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Biomedical subjects

R Matsushima

Publications and source records attributed to R Matsushima.

At least 19 recordsLinked to original sources
PubMed2000

Shyness in self-disclosure mediated by social skill.

The purpose of this study was to examine the effect of Shyness and Social Skills on Self-disclosure. Three scales, the Trait Shyness Scale, the Scale of Social Skill, and the Self-disclosure Questionnaire were administered to 443 university students. Scores on Shyness were highly negatively correlated with those on Social Skills and moderately negatively correlated with Self-disclosure. Furthermore, Self-disclosure scores correlated positively with Social Skills. Separate factor analyses of the Shyness and Social Skills scales yielded four and two factors, respectively. Findings suggest that shy people may have low interpersonal skills and thus, they may hesitate to engage in self-disclosure.

Adolescent↗
PubMed1993

High-level production and secretion of a mouse-human chimeric Fab fragment with specificity to human carcino embryonic antigen in Escherichia coli.

A high-level secretion system for the production of mouse-human chimeric antibody 21B2 (MHC 21B2) Fab fragment specific for human carcino embryonic antigen (hCEA) in Escherichia coli has been constructed. The genes encoding a light chain and an Fd fragment (a variable region and the CH1 domain of a heavy chain) of a mouse-human chimeric antibody were directly fused to the signal peptide of the E. coli ompF gene sequence. E. coli cells containing expression vectors in which each of the two genes are located downstream of a separate tac promoter were able to secrete the light chain and Fd fragment as two of their major cellular proteins. The signal peptides were efficiently removed from the primary products by post-translational processing, although they formed insoluble aggregates, possibly in the periplasm. In high-cell-density culture experiments using a jar fermentor, the amount of light chain and Fd fragment produced was at levels of up to 2.88 g/l and 1.28 g/l culture, respectively. By optimizing the conditions that encourage correct folding, formation of disulphide bonds, and association of the light chain with the Fd fragment, we have established a procedure that can purify, re-fold, and combine aggregated products to electrophoretically homogeneous Fab fragment with a yield of approximately 47%. Fab fragment produced in this manner shows essentially the same antigen-binding activity and specificity to hCEA as the parental mouse antibody 21B2 (MoAb 21B2).

Amino Acid Sequence↗
PubMed1991

Extracorporeal circulation for the removal of serum myoglobin in experimentally induced myonephropathic metabolic syndrome in dogs.

The removal of serum myoglobin with extracorporeal circulation using a column filled with methylmethacrylate-divinylbenzene (MMA-DVB) was studied in experimentally induced myonephropathic metabolic syndrome in the dog. All animals showed marked edema in the hind limbs and degeneration or necrosis of the adductor muscle 5 hours after the reestablishment of arterial flow. The serum levels of myoglobin, creatinine phosphokinase, glutamic oxaloacetic transaminase and aldolase increased linearly after the reperfusion of blood in the group of animals which received no extracorporeal circulation (group 1). Sediments of numerous myoglobin casts in the renal tubules and immunoreactive myoglobin in the renal epithelium of almost all the tubules were seen in 4 out of 5 cases. In the group of animals reperfused with extracorporeal circulation using the MMA-DVB column, serum myoglobin was adsorbed selectively by the column and showed a significantly lower value at 0.5, 1, 2 and 3 hours than that of the group 1 animals. Concomitantly, the immunoreactive myoglobin was absent or scant in the renal epithelium of the proximal convoluted tubule. The present study therefore indicates that extracorporeal circulation using the MMA-DVB column is useful for the removal of serum myoglobin from experimentally induced myonephropathic metabolic syndrome.

Animals↗
PubMed1991

Distribution of axons showing calcitonin gene-related peptide- and/or substance P-like immunoreactivity in the sensory trigeminal nuclei of the cat.

