Biomedical subjects

I Saito

Publications and source records attributed to I Saito.

At least 73 records · Page 4Linked to original sources

PubMed2001

HVJ-liposome-mediated transfection of HSVtk gene driven by AFP promoter inhibits hepatic tumor growth of hepatocellular carcinoma in SCID mice.

Suicide gene therapy using ganciclovir (GCV) with transfection of the herpes thymidine kinase (HSVtk) gene has been studied for cancer therapy. The present study demonstrates an efficient method of suicide gene therapy for multiple hepatic tumors, involving repetitive transfection of the HSVtk gene driven by the alpha-fetoprotein (AFP) promoter using hemagglutinating virus of Japan (HVJ)-liposomes. AFP-producing cells (HUH7) and AFP-nonproducing cells (LS180) were injected subcutaneously (s.c.) to establish tumors in nude mice. Two plasmid constructs, bacterial LacZ gene driven by the AFP promoter (AFPLacZ), and HSVtk gene driven by the AFP promoter (AFPTK1) were encapsulated into the HVJ-liposome and used. When AFPLacZ was injected into the s.c. tumors, expression of LacZ gene was confined to HUH7 tumors. Repeated transfection of AFPTK1 followed by GCV treatment markedly suppressed growth of HUH7 tumors, and apoptosis of HUH7 cells was recognized in the tumor. Next, HUH7 cells were injected into the portal vein in severe combined immunodeficiency mice to establish a hepatic tumor model. After inoculation with the tumor, HVJ-liposomes containing the AFPTK1 plasmid vector were injected into the portal vein via the splenic hilum, followed by GCV treatment. This gene therapy significantly inhibited the growth of tumors in the liver and markedly improved survival. Three injections of the AFPTK1 plasmid vector completely inhibited tumor growth. This procedure seems to have great potential for the treatment of multiple hepatic tumors.

Animals↗

PubMed2001

Relationships between baseline serum leptin levels and 2-year changes in body mass index, blood pressure and metabolic parameters in Japanese male adolescents and middle-aged men.

We and others have reported that serum leptin levels are positively correlated with body mass index (BMI), blood pressure and heart rate (HR) in cross-sectional clinical studies. However, only a few longitudinal studies have focused on the relationships between leptin, BMI and blood pressure. The present study was performed to elucidate the relationships between baseline serum leptin levels and 2-year changes in BMI, blood pressure, HR and metabolic parameters in 314 Japanese male adolescents aged 16-17 years and in 225 Japanese men aged 30-63 years. Height, weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), HR, fasting plasma glucose (FPG), serum lipids [total cholesterol (TC), triacylglycerols (TG), high-density-lipoprotein cholesterol (HDL-C) and low-density-lipoprotein cholesterol (LDL-C)], uric acid (UA), insulin and leptin levels were measured in the morning after an overnight fast. In the male adolescents, serum leptin levels in 1996 (log[leptin'96]) were significantly correlated with BMI, SBP, mean blood pressure and HR in 1998 (r=0.40, 0.13, 0.11 and 0.14, respectively). The percentage change in BMI per year (DeltaBMI) was negatively correlated with log[leptin'96], even after adjustment for baseline BMI (r=-0.12, P=0.030). In men aged 30-63 years, log[leptin'96] was also positively correlated with BMI'98, SBP'98, DBP'98, FPG'98, TC'98, log[TG'98], LDL-C'98 and UA'98 (all P<0.05), and negatively correlated with HDL-C'98, DeltaBMI, DeltaFPG, DeltaTC and DeltaLDL-C. The relationship between log[leptin'96] and DeltaTC was significant, even after adjustment for initial BMI (r=-0.15, P=0.023). These findings therefore suggest that serum leptin levels are correlated with subsequent decreases in BMI and TC in Japanese men.

Adolescent↗

PubMed2001

Suppressive effect of locally produced interleukin-10 on respiratory syncytial virus infection.

Interleukin (IL)-10 is known to be a multifunctional cytokine. This study was designed to evaluate the role of IL-10 during respiratory syncytial virus (RSV) infection using a C57BL/6 transgenic (TG) mouse model in which the expression of murine IL-10 cDNA was regulated by a human salivary amylase promoter (IL-10 TG mice). These mice expressed a large amount of IL-10 in the nasal mucosa and in salivary glands. Viral replication in the respiratory tract after intranasal infection with RSV was suppressed significantly in IL-10 TG mice compared to non-transgenic controls. This suppression was IL-10 specific, because it was prevented by treating mice with neutralizing anti-IL-10 antibodies. We also found that IL-10-stimulated T cells displayed cytotoxic activity against infected murine nasal epithelial cells. Previous data indicated that IL-10 induces Fas ligand (L) expression on mouse T cells. Taken together, these data suggest that Fas/Fas L mediated cytotoxicity is involved in the suppression of RSV replication observed in IL-10 TG mice after intranasal infection.

