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Biomedical subjects

Y Tsuji

Publications and source records attributed to Y Tsuji.

At least 73 records · Page 4Linked to original sources
PubMed2000

OUT, a novel basic helix-loop-helix transcription factor with an Id-like inhibitory activity.

Transcription factors belonging to the basic helix-loop-helix (bHLH) family are involved in various cell differentiation processes. We report the isolation and functional characterization of a novel bHLH factor, termed OUT. OUT, structurally related to capsulin/epicardin/Pod-1 and ABF-1/musculin/MyoR, is expressed mainly in the adult mouse reproductive organs, such as the ovary, uterus, and testis, and is barely detectable in tissues of developing embryos. Physical association of OUT with the E protein was predicted from the primary structure of OUT and confirmed by co-immunoprecipitation. However, unlike other bHLH factors, this novel protein failed to bind E-box or N-box DNA sequences and inhibited DNA binding of homo- and heterodimers consisting of E12 and MyoD in gel mobility shift assays. In luciferase assays, OUT inhibited the induction of E-box-dependent transactivation by MyoD-E12 heterodimers. Deletion studies identified the domain responsible for the inhibitory action of OUT in its bHLH and C-terminal regions. Moreover, terminal differentiation of C2C12 myoblasts was inhibited by exogenous introduction of OUT. These inhibitory functions of OUT closely resemble those of the helix-loop-helix inhibitor Id proteins. Based on these findings, we propose that this novel protein functions as a negative regulator of bHLH factors through the formation of a functionally inactive heterodimeric complex.

Amino Acid Sequence↗
PubMed2000

Management of cholelithiasis in combination with cardiovascular surgery.

A retrospective review of the perioperative management of patients with cardiovascular surgical disorders and cholelithiasis was conducted, and the surgical strategies employed are discussed. Between 1988 and 1998, 18 patients having cardiovascular surgical disorders underwent cholecystectomy. These patients were divided into three groups: group I, given a one-stage operation (n = 9); group II, given a two-stage operation (n = 3); and group III, given cholecystectomy during follow-up after cardiovascular surgery (n = 6). In group I, a median laparotomy was adopted for patients with an abdominal aortic aneurysm (AAA) to allow both disorders to be treated through the same incision, whereas a right subcostal approach was employed to separate the incisions for patients who underwent cardiac operations. In group II, one patient underwent cholecystectomy before cardiac surgery, and two patients underwent cholecystectomy for postoperative cholecystitis after cardiovascular operations. One patient from group II and all from group III were on preoperative anticoagulant therapy, two of whom underwent laparoscopic cholecystectomy. No fatal complications such as prosthetic infection, intraperitoneal hemorrhage, or cerebral attack were encountered. In conclusion, we consider that performing cholecystectomy during AAA repair may be safe and prevents the risk of postoperative cholecystitis; it is preferable to treat cholelithiasis coexisting with cardiac disorders concomitantly with or before cardiac operations; and laparoscopic cholecystectomy can be safely performed under anticoagulant therapy.

Adult↗
PubMed2000

Pacing-induced heart failure causes a reduction of delayed rectifier potassium currents along with decreases in calcium and transient outward currents in rabbit ventricle.