Distribution of axons with calcitonin gene-related peptide (CGRP)-like and/or substance P (SP)-like immunoreactivity (LI) within the sensory trigeminal nuclei was examined in the cat before and after trigeminal rhizotomy. Axons with CGRP-LI or SP-LI were seen throughout the principal sensory trigeminal nucleus (Vp) and spinal trigeminal nuclei, including the medullary dorsal horn (MDH). They were densely distributed particularly in the dorsolateral part of the dorsal subnucleus of the Vp, ventromedial marginal zone of the ventral subnucleus of the Vp, dorsomedial and ventromedial parts of the oral spinal trigeminal nucleus, ventromedial and lateral marginal zones of the interpolar spinal trigeminal nucleus, and lamina I, outer part of lamina II and lamina V of the MDH. Most of the CGRP-LI axons exhibited SP-LI, while many SP-LI axons did not show CGRP-LI. After trigeminal rhizotomy, almost all CGRP-LI axons disappeared from the ipsilateral sensory trigeminal nuclei, while a considerable number of SP-LI axons remained intact throughout the nuclei; these SP-LI axons did not show CGRP-LI. The results indicate that CGRP-LI axons within the sensory trigeminal nuclei exhibit SP-LI and are of peripheral origin, and that SP-LI axons without CGRP-LI are of central origin.

Animals↗
PubMed1991

Re-examination of the topographical distribution of motoneurons innervating the digastric muscle in the rabbit and guinea pig.

The topographical distribution of motoneurons innervating the digastric muscle in the rabbit and guinea pig was re-examined by the retrograde tracing method of HRP (horseradish peroxidase). Motoneurons innervating the anterior belly of the digastric muscle of the rabbit and guinea pig constituted a longitudinal cell column in the ventromedial part of the motor nucleus of the trigeminal nerve. Motoneurons innervating the posterior belly of the digastric muscle were localized in the accessory facial nucleus. No motoneurons supplying the digastric muscle were found within the main facial nucleus.

Animals↗
PubMed1990

In vitro and in vivo effects of protein phosphatase inhibitors, microcystins and nodularin, on mouse skin and fibroblasts.

Three microcystins, YR, LR and RR and nodularin, all of which are hepatotoxic compounds, inhibited dose-dependently the activity of protein phosphatase 2A in and the specific [3H]okadaic acid binding to a cytosolic fraction of mouse skin, as strongly as okadaic acid. However, microcytins and nodularin did not induce any effects on mouse skin or primary human fibroblasts. Microinjection of microcystin YR into primary human fibroblasts induced morphological changes which were induced by incubation with okadaic acid. Microcystins and nodularin penetrate into the epithelial cells of mouse skin and human fibroblasts with difficulty, which reflects tissue specificity of the compounds.

Animals↗
PubMed1990

Tumor-promoting activity of staurosporine, a protein kinase inhibitor on mouse skin.

Staurosporine, which is a potent inhibitor of protein kinases, such as protein kinase C, inhibited both inductions of adhesion of human promyelocytic leukemia cells (50% effective dose = 9.0 nM) and Epstein-Barr virus early antigen in Raji cells (50% effective dose = 3.4 nM) by teleocidin. However, staurosporine induced irritation on mouse ear and histidine decarboxylase activity in mouse skin. It did not induce ornithine decarboxylase activity in mouse epidermis. The two-stage carcinogenesis experiments of staurosporine were carried out at two different doses. Experiment 1 revealed that the group treatment with a single application of 100 micrograms of 7,12-dimethylbenz(a)anthracene, followed by repeated applications of 50 micrograms of staurosporine, resulted in 85.7% of tumor-bearing mice at Wk 30, whereas group treatment with staurosporine alone or 7,12-dimethylbenz(a)anthracene alone gave 6.7% and 0%, respectively. Experiment 2 showed that group treatment with 7,12-dimethylbenz(a)anthracene followed by applications of 10 micrograms of staurosporine resulted in 33% of tumor-bearing mice at Wk 30. In addition, staurosporine treatment reduced the percentages of tumor-bearing mice treated with teleocidin from 100% to 67% in Wk 15. These results demonstrated that staurosporine is a weak tumor promoter of mouse skin compared with teleocidin, but staurosporine has some potency to inhibit tumor promotion by teleocidin.

Alkaloids↗
PubMed1990

Distribution of axons showing both enkephalin- and serotonin-like immunoreactivities in the lumbar cord segments of the Japanese monkey (Macaca fuscata).

Axons exhibiting both enkephalin- and serotonin-like immunoreactivities were observed by the double immunofluorescence method in the lumbar cord segments of the Japanese monkey. Double-labeled axons were seen almost exclusively in the dorsal horn, particularly in lamina I, lamina IIa and the lateral part of lamina V. After thoracic cordotomy, almost all of the double-labeled axons disappeared from the lumbar cord segments.

