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Biomedical subjects

S Fujiwara

Publications and source records attributed to S Fujiwara.

At least 343 records · Page 19Linked to original sources
PubMed1990

Reciprocal expression of human ETS1 and ETS2 genes during T-cell activation: regulatory role for the protooncogene ETS1.

The expression of the protooncogenes ETS1 and ETS2 has been studied in purified human T cells activated either by cross-linking of the T-cell receptor-CD3 complex on their cell surface or by direct stimulation with phorbol esters and ionomycin. Our results show that resting T cells express high levels of ETS1 mRNA and protein, while expression of ETS2 is undetectable. Upon T-cell activation, ETS2 mRNA and proteins are induced, while ETS1 gene expression decreases to very low levels. Late after stimulation, ETS1 mRNA is reinduced and maintained at a high level, while ETS2 gene expression decreases to undetectable levels. Therefore, it appears that in human T cells, ETS2 gene products are associated with cellular activation and proliferation, while ETS1 gene products are preferentially expressed in a quiescent state.

Calcium↗
PubMed1990

cDNA cloning, sequence, and expression of carbonic anhydrase in Chlamydomonas reinhardtii: regulation by environmental CO2 concentration.

cDNA clones for the periplasmic carbonic anhydrase (CA; carbonate hydro-lyase, EC 4.2.1.1) of Chlamydomonas reinhardtii cells were isolated and characterized. The fact that the cloned cDNA fragments encoded a 377-amino acid polypeptide (41,626 Da) consisting of an NH2-terminal hydrophobic signal peptide of 20 amino acids, a large (35,603 Da) subunit polypeptide, and a small (4144 Da) subunit polypeptide indicates that the two subunits are cotranslated as a precursor polypeptide. The amino acid sequence of mature subunits deduced from the nucleotide sequence showed 20-22% homology with human CA isozymes (CAI, CAII, and CAIII). Three zinc-liganded histidine residues and those forming a hydrogen-bond network to zinc-bound solvent molecules were highly conserved in the plant and animal enzymes. Three possible asparagine-linked glycosylation sites were found in the large subunit. Northern blot analysis was carried out using the cDNA fragment as a probe. The level of 2.0-kilobase CA mRNA increased within 1 hr when CO2 concentration of the bubbling gas was changed from 5% to 0.04% (air level) in the presence of light. On the other hand, CA mRNA did not accumulate when CO2 concentration was lowered in the dark. Experiments using 3-(3,4-dichlorophenyl)-1,1-dimethylurea showed that photosynthesis is absolutely required for the accumulation of CA mRNA. These results indicate that CA biosynthesis is regulated by changes in environmental CO2 concentration as well as light at the level of mRNA abundance.

Amino Acid Sequence↗
PubMed1990

Structure and differential expression of two genes encoding carbonic anhydrase in Chlamydomonas reinhardtii.

Two copies of structurally related genes (CAH1 and CAH2) for carbonic anhydrase (EC 4.2.1.1) were found to be tandemly clustered on the Chlamydomonas reinhardtii genome. The previously isolated cDNA clones for carbonic anhydrase polypeptides were derived from the upstream gene, CAH1, which has 10 introns in its coding region. The downstream gene, CAH2, also has 10 introns, at positions identical to those of CAH1. Although amino acid sequences deduced from the two genes showed 91.8% identity, partial sequences of the authentic enzyme isolated from air-induced cells were identical only to those of the CAH1 product. Northern hybridization using gene-specific probes showed that the level of 2.0-kilobase CAH1 mRNA increased in response to a decrease in CO2 concentration in the presence of light. The CAH1 mRNA did not accumulate when CO2 was lowered in the dark. In contrast, the level of 2.0-kilobase CAH2 mRNA decreased in response to lowering of CO2 and increased upon transfer to the high-CO2 condition in light. The decrease of CAH2 mRNA under the low-CO2 condition was not observed in the dark. The fully induced mRNA level was much higher for CAH1 than for CAH2. These results indicate that CAH1 is a gene coding for the major periplasmic carbonic anhydrase whose level of transcript is rapidly induced under the low-CO2 condition in the presence of light, and that CAH2 may encode another periplasmic isozyme, which is made under the high-CO2 condition.