Animals↗

PubMed2001

Effects of intestinal fatty acid-binding protein gene Ala54Thr polymorphism and beta3-adrenergic receptor gene Trp64Arg polymorphism on insulin resistance and fasting plasma glucose in young to older Japanese men.

The present study was performed to investigate the effects of the intestinal fatty acid-binding protein (FABP2) gene Ala54Thr polymorphism and the beta(3)-adrenergic receptor (beta3AR) gene Trp64Arg polymorphism on body mass index (BMI), blood pressure, heart rate, glucose and lipid profiles, and serum leptin level in 196 young men aged 21 to 39 years, 186 older normoglycemic men (fasting plasma glucose [FPG] < 110 mg/dL) aged 40 to 65 years, and 122 older hyperglycemic men, including 77 type 2 diabetic patients. Genomic DNA was extracted from the peripheral blood, and these polymorphisms were assessed by the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. In the older groups, the beta3AR Arg64-allele frequency tended to be lower and the FABP2 Thr/Thr54 genotype frequency tended to be higher in hyperglycemic patients, although these differences did not reach statistical significance. Also, there were no significant differences in the genotype or allele frequency of either variant between the 27 hyperlipidemic and 204 normolipidemic subjects. In the younger group, there were no significant differences in any of the parameters measured between the genotypes of beta3AR or FABP2. In the older normoglycemic subjects, heart rate was significantly lower (P =.037) in beta3AR Arg64-positive subjects, and FPG was significantly higher in subjects with the FABP2 Thr/Thr genotype than the other genotypes (99.8 +/- 5.6 v 96.5 +/- 5.6 mg/dL, P =.010). In the older hyperglycemic group, the beta3AR Arg64-positive group had significantly lower high-density lipoprotein (HDL) cholesterol and free fatty acid (FFA) levels (P =.024 and P =.043, respectively). There were no synergistic effects of these 2 variants on any measured parameter, but only the FABP2 Thr/Thr genotype was related to a higher FPG in the older normoglycemic men. In conclusion, no major difference was associated with the beta3AR Trp64Arg or FABP2 Ala54Thr polymorphism in terms of type 2 diabetes or hyperlipidemia in young to older Japanese men. However, a slight but significant increase in FPG was observed in older Japanese men with the FABP2 Thr/Thr genotype.

Adult↗

PubMed2001

Infection of human lung fibroblasts with Epstein-Barr virus causes increased IL-1beta and bFGF production.

An association between Epstein-Barr virus (EBV) infection and fibroblast proliferation in the interstitial spaces of the lung has been suggested in idiopathic interstitial pneumonia. In this study we show that EBV can infect human lung fibroblasts in vitro. A primary-cultured human lung fibroblast cell line, designated CCD-32Lu, expressed EBV nuclear antigen 1 after coculture with lethally irradiated EBV producing cells. The infection further induced CCD-32Lu cells to produce the fibrogenic cytokines basic fibroblast growth factor (bFGF) and interleukin-1beta. These findings indicate that lung fibroblasts may be a target for EBV infection and suggest that EBV may play a role in increased production of these cytokines and induce fibroblast proliferation in idiopathic interstitial pneumonia.

Antibodies, Blocking↗

PubMed2001

Eleven phthalate esters and di(2-ethylhexyl) adipate in one-week duplicate diet samples obtained from hospitals and their estimated daily intake.

Plasticizers in duplicate diet samples obtained over 1 week were analysed in order to estimate daily intake. The phthalate esters were as follows: diethyl, dipropyl, dibutyl, dipentyl, dihexyl, butylbenzyl, dicyclohexyl, di(2-ethylhexyl), dioctyl, diisooctyl (mixture of isomers) and diisononyl (mixture). Di(2-ethylhexyl) adipate was also determined. Homogenized samples of composite meals were extracted with acetonitrile, lipids were removed by extraction into n-hexane and the acetonitrile layer was cleaned using Florisil and Bondesil PSA dual layer column. Phthalates were determined by GC/MS (SIM). Phthalate recovery from the fortified food mixture by this method was 62.5-140.8%. Quality assurance as assessed by three laboratories indicated coefficient of variance in the levels of detected phthalates in same lot samples as below 10%. Detection limits were 0.1-23 ng/g for each phthalate. One-week duplicate diet samples provided by three hospitals in three remote prefectures of Japan were analysed as individual meals. In all 63 samples, DEHP was present at the highest level among all phthalates in the range 10-4400 ng/g. The intake of plasticizers estimated from all samples was 519 microg DEHP/day, 86 microg DEHA/day, 65 microg DINP/day, and 4.7 microg BBP/day. Calculated DEHP in 2-day samples out of 21 days exceeded EU TDI for a person of 50 kg body weight (1850 microg per day). Disposable PVC gloves used during the preparation of meals were suspected as the source of the high DEHP content. One-day intake of the other phthalates and DEHA was below 7% of TDI in all cases. High concentrations of DEHP (5990 ng/g) was found in baby food used in quality assurance work. The source of contamination was the PVC-tube used during production and was effectively reduced by replacing the tube by one made of stainless steel.

