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S Tsuzuki

Publications and source records attributed to S Tsuzuki.

At least 55 records · Page 3Linked to original sources
PubMed1995

Developmental changes in the electrophysiological properties of neonatal rat oculomotor neurons studied in vitro.

The electrophysiological properties of oculomotor neurons were studied in neonatal rats aged 1-15 days. Action potentials were recorded from brainstem slices (frontal section) using the intracellular recording method at 35 degrees C. No significant age-dependent differences were detected in the resting potential (around -55 mV) and in the amplitude of the action potential (approximately 60 mV). However, the input resistance of oculomotor neurons declined with age from a mean of 60.8 M omega for rats 1-3 days old to 17.0 M omega for rats 14-15 days old. In addition, the duration of the action potential measured at the half-amplitude gradually decreased from 0.74 ms to 0.34 ms with increasing age. Increases were detected in the maximum rate of rise (from 117 V/s to 181 V/s) and the maximum rate of fall (from -67 V/s to -103 V/s) of the action potential. When long-lasting (500 ms) depolarizing current pulses were applied to oculomotor neurons, some neurons exhibited continuous repetitive discharge (i.e. tonic firing) while others showed transient discharge (phasic firing). The proportion of tonic-type neurons increased with age: the value was 9% for rats 1-5 days old, 37% for rats 6-10 days old and 54% for rats 11-15 days old. Concomitantly, the number of neurons showing a time-dependent inward rectification increased and the average maximum frequency of the discharge rose from 150 to 420 Hz, approximately, with age. Furthermore, it was found that the electrophysiological properties of oculomotor neurons of rats 14-15 days old were similar to those in adult rats. It is concluded that oculomotor neurons in neonatal rats show rapid alterations in their electrophysiological properties and that the ratio of tonic-type to phasic-type neurons changes during the early stages of development.

Action Potentials↗
PubMed1995

Localization of the genes encoding the three rat angiotensin II receptors, Agtr1a, Agtr1b, Agtr2, and the human AGTR2 receptor respectively to rat chromosomes 17q12, 2q24 and Xq34, and the human Xq22.

Using fluorescence in situ hybridization, we determined the regional localization of the 3 rat genes encoding angiotensin II receptors at 17q12 (Agtr1a), 2q24 (Agtr1b) and Xq34 (Agtr2). In parallel, we showed that the type 2 human gene, AGTR2, also maps on the X chromosome, at band Xq22.

Animals↗
PubMed1995

[Cell kinetics of rat lens epithelium by cytofluorometric nuclear DNA determination].

The cell kinetics of rat lens epithelium was assessed by measuring the changes in the nuclear DNA contents during sugar cataract formation. Six-and-12-week-old Sprague-Dawley male rats were used and divided into the following groups: fed on normal chow, fed on 25% galactose diet, and fed on normal chow after 5 days on the 25% galactose diet. Every second day following the beginning of each chow feeding, lenses were extracted, and lens capsules with epithelial cells were obtained. After a few day's fixation in 4% paraformaldehyde dissolved in 0.1M phosphate buffer (pH 7.4), DAPI (4'6-diamidino-2-phenylindole)-stained lens epithelial cells were measured by fluorescence cytophotometry. The epithelia in the normal chow-fed rats contained many 2C and a few 4C nuclei. In the 25% galactose-fed rats, 4C nuclei increased gradually in number until the fifth day, and then decreases slowly day by day. Abnormal polyploid nuclei (8C) were observed in the 25% galactose-fed rats. 4C nuclei decreased rapidly after the diet reversal. These results indicate that galactose feeding caused higher DNA synthesis of rat lens epithelial cells and a higher possibility of abnormal cell division.

Animals↗
PubMed1994

Molecular cloning and expression of the gene encoding human angiotensin II type 2 receptor.

The gene of human angiotensin II type 2 (AT2) receptor was isolated from a genomic DNA library prepared from human placenta. The coding region of the human AT2 receptor gene was contained in a single exon coding segment of the gene indicating an intronless structure of the coding region. The amino acid sequence of human AT2 receptor deduced from its nucleotide sequence has 363 amino acids and shows a high degree of sequence identity to rat and mouse receptor sequences. Specific binding of [125I]Sar1Ile8-angiotensin II was demonstrated in COS-7 cells transfected with a plasmid containing the human AT2 sequence. Scatchard analysis and ligand displacement profile were typical of the AT2 receptor. Reverse transcription-polymerase chain reaction analysis showed that AT2 receptor mRNA was expressed in adult uterus and pheochromocytoma.

Amino Acid Sequence↗
PubMed1994

[Allogeneic cryopreserved marrow transplantation in a patient with chronic myelogenous leukemia].

