Biomedical subjects

K Sano

Publications and source records attributed to K Sano.

At least 469 records · Page 26Linked to original sources

PubMed1990

Atrophy of the ipsilateral substantia nigra following middle cerebral artery occlusion in the rat.

Following occlusion of the left middle cerebral artery in the rat, marked atrophy was observed in the ipsilateral substantia nigra in and after the second week. The mechanism of this neuropathological change in the substantia nigra, which is remote from the site of infarction, may be explained by transsynaptic, neurotransmitter-mediated disinhibition as a result of infarction of the striatum.

Animals↗

PubMed1990

The budding of defective human immunodeficiency virus type 1 (HIV-1) particles from cell clones persistently infected with HIV-1.

Three cell clones producing large numbers of infectious or noninfectious particles of human immunodeficiency virus type 1 (HIV-1), designated M 10/LAV-2, M 16/LAV-3, and MT/LAV-17, were isolated from persistently HIV-1-infected MT-4 cells. In M 10/LAV-2, the HIV-1 proteins were defective in the cleavage of gag precursor protein, and the particles were doughnut-shaped with a double-ring structure. These particles were produced by budding at the cell surface from crescentic structures followed by the formation of double-ring structures. The viral proteins in M 16/LAV-3 were defective in the cleavage of env precursor protein. The morphology of the virus particles was intact, and an electron dense bar-shaped core was seen inside a single-ring enveloped structure. The intact particles were released from the cell surface by a budding process in which crescent shape structures first appeared at the cell membrane, then subsequently just before release matured to a complete structure with an electron dense core. In MT/LAV-17, the synthesis of HIV-1 proteins was normal, and the particles were teardrop-shaped with an intact core structure. These particles were produced by budding with an electron dense core at the cell surface. Thus, it was suggested that the morphological maturation of HIV-1 particles was completed just before release from the cell surface in several cell clones producing HIV-1 particles of different morphology.

Antibodies, Monoclonal↗

PubMed1990

A case of gallbladder cancer producing granulocyte-colony-stimulating factor.

A patient with pleomorphic giant cell carcinoma of the gallbladder also had mild neutrophilia, and this tumor was found to be human granulocyte colony-stimulating factor (G-CSF)-positive on immunohistochemical staining. CSF activity in urine and serum was not examined, but leukocytosis disappeared immediately after cholecystectomy. These findings suggest that this was a G-CSF-producing tumor.

Aged↗

PubMed1990

Changes in cerebral free fatty acids and triacylglycerols in focal cerebral ischemia.

1. Focal cerebral ischemia was induced in anesthetized rats by occluding the stem of the proximal middle cerebral artery. 2. The levels of free fatty acids, such as stearic and arachidonic acids, in the ischemic cerebral cortex increased progressively until 60 min after occlusion, but thereafter they decreased rapidly. 3. In contrast to the time-dependent changes in free fatty acids, the levels of triacylglycerol (TAG) in the ischemic cerebral cortex continued to increase for 120 min after occlusion. Increases in TAG-palmitate, -stearate and -arachidonate accounted for the increase in the triacylglycerol level. 4. The pattern of the lipid changes in focal cerebral ischemia differs from those reported in bilateral diffuse cerebral ischemia induced by arterial occlusion or in decapitation ischemia.

Animals↗

PubMed1990

Osteoradionecrosis of sphenoid and temporal bones in a patient with maxillary sinus carcinoma: a case report.

A case of radionecrosis of sphenoid and temporal bones is reported. The patient received a combination of surgery, radiotherapy, and chemotherapy for his left maxillary sinus carcinoma. After the combined therapy, necrosis accompanying inflammation developed in the maxillary and temporal regions. Excision of the necrotic tissues was done, and the left ascending ramus of the mandible was resected because of persistent tumor mass at the left infratemporal fossa. Although the excision wound of the maxilla healed by epithelialization, an area of nonvital bone remained exposed in the temporal region, where progressive osteonecrosis with infection led to breakdown of the skin. The necrotic bones of the zygomatic arch and the sphenotemporal sutural region became visible through the skin defect, and computerized tomography scan revealed bone necrosis involving the inferolateral area and the base of the skull. Excision of the necrotic bone and reconstruction with sternocleidomastoid myocutaneous flap were performed.

