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Biomedical subjects

T Sawada

Publications and source records attributed to T Sawada.

At least 37 records · Page 2Linked to original sources
PubMed2005

CUL1, a component of E3 ubiquitin ligase, alters lymphocyte signal transduction with possible effect on rheumatoid arthritis.

Ubiquitination affects various immune processes and E3 ubiquitin ligases (E3) play an important role in determining substrate specificity. We identified 11 human E3 ligase genes of potential importance in pathogenesis of autoimmune diseases by search of public databases and screened them for candidacy of biological investigation with case-control linkage disequilibrium tests on multiple SNPs in the genes using rheumatoid arthritis (RA) as a model of autoimmune diseases. Significant association with RA was observed in an SNP in intron 3 of Cullin 1 (CUL1) that affected transcriptional efficiency of the promoter activity in lymphocytic cell lines. Quantitative expression analysis revealed that CUL1 mRNA was highly detected in lymphoid tissues including spleen and tonsil, and was specifically expressed in T and B lymphocytes in fractionated peripheral leukocytes. Histological evaluation of tonsils indicated that CUL1 protein expression was relatively specific for maturing germinal centers. Suppression of CUL1 expression had influence on the phenotype of T-cell line, that is, it inhibited IL-8 induction, which is known to play an important role in the migration of inflammatory cells into the affected area seen in RA. Our data suggest that the regulation of CUL1 expression in immunological tissues may affect the susceptibility of RA via altering lymphocyte signal transduction.

Arthritis, Rheumatoid↗
PubMed2005

Bacteriological study of autologous cryoprecipitate-derived fibrin glue as the operative sealant.

Fibrin glue (FG) is frequently used to seal and cover the anastomoses in many operations such as cardiovascular surgery or orthopaedic surgery. However, in case of gastrointestinal surgery, anastomoses are potentially contaminated, and FG may promote bacterial growth, increasing the risk of leakage. The purpose of this study was to examine the effect of cryoprecipitate-derived FG (CryoFG) on bacterial growth. Bacterial growth on the CryoFG and on the commercial FG (Beriplast P) was evaluated and compared with that on control medium. In addition, the complement activities were evaluated by heat inactivation or addition of guinea-pig complement to the experimental settings. The CryoFG inhibited the growth of Escherichia coli, whereas the commercial FG had no effect. Heat inactivation of the CryoFG inhibited the bactericidal effect of CryoFG. Addition of guinea-pig complement to the heat-inactivated CryoFG could almost restore the bactericidal activity, suggesting the important role of complement. This study showed that the CryoFG preserved the complement activity, which inhibited the in vitro growth of E. coli. Therefore, we concluded that the application of the CryoFG for gastrointestinal surgical anastomoses not only would be safe but also has the advantage of reducing bacterial infection.

Bacteria↗
PubMed2005

Detection of transforming growth factor-alpha and epidermal growth factor receptor mRNA and immunohistochemical localization of the corresponding proteins in the canine uterus during the estrous cycle.

Uterine expression of the epidermal growth factor (EGF) family of growth factors has not been studied in the dog. The present study looks at the presence of mRNA transcripts and immunohistochemical localization for transforming growth factor-alpha (TGF-alpha), which is the potent EGF family member, and for EGF receptor (EGF-R) in the canine uterus during the estrous cycle. The reverse transcriptase-polymerase chain reaction together with sequencing of the products confirmed the presence of their mRNA transcripts in the endometrium throughout the estrous cycle. Immunohistochemical analysis found clear positive staining for TGF-alpha and EGF-R in the luminal and glandular epithelia at proestrus and estrus. Immunoreactivity decreased at the early stage of diestrus. In the mid stage of diestrus, clear staining for TGF-alpha was again found in the glands of the luminal region, and staining for EGF-R was observed in all glands. Very little staining was seen at anestrus for either TGF-alpha or EGF-R. These results suggest that TGF-alpha expressed in the uterus may be involved in regulating growth, differentiation and regression in the endometrial epithelial cells during the estrous cycle in the dog.