OBJECTIVE: Heart failure in patients and in animal models is associated with action potential prolongation of the ventricular myocytes. Changes in several membrane currents have been already demonstrated to underlie this prolongation. However, information on the two components (I(Kr) and I(Ks)) of the delayed rectifier potassium current (I(K)) in rapid pacing induced heart failure is lacking. METHODS AND RESULTS: Action potentials and whole-cell currents, I(K), I(to1), I(K1), and I(Ca-L) were recorded in apical myocytes of left ventricle from 10 rabbits subjected to left ventricular pacing at 350-380 beats/min for 3-4 weeks and 10 controls with sham operation. Action potential duration at 90% repolarization (APD(90)) was prolonged in myocytes from failing hearts compared to controls at both cycle lengths of 333 and 1000 ms. Both E-4031-sensitive and -resistant components of I(K) (I(Kr), I(Ks)) in myocytes from failing hearts were significantly less than those of control hearts; tail current densities of I(Kr) and I(Ks) following depolarization to +50 mV were 0.62+/-0.05 vs. 0.96+/-0.12 pA/pF (P<0.05), and 0.27+/-0.08 vs. 0.52+/-0.08 pA/pF (P<0.05), respectively. There was no significant difference between control and failing myocytes in the voltage- and time-dependence of activation of total I(K), I(Kr) and I(Ks). The peak of L-type Ca(2+) current (I(Ca-L)) was significantly reduced in myocytes from failing hearts (at +10 mV, -9.29+/-0.52 vs. -12.28+/-1.63 pA/pF, P<0.05), as was the Ca(2+)-independent transient outward current (I(to1); at +40 mV, 4.8+/-0.9 vs. 9.6+/-1.3 pA/pF, P<0.05). Steady state I-V curve for I(K1) was similar in myocytes from failing and control hearts. CONCLUSIONS: Decrease of I(K) (both I(Kr) and I(Ks)) in addition to reduced I(to1), may underly action potential prolongation at physiological cycle length and thereby contribute to arrhythmogenesis in heart failure.

Action Potentials↗
PubMed2000

Qualitative and quantitative characterization of Fas (CD95) expression and its role in primary human acute leukemia cells.

Fas antigen, a cell surface molecule, directly mediates apoptosis, and is expressed on a limited number of human tissues. Blood or bone marrow samples from patients with acute myelogenous leukemia (AML), acute lymphoblastic leukemia (ALL) and mixed leukemia were examined qualitatively and quantitatively for the expression of Fas as well as its function using flow cytometry and the annexin V staining method. Fas expression was flow cytometrically unimodal with heterogeneous density, and showed quantitatively characteristic features in different diseases: undetectable in mixed leukemia, faint to weak in ALL, low in M0 and M1, and variable (low to strong) in M2, M3, M4, and M5. Both the full-length and the alternatively spliced truncated mRNAs were detected constitutively even in acute leukemia cells with qualitatively negative and quantitatively faint Fas, and the band density of the former transcripts detected by RT-PCR was correlated with the level of expression of the Fas protein. Short-term culturing of freshly isolated leukemia cells gave rise to an increase of Fas density. In acute leukemia cells, the apoptosis induced by anti-Fas MoAb was compared with that induced by etoposide (a topoisomerase II inhibitor). We found that fresh ALL and AML cells were resistant to the anti-Fas IgM antibody, while etoposide could trigger apoptosis in all types of leukemia tested. The combined effects of the anti-Fas MoAb and etoposide were not always synergistic. These results suggest that Fas is a biological marker for characterizing ALL and AML cells, and provide insight into creating a new therapeutic modality using cytotoxic drugs and cytokines together with modulation of Fas.

Acute Disease↗
PubMed2000

IL-18 in pregnancy; the elevation of IL-18 in maternal peripheral blood during labour and complicated pregnancies.

Serum interleukin-18 (IL-18) levels were measured in women in different trimesters of pregnancy, in labour, puerperium and in various complicated pregnancies. There was a significant elevation of IL-18 levels in pregnant sera from the first trimester until the onset of labour. Once labour began, IL-18 levels increased further and remained until at least the third day of puerperium. The high levels of IL-18 in sera were also observed in various complicated pregnancies, such as premature rupture of membranes (PROM), acute fatty liver of pregnancy and fetal growth restriction. IL-18 is likely to play a role in pregnancy.

Female↗
PubMed2000

HLA-DR and HLA-DQ gene typing of infertile women possessing sperm-immobilizing antibody.