Carcinoma, Squamous Cell↗

PubMed1990

Computed tomography in the evaluation of postoperative maxillary cysts.

Twenty-two cases (34 sides) of postoperative maxillary cysts evaluated with axial and coronal computed tomograms were reviewed. Precise characteristics pertaining to the extent of maxillary sinus involvement, loculation, presence of septae, bony perforation, and associated cystic projection or extension into adjacent structures were determined. Of the 34 sides, 13 cysts involved the sinus completely. Twelve were multilocular. Thirteen exhibited incomplete septae. Perforations were most frequent in the anterolateral and medial bony walls (28 and 27, respectively); however, the 14 posterolateral wall perforations showed a higher percentage of cystic projection into adjacent structures. Ethmoid extension was seen on two sides, orbital extension on one. Nine sides showed tooth roots communicating with the cyst. The routine use of computed tomography in the evaluation of this type of cyst is proposed.

Adult↗

PubMed1990

Time-sequential change of amino acid neurotransmitters--GABA, aspartate and glutamate--in the rat basal ganglia following middle cerebral artery occlusion.

To clarify the involvement of neurotransmitters in the remote metabolic effect following focal ischaemia, amino acid neurotransmitter candidates--GABA, aspartate and glutamate--were measured time-sequentially in the basal ganglia following middle cerebral artery occlusion in the rat, which is known to produce a change in glucose metabolism and blood flow in the remote basal ganglia. GABA and aspartate content decreased in the ipsilateral substantia nigra from the second to the 28 th postoperative day. The same tendency was observed in the ipsilateral globus pallidus. Glutamate did not change significantly in either nucleus. In the contralateral side, GABA increased significantly in the substantia nigra throughout the experimental period and in the striatum during the first seven days. These results indicate that the destruction of strionigral tract by focal ischaemia induced the decrease of inhibitory GABA in the ipsilateral substantia nigra. The increase of metabolism in this nucleus may be caused by the decrease of the inhibitory effect.

Animals↗

PubMed1990

Cell division-associated expression of an epitope, KH17, on early developing thymocytes.

A newly established monoclonal antibody, KH17, detects a unique epitope temporarily expressed on early developing CD3-thymocytes confined to a cycling stage. KH17 is detectable on a part of CD4-CD8-,CD4-CD8+, and CD4+CD8+ cells, but not on CD4+CD8- thymocytes. By four-color flow cytometry analysis using KH17, we were able to define the heterogeneity of immature CD4-CD8- thymocytes by the expression of KH17 and IL-2R. In Thy-1-congeneic bone marrow chimeras, the appearance of KH17-IL-2R+ thymocytes preceded the increase of KH17+IL-2R- cells. The antibody could also divide CD3-CD4-CD8+ cells into two subpopulations, KH17+ and KH17-, which showed a continuum. In the fetal thymus there was a rapid and dramatic increase of KH17-CD4+CD8+ thymocytes concomitant with a decrease of KH17+CD4-CD8+ thymocytes in later gestation days. KH17 is not expressed on resting peripheral T cells, but is expressed on a large proportion of Con A-activated blastic spleen cells. The KH17 molecules precipitated from Con A-activated spleen cells were 55 and 75 kd polypeptides, but different from IL-2R subunits.

Animals↗

PubMed1990

Characterization of C-protein isoforms expressed in developing, denervated, and dystrophic chicken skeletal muscles by two-dimensional gel electrophoresis.

