimodal (taste/tactile) fibers. Of the 60 single fibers recorded, 14 (23%) responded to both taste (amino acid) and tactile stimulation, 43 (72%) were responsive to only tactile stimulation and three (5%) responded only to taste stimulation. Quinine hydrochloride at a concentration of > or = 1.0 mM suppressed the mechanosensory activity of the bimodal fibers, but had no effect on the tactile-only fibers.

Action Potentials↗
PubMed1995

Interspecies variation of compressive biomechanical properties of the meniscus.

Various animal models have been used to investigate the normal and reparative properties of the knee meniscus. Yet, only limited data on meniscal biomechanical properties of various animals are available. It was therefore the objective of this study to compare measurements of meniscal biomechanical properties between six species: human, bovine, monkey, canine, sheep, and porcine. Uniaxial confined compression tests were conducted on 1-mm-thick, 4-mm-diameter meniscal discs, and the viscoelastic creep deformation was obtained. Two biomechanical parameters, the aggregate modulus (HA) and permeability (K), were found by implementing the linear biphasic theory and a newly developed nonlinear regression scheme. A one-way analysis of variance was conducted along with Student-Newman-Keuls comparison tests to assess the differences in these parameters among the species. Sheep menisci exhibited HA and K values most similar to human menisci. The water content of each specimen was also measured and correlated significantly with K. The interspecies variations found in material properties of the knee meniscus indicate the need for caution in extrapolating data on the biomechanical behavior of the human meniscus from animal models.

Adult↗
PubMed1988

Topographical organization of taste and tactile neurons in the facial lobe of the sea catfish, Plotosus lineatus.

An extraordinary development of the paired medullary facial taste nuclei, the facial lobes, occurs in the sea catfish, Plotosus lineatus. Each of the facial lobes is divided by fiber fascicles into 5 highly distinct lobules or subnuclei, constituting 5 longitudinal columns through the lobe. Extracellular, electrophysiological recordings of neurons within the respective subnuclei of the facial lobe indicate superimposable taste and tactile neural maps organized in a somatotopic manner.

Animals↗
PubMed1986

Morphological evidence for a direct projection of trigeminal nerve fibers to the primary gustatory center in the sea catfish Plotosus anguillaris.

The central projections of the ramus mandibularis were examined in the Japanese sea catfish, Plotosus anguillaris by using the technique of transganglionic tracing with horseradish peroxidase (HRP). This ramus receives fibers from both the trigeminal and facial nerves and supplies primarily the two mandibular barbels. Two pathways for a direct trigeminal projection to the facial lobe (FL) were found: one from the main descending root of the Vth nerve (MRDV) to the medial portion of the FL, approximately midway between the rostro-caudal axis of the FL and a second, from deep RDV to the intermediate nucleus (NIF), beneath the medial lobule of the FL. The facial fibers project exclusively onto the medial portion of the FL and the NIF. The results show that fibers of these two cranial sensory nerves supplying the mandibular barbels converge centrally on the medial portion of the FL, indicating that the FL of the Japanese sea catfish is a highly differentiated center for both gustation and somatosensation.

Animals↗
PubMed1982

Electrophysiological evidence for the topographical arrangement of taste and tactile neurons in the facial lobe of the channel catfish.

Neural responses in the facial lobe of th channel catfish to chemical and mechanical stimulation of the external skin surface were studied electrophysiologically. Taste and tactile neurons in the lobe were organized in a somatotopic manner, which confirms the anatomical reports of the facial lobe in the bullhead catfish, but is markedly different from that of the Cyprinidae. The taste neurons were arranged generally in the more dorsal regions of the tactile sensitive areas and responded with highest frequency to L-alanine or L-arginine HCI among several amino acids tested. The mechanically responsive neurons in the deeper layer of the antero-medial portion of the lobe, possibly corresponding to the intermediate nucleus of the facial lobe, had large receptive fields ranging from 100 mm to the whole body surface; in addition, some of these neurons showed lateral inhibition. The present study revealed that the facial lobe of the channel catfish is a center not only for gustatory input, but also for tactile information.

Animals↗
PubMed1981

Taste responses in the superior secondary gustatory nucleus of the carp, Cyprinus carpio L.

Single unit discharges in the superior secondary gustatory nucleus of the carp, Cyprinus carpio L., were studied electrophysiologically in response to chemical stimulation of the external chemoreceptors of the facial skin surface. Of 36 gustatory neurons recorded, 80.6% were facilitated by taste stimuli and 19.4% were inhibited. The gustatory neurons were classified according to their responsiveness to the 4 basic taste substances and, except the inhibitory type, did not differ remarkably from the primary and secondary gustatory neurons. More inhibitory type (19.4%) neurons occurred at higher levels of the gustatory system. As in the primary and secondary levels, sodium chloride and acetic acid solutions were more effective stimuli than quinine HCl and sucrose. The ascending secondary gustatory fibers project bilaterally to the superior gustatory nucleus of the carp. About 20% of the gustatory neurons respond to stimulation of only the contralateral facial skin while 27.8% respond to stimulation of either side of the face. The latter neuron type showed very complicated responses, and were classified into 'Uniform', 'Summation', 'Contra. greater than Ipsi.' and 'Quality field' types. The remaining 50% of the neurons respond only to stimulation on the ipsilateral side.