Animals↗
PubMed2005

Toxicity and roles of reactive oxygen species.

The history of studies in biology regarding reactive oxygen species (ROS) is approximately 40 years. During the initial 30 years, it appeared that these studies were mainly focused on the toxicity or microbicidal-related agents of ROS. However, recent studies have identified another action regarding oxidative signaling, other than toxicity of ROS. Basically, it is suggested that ROS are reactive, and degenerate to biomacromolecules such as DNA and proteins, leading to deterioration of cellular functions as an oxidative stress. On the other hand, recent studies have shown that ROS act as oxidative signaling in cells, resulting in various gene expressions. For example, NADPH oxidase, a major source of superoxide radicals (O(2)(-)), expresses in various tissues such as leukocytes and cardiovascular systems, and ROS derived from the enzyme play important roles in cell proliferation, differentiation, and cell death. In this review, we have focused on and described the basic properties, toxicity, and roles of ROS.

Animals↗
PubMed2005

Efficacy of Helicobacter pylori eradication on the chronic mucosal inflammation of the remnant stomach after distal gastrectomy for early gastric cancer.

Although eradication of Helicobacter pylori (Hp) after early gastric carcinoma has been recommended, very limited studies have been reported and the method differs from standard therapy. Here, we attempted the eradication of Hp in the remnant stomach after surgery for primary gastric cancer with the standardized method. We examined efficacy and the safeness of the treatment. Thirty-three H. pylori-positive patients after distal gastrectomy were treated with proton pump inhibitor (PPI)-based triple therapies. After eradication, endoscopic and histological changes were classified on the basis of the Updated Sydney System. The eradication rate in the remnant stomach was 90.9% (30 out of 33 cases) after triple therapy. Temporal minor side effects were notified in 3 cases. After eradication, the remnant stomach showed significant decreases in inflammation- and activity-scores. Moreover, significant improvement in glandular atrophy to normal mucosa was found. In conclusion, PPI-based standard therapy is just as effective for Hp eradication in the remnant stomach than it is in the non-operative stomach. Eradication therapy could be performed safely and resulted in a significant improvement in inflammation and atrophy of the mucosal layer in the remnant stomach after early gastric cancer surgery.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2004

The inhibition of antithrombin by peptidylarginine deiminase 4 may contribute to pathogenesis of rheumatoid arthritis.

OBJECTIVE: The gene for peptidylarginine deiminase 4 (PADI4) has been found to be closely associated with rheumatoid arthritis (RA). Peptidylarginine deiminase (PADI) catalyses the post-translational modification of peptidylarginine to citrulline, a reaction known as citrullination. PADI extracted from rabbit muscle has been reported to citrullinate antithrombin, a principal plasma inhibitor of thrombin. Thrombin is known to induce angiogenesis, fibrin formation and inflammation, the primary events of the RA joint. Here, we investigate whether human PADI4 can inhibit antithrombin by catalysing antithrombin citrullination and how the enzyme is involved in RA pathogenesis. METHODS: Antithrombin was incubated with recombinant PADI4 protein, and the inactivation of antithrombin was determined by reduction of its thrombin-inhibiting activity. Citrullination of antithrombin was detected by western blotting and enzyme-linked immunosorbent assay (ELISA). In addition, the citrullination level, activity and concentration of antithrombin in RA plasma were investigated by sandwich ELISA. RESULTS: Incubation of antithrombin with PADI4 resulted in loss of thrombin-inhibitory activity and in citrullination of antithrombin. RA plasma showed higher levels of citrullinated antithrombin than controls with non-arthritis disease and healthy individuals. CONCLUSION: The results indicate that PADI4 could inactivate antithrombin through citrullination. The abnormal expression or activation of PADI4 in RA synovium is suggested to be responsible for the high level of citrullinated antithrombin in RA plasma. Local inhibition of antithrombin activity in RA synovium might lead to the excessive angiogenesis, fibrin deposition and inflammation of the tissue.