C-Proteins in developing, denervated, and dystrophic chicken skeletal muscles were examined by means of two-dimensional (2D) gel electrophoresis in combination with immunoblotting. In this analysis, the electrophoresis system which was devised by Hirabayashi (Anal. Biochem. 117, 443-451, 1981) provided excellent resolution; three C-protein variants, one fast-type (Cf) and two slow-types (CS3 and CS4) with different Mrs and pIs, were distinguished on a 2D gel. In the neonatal breast muscle, both Cf and CS3 were detected, but during postnatal development, CS3 disappeared from this muscle and Cf became only the C-protein isoform in the adult muscle. In posterior latissimus dorsi (PLD) muscle, both Cf and CS3 were similarly detected at the neonatal stage, but CS3 was replaced by CS4 as this muscle developed. When the breast and PLD muscles were denervated or suffered from muscular dystrophy, both CS3 and CS4 were co-expressed in these muscles in addition to Cf. These results definitely show that the C-protein isoform pattern varies during development and degeneration of chicken skeletal muscles, and in addition the dystrophic or denervated muscle differs from the neonatal muscle with regard to C-protein isoform expression. We suggest that chicken skeletal muscle degenerating due to denervation or muscular dystrophy does not simply recapture the nature of the neonatal muscle, but shifts in a somewhat different direction.

Aging↗

PubMed1990

Analysis of age-related degeneracy of T-cell repertoire: localized functional failure in CD8+ T cells.

The repertoire and frequency of alloreactive T cells in aged mice were examined by limiting dilution analysis of the mixed-lymphocyte reaction (MLR). Mice were aged in specific pathogen-free conditions up to 31 months, and MLR of their spleen cells under limiting dilution conditions was examined at various stages of ageing. The frequency of alloreactive T cells was found to decrease in mice more than 14 months of age, and the value reached about 1/3 of that of young mice of 2 months of age. The slope analysis of cell dose-response curves of MLR indicated the existence of two interacting T-cell populations, i.e. CD4+ and CD8+, cooperation between which is required for the full manifestation of MLR in limiting dilution conditions. The decrease in the alloreactivity of aged spleen cells was ascribed to the selective functional loss of the CD8+ population, because the CD4+ but not the CD8+ T-cell fraction from aged mice could restore the limiting factor in MLR. The decrease in the cooperative activity of CD8+ T cells in allo-MLR starts much earlier than the decrease in the number of CD8+ T cells in the spleen.

Aging↗

PubMed1990

The threshold of pain and neurotransmitter's change on pain in Parkinson's disease.

Among Parkinson's disease (PD) patients complaining of pain, 10 with pain not associated with a motor fluctuation or L-dopa therapy were evaluated. The controls were 14 PD without pain and eight with thalamic pain syndrome. The threshold of pain and neurotransmitters in CSF were measured in the three groups. In PD with pain, the maximum tolerance level and tourniquet pain ratio decreased significantly. In PD with pain, the score on the self-depression scale increased significantly and 5-hydroxy-indole acetic acid (5-HIAA) among the neurotransmitters decreased significantly. These results suggest that decreases in the threshold of pain and changes of serotonin in CSF are involved in the development of specific pain in PD who do not respond to L-dopa.

Aged↗

PubMed1990

[HIV isolation and clinical markers on the seropositive subjects].

We investigated 18 anti-HIV seropositive subjects with respect to the isolation of HIV from peripheral blood mononuclear cells (PBMC) and cellular and serologic markers for progression to AIDS. The subjects included homosexuals and recipients of blood products. Three had AIDS, an asymptomatic subject developed AIDS during the study and 14 of the remaining have remained asymptomatic. HIV was isolated from all AIDS patients and 7 asymptomatic subjects. Moreover HIV was detected significantly sooner in symptomatic patients than in asymptomatic subjects. The reductions in CD4 lymphocytes number and CD4/CD8 ratio, as well as anti-HIV core (p24, p17) antigens negativity correlated with deterioration of clinical symptoms and successful HIV isolation. The isolates from AIDS patients and from an asymptomatic subject who 9 months later developed AIDS were infective and cytotoxic to MT-4 cells, however isolates from asymptomatic subjects were not infective. These findings indicate that disease progression correlates with the appearance of variant viruses that are more infective and cytopathic.

