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Biomedical subjects

A Shiozaki

Publications and source records attributed to A Shiozaki.

At least 19 recordsLinked to original sources
PubMed2004

Decidual and peripheral blood CD4+CD25+ regulatory T cells in early pregnancy subjects and spontaneous abortion cases.

Human pregnancy represents a situation of semiallograft to maternal host. Therefore, it has been reported that tolerance to the fetal allograft represents a mechanism for maintaining a pregnancy. CD4(+)CD25(bright) regulatory T cells are known to play an important role in the development and maintenance of tolerance in peripheral tissues. However, the potential role of CD4(+)CD25(bright) T cells in maintaining human pregnancy has not been reported. In this study, we show that early human pregnancy decidua contains an abundance of CD4(+)CD25(bright) T cells, which express CD152(CTLA-4) at a high level. CD4(+)CD25(bright) T cells mediate potent inhibition of autologous T-cell proliferation by anti-CD3 stimulation. Furthermore, these cells inhibit the proliferation of autologous CD4(+)CD25(-) T cells in a dose-dependent fashion. This suppressive function of decidual CD4(+)CD25(+) T cells required cell-to-cell contact. The proportion of decidual CD4(+)CD25(bright) T cells was significantly lower in specimens from spontaneous abortion compared to those from specimens from induced abortions. These results suggest that decidual CD4(+)CD25(bright) T cells contribute to the mechanisms mediating maternal immune tolerance of conceptus antigens and therefore might contribute to the maintenance of pregnancy.

Abortion, Spontaneous↗
PubMed2004

Serum granulysin is a marker for Th1 type immunity in pre-eclampsia.

Recent studies suggest that pre-eclampsia is associated with a Th1 predominant state and may be considered a failure of tolerance. Granulysin is a cytotoxic granule protein of natural killer (NK) cells and cytotoxic T lymphocytes (CTLs). Recently, we developed an enzyme-linked immunosorbent assay (ELISA) system for detecting serum granulysin, and reported that serum granulysin is a useful marker to evaluate the cell-mediated immunity. In this study, we show that the serum levels of granulysin were significantly elevated in pre-eclamptic patients compared with those in normal pregnancy subjects. In addition, the serum granulysin levels in pre-eclamptic patients were well associated with mean blood pressure, percentage of peripheral blood Th1 cells and Th1/Th2 ratios. The present results suggest that the serum granulysin levels would be a useful and novel serum marker to evaluate the Th1/Th2 balance, especially Th1 type immunity in pre-eclampsia.

Adult↗
PubMed2003

Survivin inhibits apoptosis in cytotrophoblasts.

Survivin, a protein that inhibits apoptosis, is expressed in a variety of tumour cells. We detected survivin-specific mRNA and protein in normal placental tissues, two human choriocarcinoma cell lines (JEG-3 and BeWo), and a trophoblastic cell line (tPA30-1) by reverse transcription-polymerase chain reaction (RT-PCR), Northern blotting, and Western blotting. Immunohistochemically, survivin was localized to normal villous cytotrophoblasts, normal extravillous trophoblasts, cytotrophoblasts in hydatidiform mole, and choriocarcinoma cells. Antisense oligonucleotides for survivin dose-dependently induced apoptosis in two choriocarcinoma cell lines (JEG-3 and BeWo) and a trophoblastic cell line (tPA30-1), while sense oligonucleotides showed little effect. These findings suggest that survivin antagonizes apoptosis in cytotrophoblasts, extravillous trophoblasts, and choriocarcinoma cells.

Adult↗
PubMed2002

Proteomic profiling and neurodegeneration in Alzheimer's disease.

Quantitative proteome analysis of Alzheimer's disease (AD) brains was performed using 2-D gels to identify disease specific changes in protein expression. The task of characterizing the proteome and its components is now practically achievable because of the development and integration of four important tools: protein, EST, and complete genome sequence databases, mass spectrometry, matching software for protein sequences and protein separation technology. Mass spectrometry (MS) instrumentation has undergone a tremendous change over the past decade, culminating in the development of highly sensitive, robust instruments that can reliably analyze biomolecules, particularly proteins and peptides; we identified 35 proteins from over 100 protein spots on a 2-D gel. Using this current technology, protein-expression profiling, which is actually a specialized form of mining, is an important principal application of proteomics. The information obtained has tremendous potential as a means of determining the pathogenesis, and detecting disease markers and potential targets for drug therapy in AD.