Animals↗
PubMed2004

Localization of peptidylarginine deiminase 4 (PADI4) and citrullinated protein in synovial tissue of rheumatoid arthritis.

OBJECTIVES: Peptidylarginine deiminases (PADIs) convert peptidylarginine into citrulline via post-translational modification. Anti-citrullinated peptide antibodies are highly specific for rheumatoid arthritis (RA). Our genome-wide case-control study of single-nucleotide polymorphisms found that the PADI4 gene polymorphism is closely associated with RA. Here, we localized the expression of PADI4 and the citrullinated protein product in synovial RA tissue. METHODS: We used immunohistochemistry, double immunofluorescent labelling and western blotting. RESULTS: We found that PADI4 is extensively expressed in T cells, B cells, macrophages, neutrophils, fibroblast-like cells and endothelial cells in the lining and sublining areas of the RA synovium. We also found extracellular and intracellular expression of PADI4 in fibrin deposits with loose tissue structures where apoptosis was widespread. Unlike PADI4, citrullinated protein generally appeared in fibrin deposits that were abundant in the RA synovium. The citrullinated fibrin aggregate was immunoreactive against immunoglobulin (Ig) A and IgM, but not IgG and IgE. Although a little PADI4 was expressed in osteoarthritic and normal synovial tissues, significant citrullination was undetectable. CONCLUSIONS: The results showed that PADI4 is mainly distributed in cells of various haematopoietic lineages and expressed at high levels in the inflamed RA synovium. The co-localization of PADI4, citrullinated protein and apoptotic cells in fibrin deposits suggests that PADI4 is responsible for fibrin citrullination and is involved in apoptosis. The immunoreactivity of citrullinated fibrin with IgA and IgM in the RA synovium supports the notion that citrullinated fibrin is a potential antigen of RA autoimmunity.

Apoptosis↗
PubMed2004

Characterizing the new transcription regulator protein p60TRP.

Active cell death ('apoptosis' or 'programmed cell death') is essential in the development and homeostasis of multicellular organisms and abnormal inhibition of apoptosis is an indicator of cancer and autoimmune diseases, whereas excessive cell death might be implicated in neurodegenerative disorders such as Alzheimer's disease (AD). Using bioinformatics-, Western-blotting-, yeast-two-hybrid-system-, polymerase chain reaction (PCR)-, and fluorescence microscopy-analyses, we demonstrate here that the neuroprotective protein p60TRP (p60-transcription-regulator-protein) is a basic helix-loop-helix (bHLH) domain-containing member of a new protein family that interacts with the Ran-binding-protein-5 (RanBP5) and the protein-phosphatase-2A (PP2A). The additional findings of its influence on NNT1 and p48ZnF (new-neurotrophin-1, p48-zinc-finger-protein)-signaling and its down-regulation in the brain of AD subjects point to a possible pivotal role of p60TRP in the control of cellular aging and survival.

Aged↗
PubMed2004

Improved conception in timed-artificial insemination using a progesterone-releasing intravaginal device and Ovsynch protocol in postpartum suckled Japanese Black beef cows.