Biomarkers↗

PubMed1990

In situ hybridisation with digoxigenin-labelled DNA probes for detection of viral genomes.

The applicability of a recently developed non-radioactive DNA labelling and detection method, which uses the digoxigenin (DIG) enzyme linked immunosorbent assay (ELISA) system, for the detection of viral infections in pathology specimens by in situ hybridisation, was examined. Its efficacy was compared with that of biotin and radioisotope labelling methods. Three cases of progressive multifocal leucoencephalopathy, two of verruca vulgaris, and seven cases of laryngeal papilloma were studied. The sensitivity of the DIG labelled probe was almost the same as that of a 35S-labelled probe in the dot-blot hybridisation test. Using in situ hybridisation with 35S-labelled and DIG labelled probes, the levels of the hybridised signals detected were similar. The biotin labelled probe was less sensitive, particularly in the cases of laryngeal papilloma. The DIG labelling and detection method was highly sensitive and applicable to the detection of viral infection by ISH, and is preferable to a radiolabelled probe, especially when in situ hybridisation is done in the pathology laboratory.

Biotin↗

PubMed1990

Age-related degeneracy of T cell repertoire: influence of the aged environment on T cell allorecognition.

The present study was undertaken to understand the mechanism of alteration of the alloreactivity of T cells in aged mice. The experiment utilized bone marrow chimeras revealed that the age-associated changes in alloreactivity are not primarily determined by the bone marrow stem cells but determined by the environment where stem cells differentiate into mature T cells. The limiting dilution analysis and microfluorometry analysis indicated that the changes lie in both frequency of alloreactive T cells and the expression of T cell antigen receptor. Such quantitative and qualitative changes seems to be the causes for declined alloreactivity of T cells in aged mice.

Age Factors↗

PubMed1990

[Anti-allergic effects of tazanolast [butyl 3'-(1H-tetrazol-5-yl) oxanilate, WP-833] metabolites].

WP-833 is an orally active new antiallergic drug. The effects of WP-833 metabolites on experimental allergic reactions were investigated in various animal models. MTCC [3'-(1H-tetrazol-5-yl) oxanilic acid], the main metabolite of WP-833, dose-dependently inhibited 48-hr homologous passive cutaneous anaphylaxis (PCA) in rats and 8-day PCA in guinea pigs after intravenous administration. The inhibitory effect of MTCC on PCA was nearly equal to that of WP-833. MTCC also inhibited 48hr PCA in rats after the peroral administration, although its inhibitory effect was about 6 times weaker than that of WP-833. MTCC also showed a dose-dependent inhibition on the release of histamine or slow reacting substance of anaphylaxis (SRS-A) from passively sensitized rat peritoneal mast cells and guinea pig lung fragments in vitro with a similar potency to WP-833. MTA [3-(1H-tetrazol-5-yl) aniline] and MTAA [3'-(1H-tetrazol-5-yl) acetanilide], other metabolites of WP-833, inhibited PCA and anaphylactic histamine release from rat peritoneal mast cells at considerably higher doses than WP-833, and they showed no effects on the release of histamine and SRS-A from guinea pig lung fragments. Moreover, only small amounts of MTA and MTAA were detected in the blood after the oral administration of WP-833. From these results, it was suggested that MTCC may be the main active metabolite of WP-833.

Administration, Oral↗

PubMed1990

[Effects of methylmercury on ethanol-induced sleeping time of mice].