Adipates↗

PubMed2001

Modulation of DNA-mediated hole transport efficiency by DNA-protein complex formation.

To investigate how protein interactions to DNA affects DNA-mediated hole transport, hole transport through the DNA bound to restriction endonuclease BamHI was examined. The DNA bound to BamHI retains a regular B-DNA type of conformation, but have a number of hydrogen bonding interaction. These hydrogen bondings in BamHI-DNA complex suppressed the guanine oxidation and the hole transport in sequence selective manner.

Base Sequence↗

PubMed2001

Template directed DNA photoligation via substituted 2'-deoxyuridine.

An efficient and reversible template-directed photoligation of oligodeoxynucleotides (ODNs) using 5-carboxyvinyldeoxyuridine (CVU) was described. We have also demonstrated about photochemical synthesis of circularized DNA and padlocking plasmid DNA via CVU mediated photoreaction.

Base Sequence↗

PubMed2001

Molecular design of hairpin imidazole-pyrrole polyamide for effective DNA alkylation.

A new type of hairpin polyamide-CPI conjugate possessing a vinyl linker has been synthesized. Sequence-selective alkylation of double-stranded DNA by conjugates was investigated by high resolution denaturing gel electrophoresis using 450 bp DNA fragments. Highly-efficient DNA alkylation predominantly occurs at the purines of 5'-(A/T)G(T/A)CPu-3' site at nanomolar concentration.

Alkylation↗

PubMed2001

Inhibitory effects of sodium butyrate on proliferation and invasiveness of human glioma cells.

OBJECTIVE: Sodium butyrate (SB), a differentiation-inducing agent, has been demonstrated to inhibit cellular proliferation in a number of human cell lines. Its precise mechanisms remain to be clarified, however. We investigated molecular mechanisms of SB-induced growth suppression as well as the effects of SB on the invasiveness of human glioma cells. METHODS: Human glioma U87MG and U251MG cells were treated with 1 or 2 mmol/L SB for 48 hours, and the inhibition of cell growth was assessed by spectrophotometric analysis. Cell cycle analysis was carried out by the 5-bromo-2'-deoxyuridine incorporation method, and expression of cell cycle-regulatory proteins was determined by immunoblotting. In addition, invasiveness was assessed using a Transwell chamber (Iwaki, Tokyo, Japan) with extracellular matrix substrate fibronectin or laminin (Iwaki). RESULTS: SB treatment resulted in significantly suppressed proliferation of both U87MG and U251MG cells in a dose-dependent manner. It inhibited the G1-S transition, which was associated with increased expression of p21 and cyclin D1 and reduced pRb phosphorylation. Treatment with antisense oligonucleotide for Rb abrogated SB-induced G1 arrest. p21 up-regulation was independent of the p53 status of the glioma cells. SB treatment also inhibited invasiveness on fibronectin and laminin. CONCLUSION: Our results indicate that SB may suppress the growth of human glioma cells through modulation of cell cycle progression and also may affect their invasiveness on extracellular matrix substrates, which suggests that SB may be a useful therapeutic agent in treating multiple aspects of malignant gliomas.

Brain Neoplasms↗

PubMed2001

DNA substrates influence the recombination efficiency mediated by FLP recombinase expressed in mammalian cells.