Thirty-eight infertile women, possessing sperm-immobilizing antibody (SIA), were examined for their HLA-DR and -DQ types using DNA obtained from peripheral blood cells. The typing of HLA-DR and DQ was performed by polymerase chain reaction sequence specific oligonucleotide probes (PCR-SSOP) and PCR-restriction fragment length polymorphism (RFLP), respectively. In comparison to the normal Japanese population, the SIA positive patient population had higher genes frequencies in HLA-DRB1*0901 (26.3 vs. 13.6%, P<0.005), DQB1*0602 (13.2 vs. 6.2%, P<0.05) and -DQB1*0303 (26.3 vs. 14.8%, P<0.01), but not in any HLA-DQA1 gene types by chi2 test. After Bonferroni correction, the high frequency of HLA-DRB1*0901 remained significant (P<0.05) and HLA-DQB1*303 was slightly significant (P<0.07) but no other genes had a gene frequency significantly higher than that of the normal Japanese population. HLA-DRB1*0901 and HLA-DQB1*0303 are very rare among Caucasians but characteristically high among Japanese. The high frequency of HLA-DRB1*0901 and DQB1*0303 genes in the Japanese population may account for higher frequency of sperm-immobilizing antibody in Japanese compared to other ethnic groups.

Antibody Specificity↗
PubMed2000

Molecular cloning and chromosomal localization of human salt-tolerant protein.

We have isolated a novel human cDNA coding for human salt-tolerant protein (HSTP), that is a homologue of the rat salt-tolerant protein (STP) and may contribute to salt-induced hypertension by modulating renal cation transport. The nucleotide sequence (1988bp) of the HSTP cDNA contains an open reading frame encoding a polypeptide comprising 545 amino acids, two residues fewer than the rat STP cDNA. The predicted amino acid sequence exhibits 92% identity to that of the rat protein. HSTP contains predicted coiled-coil domains and Src Homology 3 domain, and shows a high degree of identity to CIP4 (Cdc42 target protein) and human Trip 10 (thyroid-hormone receptor interacting protein). We have mapped the HSTP gene to human chromosome 19 by fluorescence in situ hybridization.

Amino Acid Sequence↗
PubMed2000

Automatic detection of rapid eye movements by discrete wavelet transform.

In order to detect rapid eye movements (REM) automatically, the Discrete Wavelet Transform was applied to each 8-s segment of electrooculogram (EOG) data for 30 min of 8 h of normal sleep. The Haar function was used as an analysing wavelet because this function is similar to the REM waveform. By shifting the phase of the analysing wavelet by pi/4 of the function, 96% of REM could be detected. The artifacts caused by body movements could be detected simultaneously by this method. Computing time required for the detection of REM was only 11 s for 30 min EOG data.

Algorithms↗
PubMed2000

Non-ruptured large dorsal internal carotid artery aneurysm presenting with temporal quadrantanopsia.

A 63-year-old woman presenting with temporal lower quadrantanopsia of the right eye was found to have a large dorsal internal carotid artery aneurysm. Large dorsal aneurysms of the internal carotid artery are rare. Lateral compression of the optic nerve by the aneurysm might damage the optic nerve at the medial side of the right optic foramen. Direct clipping surgery was performed uneventfully. Since the dome of the aneurysm was buried in the frontal lobe and also attached to the anterior skull base, a careful approach to the aneurysm with removal of the anterior clinoid process and drilling into the planum sphenoidale around the aneurysm dome was needed. The surgical strategy is discussed.

Carotid Artery, Internal↗
PubMed2000

Coordinate transcriptional and translational regulation of ferritin in response to oxidative stress.

The global increase in transcription of cytoprotective genes induced in response to oxidative challenge has been termed the antioxidant response. Ferritin serves as the major iron-binding protein in nonhematopoietic tissues, limiting the catalytic availability of iron for participation in oxygen radical generation. Here we demonstrate that ferritin is a participant in the antioxidant response through a genetically defined electrophile response element (EpRE). The EpRE of ferritin H identified in this report exhibits sequence similarity to EpRE motifs found in antioxidant response genes such as those encoding NAD(P)H:quinone reductase, glutathione S-transferase, and heme oxygenase. However, the EpRE of ferritin H is unusual in structure, comprising two bidirectional motifs arranged in opposing directions on complementary DNA strands. In addition to EpRE-mediated transcriptional activation, we demonstrate that ferritin is subject to time-dependent translational control through regulation of iron-regulatory proteins (IRP). Although IRP-1 is initially activated to its RNA binding (ferritin-repressing) state by oxidants, it rapidly returns to its basal state. This permits the translation of newly synthesized ferritin transcripts and ultimately leads to increased levels of ferritin protein synthesis following oxidant exposure. Taken together, these results clarify the complex transcriptional and translational regulatory mechanisms that contribute to ferritin regulation in response to prooxidant stress and establish a role for ferritin in the antioxidant response.

