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Biomedical subjects

N Suzuki

Publications and source records attributed to N Suzuki.

At least 181 records · Page 10Linked to original sources
PubMed2001

Endorphin and enkephalin ameliorate excessive synovial cell functions in patients with rheumatoid arthritis.

OBJECTIVE: To determine whether endorphin (END) and enkephalin (ENK) modulate excessive synovial cell functions in patients with rheumatoid arthritis (RA). METHODS: Effects of leucine-enkephalin (leu-ENK), methionine-enkephalin (met-ENK), and beta-endorphin (END) on proinflammatory cytokine and matrix metalloproteinase (MMP) production by RA synovial cells were analyzed by immunoblotting, and their mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR) using limiting dilution of complementary DNA. Expression of opioid receptors on RA synovial cells was assessed by immunohistochemical staining, radioreceptor assay, and RT-PCR. RESULTS: Leu-ENK, met-ENK, and END inhibited tumor necrosis factor-alpha and interleukin 1beta production at the level of mRNA expression. ENK and END inhibited MMP-9 production and its enzymatic activity by RA synovial cells. The mu-subtype opioid receptor was expressed in the RA synovial lining and sublining cells. Radioreceptor assay suggested expression of high affinity receptor for END on RA synovial cells. The mu-subtype opioid receptor-specific antagonist, naloxone, reversed the inhibitory effect of the opioid peptides. The opioid peptides inhibited nuclear translocation and phosphorylation of the transcription factor, cyclic AMP responsive element binding protein (CREB) in RA synovial cells. CONCLUSION: Leu-ENK, met-ENK, and END inhibited excessive RA synovial cell functions in vitro. The opioid hormones may have not only antinociceptive action, but also antiinflammatory effects on synovitis itself in RA.

Aged↗
PubMed2001

[Is the prevalence of adult asthma increasing?].

Many studies from all over the world suggest that the prevalence of asthma, especially atopic asthma, is increasing. While this was already confirmed concerning childhood asthma, evidence of an increase in the prevalence of adult asthma is now accumulating. This phenomenon is probably related to urbanization, such as air pollution, air-tightness of dwellings and buildings, favorable environment for the propagation of mites and molds, habits of keeping furry and feathered pets, and so on. Changes in the infection patterns, including M. tuberculosis infection, especially in early childhood, might be involved in the recent prevalence of asthma. There is possibility that human population with low Th1 cell function (with relatively up-regulated Th2 function), which may be related to atopic pre-disposition, are increasing in the recent world.

Adolescent↗
PubMed2001

Exercise intensity based on heart rate while walking in spastic cerebral palsy.

We examined the heart rate (HR) of subjects with spastic cerebral palsy (CP) in order to estimate exercise intensity while walking. The subjects were 17 subjects with CP (14.0 +/- 3.7 years of age) containing 7 subjects rated as level 1, 4 subjects rated as level 2, and 6 subjects rated as level 3 by the Gross Motor Function Classification System, and 7 normal subjects (12.4 +/- 2.8 years of age) were used as a controls. Even in subjects whose gross motor function was excellent (rated as level 1), the HR significantly increased while walking when compared to normal subjects (p < 0.05), although the walking speed between the groups was not different. According to the HR, the exercise intensity while walking was adapted from weakly to moderately and thought to be appropriate for exercise. On the other hand, walking speed was significantly reduced in the subjects rated as level 2 and 3 (p < 0.05), and the HR increased significantly (p < 0.05). Seven of the ten subjects rated as either level 2 or 3 showed a high HR of over 150 beats/min while walking. The HR while walking of the two subjects rated as level 3 continued to increase although the walking speed was kept constant. The walking exercise would be too strong and become detrimental to such subjects.

Adolescent↗
PubMed2001

Enhancement of protease activity involved in modulation of cell mutability by microgravity stress in UVC-irradiated human cells.

It is an intriguing question whether gravity-changing stress modulates human cell mutability. To resolve this problem, it is necessary to determine the cellular events leading to modulation. We previously detected protease activation just after UV (UVC, principally 254 nm wavelength) irradiation followed by hypomutability in cultured human cells. We here investigated whether UV-activated protease activity is affected in human UVAP-1 cells exposed to gravity-changing stress prior to UV irradiation.

Cell Line↗
PubMed2001

Modification of urinary secretion of 8-hydroxy-2'-deoxyguanosine and serum ACTH concentration following repetitive parabolic flights.

