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Biomedical subjects

T Tsutsui

Publications and source records attributed to T Tsutsui.

At least 91 records · Page 5Linked to original sources
PubMed1999

Bow hunter's stroke associated with atlantooccipital assimilation--case report.

A 39-year-old male presented with bow hunter's stroke manifesting as repeated vertebrobasilar ischemic attacks induced by head rotation 45 degrees to the left. Three-dimensional computed tomography angiography clearly showed the occluded right vertebral artery (VA) between the axis and atlas. Single photon emission computed tomography study showed diffuse hypoperfusion of the brain stem and bilateral cerebellar hemispheres, suggesting hemodynamic compromise of these regions. He refused surgery and was treated conservatively. The most likely mechanism is that the affected VA was fixed by the ossification of the atlantooccipital membrane, vascular groove, and transverse foramen of the atlas, and therefore became elongated and compressed by head-turning.

Adult↗
PubMed1999

Evidence for beta3-adrenoceptor subtypes in relaxation of the human urinary bladder detrusor: analysis by molecular biological and pharmacological methods.

The purpose of the present study was to confirm the presence of beta3-adrenoceptor subtype in the relaxation of human urinary bladder detrusor tissue by reverse transcription-polymerase chain reaction (PCR); direct sequencing of the PCR product, in situ hybridization; and isometric contraction. Using reverse transcription-PCR, the mRNAs of three receptor subtypes (beta1, beta2, and beta3) were expressed in the human urinary bladder detrusor tissue. Direct sequencing of the PCR product of the above beta3-adrenoceptor revealed no mutation in the amplified regions. In situ hybridization with digoxygenin-labeled oligonucleotide probe revealed the presence of the mRNA of beta3-adrenoceptor subtype in the smooth muscle of the urinary bladder. The relaxant effects of isoproterenol (a nonselective beta-adrenoceptor agonist); ZD7114, BRL37344, and CGP12177A (putative selective beta3-adrenoceptor agonists); and SR59230A (a putative selective beta3-adrenoceptor antagonist) were tested using an isometric contraction technique. Isoproterenol in either the presence or absence of both atenolol (a beta1-adrenoceptor-selective antagonist) and butoxamine (a beta2-adrenoceptor-selective antagonist) revealed a relaxant effect on the carbachol-induced contraction of the human urinary bladder detrusor. Both BRL37344 and CGP12177A also revealed relaxant effects on the human urinary bladder detrusor, but ZD7114 did not elicit any relaxation. These results suggest that beta3-adrenoceptor may have some role in urine storage in the human urinary bladder.

Adrenergic beta-Agonists↗
PubMed1999

Pharmacological and molecular biological evidence for ETA endothelin receptor subtype mediating mechanical responses in the detrusor smooth muscle of the human urinary bladder.

The aim of this study was to characterize endothelin receptor subtypes of the detrusor muscle of the human urinary bladder. The receptor subtypes mediating endothelin (ET)-1-induced activity in the human detrusor smooth muscles have been characterized using isometric contraction and reverse transcription-polymerase chain reaction (RT-PCR). ET-1 (a non-selective ET receptor agonist; 10(-10) M to 10(-6) M) exhibited concentration-dependent contractions in human urinary bladder with a plateau at concentrations above 3x10(-7) M. Neither IRL1620 nor sarafotoxin S6c (both ETB-selective agonists; 10(-10) M to 10(-6) M) elicited contractile activity in the human urinary bladder detrusor smooth muscle. FR139317 (an ETA-selective antagonist; 10(-7) M to 10(-5) M) produced a marked shift to the right of the ET-1 concentration-response curve in human urinary bladder detrusor smooth muscle (from the Schild plot TpA2=7.96; slope=0.95). In contrast, RES701-1 (an ETB-selective antagonist; 10(-7) M to 10(-5) M) had no effect on the ET-1 concentration-response curve. RT-PCR revealed positive amplification of ETA receptor mRNA fragment, but not ETB. These results indicate that the ET-1-induced contractile effects of urinary bladder detrusor smooth muscle seem to be mediated mainly by the ETA receptor, not by the ETB receptor.