Amino Acid Sequence↗
PubMed1990

Monoclonal antibodies specific to human ETS-2 oncoprotein: recognition of epitopes clustered on the B domain.

Six monoclonal antibodies were prepared from mice immunized with a bacterially expressed human ets-2 protein. These antibodies specifically recognize the two human ets-2-encoded proteins p56 and p54 but failed to react with chicken, mouse, rat, bovine, or monkey proteins, suggesting that the antibodies recognize epitopes specific to the human ets-2 protein. Differential reactivities of these monoclonal antibodies with the peptide fragments generated by partial proteolytic digestion of the bacterially expressed ets-2 protein indicated that the six antibodies recognize at least three distinct epitopes in the B domain of the ets-2 protein. Immunoprecipitation experiments comparing native and denaturing conditions suggested that the ets-2 domain detected by the monoclonal antibodies is masked in the native condition by either protein folding or interacting proteins. The biochemical analysis of the ets-2 protein will be facilitated by the development of these monoclonal antibodies, which may be useful as both domain-specific probes and tools for specifically detecting the human ets-2 protein in heterologous expression systems.

Animals↗
PubMed1990

Tumors of the lateral ventricular wall, especially the septum pellucidum: clinical presentation and variations in pathological features.

The clinical and histopathological features of 19 patients with tumors involving the septum pellucidum are presented. These tumors predominantly affected young adults, and the clinical manifestations were usually the results of raised intracranial pressure related to obstructive hydrocephalus, mental abnormality, epileptic seizures, or a combination of these. Seventeen of the tumors grew mainly in the lateral and third ventricles, and the other 2 grew both into the lateral ventricle and the cerebral parenchyma. The direction of cellular differentiation of the tumor cells varied from patient to patient and consisted of 8 neurocytomas, 1 mature neuronal tumor with ganglionic and small round neuronal cells, 3 subependymomas, 3 subependymal giant cell astrocytomas, 2 pilocytic astrocytomas, 1 malignant astrocytoma, and 1 teratoma with embryonal carcinoma. These tumors were considered to have arisen from the multipotential cells in the subependymal plate or germ cell rests in the lateral ventricular wall, especially in the septum pellucidum. Because of the relatively inert biological behavior and histological features of most of these tumors, we favor the malformative theory of their origin. Either total or an extensive excision of the tumors in this series, which had developed mainly in the ventricular system, provided long-term survival in many cases.

Adolescent↗
PubMed1990

A human case of zoonotic onchocerciasis in Japan.

A 2-year-old girl living in southwestern Japan had a nodule of 2 months' duration on the left foot. A biopsy from the lesion showed transverse sections of a worm surrounded by granulomatous tissue. The worm was identified as an Onchocerca sp. from the morphological characteristics such as relatively thick cuticles, annular ridges on the cortical layer, and high somatic muscles. Positive serological tests using ELISA for Onchocerca gutturosa and Onchocerca volvulus supported the diagnosis. This was the first case of zoonotic Onchocerca infection detected in Japan. The clinicopathological aspects of zoonotic onchocerciasis of this case were discussed.

Child, Preschool↗
PubMed1990

Phosphorylation of the ETS-2 protein: regulation by the T-cell antigen receptor-CD3 complex.

Phosphorylation of the human ets-2 protein in response to mitogenic signals to T lymphocytes was investigated in Jurkat cells. Activation of the cells by antibodies against the T-cell antigen receptor-CD3 complex or by concanavalin A was followed within 5 min by increased phosphorylation of the protein, as shown by a mobility shift of the protein from 54 to 56 kilodaltons in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and increased incorporation of 32P. The Ca2+ ionophores A23187 and ionomycin were able to mimic this effect, suggesting that this phosphorylation is mediated by Ca2+.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1990

Two cases of spontaneous internal carotid artery occlusion due to giant intracranial carotid artery aneurysm.