It is important to clarify the molecular mechanisms of physiological responses of the human body to changes in gravity. Previous reports demonstrated that gravity-changing stress increases the human urinary concentration of 8-hydroxy-2'-deoxyguanosine (8-OHdG). However, it has yet to be clarified whether repetitive parabolic flight modulates the urinary concentration of 8-OHdG after exposure to gravity-changing stress. In the present study, the effects of the number of previous experiences with parabolic flight on urinary excretion of 8-OHdG and concentration of serum ACTH were examined in 12 healthy volunteers.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2000

Genetic analysis of the gene cluster for the synthesis of serotype a-specific polysaccharide antigen in Aactinobacillus actinomycetemcomitans.

The serotype a-specific polysaccharide antigen (SPA) of Actinobacillus actinomycetemcomitans consists of 6-deoxy-D-talose. A gene cluster associated with the biosynthesis of SPA was cloned and sequenced from the chromosomal DNA of A. actinomycetemcomitans SUNYaB 75 (serotype a). This cluster consisted of 14 open reading frames. Insertional inactivation of eight genes in this cluster resulted in loss of the ability of A. actinomycetemcomitans SUNYaB 75 cells to produce the polysaccharide. A protein database search revealed that the 11 sequential genes containing these eight genes were not found in SPA-associated gene clusters of the other serotypes of A. actinomycetemcomitans. These results suggest that the gene cluster is unique to serotype a and is essential to the synthesis of the SPA.

Aggregatibacter actinomycetemcomitans↗
PubMed2000

p41 as a possible marker for cell death is generated by caspase cleavage of p42/SETbeta in irradiated MOLT-4 cells.

We have reported previously that X-irradiated MOLT-4 cells during their rapid cell death exhibited dose and time dependently a new protein named p41 detected by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). An antibody, AM-1, raised against partial peptide of p41 stained two spots, p41 and p42, unexpectedly. Amino acid sequence analysis of partial peptides showed homology between p41 and a putative oncogene, set. In the present study, N-terminal amino acid sequencing of p41 and p42, and polyclonal antibodies newly prepared against different partial peptide sequences revealed that p41 was a N-terminal truncation form of p42, and p42 was identified as SETbeta. The cleavage site was at carboxyl end of SNHD 18 of p42. Radiation-induced p42 cleavage as well as apoptotic cell death was suppressed by a caspase-specific inhibitor Ac-DEVD-CHO but not by Ac-YVAD-CHO. Further in vitro cleavage experiments with recombinant p42 and either irradiated cell extracts or recombinant caspases concluded that the cleavage of p42 into p41 was catalyzed by caspase(s) mainly by caspase-7. One of newly raised antibodies, AM-4, specific to p41 or specific to cleavage site of p42, was found useful enabling simple detection of p41 by 1-D PAGE instead of laborious 2-D PAGE. p41 may serve as a marker of apoptotic cell death.

Amino Acid Sequence↗
PubMed2000

Calbindin-D28k in cerebrovascular extrinsic innervation system of the rat.

Calbindin-D28k, one of the calcium-binding proteins, belongs to the EF hand family and is commonly found in neurons. It serves as a representative neuronal marker for neuroanatomical investigations. The authors' knowledge of its precise function, however, is yet very limited. In this study, we examined the existence of nerve fibers with calbindin-D28k immunoreactivity in the cerebral blood vessels and ganglia that innervate the cerebral blood vessels in the rat. Numerous nerve fibers with calbindin-D28k immunoreactivity were observed on the walls of the major extracerebral arteries forming the circle of Willis and its branches. Calbindin-D28k immunoreactivity was seen in many neurons of the trigeminal, dorsal root and jugular ganglia. A small number of neurons showed calbindin-D28k immunoreactivity in the otic and superior cervical ganglia. Calbindin-D28k immunoreactivity was not detected in the sphenopalatine or internal carotid ganglia. Pericellular basket-like formations of nerve terminals with calbindin-D28k immunoreactivity were observed in the sphenopalatine, otic, internal carotid and superior cervical ganglia. The present study demonstrated calbindin-D28k immunoreactivity in the cerebrovascular nerve fibers as well as in their origins--the cranial ganglia. These findings are significant in understanding the calcium-mediated mechanism of the neural control of the cerebral blood vessels.

Animals↗
PubMed2000

Constitutive expression of a small heat-shock protein confers cellular thermotolerance and thermal protection to the photosynthetic apparatus in cyanobacteria.