Aged↗
PubMed1998

Induction of calponin-h1 by transforming growth factor-beta1 in cultured human ito cells, LI90.

We investigated the effect of transforming growth factor-beta1 (TGF-beta1) on the expression of calponin-h1, alpha-smooth muscle actin (alpha-SMA), and extracellular matrix (ECM) components in a cultured human Ito cell line, LI90. The TGF-beta1 treatment stimulated productions of hyaluronic acid and laminin, and significantly decreased the secretion of hepatocyte growth factor in LI90 cells. The functional characteristics of LI90 cells were compatible with those of human-activated Ito cells that are known as pericyte-like mesenchymal liver cells. TGF-beta1 induced a slight growth-inhibition of LI90 cells. TGF-beta1 enhanced the expressions of both alpha-SMA and calponin-h1 at the protein level, while tumor necrosis factor-alpha and interleukin-1alpha did not affect the expressions of these cytoskeletal proteins on LI90 cells. The addition of TGF-beta1 to LI90 cells resulted in a significant increase of calponin-h1 mRNA levels, but not calponin-h2. These data suggest that the expression of calponin-h1 is controlled at the level of mRNA under the coordinate regulation together with alpha-SMA as the process of perpetuation of activated Ito cells promoted by TGF-beta1. The identification of smooth muscle features promoted by TGF-beta1 support the hypothesis that the activation of Ito cells coincides with their contractile behavior, indicating that these cells may be important in vasoregulation during liver injury and fibrosis.

Actins↗
PubMed1998

Nipradilol inhibits DNA synthesis by regulating nitric oxide synthesis in cultured rat mesangial cells.

To elucidate whether nipradilol modulates mesangial cell function, we assessed the effects of nipradilol on DNA synthesis in the presence and absence of N-nitro-L-arginine methyl ester (L-NAME) in cultured rat mesangial cells stimulated with 1% fetal bovine serum. Nipradilol inhibited [3H]thymidine incorporation into mesangial cells in a dose- and time-dependent manner. In addition, the anti-mitogenic effect of 100 microM nipradilol was significantly inhibited in the presence of 10 microM L-NAME. Moreover, nipradilol increased intracellular cyclic guanosine monophosphate (cGMP). These results suggest that nipradilol exerts its efficacy in the treatment of several types of glomerulonephritis with mesangial cell proliferation by increasing in intracellular cGMP.

Adrenergic beta-Antagonists↗
PubMed1998

Bisphenol-A induces cellular transformation, aneuploidy and DNA adduct formation in cultured Syrian hamster embryo cells.

Bisphenol-A (BP-A) is a major component of epoxy, polycarbonate and other resins. For an assessment of in vitro carcinogenicity and related activity of BP-A, the abilities of this compound to induce cellular transformation and genetic effects were examined simultaneously using the Syrian hamster embryo (SHE) cell model. Cellular growth was reduced by continuous treatment with BP-A at doses > or = 100 microM. However, colony-forming efficiencies were not decreased significantly following treatment with up to 200 microM BP-A for 48 hr. Morphological transformation of SHE cells was induced by treatment of cells with BP-A at 50 to 200 microM for 48 hr. BP-A exhibited transforming activity at doses > or = 50 microM but was less active than the benzo[alpha]pyrene used as a positive control. Over the dose range that resulted in cellular transformation, treatment of SHE cells with BP-A failed to induce gene mutations at the Na+/K+ ATPase locus or the hprt locus. No statistically significant numbers of chromosomal aberrations were detected in SHE cells treated with BP-A. However, treatment of cells with BP-A induced numerical chromosomal changes in the near diploid range at doses that induced cellular transformation. 32P-Postlabeling analysis revealed that exposure of cells to BP-A also elicited DNA adduct formation in a dose-dependent fashion. Our results indicate that BP-A has cell-transforming and genotoxic activities in cultured mammalian cells and potential carcinogenic activity.