Although spontaneous thrombosis of a giant intracranial aneurysm is relatively common, occlusion of its parent artery is rare. We describe two recent patients in whom the parent artery spontaneously occluded. One patient had severe stenosis of the left internal carotid artery, with delayed appearance of a faint shadow of vascular widening near the posterior clinoid process. One month later, complete occlusion of the left internal carotid artery was shown angiographically. The second patient had dysarthria and left hemiparesis, resulting in the diagnosis of a left internal carotid artery giant aneurysm. He had suffered an episode of visual disturbance of the right eye 5 years before. Angiography showed the right cervical internal carotid artery to be occluded. We believe the mechanism of parent artery occlusion in our two patients to be due first to stretching of the internal carotid artery by the enlarged aneurysm, followed by compression of the internal carotid artery by the aneurysm itself. Next, the anterior clinoid process and the optic nerve are involved, and, finally, thrombosis of the aneurysmal cavity extends into the internal carotid artery itself.

Adult↗
PubMed1990

Regression of left ventricular hypertrophy in hypertensive patients: responses to exercise by antihypertensive treatment.

The effects of various antihypertensive treatments on the echocardiographic and electrocardiographic findings of left ventricular (LV) hypertrophy were studied in 75 patients with essential hypertension. The hemodynamic effects of the therapy during exercise were also compared. LV mass by echocardiogram was significantly reduced by beta-blockade and angiotensin converting enzyme inhibition (ACEI), but only slightly reduced by Ca channel blockade. QRS high voltage criteria of LV hypertrophy by electrocardiogram were reduced by all 3 of these antihypertensive treatments. At submaximal exercise, the pressor responses were attenuated by captopril, but not influenced by metoprolol or nifedipine. The increase in plasma norepinephrine by exercise was significantly suppressed after captopril, but was somewhat augmented after metoprolol or nifedipine. These observations indicate that the responses of hemodynamics and sympathetic nervous activity to exercise are different after the treatment by beta-blocker, Ca channel blocker or ACEI, in spite of the equal antihypertensive effect. However, it is suggested that the regression of LV hypertrophy might be induced by antihypertensive therapy, though the different grade by the individual drug.

Adrenergic beta-Antagonists↗
PubMed1990

The anticonflict effect of MK-801, an NMDA antagonist: investigation by punishment procedure in mice.

The NMDA antagonist MK-801 at 0.3 mg/kg, i.p. increased the punished response under a MULT VI 1.5/FR 5-punishment schedule of food reinforcement in mice. Furthermore, although neither MK-801 (0.1 mg/kg, i.p.) nor diazepam (0.25 mg/kg, s.c.) was without effect when separately administered, a significant increase in the punished response appeared after the combined administration of these two drugs. The present results suggest that MK-801 not only shows an anticonflict effect, but also enhances the anticonflict effect of benzodiazepine anxiolytics in mice.

Animals↗
PubMed1990

Effects of repeated administration of pentazocine on ambulatory activity in mice: comparison with the effects of morphine and methamphetamine.

Effects of single and repeated administration of pentazocine (5 times at intervals of 3-4 days) were compared with those of morphine and methamphetamine by means of ambulatory activity in mice. The interactions among these 3 drugs were also investigated. Pentazocine (25 mg/kg, s.c.), morphine (10 and 20 mg/kg, s.c.) and methamphetamine (2 mg/kg, s.c.) significantly increased the activity, and the effect progressively enhanced (defined here as development of reverse tolerance) during the repeated administration schedule. The induction of reverse tolerance to pentazocine was less dependent on the environmental conditions, and it was abolished within 2 months. A cross reverse tolerance was demonstrated from methamphetamine to pentazocine and to morphine, and from morphine to pentazocine. However, no significant cross reverse tolerance was induced from pentazocine to morphine and to methamphetamine, and from morphine to methamphetamine. The present results suggest that pentazocine possesses an ambulation-increasing effect, although the characteristics are different from that of either morphine or methamphetamine.

Animals↗
PubMed1990

T1 and T2 relaxation times on gadolinium-diethylenetriaminepentaacetic acid enhanced magnetic resonance images of brain tumors.

