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Biomedical subjects

M Sato

Publications and source records attributed to M Sato.

At least 289 records · Page 16Linked to original sources
PubMed2001

Immunological and PCR analyses for Borna disease virus in psychiatric patients and blood donors in Japan.

The involvement of Borna disease virus (BDV) in psychiatric diseases in humans remains controversial. T-cell memory response and seroprevalence of BDV in patients with psychiatric disorders and blood donors in Japan were evaluated collectively by Western blot (WB) analysis with inhibition test, electrochemiluminescence immunoassay, immunofluorescence assay, and T-cell proliferative response as well as detection of BDV p24 RNA in peripheral blood mononuclear cells (PBMCs). Positive proliferative responses to both BDV p40 and p24 proteins were detected in 9% of patients with mood disorders (4 of 45), 4% of schizophrenic patients (2 of 45), and 2% of blood donors (1 of 45). By WB analysis, the antibody to BDV p40 was detected only in 2% of patients with mood disorders (1 of 45). The BDV p24 antibody was detected in 2% of patients with mood disorders (1 of 45) and 9% of schizophrenic patients. (4 of 45) No plasma reacted with both BDV proteins. The finding of a lower seroprevalence than previously reported suggests the presence of false-positive cases in the previous report. BDV RNA was detected only in 2% of patients with mood disorders (1 of 45). In these three serological assays, T-cell responses, and PCR analysis, there was no significant difference in the prevalence among the three groups. However, we found three psychiatric patients who were positive for both BDV antibodies and T-cell proliferative responses and one patient who was positive for BDV RNA in PBMCs. These findings suggest the usefulness of the proliferative T-cell response and that certain individuals are infected with BDV or a BDV-related virus.

Adolescent↗
PubMed2001

Hepatocellular carcinoma: involvement of the internal mammary artery.

PURPOSE: To investigate factors related to the development of internal mammary arteries (IMAs) as feeding arteries of hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: In 30 patients with HCC located in ventral hepatic areas directly beneath the diaphragm, bilateral internal mammary arteriography was performed to explore involvement of the IMA with HCC. The number of previous transcatheter arterial embolizations (TAEs), tumor size, time from initial TAE to IMA angiography, inferior phrenic artery (IPA) involvement with tumor, presence of hepatic artery occlusion, and use of other treatments were compared in groups with and without involvement of the IMA. RESULTS: The group with IMA involvement included 10 patients; the group without involvement, 20 patients. TAE had been performed two to 12 times in the group with involvement and zero to six times in the group without involvement (P =.01). Mean tumor sizes in these two groups were 5.1 and 6.0 cm, respectively; hepatic artery occlusion was noted in nine and zero patients (P =.01) in the two groups. The time from initial TAE to IMA angiography ranged from 3 to 53 months (median, 31.5 months) and from zero to 89 months (median, 0 months) (P =.01). IPA involvement was observed in seven and four patients (P =.015). CONCLUSION: These results strongly suggest that, regardless of tumor size, when HCCs are located in the ventral hepatic areas directly beneath the diaphragm, the IMAs serve as feeding arteries in patients with hepatic artery occlusion caused by repeated TAE.

Aged↗
PubMed2001

Effects of allopurinol on renal stone formation and osteopontin expression in a rat urolithiasis model.

BACKGROUND: The inhibitory effect of allopurinol on calcium oxalate urolithiasis has been reported, but its effect on stone matrix proteins has not been studied in vivo. To clarify the effect of allopurinol on the matrix, we investigated its effect on the expression of osteopontin (OPN), which we previously identified as an important stone matrix protein. METHODS: Control rats were not treated. Rats of the stone group were given ethylene glycol (EG) and vitamin D(3), while the allopurinol groups (low-dose group and high-dose group) were treated with allopurinol in addition to receiving EG and vitamin D(3). RESULTS: The rate of renal stone formation was lower in the allopurinol groups than in the stone group. This was associated with a low expression of OPN mRNA in allopurinol-treated rats relative to that in the stone group. CONCLUSION: Allopurinol was effective in preventing calcium oxalate stone formation and reduced OPN expression in rats. Our results suggest that allopurinol prevents renal stone formation by acting against not only the control of oxalate but also OPN expression.

Allopurinol↗
PubMed2001

TU-572, a potent and selective CD45 inhibitor, suppresses IgE-mediated anaphylaxis and murine contact hypersensitivity reactions.