Aneuploidy↗
PubMed1998

Chlormadinone acetate pellet implantation plus short-term oral administration in dogs with benign prostatic hypertrophy.

Eight beagles with benign prostatic hypertrophy (BPH) were treated by subcutaneous implantation of pellets containing 10 mg/kg chlormadinone acetate (CMA), a synthetic anti-androgen, plus daily oral administration of CMA at 2 mg/kg per day for 7 days as a therapy for BPH. Prostatic and testicular size were measured and prostatic and testicular biopsies were performed by laparotomy before and after CMA treatment. Plasma levels of luteininzing hormone (LH), testosterone and oestradiol were also measured. The clinical signs of BPH, for example haematuria and dysuria, resolved within 1 week of treatment. Mean prostatic volume decreased to 56% of the pretreatment value. At 40 weeks after treatment, prostatic volume had decreased by 36%. Histological examination of the prostate 1 week after treatment revealed reduction in diameter of the alveoli and in height of the glandular epithelium. Degeneration and atrophy of the glands were marked 4-12 weeks after treatment. In the testis, the diameter of seminiferous tubules and the number of germ cells in the seminiferous tubules had decreased markedly at 12 and 24 weeks after treatment. Although plasma LH concentrations did not undergo any marked fluctuations after CMA treatment, levels of testosterone and oestradiol were lower than before treatment. The results indicate that implantation of 10 mg/kg CMA, plus 7-day oral administration of 2 mg/kg CMA, bring about resolution of the clinical signs and marked reduction in prostatic volume within 1 week of treatment.

Administration, Oral↗
PubMed1998

Eicosapentaenoic acid inhibits mitogen-induced endothelin-1 production and DNA synthesis in cultured bovine mesangial cells.

The present study was designed to examine whether eicosapentaenoic acid (EPA) inhibits the production of basal or stimulated endothelin (ET)-1 by platelet-derived growth factor (PDGF)-BB or epidermal growth factor (EGF), and DNA synthesis in cultured bovine mesangial cells. PDGF-BB and EGF stimulated ET-1 secretion in a dose-dependent fashion in these cells. EPA (10-100 microM) exhibited dose-related inhibition of PDGF-BB- and EGF-stimulated ET-1 secretion. EPA had no inhibitory effects on basal ET-1 secretion in these cells. Moreover, 50 microM EPA significantly attenuated PDGF-BB- and EGF-stimulated [3H]thymidine incorporation into mesangial cells. Receptor-binding experiments showed that EPA competitively inhibited 125I-PDGF-BB or 125I-EGF binding to mesangial cell surface receptors. Scatchard analysis for PDGF-BB receptor or EGF receptor revealed a linear regression fit and one binding site. Pretreatment with 50 microM EPA suppressed the number of maximum binding sites, but did not affect the Kd values. These results indicate that EPA potentially inhibits mesangial cell ET-1 production, when stimulated by PDGF-BB or EGF. This inhibitory effect of EPA could be related to the attenuation of mesangial cell proliferation via inhibition of the binding of PDGF-BB or EGF to their receptors due to alteration of the physicochemical characteristics of the cell membrane.

Animals↗
PubMed1998

Induction of dog sperm capacitation by oviductal fluid.