Aged↗
PubMed1994

Ellagic acid/phospholipid-induced coagulation and dextran sulfate-induced fibrinolytic activities in beta 2-glycoprotein I-depleted plasma.

Beta 2-glycoprotein I (beta 2-GPI) binds negatively charged substances and inhibits intrinsic blood coagulation in the presence of ellagic acid-phospholipid suspension. Beta 2-GPI is thought to be an important protein in the reaction between negatively charged phospholipids and anti-phospholipid antibodies which appear in patients with lupus anticoagulant/antiphospholipid antibody syndrome. We prepared a monoclonal antibody against beta 2-GPI purified from human plasma and obtained beta 2-GPI-depleted plasma using a monoclonal antibody-coupled column. Either partial thromboplastin time or the activation of prekallikrein induced by diluted ellagic acid-phospholipid suspension in beta 2-GPI-depleted plasma was not different from that in control plasma. Beta 2-GPI inhibited the intrinsic blood coagulation only when added to control or beta 2-GPI-depleted plasma in excess (more than physiological concentrations). The intrinsic fibrinolysis in beta 2-GPI-depleted plasma induced by dextran sulfate was not impaired and, again, beta 2-GPI inhibited the intrinsic fibrinolysis only when added to control or beta 2-GPI-depleted plasma in excess. These results indicate that both in vitro Actin-induced intrinsic coagulation and dextran sulfate-induced fibrinolytic activities are significantly inhibited by more than physiological concentrations of beta 2-GPI.

Amino Acid Sequence↗
PubMed1993

Congenital antithrombin III deficient neonate treated with antithrombin III concentrates.

A patient with antithrombin III deficiency developed deep vein thrombosis during her first pregnancy. Her pregnancy and delivery were successfully treated with simultaneous administration of antithrombin III concentrates and low molecular weight heparin. She delivered a 2,412g girl at 39 weeks' gestation. The baby was administered with antithrombin III concentrates as prophylaxis for neonatal arterial and venous thrombosis because the antithrombin III level was extremely low to be 2%. Her second pregnancy was uneventful at 38 weeks' gestation, and she was treated with administration of antithrombin III concentrates prophylactically. She delivered a 3,256g boy at 42 weeks' gestation without any complications. The antithrombin III level of the second baby was normal. These results showed that in a neonate with congenital antithrombin III deficiency the antithrombin III concentrates would be administered to prevent neonatal arterial and venous thrombosis.

Adult↗
PubMed1992

[Coronary artery disease in diabetic patients].

Although it is well known that diabetics have high mortality rates due to ischemic heart disease (IHD), controversies still exist about the severity of coronary artery disease in diabetics compared to nondiabetics. We compared coronary arteriographies of 50 diabetics with IHD to those of 50 nondiabetics with IHD. In regard to coronary risk factors, incidence of obesity was significantly higher in diabetics. Incidence of hypertension, hypercholesteremia, hyperuricemia was higher, although not significant, in diabetics. Incidence of smoking was significantly higher in nondiabetics. The diabetic group showed a significantly higher incidence of patients with more than two or three diseased vessels, and a significantly higher number of diseased coronaries with more than 50% stenosis per patient compared to nondiabetics (5.6 +/- 3.7 vs 3.7 +/- 3.2). The distribution of diseased coronaries with more than 75% stenosis showed no difference between diabetics and nondiabetics. The incidence of coronary spasm was significantly lower in diabetics (12% vs 28%). The high incidence of multiple vessel disease in diabetics was thought to be due to other complicated coronary risk factors, especially hypertension and hypercholesteremia.

Aged↗
PubMed1990

[Silent myocardial ischemia in diabetics--by treadmill exercise testing].