BACKGROUND: CD45, receptor-type protein tyrosine phosphatases (PTPases) are essential components of signaling through both the T cell receptor and the B cell antigen receptor. However, the functional significance of CD45 in the signaling pathway through the high-affinity immunoglobulin (Ig) E receptor has not yet been established. In this study, we demonstrate that the potent CD45 inhibitor negatively regulates IgE-dependent anaphylaxis and contact hypersensitivity reactions. METHOD: We have previously found that TU-572, 2-[(4-methylthiopyridin-2-yl)methylsulfinyl]-5-isopropoxybenzimidazole, had a potent and selective inhibitory effect against PTPase activity of CD45. Using a CD45 inhibitor, we examined in vitro and in vivo IgE-mediated responses. RESULTS: TU-572 potently inhibited histamine release from rat peritoneal mast cells and mouse systemic anaphylaxis reaction using monoclonal anti-dinitrophenyl (DNP) IgE and DNP-BSA. TU-572 also suppressed the immediate-type hypersensitivity response induced by repeated epicutaneous application of trinitrochlorobenzene in BALB/c mice. CONCLUSION: These findings revealed that the PTPase activity of CD45 played a critical role in signal transduction of IgE-mediated anaphylaxis in vitro and in vivo. PTPase inhibitors such as TU-572 are useful in the treatment of allergic diseases.

Anaphylaxis↗
PubMed2001

Liposome-mediated gene therapy using HSV-TK/ganciclovir under the control of human PSA promoter in prostate cancer cells.

To more accurately determine the tissue-specific expression of the target gene in prostate cancer cells, we introduced the enhancer element (-4,777 to -3,934; PSAR) and the promoter region (PSAP) of the prostate-specific antigen (PSA) gene. Furthermore, to elucidate the advantages of using liposomes as a gene carrier, we screened more than 20 liposome preparations in this study. The 5' upstream region of PSA gene (PSARPSAP) was conjugated to either the chloramphenicol acetyltransferase (CAT) gene or herpes simplex virus thymidine kinase (TK) gene, and the transfection of these plasmids was carried out using cationic liposomes, DMRIE-C (Gibco) or LipoTAXI (Stratagene). The expression of CAT activity was clearly observed when PSARPSAP-CAT plasmid was transfected into PSA-positive LNCaP cells, whereas no CAT activity was detected in PSA-negative DU145 cells or bladder carcinoma T24 cells. The CAT activity increased after the addition of testosterone. We then evaluated the therapeutic effect of the PSARPSAP-TK plasmid in vitro. When PSARPSAP-TK plasmid was transfected and ganciclovir was added to the medium, the growth of LNCaP cells was inhibited, while no growth inhibition was observed in DU145 cells. Furthermore, this inhibitory effect was observable even when the cells were cultured in a medium supplemented with dialyzed fetal bovine serum. These results suggest that the liposome-mediated transfection of PSARPSAP-TK appears to be a potentially effective approach for selecting the optimal treatment for tumor cells producing PSA even with the low androgen levels seen in patients treated by anti-androgen therapy.

Ganciclovir↗
PubMed2001

Methylprednisolone accelerates the resolution of glomerulonephritis by sensitizing mesangial cells to apoptosis.

Glucocorticoid has long been used to treat patients with glomerulonephritis because it ameliorates mesangial cell proliferation and proteinuria, in part by suppressing nuclear factor-kappa B (NF-kappaB) activation, which regulates the transcription of various pro-inflammatory genes. Recent evidence shows that NF-kappaB activation increases the resistance to TNF-alpha-induced apoptosis in mesangial cells. We examined glomerular cell proliferation and apoptosis along with NF-kappaB activation in the Thy-1.1 nephritis model. We also evaluated TNF-alpha-induced apoptosis in cultured mesangial cells. Methylprednisolone treatment ameliorated mesangial hypercellularity in Thy-1.1 nephritis by decreasing proliferating cells and increasing apoptosis in the glomeruli. These effects were associated with suppressed NF-kappaB activation. This in vitro study revealed that treatment with methylprednisolone and TNF-alpha induced cultured mesangial cell apoptosis. These results suggest that methylprednisolone may accelerate the resolution phase of Thy-1.1 nephritis in part by sensitizing mesangial cells to apoptosis.

Animals↗
PubMed2001

Growth hormone prevents Fas-induced apoptosis in lymphocytes through modulation of Bcl-2 and caspase-3.