Animals↗
PubMed1990

Infrahyoid and accessory motoneurons in the Japanese monkey (Macaca fuscata).

The segmental and topographical organization of motoneurons innervating the infrahyoid (IH) and the spinal accessory (AC) muscles was studied in the Japanese monkey (Macaca fuscata) with the retrograde horseradish peroxidase (HRP) method after application of HRP to the peripheral nerve branches supplying the IH and AC muscles. IH motoneurons constitute two distinct slender cell columns, a longer medial and a shorter lateral one. The medial cell column extends from the most caudal level of the hypoglossal nucleus to the lower levels of the second cervical (C2) cord segment. In the medial column, motoneurons supplying the sternohyoid and sternothyroid muscles are distributed at the medullary and C1 levels, while those innervating the omohyoid muscle are primarily distributed at the C2 level. The lateral cell column consists of motoneurons supplying the thyrohyoid muscle and extends from the most caudal level of the hypoglossal nucleus to the middle levels of the C1 cord segment. Axons of thyrohyoid motoneurons follow a dorsomedially directed bent emergent course, making a hairpin turn. AC motoneurons supplying the sternocleidomastoid (SC) and trapezius (TZ) muscles form a single slender cell column extending from the most rostral level of the pyramidal decussation to the middle levels of the C6 cord segment. SC motoneurons are distributed from the most rostral level of the pyramidal decussation to the middle levels of the C3 cord segment, while TZ motoneurons are distributed from the upper levels of the C2 cord segment to the lower levels of the C6 cord segment. At the levels of the C2 and C3 cord segments, both SC and TZ motoneurons are distributed in the AC cell column; the cluster of SC motoneurons is located dorsomedial to that of TZ motoneurons.

Animals↗
PubMed1990

Inhibition of protein phosphatases by microcystins and nodularin associated with hepatotoxicity.

Microcystins and nodularin, isolated from toxic blue-green algae, are hepatotoxic monocyclic polypeptides. Both microcystins and nodularin inhibited in vitro protein phosphatase activity present in a cytosolic fraction of mouse liver, bound to the okadaic acid receptors, protein phosphatases 1 and 2A, and thus resulted in the increase of phosphoproteins; this was referred to as the apparent "activation" of protein kinases. Their concentrations causing 50% of the maximal effects are comparable to that of okadaic acid, a potent protein phosphatase inhibitor and a potent tumor promoter, in the nanomolar range of concentration. The increase of phosphoproteins was observed in rat primary cultured hepatocytes and was subsequently associated with morphological changes, which appeared to be a step in the process of hepatotoxicity. The well-known hepatotoxic compounds, alpha-amanitin and phalloidin, did not show any effects similar to those of microcystins, nodularin and okadaic acid. It is suggested that the hepatotoxicity of microcystins and nodularin may result from inhibition of protein phosphatases and the increase of phosphoproteins.

Animals↗
PubMed1990

Afferent fibers in the hypoglossal nerve: a horseradish peroxidase study in the cat.

The existence of afferent fibers in the cat hypoglossal nerve was studied by transganglionic transport of horseradish peroxidase (HRP). Injections of wheat germ agglutinin-conjugated HRP (WGA-HRP) into the hypoglossal nerve resulted in some retrograde labeling of cell bodies within the superior ganglia of the ipsilateral glossopharyngeal and vagal nerves. A few labeled cell bodies were also present ipsilaterally within the inferior ganglion of the vagal nerve and the spinal ganglion of the C1 segment. Some of the labeled glossopharyngeal and vagal fibers reached the nucleus of the solitary tract by crossing the dorsal portion of the spinal trigeminal tract. Others distributed to the spinal trigeminal nucleus pars interpolaris and to the ventrolateral part of the medial cuneate nucleus by descending through the dorsal portion of the spinal trigeminal tract. In the spinal cord these descending fibers, intermingling with labeled dorsal root fibers, distributed to laminae I, IV-V and VII-VIII of the C1 and C2 segments. Additional HRP experiments revealed that the fibers in laminae VII-VIII originate mainly from dorsal root of the C1 segment.