The primary objective was to determine the effect of supplemental progesterone, administered via an intravaginal device (CIDR), on conception rates to timed-artificial insemination (timed-AI) in postpartum suckled Japanese Black beef cows treated with the Ovsynch protocol. A secondary objective was to compare the effects of treatments on plasma concentrations of progesterone and estradiol. Cows in the control group (Ovsynch, n=38) received a standard Ovsynch protocol (100 microg GnRH analogue on Day 0, 500 microg PGF2alpha analogue on Day 7, and 100 microg GnRH analogue on Day 9), with AI on Day 10, approximately 20 h after the second GnRH treatment. Cows in the treatment group (Ovsynch+CIDR; n=40) received a standard Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Plasma progesterone concentrations were determined on Days 0, 1, 7, 9, 10, and 17 and plasma estradiol-17beta concentrations were determined on Days 7, 9, 10, and 17. The odds ratio for likelihood of conception was 3.29 times greater (P=0.02) in the Ovsynch+CIDR group compared to Ovsynch group. The conception rate was greater (P=0.03) in the Ovsynch+CIDR group than in the Ovsynch group (72.5% versus 47.7%). Insertion of a CIDR device significantly increased plasma progesterone concentrations only on Days 1 and 7 (P<0.001 and P=0.05, respectively), but had no significant effect on plasma estradiol-17beta concentrations. Including a CIDR with the Ovsynch protocol significantly improved conception rates in postpartum suckled Japanese Black beef cows.

Administration, Intravaginal↗
PubMed2004

Reduction in levels of amphiphysin 1 mRNA in the hippocampus of aged rats subjected to repeated variable stress.

Various neurobiological studies of aging indicate that elevated levels of circulating glucocorticoids lead to hippocampal vulnerability to stress, though little is known about the molecular mechanism underlying stress vulnerability in the elderly. We have compared the gene expression profiles in the hippocampus of aged (20 months) and adult (3 months) rats in response to repeated variable stress (RVS) for 4 days, using a cDNA array technique and real-time quantitative PCR, to identify putative genes involved in the mechanism of stress vulnerability in the elderly. We found a significant decrease in the levels of amphiphysin 1 mRNA in aged rats subjected to RVS compared with treated and untreated adult rats or to untreated aged rats. Similarly, we found a significant decrease in hippocampal levels of amphiphysin 1 mRNA in aged rats subjected to RVS for 8 days, but not in those subjected to a single VS. These findings suggest that the decrease in the hippocampal levels of amphiphysin 1 mRNA in response to repeated stress may be involved in the stress vulnerability in the elderly, and may lead to the disturbance of learning and memory under stressful conditions in the elderly.

Aging↗
PubMed2004

The effects of the aromatase inhibitor fadrozole hydrochloride on fetuses and uteri in late pregnant rats.

It is well known that progesterone and estrogen are essential hormones for maintaining pregnancy in most mammals. Some specific roles of progesterone for the maintenance of pregnancy have been clarified, but the role of estrogen is not well known. This study examines the effects of the aromatase inhibitor, fadrozole hydrochloride (Fad), on fetuses, uterine physical properties and the mRNA expression of the uterine enzymes that are related to collagen metabolism during late pregnancy in rats. Continuous s.c. infusion with 300 micro g/day Fad from day 14 of pregnancy (day 1=the day of sperm detection) reduced the concentration of plasma estradiol-17beta (E(2)), and did not change that of plasma progesterone, compared with controls. The treatment increased the intrauterine pressure and reduced the size and compliance of the uterine tissue framework. It also caused injuries (hematomata on the extremities) in about one-quarter of fetuses by day 20. The collagen content of the uterine ampullae was not changed by the treatment. Uterine mRNA expressions of matrix metalloproteinase-1 (MMP-1), which degrades collagens, and of lysyl oxidase (LO), which is necessary for the formation of intra- and inter-molecular cross-links of collagen, were examined by quantitative RT-PCR. The treatment with Fad had no effect on the expression of MMP-1 mRNA and increased that of LO mRNA. Daily s.c. injection with 0.2 micro g E(2) restored the changes in uterine physical properties and the mRNA expression of LO caused by the Fad treatment, and prevented fetal injury, indicating that the influences of Fad treatment are due to estrogen deficiency but not to toxicological effects of Fad. These results imply that estrogen deficiency during late pregnancy in rats obstructs development of the uterine tissue framework so as to cause fetal injury. It is possible that an increase in the uterine expression of LO gene may be involved in this obstruction.

