Biomedical subjects

N Mizuno

Publications and source records attributed to N Mizuno.

At least 253 records · Page 14Linked to original sources

PubMed1991

In vitro percutaneous transport of sodium diclofenac and diclofenac from oleaginous vehicle.

The penetration enhancement of sodium diclofenac and diclofenac by alcohols with various alkyl chains (C8 to C14) was evaluated by the steady state flux of diclofenac through rat abdominal skin. Decanol showed the greatest effect in this series. A more remarkable enhancing effect of the alcohols was observed in sodium diclofenac than in diclofenac. Diclofenac can penetrate through the ethylene-vinyl acetate membrane as a lipoid model membrane, but sodium diclofenac can not. Decanol enhanced the penetration of phenol red being dependent on its concentration in the vehicle. Therefore, decanol may interact with lipoid components of the skin and increase the aqueous pathway in the skin. These results indicate that sodium diclofenac and diclofenac may be penetrated through partially different pathways.

Animals↗

PubMed1991

Detection of ornithine decarboxylase gene expression in 12-O-tetradecanoylphorbol-13-acetate-treated mouse skin using in situ hybridization.

The localization of ornithine decarboxylase gene expression in mouse skin by tumour promoter, 12-O-tetradecanoylphorbol-13-acetate, was investigated using in situ hybridization. After 4 h of treatment with tumour promoter, the grains representing ornithine decarboxylase mRNA increased remarkably in number in the epidermis, especially in the follicular region. When the cells containing more than 5 grains were counted as positive, the number of positive cells increased by about 52-fold in the follicular epidermis, by about 19-fold in the interfollicular epidermis and by 4-fold in the dermis, as compared with controls. These results indicate that the epidermal cells are mainly responsible for the activation of ornithine decarboxylase by 12-O-tetradecanoylphorbol-13-acetate.

Animals↗

PubMed1991

Effect of retinoic acid on the infiltration of murine melanoma cells into the type I collagen gel.

Two lines of murine melanoma cells (B16 and Cloudman S91) were cultured on type I collagen gel and the effects of all-trans-retinoic acid on the growth and infiltration into the gel were assayed. In both lines, proliferation and the degree of infiltration were suppressed by the addition of all-trans-retinoic acid. The infiltration-inhibiting effect was expressed very rapidly and was dose-dependent at concentrations ranging from 10(-7) to 10(-5) M of all-trans-retinoic acid. These results suggest the anti-invasive effects of all-trans-retinoic acid on melanoma cells.

Animals↗

PubMed1991

A case of prurigo pigmentosa considered to be contact allergy to chromium in an acupuncture needle.

A 53-year-old male developed prurigo pigmentosa on his back, after undergoing acupuncture for 3 years. The eruptions were ceased on discontinuing the therapy but recurred with its resumption. The acupuncture needle contained 18.12% chromium. Erythema was induced by patch testing with potassium dichromate, and a flare-up was observed in the area of the patch test on resumption of acupuncture. We consider that the eruptions were induced by contact allergy to the chromium component of the acupuncture needles.

Acupuncture Therapy↗

PubMed1991

Effect of PUVA radiation on anaphylactic histamine release from rat dermal tissues.

We have devised a new in vitro model of type I cutaneous anaphylaxis. Male albino rats were sensitized with DNP-Ascaris. Abdominal skin was shaved, and thin, split-thickness slices of skin were cut with a dermatome. The dermis was excised and cut into 100 mg pieces. The dermal tissue was incubated with antigen in Tyrode's solution for 30 min at 37 degrees C. Antigen-induced histamine release from dermal tissue was measured fluorimetrically. Using this system, we measured histamine release from PUVA-irradiated and non-irradiated dermal tissues. A single PUVA irradiation inhibited type I cutaneous anaphylaxis, but did not affect spontaneous histamine release or total dermal histamine. Our model is considered to be useful for investigation of the mechanism of suppression of type I cutaneous anaphylaxis by PUVA.

Anaphylaxis↗

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↗

PubMed1991

Effects of food intake on the bioavailability of sulpiride from AEA film-coated tablet having a pH-dependent dissolution characteristic in normal or drug-induced achlorhydric subjects.