Animals↗
PubMed2000

Intravenous leiomyomatosis extending into the right ventricular cavity: one-stage radical operation using cardiopulmonary bypass--a case report.

The authors describe a 47-year-old woman with intravenous leiomyomatosis (IVL) extending into the right ventricular cavity. This rare entity is a neoplasm originating from smooth muscle of the uterus, with vermiform extensions into the inferior vena cava. The patient underwent a one-stage operation under simultaneous sternotomy and laparotomy, and radical excision of the tumor was successfully achieved with use of normothermic cardiopulmonary bypass. Although this tumor is histologically benign, it sometimes extends into the cardiac cavity and causes sudden death due to incarceration into the atrioventricular orifice. Moreover, recurrence or lung metastasis of IVL has been reported. The authors recommend a one stage-radical resection of the tumor or a two-staged operation within a short interval. In the literature, 24 surgical cases of the intravenous leiomyomatosis with intracardiac extension have been reported. The diagnosis and surgical treatment of this tumor are reviewed and discussed.

Cardiac Surgical Procedures↗
PubMed2000

A case of hyperreninemic hypertension after extracorporeal shock-wave lithotripsy.

A 53-year-old male was found to have hypertension caused by the significant secretion of renin from an atrophic left kidney. He had undergone extracorporeal shock-wave lithotripsy (ESWL) for left renal lithiasis 11 years previously. A renal dynamic study with 99mTc-diethylenetriaminepentaacetic acid (DTPA) indicated that the rate of renal excretion and uptake was decreased in the left kidney and normal in the right kidney. Renal angiography demonstrated a normal right renal artery and a small but nonstenotic left renal artery. The ratio of PRA in the left renal vein to that in the right renal vein was 1.7. Blood pressure could be lowered to the range of 140-150/80-90 mmHg with imidapril, an ACE inhibitor. ESWL may cause hypertension via the well-known Page kidney effect. In this case, the kidney, atrophic probably due to ESWL, released a significant amount of renin.

Angiography, Digital Subtraction↗
PubMed2000

Benefits of interhemispheric integration on the Japanese Kana script-matching tasks.

We tested Banich's hypothesis that the benefits of bihemispheric processing were enhanced as task complexity increased, when some procedural shortcomings in the previous studies were overcome by using Japanese Kana script-matching tasks. In Exp. 1, the 20 right-handed subjects were given the Physical-Identity task (Katakana-Katakana scripts matching) and the Name-Identity task (Katakana-Hiragana scripts matching). On both tasks, a pair of Kana scripts was tachistoscopically presented in the left, right, and bilateral visual fields. Distractor stimuli were also presented with target Kana scripts on both tasks to equate the processing load between the hemispheres. Analysis showed that, while a bilateral visual-field advantage was found on the name-identity task, a unilateral visual-field advantage was found on the physical-identity task, suggesting that, as the computational complexity of the encoding stage was enhanced, the benefits of bilateral hemispheric processing increased. In Exp. 2, the 16 right-handed subjects were given the same physical-identity task as in Exp. 1, except Hiragana scripts were used as distractors instead of digits to enhance task difficulty. Analysis showed no differences in performance between the unilateral and bilateral visual fields. Taking into account these results of physical-identity tasks for both Exps. 1 and 2, enhancing task demand in the stage of ignoring distractors made the unilateral visual-field advantage obtained in Exp. 1 disappear in Exp. 2. These results supported Banich's hypothesis.

Adolescent↗
PubMed2000

Schwannoma in the sigmoid colon: report of a case.