The role of a small heat-shock protein (Hsp) in the acquisition of thermotolerance in cyanobacteria was investigated. Synechococcus sp. PCC 7942 was transformed with an expression vector carrying the coding sequence of the hspA gene encoding a small heat-shock protein from Synechococcus vulcanus under the control of the tac promoter. The transformant which was shown to constitutively express HspA displayed improved viability compared with the reference strain upon transfer from 30 to 50 degrees C in the light. When the heat shock was given in darkness, the survival rate in the reference strain increased greatly, approaching a level similar to that for the HspA expressing strain after heat shock in the light. Expression of HspA increased thermal resistance of photosystem II (PS II) and protected phycocyanin from heat-induced photobleaching. Our results are indicative of a central role for HspA in amelioration of the harmful effect of light during heat stress and identified the possible sites of action of the small Hsp in vivo to be the PS II complex and the light-harvesting phycobilisomes.

Adaptation, Physiological↗
PubMed2000

Photoreceptors and olfactory cells express the same retinal guanylyl cyclase isoform in medaka: visualization by promoter transgenics.

We examined the spatial expression patterns of two orphan receptor guanylyl cyclase genes OlGC4 and OlGC5 during embryogenesis of medaka and characterized the 5' flanking region required for tissue-specific expression of OlGC4 by introducing promoter-GFP fusion constructs into medaka embryos. Expression of OlGC5 is confined to retinal photoreceptor cells, while OlGC4 is expressed in the retina, pineal organ, and olfactory pits. The OlGC4 upstream region between -2374 and +343 is sufficient to drive the sensory organ-specific gene expression. Mutations in the consensus binding sequences for OTX/CRX transcription factors did not impair the reporter gene expression. Our results suggest that the same isoform of guanylyl cyclase is utilized in both photoreceptors and olfactory cells, and that transcription factors other than OTX/CRX primarily activate the OlGC4 expression.

Animals↗
PubMed2000

Characteristics and biodistribution of cationic liposomes and their DNA complexes.

We have developed some novel liposome formulations for gene transfection. The formulations consisting of O,O'-ditetradecanoyl-N-(alpha-trimethyl ammonio acetyl) diethanolamine chloride (DC-6-14) as a cationic lipid, phospholipid and cholesterol showed effective gene transfection activity in cultured cells with serum and in vivo, i.e., intraperitoneal injection in mice. In this report, the physicochemical characteristics and biodistribution of the liposomes containing DC-6-14 (DC-6-14 liposomes) as a drug (gene) carrier for gene therapy were investigated in vitro and in vivo. DC-6-14 liposome-DNA complexes were usually thought to have positive surface charge. However, depending on the ratio of DNA to liposomes, zeta-potential of the complexes became negative. The diameter of the complexes also depended on the DNA-liposome ratio, and showed a maximum when their surface potential was neutral. When biodistribution of the complexes was determined after intravenous injection, positively charged complexes showed an immediate lung accumulation. On the other hand, negatively charged complexes did not show lung accumulation. These results have suggested that biodistribution of the DNA-liposome complexes, prepared with DC-6-14 liposomes, depends on their surface charge. Therefore, some surface modification of DC-6-14 liposomes may improve the biodistribution and hence the targetability of their DNA complexes.

Animals↗
PubMed2000

Dialysis-related spinal canal stenosis: a clinicopathological study on amyloid deposition and its AGE modification.

Three cases operated for spinal canal stenosis induced by dialysis-related amyloidosis (DRA) were investigated clinicopathologically. Cases were all-male, and had undergone hemodialysis around 20 years. In two cases, cervical plain X-rays showed only minor spondylotic changes. However, magnetic resonance imaging (MRI), myelography, and computed tomography (CT) showed extradural thickness with compression on the cervical spinal cord and cauda equina. In one case cervical X-rays showed typical destructive spondyloarthropathy (DSA), and MRI showed compression myelopathy. Surgical treatment on both cervical and lumbar spine in two cases and on cervical spine only in one case successfully reduced the symptoms. Extradural thickened tissue and ligament flavum obtained during surgery were studied histopathologically and immunostained by using anti-CD68, anti-beta2-microglobulin (beta2m), and anti-advanced glycation end product (AGE) antibody. Congo red stain showed diffuse or nodular amyloid deposition, and immunostaining with anti-beta2m and anti-AGE antibodies also demonstrated the same distribution pattern. Thus, beta2m-positive amyloid tissue in the extradural thickness (extradural amyloid deposition) was immunohistochemically demonstrated to be modified with AGE. Inflammatory reaction with histiocytic and giant cell infiltration was also shown around the amyloid tissues. There were CD68-positive cells, and some cells were positive for AGE and beta2m. These findings suggest that beta2m accumulation and inflammatory reaction finally promote destruction of connective tissues. MRI, CT and/or myelography are necessary for diagnosing spinal canal stenosis accompanied by DRA. In conclusion, we propose a more comprehensive concept of dialysis-related spinal canal stenosis, which includes both DSA and myeloradiculopathy induced by extradural thickness.