Four estrous beagles were inseminated with 1 x 10(8) sperm into both the right and left uterine horns, and the uterine horn and oviduct on one side were removed under anesthesia after 7 hr and 24 hr, respectively. The lumen of the uterine horns and oviducts was flushed with canine capacitation medium (CCM), and movement of the sperm in CCM was assessed by phase-contrast microscopy. In a second experiment, ejaculated sperm obtained from 5 normal beagles was incubated in CCM supplemented with oviductal flush fluid (OF-CCM) at 38 degrees C with 5% CO2 in air. Motility of sperm, and percentages of hyperactivated sperm (%HA) and acrosome-reacted sperm (%AR) among freely swimming (FS) sperm were investigated until 24 hr after the start of incubation. After 7 hr of incubation the sperm was coincubated with canine oocytes in OF-CCM for 2 hr, and the number of zona pellucida-binding (zona-binding) sperm was then counted. The %HA among the sperm in the oviductal flush fluid both 7 hr (mean +/- S.E.; 15.0 +/- 2.4%) and 24 hr (77.5 +/- 5.2%) after intrauterine insemination were significantly higher than in the uterine flush fluid (P < 0.05, 0.01, respectively). The motility and %HA among FS-sperm in OF-CCM were higher than in the control medium without oviductal fluid. However, there was no difference in the %AR between OF-CCM and control medium. The number of zona-binding sperm in OF-CCM (8 +/- 1) was significantly greater than in control medium (5 +/- 1) (P < 0.05). These results suggest that oviductal fluid in the estrous bitch maintains sperm motility and induces sperm capacitation.

Anestrus↗
PubMed1998

Development of in vitro fertilized feline embryos in a modified Earle's balanced salt solution: influence of protein supplements and culture dishes on fertilization success and blastocyst formation.

The effects of protein supplements and culture dish type on in vitro fertilization (IVF) and embryo development in culture were examined in the domestic cat. In Experiment I, follicular oocytes were fertilized and cultured in either 1) modified Earle's balanced salt solution, designated MK-1, supplemented with one of the following: 10% human serum (HS), 10% FCS or 0.4% BSA, or 2) Medium 199 (M-199) supplemented with 10% FCS. Fertilization rates were lower (P < 0.01) in MK-1 + BSA (74.4%), MK-1 + FCS (56.1%), and M-199 + FCS (51.4%) than in MK-1 + HS (94.7%). A greater (P < 0.01) percentage of blastocysts was obtained in MK-1 + HS (50.0%) than in other treatment groups (range, 4.3-17.2%). In Experiment II, the effect of dish type (tissue culture dish, TCD, versus suspension culture dish, SCD) on embryo development was evaluated in MK-1 supplemented with either HS or BSA. Significantly higher proportions of IVF-derived embryos developed to blastocysts at 120 and 144 hr post-insemination, respectively, when cultured in HS/SCD (47.2 and 71.7%) than in BSA/SCD (11.4 and 27.3%) or BSA/TCD (10.4 and 25.0%). At 120 hr post-insemination, there was a lower (P < 0.01) percentage of blastocysts in HS/TCD (22.2%) than in HS/SCD. In Experiment III, six embryos per cat were transferred to the uterine horns of 17 recipients at 144 hr after hCG treatment. Five of 7 recipients which received late morulae cultured in MK-1 + BSA (SCD) for 120 hr became pregnant (71.4%). Eight of 10 recipients which received early blastocysts cultured in MK-1 + HS (SCD) for 120 hr became pregnant (80.0%). We conclude that MK-1 containing HS is highly beneficial for overcoming the in vitro developmental block of IVF-derived feline embryos and increasing the success rate of IVF/ET.

Animals↗
PubMed1998

Changes in semen quality and in vitro sperm capacitation during various frequencies of semen collection in dogs with both asthenozoospermia and teratozoospermia.