OBJECTIVE: Growth hormone (GH) has been reported to have a potent effect on the immune system. However, the detailed mechanism of the effect of GH on the immune system has not yet been clarified. This study was designed to investigate the nature of this mechanism. METHODS: In the present study, we investigated the effects of GH on the susceptibility of both human CEM/C7 lymphocytes and human IM-9 lymphocytes to Fas-induced apoptosis. RESULTS: Both cell lines expressed GH receptor mRNA. GH rescued Fas-induced suppression of [(3)H]-thymidine incorporation into each cell line. GH prevented Fas-induced apoptosis in each cell line without changing Fas antigen expression. We next investigated the mechanisms of the prevention of Fas-induced apoptosis, by focusing on intracellular molecules related to the apoptotic signal. Bcl-2 expression was increased by GH treatment in both CEM/C7 and IM-9 lymphocytes. GH also downregulated caspase-3 expression and inhibited activation of caspase-3 in both cell lines. CONCLUSION: These findings suggest that GH regulates the human immune system through inhibition of Fas-induced apoptosis in activated T and B lymphocytes.

Antibodies, Monoclonal↗
PubMed2001

Phosphatidylinositol 3-OH kinase-Akt/protein kinase B pathway mediates Gas6 induction of scavenger receptor a in immortalized human vascular smooth muscle cell line.

The growth arrest-specific gene 6 encodes a secreted protein, Gas6, which was originally identified as the ligand of a receptor, Axl, with tyrosine kinase activity. The class A scavenger receptor (SRA) mediates lipid uptake into cells, leading to the formation of foam cells, an important step in atherogenesis. Although Gas6 induces SRA expression, the underlying mechanism is not clear. In this report, we show that the Gas6-induced expression of SRA was mediated by the phosphatidylinositol 3-OH kinase (PI3-kinase)-serine/threonine kinase (Akt/protein kinase B [PKB]) pathway involving Akt phosphorylation. This pathway was activated by exposure to Gas6. Furthermore, the effect of Gas6 was abrogated by wortmannin, a specific inhibitor of PI3-kinase. We also demonstrated that the constitutively active form of Akt enhanced activity of the SRA promoter but that the dominant-negative mutant of Akt completely abolished the expression of SRA after treatment with Gas6. These results show that the PI3-kinase-Akt/PKB pathway participates in Gas6-induced SRA expression and suggests that the activation of Akt/PKB plays an important role in Gas6-induced atherosclerosis and foam cell formation in human vascular smooth muscle cells.

Androstadienes↗
PubMed2001

Removal of anterior clinoid process for basilar tip aneurysm: clinical and cadaveric analysis.

The difficulty in the operation for basilar tip aneurysm is the restriction in surgical working space. To resolve this problem, aggressive skull base surgery has been reported, but these techniques are not prevalent. Pterional and subtemporal approaches are commonly used for basilar tip aneurysms. In an attempt to increase the surgical working space during the pterional approach, the anterior clinoid process and the roof of the optic nerve were removed extradurally to increase the mobilization of the intracranial internal carotid artery and optic nerve. The effects of removing the anterior clinoid process and microanatomy in the perioptic area were analyzed by cadaveric procedures in 10 cases (20 sides). With this procedure, the internal carotid artery can be retracted medially with a spatula 6.1 +/- 0.8 mm (mean +/- SD). The length and the area of dural fold in the bone defect region in the optic canal roof are 2.1 mm and 13.6 mm. In 10 clinical cases, this procedure allowed enough space to approach the basilar tip aneurysm without disturbing the internal carotid artery blood flow. The clinical outcome was satisfactory.

Basilar Artery↗
PubMed2001

Method to improve cosmetic outcome following craniotomy.

This technical note describes a simple method for reducing the dead space created by craniotome due to the loss of bone dust and improving the cosmetic outcome following a craniotomy. After drilling the burr holes for the craniotomy, the bone between the holes is drilled away in a standard fashion except that multiple regions of about 1 cm in length are left intact. These intact regions are broken using a periosteal elevator and fixed like a bridge when the bone is replaced. The resulting bone flap is readily returned to its original position without making the dead space created by regular craniotomy. The amount of the dead space caused by losing the bone dust is reduced and a good cosmetic recovery is obtained. This technique is useful for both craniotomy and facial bone surgery, which requires cosmetic results.

Bone and Bones↗
PubMed2001

Comparative evaluation of tableting compression behaviors by methods of internal and external lubricant addition: inhibition of enzymatic activity of trypsin preparation by using external lubricant addition during the tableting compression process.