We examined silent myocardial ischemia in diabetics by treadmill exercise testing. There were 28 diabetic men and 64 diabetic woman without angina, with a mean age of 59 +/- 11 years. Symptom-limited treadmill exercise testing was performed, and we used the electrocardiogram during exercise and immediately after exercise for judgement. ST segment depression was defined as positive if there was at least 0.1 mV of ST depression 80 ms from the J point. It was defined as negative if max heart rate (HR) was more than 80% of target HR and there was no significant ST depression. It was defined as equivocal if there was no significant ST depression but max HR was less than 80% of target HR. In 92 diabetics, 21 patients (23%) showed positive ST depression, 35 (38%) showed negative ST depression, 36 (39%) showed equivocal ST depression. In 56 diabetics exclusive of treadmill equivocal patients, 38% of patients showed positive ST depression. Treadmill positive diabetics had a significantly higher rate of smokers, patients with hypertension, and a higher triglyceride level as compared with treadmill negative diabetics. Coronary arteriography, which was performed in six treadmill positive diabetics, revealed coronary stenosis of more than 75% in four patients.

Adult↗
PubMed1990

[Clinical evaluation of coronary artery fistula and coronary artery-cardiac chamber shunt].

Coronary artery fistula and coronary artery-cardiac chamber shunts were observed in 16 cases out of 462 consecutive cases in which coronary angiography was performed. 9 of these cases had coronary artery fistula, 5 of the cases had coronary artery-cardiac chamber shunts. 2 cases had both of these conditions. Coronary artery fistula has a draining vein originating from the coronary artery and an entering vein terminating in the cardiac chamber or the pulmonary artery. Coronary artery-cardiac chamber shunts have no such veins, and contrast material used in the injection phase of coronary angiography escapes directly into the cardiac chamber. 2 cases of coronary artery fistula, 2 cases of coronary artery-cardiac chamber shunts, and 1 case involving the both of these conditions showed positive results in submaximal exercise tolerance tests, and no significant arteriosclerotic changes in the coronary artery. These factors lead us to suggest that coronary artery-cardiac chamber shunts cause cardiac ischemia for the same reason that coronary artery fistula does.

Adult↗
PubMed1989

[A case of coronary artery fistula with angina pectoris].

A case of coronary artery fistula with myocardial ischemia is reported. A 57-year-old-man was admitted to our hospital complaining of anterior chest pain on exertion. Submaximal Treadmill exercise showed the depression of ST segment in leads II, III, aVF, V5 and V6. 75% stenosis of right coronary artery (segment 2) and congenital coronary artery fistula originating from both the right and left coronary arteries were demonstrated by the coronary arteriography. One abnormal artery was originated from proximal portion of the right coronary artery (segment 1) and entered the pulmonary artery trunk. Another one was originated from proximal portion of the left coronary artery and terminated in angiomatous plexus which then communicated with the pulmonary artery trunk. We speculate that myocardial ischemia resulted from decreased right coronary blood flow due to coronary steal and proximal organic stenosis of right coronary artery. Recently, the reviews of coronary artery fistula are increasing, but coronary artery fistula with myocardial ischemia is relatively rare. This case was followed with medical therapy, because antianginal agents were effective. Operative coronary ligation may be necessary, if he has angina or high output heart failure during follow-up.

Angina Pectoris↗
PubMed1980

A model of distributed type associative memory with quantized Hadamard transform.

This paper proposes a new correlation matrix network model of associative memory in brain. Each memorized pattern which consists of binary (+1 or -1) elements is preprocessed by a quantized Hadamard transform to increase selectivity. The association ability of a correlation matrix network model depends on the orthogonality between key patterns by which the corresponding memorized patterns are associatively recalled. In a brain model, however, it is rare that the key patterns are mutually orthogonal since they are memorized patterns themselves. The quantized Hadamard transform, presented in this paper, renders the memorized patterns approximately orthogonal. The model is tested by computer simulation.

Animals↗
PubMed1979

A new modulation method with range resolution for ultrasonic Doppler flow sensing.

This paper proposes a new pair of sequences whose cross-correlation values are zero except for the peak value and presents a new modulation method for an ultrasonic Doppler flowmeter with high sensitivity utilizing these sequences. In this method, transmitted and received waves are modulated and demodulated, respectively, by the specified new sequences. Since ulfavourable reflected waves can be almost completely eliminated by this proposed modulation method, a high signal-to-noise ratio is easily achieved. Elementary experimental results are also given.

Doppler Effect↗