Eight male dogs with both asthenozoospermia and teratozoospermia were used in this study. In experiment 1, semen was collected 10 times at intervals of 48 hr, 24 hr and 12 hr in 4 of the 8 dogs, and the semen quality was evaluated. In experiment 2, semen was collected 5 times at 24-hr intervals in the other 4 dogs. The spermatozoa collected on day 1 and day 5 were incubated for 4-6 hr in Canine Capacitation Medium, and the percentages of hyperactivated sperm (%HA), acrosome-reacted sperm (%AR), and the zona pellucida-binding sperm count (ZP sperm count) were assessed. The results of experiment 1 showed that the percentage of motile sperm increased and the percentage of abnormal sperm decreased markedly as the intervals between semen collections became shorter. When semen was collected at 12-hr intervals, the percentage of motile sperm increased from about 65%, the value before frequent collection was started, to about 80%, and the percentage of sperm with abnormal tails decreased from 30% to 15%. In experiment 2, the percentages of HA and AR, and the ZP sperm count in specimens collected on day 5 were higher than those in specimens collected on day 1, and the differences in % HA and in ZP sperm count were significant (P<0.05). The results demonstrated that sperm motility, abnormality, and potential fertility in dogs with asthenozoospermia and teratozoospermia can be temporarily improved by frequent semen collection.

Acrosome↗
PubMed1998

Changes in plasma LH and testosterone levels and semen quality after a single injection of hCG in two dogs with spermatogenic dysfunction.

Plasma LH and testosterone (T) levels and semen quality after a single intramuscular injection of 1,000 IU hCG were investigated in a Beagle dog with azoospermia and a Beagle dog with poor semen quality. The plasma LH levels of both dogs did not change after the treatment. Although the plasma T levels of the dog with azoospermia increased temporarily, no sperm were detected in its semen. In the dog with poor semen quality high levels of plasma T were maintained for 2 weeks after hCG treatment and its semen quality was temporarily improved between 3 and 4 weeks after treatment. These findings indicate that the semen quality of dogs with oligozoospermia can be temporarily improved after a single injection of hCG.

Animals↗
PubMed1998

Right thoracotomy as an alternative for redo mitral valve replacement and concomitant repair of the tricuspid valve.

BACKGROUND: We report the results of a right thoracotomy for reoperation on the mitral plus concomitant procedures. Access to aorta or repair of other lesions by this approach is controversial. EXPERIMENTAL DESIGN AND SETTING: Retrospective study. Institutional practice (University of Tsukuba Hospital, Tsukuba Japan). METHODS: Until 1995, 9 patients underwent right thoracotomy for mitral reoperation. The indication for this approach was no retrosternal space with the pericardium left open. Seven patients had deteriorated bioprosthesis, 1 periprosthetic valve leakage, and 1 re-stenosis. Four were associated with moderate tricuspid regurgitation. Operations were performed under fibrillation. Cardioplegia was used in 1. RESULTS: Through thoracotomy, 4 underwent mitral valve re-replacement, and 4 mitral valve re-replacement plus tricuspid annuloplasty. One was abandoned because of severe pleural adhesion. No neurological injury, or perioperative myocardial infarction occurred. CONCLUSIONS: The right thoracotomy was an effective alternative to repeat sternotomy for redo mitral valve operation. Also, concomitant repair of the tricuspid valve could be safely done by this approach.

Aged↗
PubMed1997

Cell-transforming activity and genotoxicity of phenolphthalein in cultured Syrian hamster embryo cells.

Phenolphthalein is a cathartic agent widely used in non-prescription laxatives. For the simultaneous assessment of in vitro carcinogenicity and mutagenicity of phenolphthalein, the ability of this chemical to induce cell transformation and genetic effects was examined using the Syrian hamster embryo (SHE) cell model. Cell growth was reduced by treatment with phenolphthalein at 10-40 microM in a dose-related manner. Treatment with phenolphthalein for 48 hr induced a dose-dependent increase in morphological transformation of SHE cells. Over the dose range that resulted in cell transformation ( 10-40 microM), treatment of SHE cells with phenolphthalein induced gene mutations at the hprt locus but not at the Na+/K+ ATPase locus. A statistically significant level of chromosomal aberrations was elicited in SHE cells treated with phenolphthalein at the highest dose (40 microM). Meanwhile, neither numerical chromosomal changes nor DNA adduct formation, analyzed by the nuclease P1 enhancement version of 32P-post-labeling, were induced by treatment with phenolphthalein at any concentrations examined. We thus report cell-transforming activity and mutagenicity of phenolphthalein assessed with the same mammalian cells in culture. Our results provide evidence that phenolphthalein has cell-transforming and genotoxic activity in cultured mammalian cells. The mutagenic and clastogenic activities of phenolphthalein could be a causal mechanism for carcinogenicity in rodents.