A 45-year-old male with chronic myelogenous leukemia received cryopreserved allogeneic bone marrow from his HLA-identical sister. Bone marrow was harvested and cryopreserved prior to chemoradiotherapy since the donor had neurotic tendencies. The preconditioning regimen consisted of standard dosage of busulfan plus cyclophosphamide and total lymphoid irradiation (5Gy). A total of 3.1 x 10(7)/kg marrow mononuclear cells, containing 4.7 x 10(5) CD34+ cells/kg, and 8.0 x 10(6)/kg buffy coat cells collected from the donor at day 0 was infused. Marrow engraftment occurred by day 38 although hematological recovery was delayed and subsequent administration of GM-CSF, methylprednisolone and donor buffy coat cells were required. Mononuclear cells obtained from the patient's blood at day 28 had an inhibitory effect on CFU-GM formation of the donor's bone marrow mononuclear cells. We considered that this case suffered from a transient myelosuppression due to residual host cells after bone marrow transplantation.

Bone Marrow↗
PubMed1993

Molecular cloning of a novel angiotensin II receptor isoform involved in phosphotyrosine phosphatase inhibition.

There are two major isoforms of the angiotensin II receptor, type 1 (AT1) and type 2 (AT2). AT2 is distinguished from AT1 with respect to its ligand selectivity, its insensitivity to non-hydrolyzable GTP analogues, and its as yet unidentified biological functions. In the present study we have expression-cloned AT2 cDNA from a cDNA library of a rat pheochromocytoma cell line (PC12w). Rat AT2 cDNA encodes a 363-amino acid protein that has seven transmembrane domains. AT1 is the closest in homology to AT2 but with only a 32% identity of amino acid sequence. Stably expressed in COS-7 cells, the receptor showed selective binding to AT2-specific ligands PD123319 and CGP42112A but not to the AT1-specific ligand, losartan. Northern blot analysis revealed that the mRNA of rat AT2 was expressed not only in PC12w cells but also in the adrenal glands and in the inferior olive of the brain, both of which are known to contain AT2 type binding sites. The expressed AT2 receptor mediated angiotensin II-induced inhibition of protein tyrosine phosphatase, an action that was dependent on a pertussis toxin-sensitive G-protein-coupled mechanism in COS-7 cells. The AT2-specific ligand CGP42112A was an agonist rather than antagonist in the inhibition of phosphotyrosine phosphatase. AT2 did not cause a decrease in cGMP in PC12w or COS-7 cells expressing AT2 stably. These results indicate that the AT2 receptor is structurally and functionally different from AT1 and suggest novel functional roles of the renin-angiotensin system in cross-talk with phosphotyrosine signaling by modulating protein phosphotyrosine levels.

Amino Acid Sequence↗
PubMed1993

Long persistent bcr-abl positive transcript detected by polymerase chain reaction after marrow transplant for chronic myelogenous leukemia without clinical relapse: a study of 64 patients.

We report here the results of polymerase chain reaction (PCR) for bcr-abl transcript and clinical details derived from 64 chronic myelogenous leukemia (CML) patients after allogeneic bone marrow transplantation (BMT). A total of 139 samples (2 to 220 weeks after BMT) were analyzed and bcr-abl transcript was detected in 99 samples from 52 patients. Patients were defined as bcr-abl early negative (EN) if they had > or = 1 negative PCR result < or = 1 year post-BMT (n = 13), and bcr-abl late positive (LP) if they had > or = 1 positive PCR result > or = 1 year post-BMT (n = 21). Among LP patients, only two patients had hematologic/cytogenetic (clinical) relapse. Another 19 LP patients remained in clinical remission 7 to 130 weeks after positive analysis for bcr-abl transcript, including 5 patients who had persistent bcr-abl transcript detectable even 2 years after BMT. To estimate the relationship between clinical data and residual bcr-abl transcript, EN patients are compared with LP patients. However, no clinical data studied were significantly associated with the persistent PCR positivity. If only patients in chronic phase are compared, the t-test showed significant correlation between leukocyte count just before BMT and sustained bcr-abl transcript (P < .05). These results suggest that PCR positivity is frequently observed in CML patients who sustain clinical remission after BMT, without being predictive of imminent clinical relapse. Tumor burden at the time of BMT may play an important role in the latency of bcr-abl positivity after BMT.

Adolescent↗
PubMed1993

[Analysis of chronic graft-versus-host disease in patients after bone marrow transplantation from HLA-identical siblings].