This study evaluated tableting compression by using internal and external lubricant addition. The effect of lubricant addition on the enzymatic activity of trypsin, which was used as a model drug during the tableting compression process, was also investigated. The powder mixture (2% crystalline trypsin, 58% crystalline lactose, and 40% microcrystalline cellulose) was kneaded with 5% hydroxypropyl cellulose aqueous solution and then granulated using an extruding granulator equipped with a 0.5-mm mesh screen at 20 rpm. After drying, the sample granules were passed through a 10-mesh screen (1680 microm). A 200-mg sample was compressed by using 8-mm punches and dies at 49, 98, 196, or 388 MPa (Mega Pascal) at a speed of 25 mm/min. The external lubricant compression was performed using granules without lubricant in the punches and dies. The granules were already dry coated by the lubricant. In contrast, the internal lubricant compression was performed using sample granules (without dry coating) containing 0.5% lubricant. At 98 MPa, for example, the compression level using the external lubricant addition method was about 13% higher than that for internal addition. The significantly higher compressing energy was also observed at other MPas. By comparison, the friction energy for the external addition method calculated based on upper and lower compression forces was only slightly larger. The hardness of tablets prepared using the internal addition method was 34% to 48% lower than that for the external addition method. The total pore volume of the tablet prepared using the external addition method was significantly higher. The maximum ejection pressure using the no-addition method (ie, the tablet was prepared using neither dry-coated granules nor added lubricant) was significantly higher than that of other addition methods. The order was as follows: no addition, external addition, and then internal addition. The ejection energy (EE) for internal addition was the lowest; for no addition, EE was the highest. In the dissolution test, the tablets obtained using external addition immediately disintegrated and showed faster drug release than those prepared using internal addition. This result occurred because the water penetration rate of the tablet using the external addition was much higher. The trypsin activity in tablets prepared using the external addition method was significantly higher than that produced using the internal addition method at the same pressure. All these results suggest that the external addition method might produce a fast-dissolution tablet. Because the drug will be compressed using low pressure only, an unstable bulk drug may be tableted without losing potency.

Algorithms↗
PubMed2001

Association between serum leptin concentrations and bone mineral density, and biochemical markers of bone turnover in adult men.

Leptin, the product of the ob gene, has been shown to inhibit bone formation in mice. We addressed whether leptin has any role in the regulation of bone mineral density (BMD) in humans. Subjects were 221 adult men with a mean (+/-SD) age and body mass index of 52.1 +/- 8.7 yr and 23.6 +/- 2.8 kg/m2. Serum leptin, carboxyterminal propeptide of type 1 procollagen (PICP; a marker of bone formation), and cross-linked carboxyterminal teleopeptide of type 1 collagen (a marker of bone resorption) were measured by RIA. BMD was assessed by single photon absorptiometry, and total fat mass was determined by bioimpedance analysis. BMD was inversely associated with serum leptin concentrations and total fat mass after adjustment for body weight. PICP, but not cross-linked carboxyterminal teleopeptide of type 1 collagen, was inversely correlated with serum leptin. These results may suggest that an increase in serum leptin reduces bone formation and decreases BMD in adult men. Leptin may be a regulator of BMD in humans.

Adult↗
PubMed2001

Nuclear deviation in hepatic parenchymal cells on sinusoidal surfaces in Arctic animals.

In normal rat and human, most of the nuclei of hepatic parenchymal cells are centrally located in the cytoplasm. However, it is reported that the nuclei of hepatic parenchymal cells are situated at a deviated position on sinusoidal surfaces under pathological situations such as chronic hepatitis, hepatocellular carcinoma, adenomatous hyperplasia, or regeneration. During a study on the mechanism of extreme vitamin A-accumulation in hepatic stellate cells of arctic animals including polar bears, arctic foxes, bearded seals, and glaucous gulls, we noticed that these arctic animals displayed the nuclear deviation in hepatic parenchymal cells on sinusoidal surfaces. In this study, we assessed the frequency of hepatic parenchymal cells showing the nuclear deviation on the sinusoidal surfaces in arctic animals. A significantly higher frequency of the nuclear deviation in hepatic parenchymal cells was seen in polar bears (89.8+/-3.4%), arctic foxes (68.6+/-10.5%), bearded seals (63.6+/-8.4%), and glaucous gulls (24.2+/-5.8%), as compared to that of control rat liver (9.8+/-3.5%). However, no pathological abnormality such as fibrosis or necrosis was observed in hepatic parenchymal and nonparenchymal cells of arctic animals, and there were no differences in the intralobular distribution of parenchymal cells displaying the nuclear deviation in the livers from either arctic animals and control rats. The hepatic sinusoidal littoral cells such as stellate cells or extracellular matrix components in the perisinusoidal spaces may influence the nuclear positioning and hence the polarity and intrinsic physiological function of parenchymal cells.