Amyloid↗
PubMed2000

Telomere repeat DNA forms a large non-covalent complex with unique cohesive properties which is dissociated by Werner syndrome DNA helicase in the presence of replication protein A.

We describe the unique structural features of a large telomere repeat DNA complex (TRDC) of >20 kb generated by a simple PCR using (TTAGGG)(4) and (CCCTAA)(4) as both primers and templates. Although large, as determined by conventional agarose gel electrophoresis, the TRDC was found to consist of short single-stranded DNA telomere repeat units of between several hundred and 3000 bases, indicating that it is a non-covalent complex comprising short cohesive telomere repeat units. S1 nuclease digestion showed that the TRDC contains both single- and double-stranded portions stable enough to survive glycerol density gradient centrifugation, precipitation with ethanol and gel electrophoresis. Sedimentation analysis suggests that a part of the TRDC is non-linear and consists of a three-dimensional network structure. After treatment with Werner DNA helicase the TRDC dissociated into smaller fragments, provided that human replication protein A was present, indicating that: (i) the TRDC is a new substrate for the Werner syndrome helicase; (ii) the telomere repeat sequence re-anneals rapidly unless unwound single-stranded regions are protected by replication protein A; (iii) the TRDC may provide a new clue to understanding deleterious telomere-totelomere interactions that can lead to genomic instability. Some properties of the TRDC account for the extra-chromosomal telomere repeat (ECTR) DNA that exists in telomerase-negative immortalized cell lines and may be involved in maintaining telomeres.

Centrifugation, Density Gradient↗
PubMed2000

A gene cluster for the synthesis of serotype d-specific polysaccharide antigen in Actinobacillus actinomycetemcomitans.

The serotype d antigen of Actinobacillus actinomycetemcomitans consists of D-glucose, D-mannose, and L-rhamnose in a molar ratio of 1:2:1. A gene cluster involved in the synthesis of serotype-specific polysaccharide antigen was cloned from the chromosomal DNA of A. actinomycetemcomitans IDH 781 (serotype d). This cluster consisted of 12 open reading frames. Insertional inactivation of six genes in this cluster resulted in loss of ability of A. actinomycetemcomitans IDH 781 cells to produce the polysaccharide. Comparing the structure of the gene cluster with similar clusters from other serotypes of A. actinomycetemcomitans, showed that eight genes are unique to serotype d; the other four genes are involved in the biosynthesis of dTDP-L-rhamnose. These results suggest that the synthesis and structure of serotype d-specific polysaccharide of A. actinomycetemcomitans is quite different from those of other serotype strains.

Actinobacillus↗
PubMed2000

Mouse group X secretory phospholipase A2 induces a potent release of arachidonic acid from spleen cells and acts as a ligand for the phospholipase A2 receptor.

Group X secretory phospholipase A2 (sPLA2-X) has recently been shown to possess a powerful potency for releasing arachidonic acid from cell membrane phospholipids. Here, we report the purification of mouse pro- and mature forms of sPLA2-X, as well as its expression and biological functions. Purified pro-sPLA2-X was found to possess a propeptide of 11 amino acid residues attached at the NH2-terminals of the mature protein, and showed as little as 8% of the PLA2 activity of the mature form. Limited proteolysis of pro-sPLA2-X with trypsin resulted in the appearance of the mature form with a concomitant increase in PLA2 activity, suggesting a requirement of proteolytic removal of the propeptide for the optimal activity. The expression of sPLA2-X mRNA was detected in various tissues including the lung, thymus, and spleen, and immunohistochemical analysis revealed its expression in splenic macrophages. In the spleen cells, mature sPLA2-X elicited a prompt release of arachidonic acid with significant production of prostaglandin E2 more efficiently than group IB and IIA sPLA2s. In addition, sPLA2-X was identified as a high-affinity ligand for both native and recombinant form of mouse PLA2 receptor (PLA2R). However, there was no significant difference in the sPLA2-X-induced arachidonic acid release responses in the spleen cells between wild-type and PLA2R-deficient mice. These findings strongly suggest that sPLA2-X possesses two distinct biological functions in mice: it elicits a marked release of arachidonic acid from membrane phospholipids leading to the production of lipid mediators based on its enzymatic potency, and it acts as a natural ligand for the PLA2R that has been shown to play a critical role in the production of inflammatory cytokines during endotoxic shock.

Animals↗