The FLP recombinase derived from Saccharomyces cerevisiae mediates precise site-specific recombination between a pair of FLP recognition targets (FRTs). Like the Cre/loxP system derived from bacteriophage P1, the FLP/FRT system has recently been applied to gene regulation systems using an FLP-expressing recombinant adenovirus (rAd) (Nakano et al, Nucleic Acids Res. 29: e40, 2001). In an attempt to improve the FLP/FRT system by altering its DNA substrates, we compared the recombination efficiency among different substrates by a quantitative in vitro assay using FLP expressed in mammalian cells. Unexpectedly, we found that one linearized DNA substrate showed 4- to >20-fold lower recombination efficiency than other substrates, which phenomenon has not been observed in the Cre/loxP system. The quantitative in vitro assay using truncated DNA substrates suggested that the recombination efficiency seemed to be influenced not only by the linearized position of the substrate, but also by the length between a pair of FRTs. Such substrate preference of FLP expressed in mammalian cells should probably be noted when designing versatile applications of the FLP/FRT system as a gene regulation system in mammalian systems. Fortunately, however, we demonstrated that no substrate preference was observed when using a particular substrate (pCAFNF5) and the preference was reduced when using a certain pair of mutant FRTs (f72), which will also be a promising tool for simultaneous gene regulation in combination with wild-type FRT.

Animals↗

PubMed2001

[Multiresidue analysis of organophosphorus pesticides in vegetables and fruits using dual-column GC-FPD, -NPD].

We investigated simultaneous and consecutive analytical methods for pesticide residues in large numbers of vegetable and fruit samples. Extraction of the sample with acetonitrile was followed by a salting-out step using a graduated cylinder. Co-extractives were removed by gel permeation chromatography (GPC) and the pesticide eluate was separated to 2 fractions. Firstly, the second fraction (85-125 mL) was passed through a silica-gel mini-column. After putting a Florisil mini-column before the silica-gel mini-column, the first fraction (55-85 mL) was passed through the tandem mini-columns, which were then eluted with 15 mL of 50% acetone/petroleum ether. The eluate was subjected to dual-column GC with dual FPD (P mode, column Rtx-OPPesticides) and NPD (column Rtx-200) detectors. Recoveries of 63 organophosphorus pesticides from fortified spinach, tomato, apple and strawberry, ranged from 71 to 126% with RSD values of 1-18%, except for the RSDs of omethoate, isoxathion, and pyraclofos (20% <). Detection limits of pesticides were 0.5-2 ng/g. Surveillance of pesticides in vegetables and fruits was carried out by using the present method. From 20 out of 30 samples, 15 pesticides (39 in total) were detected. The results indicated that the present method can be applied as an efficient and reliable tool for monitoring organophosphorus pesticide residues in vegetables and fruits.

Chromatography, Gas↗

PubMed2001

Improvement of lacrimal function by topical application of CyA in murine models of Sjögren's syndrome.

PURPOSE: The object of this study was to evaluate improvement of lacrimal gland (LG) function after topical cyclosporin A (CyA). METHODS: Topical CyA (0.01% and 0.1%) was applied to two mouse models of Sjögren's syndrome, the NFS/sld after thymectomy and the nonobese diabetic (NOD) mouse, and the functional integrity of the lacrimal gland was evaluated by measuring basal and stimulated tear secretion and its histologic integrity by examining it for apoptosis and lymphocyte invasion. RESULTS: After treatment with CyA at 0.1% in the NFS/sld mice, tear function increased, and there was a decrease in lymphocyte infiltration of the LG and a decrease in apoptotic figures among the acinar cells. In the NOD mice, tear function also improved, but there was no associated decrease in lymphocyte infiltration. However, the expression of Fas ligand (FasL) in NOD mice by infiltrating lymphocytes was suppressed with 0. 1% CyA eye drops. CONCLUSIONS: CyA appears to improve tear secretion in mouse models of Sjögren's syndrome by preventing lymphocyte-induced apoptosis of acinar cells. In one model this was achieved by preventing lymphocyte infiltration and in the other by reducing expression of FasL expression on infiltrating lymphocytes.

Administration, Topical↗

PubMed2001

One month survival with the undulation pump total artificial heart in a goat.

The undulation pump is a small continuous flow displacement-type blood pump. The undulation pump total artificial heart (UPTAH) is a unique implantable total artificial heart using undulation pumps. An adult female goat weighing 45.8 kg was used for implantation. The natural heart was replaced with the UPTAH under extracorporal circulation. The cardiac output (CO) was maintained to 100 ml/kg/min by controlling the right pump manually. To prevent lung edema, the left pump was controlled automatically to maintain the left atrial pressure below 20 mm Hg. The CO was maintained for 2 weeks. Thereafter, the CO gradually decreased. The goat suddenly died because of a brain stroke on the 31st postoperative day. At autopsy, the cavity of the left atrial cuff was almost occupied by the big pannus-like thrombus, which was thought to be the cause of death. Improvement of the atrial cuff is necessary to obtain longer survival and is being modified. No thrombus was found inside the pumps. However, temperature rise in a left motor was a problem. Improvement of the efficiency in a motor is necessary. Although many problems still remained, 1 month survival could be obtained with this unique implantable TAH using continuous flow displacement-type blood pumps.