The incidence of chronic GVHD, involved organs, and outcome were evaluated in 59 patients aged 15 years or more who survived for 2 months or more after HLA-matched bone marrow transplantation. The incidence of chronic GVHD was 65.3%. The incidence was not correlated with the age at the time of transplantation, underlying disease, or the method to prevent GVHD (group treated with MTX alone and CSP-treated group). Concerning the degree of organ involvement, the CSP-treated group more frequently showed slight involvement and, especially a significantly lower incidence of dryness of the eyeballs. According to organs, the oral cavity was most frequently involved (87%), followed in order by the liver (74%), skin (52%), and the eyes (30%). The oral cavity alone was involved in 6 patients, and the outcome was generally good. The outcome of multi-organ involvement of chronic GVHD was poor, and the major causes of death were interstitial pneumonia and sepsis. Even of patients who did not develop chronic GVHD, 25% showed dryness of the eyeballs and oral cavity. Biopsy and careful observation of the clinical course are needed for diagnosing GVHD.

Adolescent↗
PubMed1992

Molecular cloning and characterization of genes encoding rat pancreatic cholecystokinin (CCK)-releasing peptide (monitor peptide) and pancreatic secretory trypsin inhibitor (PSTI).

The genes encoding a rat pancreatic cholecystokinin (CCK)-releasing peptide (monitor peptide) and its structurally related peptide, rat pancreatic secretory trypsin inhibitor (PSTI), have been isolated and sequenced. The two genes share extremely high sequence similarity in the 5' flanking regions, suggesting that these regions may be responsible for the characteristic coordinate expression of the two peptides.

Amino Acid Sequence↗
PubMed1992

Monitor peptide gene expression is increased by exogenous CCK in the rat pancreas and in a rat pancreatic acinar cell line (AR4-2J).

Monitor peptide (CCK-releasing peptide) mRNA increased on the administration of CCK in rat pancreas and the AR4-2J pancreatic cell line. Subcutaneous injection of CCK into rats at 8 h intervals increased the level of monitor peptide mRNA in the pancreas. Concomitant injection of CCK antagonist CR-1409 strongly decreased it. The monitor peptide mRNA was also increased by CCK in AR4-2J cells and was decreased by the antagonist. These findings suggest that the plasma CCK induced by prolonged intake of a high protein diet may be responsible for the adaptative increase in the monitor peptide as well as exocrine proteases in the pancreas.

Amylases↗
PubMed1992

[Treatment of aplastic anemia with antilymphocyte globulin, high-dose methylprednisolone and androgen].

Twenty-seven patients with aplastic anemia (20 severe: 7 moderate) were treated with combined immunosuppression consisting of antilymphocyte globulin (ALG: Ahlbulin, Green Cross Co., Osaka, Japan) and high-dose methylprednisolone. Danazol or meptiostane was administered concurrently for at least 3 months. Ten of 27 patients had sustained improvement in hematopoiesis within 3 months of treatment. Three patients with hematological response had a recurrence of pancytopenia 12-36 months after the combined immunosuppressive therapy. Six patients died due to fungal pneumonia (2), hepatic failure (2), interstitial pneumonitis (1) and complication following allogeneic bone marrow transplantation (1). By life table analysis, the survival rate for all patients was 76 +/- 8% at 4 years, with 70 +/- 10% survival rate for patients with severe aplastic anemia and 100% for patients with moderate aplastic anemia. The factors predicting the good response to the therapy were a longer interval from diagnosis to the therapy and higher counts of platelet and reticulocyte at admission.

Adolescent↗
PubMed1992

[A case report of multiple-transfused aplastic anemia complicated by hemolysis and delayed neutrophil recovery after bone marrow transplantation].

The authors report an 18-year-old female who developed severe hemolytic reaction and delayed neutrophil recovery after bone marrow transplantation (BMT) for aplastic anemia from her HLA-identical sibling. She had received much transfusion (61 units of red blood cells including 4 units of fresh whole blood from her parents and 350 units of platelets) for 12 years before BMT. To prevent graft rejection, she received an intensified preparative regimen consisted of cyclophosphamide 200 mg/kg followed by 5 Gy total body irradiation and 5 Gy total lymphoid irradiation. Prophylaxis for GVHD was short term methotrexate and cyclosporin-A. Despite of the removal of the red cells from the marrow, marked hemolytic reaction caused by antibodies directed to rh" (E) and hr' (c) red cell antigens was observed when rh" (E) and hr' (c) positive donor erythroid began to recover. The recovery of neutrophils, especially the fraction of segmented cells was also delayed. Flow cytometry showed that the serially collected patient's sera reacted to neutrophils derived from both patient's blood on the 64th post-transplant day and the donor's blood. The reactivity was strongest in pre-BMT sera. We conclude that residual antibodies sensitized before BMT are a major cause of these hematological problems.

Adolescent↗
PubMed1991

Effect of a high-protein diet on the gene expression of a trypsin-sensitive, cholecystokinin-releasing peptide (monitor peptide) in the pancreas.