The effect of food intake on the bioavailability of sulpiride from a commercial film-coated tablet (100 mg/T) treated with polyvinylacetal diethylaminoacetate (AEA), which remains undissolved at pH above 4 approximately 5, were investigated in four healthy male subjects in the normal state or in a drug-induced achlorhydric state. The drug was administered as a single oral 100 mg dose of sulpiride under the fasting and nonfasting state using a crossover study design. Fifteen urine samples were collected over a 48 h period following sulpiride administration to determine sulpiride concentrations by HPLC. The bioavailability was estimated from the cumulative amount excreted unchanged in urine over 48 h (Du48). When AEA film-coated tablet was taken by subjects in the normal state, the bioavailability under the fasting state differed markedly among the four subjects due to differences in gastric acidity. The effect of food intake on the bioavailability also differed markedly among the individuals, being lower in high gastric acidity subject and higher in those with low gastric acidity subjects. When AEA film-coated tablet was taken by subjects in a simulated achlorhydric state, the bioavailability under the fasting state was very poor for all four subjects and did not show inter-subject variation. With food intake, the bioavailability increased 6-fold, probably due to the more vigorous movement of the formulation in the gastrointestinal tract, since both the basal and the meal-stimulated gastric acid secretion were markedly inhibited in the simulated achlorhydric state.

Achlorhydria↗

PubMed1991

An immunocytochemical analysis of a class-specific antibody response against Trichinella spiralis in humans.

The response of different classes of antibodies against antigens of the muscle larvae of Trichinella spiralis was tested using an immunocytochemical approach. Ultrathin sections of resin-embedded larvae were treated with sera from patients with trichinosis, then exposed to a biotinated second antibody and stained with avidin-gold complex. Antibody of the M-class was a major component in the response against a slow-responding group of antigens that included stichocyte granules, the cuticle surface, and the esophagus-occupying substance; a minor component in the response against antigens of the rapid-responding group that included cuticle inner layers, hypodermis, hemolymph, and intestinal gland granules. The response of G-class antibody against the rapid-responding group of antigens was detected in all patients tested, while against the slow-responding group of antigens it was detected in only half of the patients, suggesting that an antibody shift from the M to the G class occurred in some patients. The results, obtained in humans, were similar to those we obtained previously in rats (J. Parasitology, 76,230-239, 1990), suggesting that the rat immune system can serve as an experimental model of human trichinosis.

Animals↗

PubMed1990

Topographical projections from the thalamus, subthalamic nucleus and pedunculopontine tegmental nucleus to the striatum in the Japanese monkey, Macaca fuscata.

Topographical projections from the thalamus, subthalamic nucleus (STN) and pedunculopontine tegmental nucleus (PPN) to the striatum were examined in the Japanese monkey (Macaca fuscata) by using the retrograde axonal transport technique of WGA-HRP (wheat germ agglutinin-conjugated horseradish peroxidase). After WGA-HRP injection in the head of the caudate nucleus (CN) or putamen (Put), labeled neuronal cell bodies in the thalamus were distributed mainly in the nucleus ventralis anterior (VA)-nucleus ventralis lateralis (VL) complex and the nucleus centrum medianum (CM)-nucleus parafascicularis (Pf) complex, and additionally in the paraventricular, parataenial, rhomboid, reuniens, centrodorsal, centrolateral, paracentral, and centromedial nuclei. The data indicated that the pars principalis of VA (VApc) projected mainly to CN and additionally to Put, and that the pars magnocellularis of VA (VAmc) or pars oralis of VL (VLo) projected selectively to CN or Put, respectively. It was also indicated that CM projected to the middle and caudal parts of Put, while Pf projected to CN and the rostral part of the Put. The data further indicated that the dorsomedial, ventromedial, or lateral part of CM projected respectively to the dorsolateral, ventromedial, or intermediate part of Put, and that the medial or lateral part of Pf projected respectively to the medial or lateral part of the head of CN. Direct projections from STN and PPN to the striatum were confirmed. The subthalamostriatal projections showed a mediolateral topography. The PPN was shown to project bilaterally to the striatum with an ipsilateral predominance.

Animals↗

PubMed1990

The subparafascicular thalamic nucleus of the rat receives projection fibers from the inferior colliculus and auditory cortex.