MRI of brain tumors was performed with CPMG pulse sequence, and T1 and T2 relaxation times were measured before and after the administration of 0.1 mmol/kg Gd-DTPA. T1 and T2 became significantly shorter than before with the T1 shortening being about twice the T2's. Three types of T2 shortening were classified by the difference in the intra-tumoral transport of Gd-DTPA in the time-course study after the administration. Transportal activity of Gd-DTPA seemed to be reflected by the physiologic viability of tumor suggested by pre-contrast T2.

Adolescent↗
PubMed1990

Follow-up study on ruptured aneurysms treated by wrapping.

The authors experienced 1903 cases of ruptured aneurysm between 1961 and 1986. Most cases were treated by clipping or ligating the aneurysmal neck. However, these procedures were impossible in 52 cases (2.7%), for which wrapping alone (21 cases), aneurysmal body clipping and wrapping (11 cases), or body ligation and wrapping (20 cases) was performed. We studied the long-term results in 44 of these 52 cases. Rerupture occurred in only two cases with incomplete wrapping. We concluded that complete wrapping, and wrapping of residual portions following aneurysmal body clipping or body ligation produce favorable results.

Adolescent↗
PubMed1990

[Effects of calcium antagonists or beta-blockade on left ventricular diastolic function in essential hypertension].

This study was performed to assess the effect of a calcium channel blocker (nifedipine) and beta-blockade (atenolol) on left ventricular early diastolic function and filling in essential hypertension (WHO stage I, II; HT). Twenty-two untreated patients were randomly divided as nifedipine (11 patients) and atenolol (11 patients) treatment groups and both the groups had complete echocardiographic and Doppler studies. Twenty normotensive cases served as controls. Clinical and echo-Doppler data obtained at baseline and four weeks after initiation of each therapy showed no difference between the two HT groups as to mean blood pressure (before therapy, 119 +/- 3 vs 117 +/- 11 mmHg; after therapy, 106 +/- 3 vs 110 +/- 3 mmHg), left ventricular dimension, left atrial dimension, and wall thickness. To evaluate early diastolic function, the interval from the aortic closure sound (IIA, phonocardiography) to the opening of the mitral valve (MVO, echocardiography) and that from MVO to the O point of the apexcardiogram were measured. The IIA-O interval was also calculated. The peak velocities in the rapid filling (R) and atrial contraction phases (A) were measured using pulsed Doppler echocardiography at the center of the mitral orifice. The MVO-O/IIA-MVO and A/R ratios were also calculated. Compared with the controls, the IIA-O interval (143.9 +/- 6.8 msec) and the IIA-MVO interval (81.5 +/- 4.9 msec) were significantly prolonged in HT (p less than 0.01). There was no significant difference between the MVO-O interval and R. Velocity A (54.2 +/- 2.7 cm/sec) and the A/R ratio (1.01 +/- 0.11) increased significantly in HT (p less than 0.05). The IIA-O interval (before therapy, 153.3 +/- 7.6 vs after therapy, 134.3 +/- 6.2 msec) and IIA-MVO interval (87.3 +/- 6.3 vs 77.8 +/- 5.9 msec) decreased and R (43.7 +/- 3.8 vs 49.1 +/- 3.0 cm/sec) increased significantly with nifedipine. The IIA-O interval (135.7 +/- 11.3 vs 150.4 +/- 7.6 msec) and the MVO-O (58.4 +/- 3.9 vs 66.5 +/- 4.7 msec) interval were significantly prolonged with atenolol, however the IIA-MVO interval, R, and A/R did not change. A (57.5 +/- 4.0 vs 50.2 +/- 2.9 cm/sec) was also significantly decreased with atenolol. There was a significant correlation between reduction in velocity A and prolongation in the MVO-O interval (r = -0.62, p less than 0.05) with atenolol. These results suggested that the prolongation of the diastolic closure rate of the mitral valve by atenolol was related to increased ventricular filling and decreased atrial contraction.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

Extracorporeal removal of anticancer drugs in hepatic artery infusion: the effect of direct hemoperfusion combined with venovenous bypass.