Animals↗
PubMed1981

Taste response in the facial nerve of the carp, Cyprinus carpio L.

The stimulating effect of taste substances on the external chemoreceptors of the carp, Cyprinus carpio L., was studied by recording the electrical activity from the facial taste fibers innervating the facial skin surface. The integrated responses from each whole nerve bundle of the trigemino-facial complex nerve revealed that gustatory receptors on the snout of the carp were extremely sensitive to salts, acids and the extract of silk worm pupae. Quinine-HCl and sucrose elicited relatively small responses. Responses occurred to several amino acids, and especially to betaine. The threshold concentration for both mono- and di-valent salts was estimated to be about 5 X 10-3 M and that for acids about 10-4 M. Single fiber analysis was performed on 77 preparations. According to responsiveness to the 4 basic chemicals, the fibers were classified into 5 types: type I, activated by one stimulus (22 fibers out of 77); type II by two (29); type III by three (11); type IV by four (13); and type V showing inhibition by quinine-HCl (2) as their notable feature. Single fibers responsive to several amino acids, and the worm extract were found, among which the last was the most effective stimulus as shown in the whole nerve experiments.

Animals↗
PubMed1981

[Synergistic effect of thiamphenicol and cephalothin on Bacterioides fragilis (author's transl)].

Synergistic effect of thiamphenicol (TP) and cephalothin (CET) on Bacteroides fragilis was proved in vitro. Especially its effect was much clear on B. fragilis which is possible to produce beta-lactamase. Synergistic bactericidal effect of TP and CET was proved. Chemotherapeutic effect of TP and CET against experimental mixed infectious mouse due to E. coli (beta-lactamase -) and B. fragilis (beta-lactamase +) was proved.

Animals↗
PubMed1980

Comparison of chemoreceptions of terminal buds and pit organs of the carp, Cyprinus carpio L.

Neural responses to several chemicals of the pit organs and terminal buds on the facial skin of the carp were compared electrophysiologically. Nerve inpulses from the pit organs were larger than those from the terminal buds. The pit organs were more sensitive to salts and especially acids than the terminal buds. The former did not respond to sucrose, silk worm pupa extract, betaine and amino acids except acidic ones. The latter, however, responded well to them.

Animals↗
PubMed1980

[Antibacterial activity of cefoperazone against anaerobic bacteria (author's transl)].

The following results were obtained from the comparison of cefoperazone (CPZ) with cefazolin (CEZ), cephalothin (CET) and cefoxitin (CFX) in respect to their antibacterial action against anaerobic bacteria: 1) CPZ showed an antibacterial spectrum which was comparable to those of the known antibiotics, CEZ, CET and CFX. CPZ was particularly effective against anaerobic Gram-positive bacteria. 2) CPZ showed a distribution of susceptibility against clinically isolated strains which was comparable to those of CEZ, CET and CFX, CPZ was slightly inferior to CFX against B. fragilis and B. thetaiotaomicron, but was somewhat superior to any of CEZ, CET and CFX against anaerobic Gram-positive rods and B. distasonis. 3) The susceptibility of B. fragilis and F. necrophorum to CPZ decreased with an increase in the amount of inoculation, while C. perfringens and P. asaccharolyticus did not show any difference in susceptibility with the amount of inoculation. 4) The values of MIC and MBC of CPZ showed good coincidence with each other, thereby testifying its superior bactericidal action. 5) Natural resistant mutants were not obtained. 6) According to the examination of resistance in a test tube, P. variabilis did not show any appreciable increase in resistance, but F. varium increased its resistance rapidly. 7) CPZ was inferior only to CFX in stability against the beta-lactamase of B. fragilis. All of CEZ, CET and CMD lacked stability against the beta-lactamase of B. fragilis. 8) CPZ was found effective for the treatment of experimental subcutaneous abscess in mice caused by F. necrophorum.

Abscess↗
PubMed1977

Taste responses in the facial lobe of the carp, Cyprinus carpio L.

Single unitary discharges in the facial lobe of carp, Cyprinus carpio L., were studied electrophysiologically in response to chemical stimulation of the chemoreceptors of the facial skin. Of 258 neurons recorded, 95% were facilitated by taste stimuli and 5% were inhibited. According to responsiveness to the 4 basic tasting substances, the taste neurons were classified into 5 types: type I which was activated by one stimulus (43% of total neurons), type II by two (35%), type III by three (12%), type IV by 4 (5%), and type V which was inhibited by certain qualities (5%). Statical analysis revealed that responsiveness of taste neurons differed somewhat in receptive fields of the face. The taste neurons in the barbel and lip areas of the facial lobe showed variable responsiveness to chemical solutions, but those in other areas belonged generally to types I or II and did not respond to sucrose. Sodium chloride solution was the most effective among the 4 basic stimuli in this experiment. About 90% of the taste neurons also responded to mechanical stimulation of taste receptive fields. Tactile neurons in the facial lobe were localized in a topographical manner and the taste neurons were arranged in the tactile areas, but chemotopical organization was not recognized in the present study.

Animals↗