Animals↗
PubMed2004

Effects of high pressure on the solubility and growth kinetics of monoclinic lysozyme crystals.

Average growth rates of the (0 1 0) and (0 1 0) faces (R<0 1 0>) of monoclinic lysozyme crystals were measured in situ under 0.1 and 100 MPa. From the dependence of the growth rates on the lysozyme concentration, we determined the solubility of the crystal as a function of temperature at 0.1 and 100 MPa. The solubility increased with an increase in pressure. From the comparison between the growth rates under 0.1 and 100 MPa at the same supersaturation level, we found that the growth rates of the monoclinic lysozyme crystals kinetically increase with an increase in pressure. Supersaturation dependencies of the growth rates under 0.1 and 100 MPa were well fitted with a two-dimensional (2D) nucleation growth model of a birth-and-spread type. The fitting results suggest that the increase in the growth rates with pressure can be explained by the decrease in the average ledge surface energy of 2D island, the average distance between the kinks on a step and the activation energies in the incorporation processes of solute molecules.

Animals↗
PubMed2003

A new index, the core erosion ratio, of compression-coated timed-release tablets predicts the bioavailability of acetaminophen.

Although compression-coated tablets are a commonly used timed-release drug delivery technology, their utility is often limited by poor bioavailability. To try to improve the bioavailability of these tablets, the effect of their core composition of compression-coated tablet on in vivo pharmacokinetics was investigated. First, the extent of mass reduction of cores in different compression-coated tablet core formulations was used to establish a new index, the core erosion ratio. The data show that adding excipients with high water solubility to the core results in a greater core erosion ratio. Next, to elucidate the effect of core erosion ratio on in vivo acetaminophen (AAP) release, three compression-coated tablet formulations with similar in vitro AAP release profiles but different core erosion ratios were administered to four fasted dogs. The time for first appearance (TFA) of AAP in plasma did not differ significantly among formulations, indicating that the in vivo lag time was the same for all formulations. In separate experiments, necroscopy revealed that 3h after oral administration, the tablets were located in the ileum and colon and that all three formulations had identical GI transit times. However, the area under the AAP plasma concentration-time curve was greater in dogs given formulations with larger core erosion ratios. These results suggest that a formulation with a large core erosion ratio can significantly increase in vivo drug release from compression-coated tablets, leading to increased drug absorption from the lower GI tract.

Acetaminophen↗
PubMed2003

Mineralization of basement membrane mediates dentogingival adhesion in mammalian and nonmammalian vertebrates.

In order to elucidate the mechanism of adhesion between the gingiva and the tooth, detailed comparative ultrastructural studies of the dentogingival border were done in the monkey and shark. The tissues were prepared with or without demineralization for the ultrastructural observations. At the border, the internal basement membrane, which is firmly bound to the junctional epithelium through hemidesmosomes, was specialized differently in these species. In the monkey, the lamina densa was closely associated at its enamel side with an additional layer which had characteristics of the lamina densa and was referred to as the supplementary lamina densa. In the shark, the lamina densa showed a unique, hemidesmosome-related specialization in the form of the intermittent occurrence of bulges along its surface facing the epithelium. In nondemineralized tissues a part of the basement membrane, that is, the supplementary lamina densa (monkey) and the main lamina densa but not bulges (shark), was preferentially mineralized. The mineral deposit was continuous with that in the enamel and enameloid/dentine, thus constituting an advancing edge of mineralization. The network arrangement of the mineral crystals in the monkey basement membrane resembled the pattern of the cord network of the basement membrane, suggesting the presence of a delicate mutual basement membrane-mineral interaction. Thus, the organic phase and the mineral phase are allowed to make contact at this mineralized area of the basement membrane and firmly bind to one another. Therefore, strong gingiva-tooth adhesion is established by partial mineralization of the internal basement membrane, in a way similar to that found in the previously reported association of maturation stage ameloblasts with the enamel.