This study was carried out to clarify the effects of methylmercury intoxication on the ethanol-induced sleeping time of mice. The mice were injected with methylmercury chloride (MMC) (10 mgMMC/kg body weight) subcutaneously for 1, 5 and 10 successive days (1, 5 and 10 inj.), and control mice received only saline. Twenty-four hours, after the last injection, these mice were treated with ethanol (4.5 mgEtOH/kg body weight) intraperitoneally and subsequent sleeping time was observed. After 24 hours, mice were sacrificed to measure the concentration of MMC in various brain regions and liver. A similar experiment with ethanol treatment was also performed to assay the biogenic monoamines in various brain regions and alcohol dehydrogenase (ADH) activity in liver. The results can be summarized as follows: 1) Ethanol-induced sleeping time was 170 min. in the 10 inj. and it was significantly longer than saline, 1 and 5 inj. However, other experimental groups showed no change when compared with saline. 2) Norepinephrine levels increased in white matter and pons + medulla after 1 inj. 3) Dopamine levels increased only in white matter of the 10 inj. when compared with saline. No changes were shown in the other groups. 4) Serotonin levels increased in all the regions after 1 inj. 5) ADH activity in liver did not show any alteration during the experimental period when compared with saline.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Cloning and characterization of genes responsible for m-fluoro-D,L-phenylalanine resistance in Brevibacterium lactofermentum.

Two kinds of 3-deoxy-D-arabino-hepturosonate-7-phosphate (DAHP) synthase genes were cloned from an L-Phe-producing mutant of Brevibacterium lactofermentum, AJ11957, which was resistant to m-fluoro-D,L-phenylalanine (mFP) and p-fluoro-D,L-phenylalanine (pFP) and which had DAHP synthase free from feedback inhibition. Both genes were cloned using a vector plasmid, pAJ1844, and the resulting recombinant plasmids were named pAR1 and pAR2. They had different structures on the restriction maps. Both plasmids, pAR1 and pAR2, conferred mFP and pFP resistance and L-Phe and L-Tyr productivity on a wild-type strain of B. lactofermentum, AJ12036. The degrees of L-Phe-analogue resistance and aromatic amino acid productivity of the pAR1-transformant were larger than those of the pAR2-transformant. The introduction of pAR1 to AJ12036 resulted in the alteration of DAHP synthase activity from a feedback-sensitive mechanism to a feedback-insensitive one accompanied by an elevated level of specific activity. A DAHP synthase deficient mutant of Escherichia coli was complemented by pAR2, but not by pAR1. Characteristics of the two kinds of DAHP synthase genes are discussed.

3-Deoxy-7-Phosphoheptulonate Synthase↗

PubMed1990

Ammon's horn sclerosis: its pathogenesis and clinical significance.

Sclerosis of the cornu Ammonis or Ammon's horn sclerosis (AHS) is an "often-described, yet hitherto enigmatic phenomena" as Spielmyer put it in 1927. It has been found in cases with ischemia, anoxia or hypoglycemia and in more than half of the epileptic brains examined at autopsy. Various theories about its pathogenesis have been propounded. Among them, the "Pathoklise" theory of the Vogts and the vascular theory of Spielmeyer and his associates were prevailing until recently. In 1953, two articles were published to contribute to the pathogenesis of ictal automatism (a type of complex partial or temporal lobe seizures). One is the incisural sclerosis theory by Penfield and his associates and the other is the Ammon's horn sclerosis theory by Sano and Malamud. The former authors described a diffuse sclerosis of the infero-mesial temporal structures without, however, specifically relating it to AHS. They considered it was the result of localized anoxia of that portion of the brain caused by incisural herniation occurring during parturition. Sano and Malamud maintained that AHS is a result of convulsions, a distinct scar adjacent to which epileptogenic foci may develop in the course of time to cause ictal automatism. The latter theory was corroborated by Sano, Falconer and others. Falconer expanded the theory to the assertion that not only ictal automatism but other types of intractable epilepsy may be due to "mesial temporal (Ammon's horn) sclerosis". The most recent development in the pathogenesis of AHS is the excitotoxicity theory. Namely, AHS is caused by excessive excitation of neurons, probably by putative excitatory neurotransmitters, especially, glutamate. For this theory, there is a significant body of evidence. The problem of AHS, an old research subject and a matter of long-lasting controversy, has now been updated and become one of the newest topics in the field of experimental neurobiology.

Animals↗