Animals↗
PubMed1990

Structure-activity relationship within a series of okadaic acid derivatives.

Okadaic acid (OA) is a potent non-12-O-tetradecanoyl-phorbol-13-acetate (non-TPA) type tumor promoter on mouse skin. OA acts on cells through inhibiting the activity of protein phosphatases and results in the increase of phosphorylation of proteins. Seventeen OA derivatives were evaluated as possible tumor promoters by means of three biochemical tests: inhibition of specific [3H]OA binding to a particulate fraction of mouse skin containing protein phosphatases, inhibition of protein phosphatase activity, and induction of ornithine decarboxylase in mouse skin. Potency in each of these biochemical tests correlated well for each of these derivatives. We present results indicating that the carboxyl group as well as the four hydroxyl groups at C-2, C-7, C-24 and C-27 of OA are important for activity. Acanthifolicin, which gave positive responses in these three biochemical tests as strong as those of OA and dinophysistoxin-1, is predicted to be an additional member of the OA class of tumor promoters.

Animals↗
PubMed1990

Localization of motoneurons innervating the stylohyoid muscle in the monkey, cat, rabbit, rat and shrew.

The distribution of motoneurons innervating the stylohyoid muscle was examined in the Japanese monkey (Macaca juscata), cat, rabbit, rat and house musk shrew (Suncus murinus) using the retrograde tracing method of horseradish peroxidase. The enzyme was injected into the stylohyoid muscle after ligating the central cut ends of the main peripheral branches of the facial nerve supplying the superficial facial muscles, or the trunk of the glossopharyngeal nerve supplying the pharyngeal muscles. In the monkey, cat and rabbit, stylohyoid motoneurons were identified in the reticular formation dorsomedial, dorsal or rostrodorsal to the main facial nucleus, and in the dorsomedial or dorsal border region, central part and ventral border region of the main facial nucleus. On the other hand, in the rat and shrew, stylohyoid motoneurons were found in the reticular formation dorsal or dorsomedial to the main facial nucleus and in the dorsal or dorsomedial border region of the main facial nucleus, but not in the central part and ventral border region of the main facial nucleus.

Animals↗
PubMed1989

Possible origins of substance P-like immunoreactive axons within Onuf's nucleus of the cat.

The double immunofluorescence method revealed that 30-50% of substance P-like immunoreactive (SP-LI) axons within Onuf's nucleus of cats exhibited enkephalin (ENK)-LI, and that about 5% of SP-LI axons within the nucleus showed serotonin (5-HT)-LI. After hemicordotomy, axons with both SP- and 5-HT-LI, as well as those with only 5-HT-LI, were profoundly depleted in Onuf's nucleus ipsilateral to the lesion, but no changes were detectable in axons with SP-LI and/or ENK-LI in the nucleus.

Animals↗
PubMed1989

Convergence of serotonin-, enkephalin- and substance P-like immunoreactive afferent fibers onto cat medullary dorsal horn projection neurons: a triple immunocytochemical staining technique combined with the retrograde HRP-tracing method.

Convergence of serotonin (5-HT)-, enkephalin (ENK)-, and substance P (SP)-like immunoreactive (LI) afferent fibers onto cat medullary dorsal horn projection neurons was examined by retrogradely labeling trigeminothalamic neurons and immunocytochemically labeling 5-HT, ENK and SP fibers in the same tissue section using distinct chromogens. Convergence of 5-HT-, ENK- and SP-LI fibers upon single projection neurons was often observed in laminae I and V.

Animals↗
PubMed1989

Convergence of serotonin-, enkephalin- and substance P-like immunoreactive afferent fibers on single pudendal motoneurons in Onuf's nucleus of the cat: a light microscope study combining the triple immunocytochemical staining technique with the retrograde HRP-tracing method.

Convergence of serotonin (5-HT)-, enkephalin (ENK)-, and substance P (SP)-like immunoreactive (LI) afferent fibers on single pudendal motoneurons within Onuf's nucleus was demonstrated: pudendal motoneurons were retrogradely labeled with horseradish peroxidase applied to the pudendal nerve. Subsequently, 5-HT-LI fibers were stained by the immunoperoxidase method, and then ENK- and SP-LI fibers were stained by the double immunofluorescence method.

Anal Canal↗