Animals↗
PubMed1997

Administration of IL-12 induces a CD3+ CD4- CD8- B220+ lymphoid population capable of eliciting cytolysis against Fas-positive tumor cells.

The present study investigates the effect of IL-12 administration on the generation of lymphoid cells that exhibit cytotoxicity against tumor cells expressing Fas Ag. Systemic injection of rIL-12 into BALB/c or (B6C3)F1 mice bearing syngeneic CSA1M or OV-HM tumor induced complete tumor regression. CSA1M tumor cells expressed Fas Ag, and exposure of these cells to IFN-gamma enhanced Fas expression. In contrast, Fas Ag was hardly detected on OV-HM cells even after IFN-gamma exposure. Only CSA1M cells were lysed by anti-Fas mAb or cells expressing Fas ligand (FasL), indicating that Fas on CSA1M cells is functional in mediating cell death. An increase in the frequency of lymphoid cells characterized as CD3+ CD4- CD8- B220+ was observed in spleens from both CSA1M and OV-HM tumor-bearing mice after IL-12 treatment. A splenic population enriched in cells with these unique phenotypes exhibited considerable degrees of cytotoxicity against Fas+ CSA1M, but not against Fas- OV-HM tumor cells. The lysis of CSA1M cells was almost completely blocked by addition of Fas-Fc, a fusion protein between the extracellular domain of mouse Fas and the Cgamma1 domain of human Ig. Regressing CSA1M and OV-HM tumor masses after IL-12 treatment exhibited a massive lymphoid cell infiltration and expressed significant levels of FasL mRNA, suggesting the infiltration of FasL-expressing cells to tumor sites. These results indicate that IL-12 induces the expansion of lymphoid cells that exhibit FasL-mediated cytolytic activity and accumulate into regressing tumor masses.

Animals↗
PubMed1997

Plasma endothelin-1 level in patients with renovascular hypertension - does the kidney with stenosis of the renal artery upregulate production of endthelin-1?

PROBLEM: To examine the value of plasma endothelin-1 (ET-1), we measured the level of plasma ET-1 activity of peripheral venous blood and selective renal venous blood in renovascular hypertension patients, and compared that activity with corresponding renin activity and split renal function. METHODS: ET-1 level, renin activity in selective renal venous blood and peripheral venous blood, and 99mTc-dimercaptosuccinic acid renal uptake as a split renal function test were measured in 11 patients (mean 42.1 years old) with renovascular hypertension (RVH) and 6 patients with both renal cell cancer (RCC) and essential hypertension. RESULTS: 1. In patients with RVH, resting peripheral venous plasma ET-1 ranged from 0.6 to 8.1 (mean 4.07) pg/ml and was higher than the normal level (p <0.01). However, the renal vein ET-1 ratio was nor correlated with the renal vein renin ratio. 2. In patients with RCC, resting peripheral venous plasma ET-1 was not different from the normal level. There was no step-up of plasma ET-1, or renin among renal veins, or the proximal and distal parts of the interior vena cava. 3. Both renal vein renin ratio and renal vein ET-1 ratios were inversely correlated with t99mTC-dimercaptosuccinic acid renal uptake as a split renal function examination in patients with RVH. 4. The peripheral plasma ET-1 level was correlated with the degree of stenosis of the renal artery in patients with RVH of a unilateral lesion, but not bilateral lesions. CONCLUSION: These results suggest that ET-1 may take part in the hypertensive mechanisms of RVH in addition to the renin-angiotensin system, but its significance in RVH still remains to be examined.

Adolescent↗