Animals↗
PubMed2003

Delayed implantation induced by fadrozole hydrochloride in rats.

The effect of aromatase inhibitors on the implantation process is not well known. This study examined the anti-implantation action in rats of a nonsteroidal aromatase inhibitor of high specific activity, fadrozole hydrochloride (Fad). Continuous subcutaneous infusion of Fad at 300 microg/day from Day 1 (the day of sperm detection) through Day 7 of pregnancy using a mini-osmotic pump was found to delay the initiation of implantation by 1 or 2 days with no negative effects on embryonic viability. The Fad treatment delayed preimplantation embryo development and zona shedding by embryos. The treatment also delayed the period of maximum sensitivity to a decidualizing stimulus (intraluminal infusion of sesame oil) by 2 days. The results show that continuous treatment with Fad has multiple anti-implantation effects in rats.

Animals↗
PubMed2003

Comparative gene identification-94--a pivotal regulator of apoptosis.

Apoptosis is an active form of cell death that is carried out by proteins that are designed to kill the cell during normal mammalian development and tissue homeostasis. Cell death by apoptosis comprises a sequence of events leading to the activation of caspases which execute the fragmentation of the cellular protein and DNA leading to disintegration of the cell. This physiological neuronal apoptosis allows the nervous system to eliminate excess neurons. In addition, apoptotic cell death occurs in a variety of neuronal degeneration such as Alzheimer's disease. Here we describe second mitochondria-derived activator of caspases/Diablo as a new interacting protein of CGI-94 (comparative gene identification-94) which itself is probably involved in degenerative processes of Alzheimer's disease. Our findings that CGI-94 interacts with second mitochondria-derived activator of caspases/Diablo, inhibits nerve growth factor-induced neurite outgrowth and that its neuronal expression leads to cell death point to its pivotal role in the control of cellular survival. In conclusion, CGI-94 appears to be involved in processes of neuronal degeneration.

Animals↗
PubMed2003

Exposure time-dependent bactericidal activities of amoxicillin against Actinobacillus pleuropneumoniae; an in vitro and In vivo pharmacodynamic model.

The pharmacodynamic effects of amoxicillin against Actinobacillus pleuropneumoniae at exposure concentration above and below minimum inhibitory concentration (MIC) were evaluated in both in vitro and in vivo. In vitro, the growth and morphological change of A. pleuropneumoniae in culture medium was observed. In vivo, the efficacy of amoxicillin on experimentally induced A. pleuropneumoniae infection in disease-free pigs was evaluated. Fifteen pigs were divided into three groups (n = 5 per group). After the onset of clinical respiratory disease symptoms, 6 h post-infection, amoxicillin sustained-release injectable formulation was injected intramuscularly at 7.5 mg/kg/day (group I) and 15 mg/kg/day (group II). Then the serum concentration of amoxicillin was measured. An untreated infected group served as controls. In each amoxicillin administration group, if symptoms were not absent after 48 h, the pig was injected with the amoxicillin sustained-release injectable formulation again using the same dosage. In vitro, the growth of A. pleuropneumoniae inhibited by amoxicillin exposure at the concentration above the MIC (1.28 x MIC), and the inhibition time was in directly proportion to the time of amoxicillin exposure. Moreover, all the cells were lysed. Whereas the bacterial growth inhibition at the amoxicillin exposure concentration below the MIC (0.25 x MIC) was not done, and the shape of cells were normal or long filamentous. In vivo, the group I clinical and pathological score was higher than the group II, and the group I weight gain was significantly less than the group II. Performance with respect to weight gain corresponded with clinical signs. The infected control group was severely affected with an 80% (4/5) mortality rate 24-96 h post-challenge. The duration of time above MIC (T > MIC) of serum amoxicillin concentration in the group I was less than group II. The present studies suggest that amoxicillin has exposure time-dependent bactericidal activity against A. pleuropneumoniae.

Actinobacillus Infections↗