The effect of a new extracorporeal system combining direct hemoperfusion (DHP) with venovenous bypass was evaluated in the elimination of anticancer drugs in hepatic artery infusion. Adriamycin (3 mg/kg) and mitomycin C (1 mg/kg) were given to mongrel dogs through the hepatic artery with three different durations of 1, 10, and 20 minutes. Plasma drug levels were determined at the inlet and outlet of DHP and right external jugular vein (systemic level). Blood flow through DHP averaged 200 ml/min. In dogs without DHP (group I; n = 4), systemic levels of adriamycin and mitomycin C increased rapidly with 1-minute infusion, reaching the peak values of 6.61 +/- 2.44 (mean +/- SD) and 2.20 +/- 1.05 micrograms/ml, respectively. With DHP under single venous bypass (group II; n = 5), the peak values were reduced to 1.25 +/- 1.02 and 0.79 +/- 0.52 microgram/ml. Moreover, the peak levels were markedly reduced by DHP under hepatic venous isolation (group III; n = 6), the values being 0.41 +/- 0.15 and 0.13 +/- 0.07 microgram/ml with 1-minute infusion. The drug-removal rates were improved substantially in group III compared with group II. The longer the duration of infusion, the higher the removal rates tended to be in group III. These results indicate that effective elimination of anticancer drugs can be accomplished by this system during intraarterial chemotherapy of the liver.

Absorption↗
PubMed1990

[Influence of superior cervical ganglion on cerebral hemodynamics--measurements of cerebral blood flow and metabolism during superior cervical ganglionectomy in patients with moyamoya disease].

The effect of superior cervical ganglionectomy (SCG) on cerebral blood flow and metabolism was investigated in moyamoya disease. Measurement of cerebral blood flow and metabolism was performed in 12 cases (15 operations) of moyamoya disease during SCG. Mean age was 65.2 years (from 3 to 38). 4 were male and eight were female. Ischemic cases were 8 and hemorrhagic cases were 4. At encephalo-duro-anterio-synangiosis, a Laser Doppler flow meter and probes for measuring cortical tissue oxygen and carbon dioxide were set out to allow measurement from identical sites on the surface of the brain over the cortex. Moreover, an electromagnetic flow meter was placed on the common carotid artery. And the mean arterial blood pressure was also measured from femoral artery. After the electrode had been stabilized, continuous recordings were made of cerebral blood flow and metabolism during SCG. The mean arterial blood pressure fell slightly post operatively, but the changes in blood pressure were considered not to be significant enough to affect blood flow. Cortical CBF did not change immediately after SCG. However it increased gradually to 118.8% of preoperation level 30 minutes later respectively, and the difference was observed significant. The carotid blood flow and the tissue oxygen developed a tendency to increase after 30 minutes, but the tissue carbon dioxide did not changed. The present study indicates that superior cervical ganglionectomy is the useful procedure to increase in cerebral blood flow immediately after the operation on patients with moyamoya disease.

Adolescent↗
PubMed1990

[A study on display and accuracy of occlusal contacts by means of T-Scan System].

The various methods were introduced in the daily prosthodontic field evaluating occlusal contacts for diagnosis and analysis. Maness in 1987 developed the T-Scan system, which is considered as a new computerized device capable to interpret occlusal contacts information quantitatively. The system is composed of a sensor, sensor frame, handle, cable and system unit. Record and analysis mode made possible the occlusal contacts in three ways, such as the balance plot, the time display and comparison screen. However, accuracy and reproducibility of occlusal marking through this system is still uncertain. Therefore, this preliminary study was conducted on four specific points loaded on a sensor by application of the weight of 0.1 kg through 10 kg. The following results were obtained 1. There exists certain non-sensible areas caused by its constructional feature. 2. The most sensible area can be measured from 0.1 Kg to 2.1 Kg, and therefore, this device is more suitable for recording within lower loadings. 3. Although the system has a certain disadvantage of reproducibility, this contributes to attain diagnosis and treatment of occlusal contacts for a quantitative evaluation.

Dental Occlusion↗