The adaptation to a high protein diet of the concentration and mRNA level of a trypsin-sensitive, cholecystokinin-releasing peptide (monitor peptide), which was proposed to be the mediator of the cholecystokinin release in response to protein intake, was investigated in the rat pancreas. Adult rats were placed on one of two isocaloric diets. One group was fed a 22% casein diet (control diet) and the other a 64% casein diet (high-protein diet) for 14 days. In order to quantify the monitor peptide separately from pancreatic secretory trypsin inhibitor (PSTI-II), which is highly similar in its amino acid and mRNA nucleotide sequences to the monitor peptide but has less cholecystokinin-releasing activity, we used specific assay methods: HPLC was used for determining the monitor peptide concentration in zymogen granules and a synthetic oligonucleotide probe for determining the mRNA of the monitor peptide in the pancreas. The concentrations in the zymogen granules and the mRNA levels in the pancreas of the two peptides increased in parallel during the adaptation to the high protein diet, indicating that these two peptides were under the same control during the adaptation. The concentration and mRNA level of the monitor peptide, which were measured after 0, 3, and 14 days, increased throughout the experiment period, as did the concentration of trypsin. This suggested that the monitor peptide and trypsin may respond to similar signals during the adaptation to a high protein diet and that this apparent coordination may facilitate the adaptation of the pancreas to the diet.

Amino Acid Sequence↗
PubMed1991

[Delay in red blood cell recovery after major ABO incompatible bone marrow transplantation].

In 6 of 27 patients in whom major ABO incompatible marrow was transplanted, the recovery of red blood cells (reticulocyte count greater than or equal to 1%) required more than 50 days after the transplantation. In 3 of them, more than 100 days were required. High titers of pre-transplant anti-A or anti-B agglutinin correlated with the delay in red blood cell recovery (IgM: p less than 0.01, IgG: p less than 0.05). In all of the patients whose pre-transplant IgM titers were 4 or less, and whose IgG titers were 32 or less, the red blood cells recovered within 50 days. Administration of cyclosporine did not correlate with the delay in red blood cell recovery. All the patients finally developed red cell production within 8 months without any treatment.

ABO Blood-Group System↗
PubMed1990

[Crossed cerebellar diaschisis after brainstem infarction].

Metabolic depression in the cerebellar hemisphere contralateral to supratentorial stroke termed "Crossed Cerebellar Diaschisis" (CCD) was first described by Baron and coworkers and now interpreted as a transneuronal deactivation resulted from loss of excitatory afferent inputs. Among the cerebrocerebellar pathways possibly involved, the corticopontocerebellar pathway is considered to be the most important to induce CCD. According to the hypothesis that CCD results from the destruction of the corticopontocerebellar pathway, any lesion wherever located in the corticopontocerebellar pathway may induce CCD. Little is known, however, about CCD after the brainstem lesion. Our case presented here showed that a brainstem lesion actually induced CCD and that CCD resulted from transneuronal deactivation. An 80-year-old female was admitted to the neurological department of Kasugai City Hospital because of left-sided hemiparesis of sudden onset on March 19, 1989. On admission and 5 days after admission CT scan of the brain was performed, but no stroke lesion was found. Magnetic resonance imaging of the brain disclosed a localized lesion in the right peduncle and tegmentum of the midbrain. Single photon emission computerized tomography of the brain using N-isopropyl-P-(123I) iodoamphetamine (IMP) performed about a month after admission disclosed decreased blood flow in the left hemisphere of the cerebellum compared with the right one and the findings of CCD were observed.

Aged↗
PubMed1989

[A case of left hand agraphia without callosal apraxia].

A 65-year-old male who had agraphia confined to the left hand was reported. The patient was admitted to the neurological department of Kasugai city Hospital because of suddenly-developed mild right-sided hemiparesis with central facial palsy. Computerized tomography of the brain was performed 2 and 14 days after admission. As a result, low-density regions were found in the left cingulate and medial frontal gyri and the trunk of the corpus callosum. Magnetic resonance imaging of the saggital plane more clearly visualized a localized infarction affecting both the trunk of the corpus callosum and its leftward outflow. Neuropsychological findings of the patient were summarized as follows. 1) He had no difficulty in any of the actual use of object, copying the manipulation of objects, and proper use of objects according to verbal commands. 2) With the eyes closed, he could correctly name the objects handed over to the right hand, while he could do only 15 out of 20 objects handed over to the left hand. However, whichever hand an object was handed to, he could explain how to use the object. 3) He could write Hiragana, Katakana, and Kanji correctly with his right hand in accordance with verbal commands, whereas with his left hand he could do only for 20% of Hiragana, 20% of Katakana, and 90% of Kanji. 4) He could copy Kanji, Hiragana, and figures with either right or left hand. 5) He could point out verbally-presented letters using letter cards whether with the right hand or with the left hand, and could also select the letter card corresponding to the letter visually-presented.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