Animals↗
PubMed2001

Pharmacokinetics of granisetron in adults and children with malignant diseases.

Granisetron (GRN) is widely used for patients with various cancers who suffer from chemotherapy-induced vomiting and nausea. The, pharmacokinetics of GRN has not been fully evaluated in such patients, however, and its dosage regimen is still controversial. In this study, we determined GRN levels in serum and urine from lung cancer patients and children suffering from cancer after intravenous infusion. In lung cancer patients, the interindividual variations in t(1/2beta), area under the concentration-time curve (AUC), and Vd(beta) were relatively smaller than expected from previous reports on healthy subjects, while t(1/2beta) was prolonged more than 5-fold in healthy subjects. Urinary excretion of unchanged GRN in lung cancer patients was ca. 15% of dose, consistent with previous reports, and one individual demonstrated an even higher urinary excretion (ca. 45%). The pharmacokinetic parameters of GRN in child cancer patients varied markedly among individuals, and some child patients had smaller t(1/2beta) than adult patients. In these cases, GRN should be administered at shorter intervals. These results suggested that a pharmacokinetic study of GRN was necessary for planning a dosage regimen and managing chemotherapy-induced vomiting and nausea.

Adolescent↗
PubMed2001

[Evaluation and multivariate statistical analysis of factors influencing patient adherence to ophthalmic solutions].

In this study, factors influencing patients adherence to ophthalmic solutions were investigated. Seventy-one subjects (aged 62.3 +/- 15.5 years) were randomly selected from patients admitted to the Ophthalmology Department at Hiroshima University Hospital. The patients (n = 71) completed questionnaires, which were evaluated by clinical pharmacists. The patient group to which the ophthalmic solutions were applied once or twice daily was more compliant than other patient groups (p = 0.00057). A multivariate statistical analysis revealed that the factors influencing patients adherence were the number of ophthalmic solutions used, patient age, taste, administration intervals, the number of drops used, and hand washing before the application of ophthalmic solutions. Patients who understood the significance of the medication made fewer mistakes than those who understood only the route of administration but not the significance. In conclusion, our study shows that patient counseling should emphasis the significance of the administered medicine as well as the route of administration.

Aged↗
PubMed2001

Effects of hot bath immersion on autonomic activity and hemodynamics: comparison of the elderly patient and the healthy young.

Hot bathing has been associated with sudden death and so the present study investigated its effects on autonomic activity and hemodynamics in the elderly patient and the healthy young by analyzing heart rate variability (HRV). Subjects were 9 elderly men (mean age, 75 years) and 9 young men (mean age, 27 years), who were immersed up to shoulder level while in a sitting position for 10min with the bath temperature at 40 degrees C. Blood pressure (BP) and heart rate (HR) were monitored. BP in the young decreased during bathing (p<0.01), whereas in the elderly BP had a maximum value just at the start of immersion (p<0.05) with a slight decline at 4 min after the start of immersion. Although HR in the young increased (p<0.01), in the elderly there was an abrupt increase in HR just at the start of immersion (p<0.05), followed by a decrease in HR. With regard to HRV, the high-frequency (HF) component in the young men was suppressed during immersion (p<0.01), but was unaffected in the elderly. The LF (low frequency)/HF ratio in the elderly decreased at 4 min (p<0.05). In conclusion, hypotensive syncope may cause sudden death by drowning during hot bathing, and is a consequence of the decrease in sympathetic tone that develops approximately 4min after immersion.

Adolescent↗
PubMed2001

Lactobacillus casei NY1301 increases the adhesion of Lactobacillus gasseri NY0509 to human intestinal caco-2 cells.

In the presence of Lactobacillus casei NY1301, the adhesion of Lactobacillus gasseri NY0509 to cultured human intestinal Caco-2 cells was significantly increased (P<0.01). In contrast, L. gasseri NY0509 did not affect the adhesion of L. casei NY1301. A heat-stable cell component of L. casei NY1301 was involved in this increase of adhesion. These results suggest that a combination of these strains may have synergistic effects of adhesion to human intestinal mucosa.

Bacterial Adhesion↗