Schwann cell tumor occurring in the intestines is rare. A 68-year-old female came to our hospital because of hematemesis. Barium enema and colonoscopic examination revealed submucosal tumor in the sigmoid colon. Laboratory data showed mild anemia. No other abnormal finding was found in the blood chemistry. Tumor marker levels of carcinoembryonic antigen (CEA), CA19-9, alpha feto protein (AFP) and neuron specific enolase (NSE) were within normal limits. The exploratory laparotomy confirmed a large sigmoid colon tumor. She received sigmoid colectomy. The resected specimen was a submucosal tumor with central depression, measuring 4.7 x 3.5 x 3.0 cm in size. The cut surface of the tumor was yellowish hue with necrosis. Histological examination showed spindle-shaped tumor cells with palisading comma-shaped nuclei and the nuclear pleomorphism. Immunohistochemical examination revealed that the tumor was positive for S-100 protein staining, and negative for Actin and for H.H.F. staining. These findings showed that this tumor was of Schwann cell origin. We report here the case in detail of a schwannoma in the sigmoid colon.

Aged↗
PubMed2000

[Three cases in which CR was obtained in residual metastatic lesions by intrahepatic arterial infusion after resection of hepatic metastases from colorectal carcinoma].

We report three cases in which CR was maintained after infusion (WHF) was performed for residual metastatic lesions following resection of hepatic metastases from colorectal cancer. (Case 1) A 55-year-old female with sigmoidal cancer and hepatic metastases, H2 (4 lesions). Right lobectomy and partial resection of the left lobe were performed. On the third month following surgery, CT showed two lesions in the lateral segment of the left lobe, and WHF was then begun. One month after the start of infusion, the lesions calcified and following that, disappeared. Infusion was performed for 12 months and the total amount of 5-FU was 52.8 g. Eight years and nine months following surgery, the patient is currently alive and without recurrence. (Case 2) A 65-year-old male with rectal cancer and hepatic metastases, H3 (6 lesions). Four lesions were removed by hepatic resection; however, 2 deep lesions in S4 and S5 were left unresected. WHF was begun one month following surgery, following which the lesions were undetectable by either CT or US. Infusion was performed for 18 months and the total amount of 5-FU was 81 g. Two years and ten months after surgery an isolated lung metastasis was discovered in the right lung and a thoracoscopic partial resection was performed. Eight years and four months following the original surgery and five years and four months following the lung operation the patient is alive and without recurrence. (Case 3) A 55-year-old male with rectal cancer and subsequently discovered hepatic metastases, H3 (5 lesions). Resection of the lateral segment and a partial resection of the right lobe were performed; however, one deep lesion in S7 was left unresected. WHF was begun on the 10th day following surgery. At about eight months there was a change in shape and shrinkage of the lesion. Infusion was performed for 11 months and the total amount of 5-FU was 48 g. Ten months following surgery, CT showed a new lesion in S7 and a partial resection was performed. Intraoperative US confirmed the disappearance of the previous residual lesion in S7. One year and one month following the original surgery, the patient is alive and without recurrence. From these results, it is suggested that with postoperative WHF it is possible to obtain a complete cure in cases of colorectal cancer with hepatic metastases without the resection of all lesions. (*WHF: 5-FU 1,000 mg/m2/5 hrs/week).

Aged↗
PubMed1999

Adenovirus E1A blocks oxidant-dependent ferritin induction and sensitizes cells to pro-oxidant cytotoxicity.

Ferritin is a protein that oxidizes and sequesters intracellular iron in a mineral core. We have reported that the E1A oncogene selectively represses ferritin H transcription, resulting in reduced levels of the ferritin H protein. Here we demonstrate that cells respond to pro-oxidant challenge by inducing ferritin mRNA and protein, and that this response is completely blocked by E1A. Concordantly, E1A sensitized cells to the cytotoxic effects of oxidative stress and enhanced the accumulation of reactive oxygen species in response to pro-oxidant challenge. These results demonstrate that expression of E1A impedes the cellular response to oxidative stress, including the induction of ferritin.

3T3 Cells↗