Animals↗

PubMed2001

[Lung involvement in rapidly progressive glomerulonephritis].

The purpose of this study is to evaluate pulmonary involvement in rapidly progressive glomerulonephritis (RPGN). Of 71 patients in whom RPGN was diagnosed, 32 (45.1%) had pulmonary involvement: 12, alveolar hemorrhage (AH) (16.9%); 10, interstitial pneumonia (IP) (14.1%); four, chronic bronchial lesions (5.6%); two, consolidation (2.8%), and four, old inflammatory lesions (5.6%). Investigation of which organ of the twelve AH patients, the kidney or the lung, was the first to be involved, showed that the lung preceded in one patient, the kidney was first in three, and the lung and kidney occurred at the same time in the other eight. Of the ten IP patients, the lung preceded in eight, the kidney was ahead in two, and lung and kidney were simultaneous in one. Three patients had a history of pneumoconiosis, and two had acute progressive IP. Seventeen (45.9%) of 37 patients who tested positive for antineutrophil cytoplasmic autoantibodies (MPO-ANCA) had lung involvement, and three (30.0%) of the ten patients who tested negative for MPO-ANCA, PR 3-ANCA and anti-GBM antibody also had lung involvement.

Aged↗

PubMed2001

[Secondary hypertension].

In patients with hypertension and chronic renal parenchymal disease, BP should be controlled to 130/85 mmHg or lower (125/75 mmHg) in patients with proteinuria in excess of 1 g/day. Reducing dietary sodium (< 7 g/day) and protein (< 0.6-0.7 g/kg) helps control high BP and renal function in patients with renal insufficiency. As first antihypertensive drug, ACE inhibitors or long-acting Ca antagonists are recommended. In patients with renovascular hypertension, angioplasty is the first choice increasingly to be accompanied by stenting, and surgical revascularization is the next choice. As antihypertensive drugs, beta blockers, ACE inhibitors, and AII-receptor blockers are recommended. Hypertension accompanied by endocrine disease with adenoma or tumor is almost cured or improved by surgical removal. Spironolactone and Ca antagonists are used in patients with idiopathic aldosteronism (bilateral hyperplasia). Alpha and beta blockers are used in patients with pheochromocytoma during preoperative period.

Adrenergic beta-Antagonists↗

PubMed2001

[Surgical management for an unruptured cerebral aneurysm accompanied by anti-phospholipid antibody syndrome: a case report].

Anti-phospholipid antibody syndrome(APS) is characterized by the presence of antibodies to phospholipids and various symptoms including those derived from thrombosis. APS has been shown to be frequently accompanied by multiple and recurrent cerebral ischemic lesions, suggesting that APS may play a critical role in developing cerebral ischemia of unknown etiology. Here, we present a case with an unruptured cerebral aneurysm accompanied by a severe stenosis of the middle cerebral artery as a manifestation of APS. The aneurysm was successfully treated surgically employing the following precaution to prevent potential damage on the fragile ischemic brain: preoperative administration of anticonvulsant, intermittent brain retraction, intraoperative SEP monitoring, and postoperative administration of anticoagulant. Our experience suggests that unruptured cerebral aneurysms accompanied by APS could be safely treated by strict paraoperative management.

Aged↗

PubMed2001

[Repeated vertebrobasilar ischemic stroke caused by an intracranial vertebral artery dissection not detected on the initial angiogram: a case report].

Spontaneous dissection of the intracranial vertebral artery has been increasingly recognized as a cause of vertebrobasilar ischemic stroke. However, little is known about its natural history and clinical course. The authors report a young patient with repeated cerebral infarction in the posterior cerebral circulation caused by dissection of the vertebral artery, which was not detected on the first angiogram. The otherwise healthy 22-year-old male suddenly developed visual disturbance. Neuroradiological examination revealed right occipital infarction, but cerebral aniography revealed no caliber change or other pathological findings. He was treated with antiplatelet therapy. Two years later, he suffered vertigo, nausea, and dysarthria due to newly developed left cerebellar and medullary infarction. Cerebral angiography revealed left vertebral artery occlusion. T1-weighted MR image demonstrated Gadlinium-enhanced intramural hematoma in the occluded left vertebral artery, which was compatible to the arterial dissection. The present case argues serial neuroimaging studies especially in young patients with vertebrobasilar stroke in order to rule out the arterial dissection, even if initial angiography failed to demonstrate any radiographical evidence.

Adult↗