The sources of afferent fibers to the subparafascicular thalamic nucleus (SPF) of the rat were investigated by the retrograde WGA-HRP and anterograde PHA-L methods. Layer V of the areas 3, 1 and 2 of the temporal cortex as well as the dorsal and external cortices of the inferior colliculus were found to send projection fibers to the whole rostrocaudal extent of the SPF bilaterally with a clear-cut ipsilateral dominance. The results indicate that the SPF of the rat may constitute a relay nucleus in the central auditory pathways.

Animals↗

PubMed1990

Increase of tyrosine hydroxylase-like immunoreactive neurons in the nucleus accumbens and the olfactory bulb in the rat with the lesion in the ventral tegmental area of the midbrain.

A small number of neurons in the nucleus accumbens of the rat showed tyrosine hydroxylase-like immunoreactivity (TH-LI). These TH-LI neurons had medium-sized cell bodies with several spiny dendrites. When a lesion was produced in the ventral tegmental area of the midbrain by injecting 6-hydroxydopamine, TH-LI neurons in the nucleus accumbens, as well as those in the olfactory bulb, were increased in number on the side ipsilateral to the lesion. The results indicated that expression of TH might be enhanced in some neurons deprived of dopaminergic afferent fibers.

Animals↗

PubMed1990

Direct projections of non-pyramidal neurons of Ammon's horn to the amygdala and the entorhinal cortex.

When WGA-HRP (wheat germ agglutinin-horseradish peroxidase conjugate) was injected into the amygdala (lateral and basolateral amygdaloid nuclei) or entorhinal cortex of the cat, a number of nonpyramidal neurons in Ammon's horn were retrogradely labeled. The results indicate that some non-pyramidal neurons in Ammon's horn send projection fibers to the amygdala and entorhinal cortex.

Amygdala↗

PubMed1990

Origins and distribution of cerebrovascular nerve fibers showing calcitonin gene-related peptide-like immunoreactivity in the major cerebral artery of the dog.

The origins and overall distribution of perivascular nerve fibers showing calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) in the major cerebral arteries were investigated immunohistochemically in the dog by using whole-mount preparations of the arterial trees around the circle of Willis. Perivascular nerve fibers with CGRP-LI were seen most abundantly in the basilar artery, vertebral artery, common anterior cerebral artery, proximal part of the anterior cerebral artery, and terminal part of the internal carotid artery. They were far less numerous in the middle cerebral artery, posterior cerebral artery, superior cerebellar artery, and distal part of the anterior cerebral artery. Neuronal cell bodies with CGRP-LI were observed in the trigeminal, nodose, superior cervical, and dorsal root ganglia. CGRP-LI fibers in the large pial arteries in the circle of Willis were eliminated ipsilaterally after unilateral transection of the ophthalmic division of the trigeminal nerve, and slightly reduced in number ipsilaterally after unilateral transection of the maxillary division of the trigeminal nerve. They did not show any noticeable changes after unilateral transection of the mandibular division of the trigeminal nerve. On the other hand, CGRP-LI fibers in the basilar and vertebral arteries did not show any appreciable changes after unilateral transection of the trigeminal nerve, but they were eliminated after bilateral ganglionectomy of the dorsal root ganglia of the first, second, and third cervical nerves. After ganglionectomy of the ciliary, pterygopalatine, otic, nodose, or superior cervical ganglion, no changes were observed in perivascular nerve fibers with CGRP-LI in the major cerebral arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Distribution of phosphate-activated glutaminase in the human cerebral cortex.

Phosphate-activated glutaminase (PAG), which catalyses conversion of glutamine to glutamate, is a potential marker for glutamatergic, and possibly GABA, neurons in the central nervous system. A polyclonal antibody, raised in rabbits against rat brain PAG, was applied to postmortem human brain tissue to reveal the distribution of PAG in the cerebral cortex. PAG immunoreactivity was observed in pyramidal and non-pyramidal neurons but not in glial cells. In the neocortex, large to medium-sized pyramidal neurons in layers III and V were stained most intensely, while the majority of smaller pyramidal cells were labeled either lightly or moderately. Such modified pyramids as the giant Betz cells, the large pyramidal cells of Meynert, and the solitary cells of Ramón y Cajal were also stained intensely. Fusiform cells in layer VI showed moderate to intense labeling. A number of cortical non-pyramidal neurons of various sizes stained moderately to intensely. These included large basket cells which were identified by their characteristic morphology and size in primary cortical areas. Pyramidal cells in the hippocampal formation as well as basket cells of the stratum oriens stained moderately to intensely. Since pyramidal cells are believed to be glutamatergic and large basket cells GABAergic, these results suggest that PAG plays a role in generating not only transmitter glutamate, but also GABA precursor glutamate.

Cerebral Cortex↗

PubMed1990

[The effect of neuropeptide Y on the hypothalamic-pituitary-adrenal axis in the dog].

There is increasing evidence that neuropeptide Y (NPY) affects the release of pituitary hormones, including adrenocorticotropic hormone (ACTH). The present study was designed to clarify the mechanism by which NPY activates the hypothalamic-pituitary-adrenal (HPA) axis in the dog. Mongrel dogs were equipped with a chronic cannula allowing intra-third (i.t.v.) or intra-lateral (i.l.v.) cerebroventricular administration. A 1.19 nmol, i.t.v. dose of NPY produced as great an ACTH and cortisol response as did equimolar ovine corticotropin releasing factor (CRF). This action of NPY was dose-dependent and shared by peptide YY (PYY) and pancreatic polypeptide (PP), other members of the PP family peptide. Intravenously (i.v.) administered NPY (1.19-11.9 nmol) was much less potent than i.v. CRF in stimulating ACTH and cortisol secretion. However, i.v. NPY significantly increased plasma ACTH and cortisol concentrations, raising the possibility that NPY may modulate the activity of corticotrophs. We next investigated the possible relationship between NPY and CRF on the HPA axis. Pretreatment with a novel CRF antagonist, alpha-helical CRF9-41 (130.9 nmol i.t.v. or 261.5 nmol i.v.), partly but significantly attenuated the ACTH and cortisol responses to i.t.v. NPY (1.19 nmol). Furthermore, adding a subthreshold dose of i.t.v. NPY (0.119 nmol) to i.t.v. CRF (1.19 nmol) or i.v. NPY (2.38 nmol) to i.v. CRF (0.595 nmol) resulted in the potentiation of CRF-induced ACTH secretion. These results indicate that NPY may activate the HPA axis in concert with CRF probably at hypothalamic and/or pituitary levels. The present findings that NPY evokes ACTH secretion and potentiates the effectiveness of CRF as a secretagogue, together with high concentrations of NPY in the hypothalamus and pituitary portal blood, suggest the NPY is involved in the multihormonal control of ACTH release.

Adrenocorticotropic Hormone↗

PubMed1990

Representation of the tensor veli palatini muscle in the trigeminal motor nucleus of the Japanese monkey (Macaca fuscata).

Distribution of motoneurons supplying the tensor veli palatini (TVP) muscle was examined in the Japanese monkey (Macaca fuscata) by the retrograde horseradish peroxidase (HRP) method. Neurons labeled with HRP which was injected into the tensor veli palatini muscle were seen in the ventromedial aspects of the dorsolateral division of the trigeminal motor nucleus, at all rostrocaudal levels of the trigeminal motor nucleus. The vast majority of these TVP motoneurons were distributed around the margin, especially the dorsal margin, of the cluster of motoneurons which innervate the lateral pterygoid muscle.

Animals↗

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

Erythrocytes suppress calcitonin gene-related peptide- and vasoactive intestinal polypeptide-like immunoreactivities in cerebrovascular nerve fibers after subarachnoid hemorrhage.

Changes of calcitonin gene related-peptide (CGRP)- and vasoactive intestinal polypeptide (VIP)-like immunoreactivities (LI) in cerebrovascular nerve fibers on the dog basilar artery were immunohistochemically examined by using whole-mount preparations after single percutaneous injection of blood components into the cisterna magna. Blood components were prepared from autologous arterial blood. CGRP- and VIP-LI in cerebrovascular nerve fibers were highly suppressed after the injection of washed erythrocytes, but only moderately after the injection of platelet-rich or platelet-poor plasma. The results suggest that erythrocytes may suppress CGRP- and VIP-LI in cerebrovascular nerve fibers after subarachnoid hemorrhage.

Animals↗