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Biomedical subjects

S Nagata

Publications and source records attributed to S Nagata.

At least 541 records · Page 30Linked to original sources
PubMed1990

Implantation of genetically manipulated fibroblasts into mice as antitumor alpha-interferon therapy.

Long-term parenteral administration of human alpha-interferon (HuIFN-alpha) is effective in the treatment of several malignancies, including chronic myelocytic leukemia. In the present study, a model for fibroblast-mediated HuIFN-alpha gene therapy for the treatment of chronic myelocytic leukemia is described. Human IFN-alpha 5 complementary DNA was inserted into a bovine papilloma virus plasmid vector (BMGNeo) containing a neomycin resistance gene. The recombinant plasmid (BMGNeo-IFN) was transfected into NIH/3T3 fibroblasts by the calcium phosphate coprecipitation method, and stably transformed cells were isolated by G418 selection. A fibroblast clone secreting a large amount of HuIFN into the culture supernatant was selected by radioimmunoassay using anti-HuIFN-alpha monoclonal antibodies. Southern blot analysis revealed that the transformed cells contained approximately ten copies of the BMGNeo-IFN plasmid per cell, and Northern blot analysis demonstrated high expression of HuIFN-alpha mRNA in the cells. This fibroblast clone strongly suppressed proliferation of a HuIFN-alpha-sensitive chronic myelocytic leukemia cell line (KU812) during cocultivation in vitro. When the HuIFN-alpha-producing fibroblasts were implanted into nude mice bearing KU812 tumors by the subcutaneous diffusion chamber method, tumor growth in vivo was also significantly suppressed. This study suggests the clinical potential of fibroblast-mediated gene therapy in the future.

Animals↗
PubMed1990

Distinct vascular and intestinal smooth muscle myosin heavy chain mRNAs are encoded by a single-copy gene in the chicken.

We examined whether the gizzard MHC gene is expressed in other smooth muscle tissues and, if so, whether there exist any smooth muscle MHC isoforms at the mRNA level. Northern blot analysis showed that the gizzard MHC gene was also expressed in the aorta and jejunum, but not in the pectoralis muscle or in fibroblasts. This indicates that striated muscle and non-muscle MHC isoforms are encoded in genes distinct from the smooth muscle MHC gene. Further, nuclease S1 mapping showed that the aortic smooth muscle MHC mRNA was distinct from the gizzard mRNA in the 5'-terminal coding region. Both of these mRNA species are expressed in the jejunum. These observations suggest that there exist at least two chicken smooth muscle MHC isoforms, vascular-type and intestinal-type, and that these isoforms are generated from a single-copy gene, probably by an alternative mRNA processing mechanism.

Animals↗
PubMed1990

Expression cloning of a receptor for murine granulocyte colony-stimulating factor.

Two cDNAs encoding the receptor for murine granulocyte colony-stimulating factor (G-CSF) were isolated from a CDM8 expression library of mouse myeloid leukemia NFS-60 cells, and their nucleotide sequences were determined. Murine G-CSF receptor expressed in COS cells could bind G-CSF with an affinity and specificity similar to that of the native receptor expressed by mouse NFS-60 cells. The amino acid sequence encoded by the cDNAs has demonstrated that murine G-CSF receptor is an 812 amino acid polypeptide (Mr, 90,814) with a single transmembrane domain. The extracellular domain consists of 601 amino acids with a region of 220 amino acids that shows a remarkable similarity to rat prolactin receptor. The cytoplasmic domain of the G-CSF receptor shows a significant similarity with parts of the cytoplasmic domain of murine interleukin-4 receptor. A 3.7 kb mRNA coding for the G-CSF receptor could be detected in mouse myeloid leukemia NFS-60 and WEHI-3B D+ cells as well as in bone marrow cells.

Amino Acid Sequence↗
PubMed1990

Multiple elements in the promoter of granulocyte colony-stimulating factor gene regulate its constitutive expression in human carcinoma cells.

Some human carcinoma cells constitutively produce granulocyte colony-stimulating factor (G-CSF) which stimulates the proliferation and differentiation of the progenitor cells of neutrophilic granulocytes. By introducing mouse G-CSF chromosomal gene or its promoter DNA into human carcinoma cell lines of CHU-2, SK-HEP-1, and U-87MG, it was shown that the constitutive expression of G-CSF in these carcinoma cells was due to the intrinsic activation of nuclear factors which work on the promoter region of the G-CSF gene. A series of 5' deletion mutants, linker scanning mutants, and internal deletion mutants was constructed in the promoter of mouse G-CSF gene and was introduced into human CHU-2 cells to analyze their promoter activities. These studies demonstrated that at least three regulatory elements in the promoter of the G-CSF gene are essential for the constitutive expression of G-CSF in CHU-2 cells. These elements include the consensus decanucleotide "GAGRTTCCA/CC" present on G-CSF, granulocyte/macrophage colony-stimulating factor, and interleukin 3 genes and the "ATTTGCAT" octamer transcription factor binding site. Some point mutations in these consensus sequences significantly diminished the promoter activity in CHU-2 cells.

Adenocarcinoma↗
PubMed1990

Peptidylarginine deiminase in rat and mouse hemopoietic cells.

Peptidylarginine (protein-L-arginine) deiminase activities have been demonstrated in extracts of rat and mouse peritoneal macrophages, bone marrow cells, splenic adherent cells, neutrophils, and mouse monocyte/macrophage cell lines. The enzyme in these cells is indistinguishable from the skeletal muscle enzyme with respect to immunochemical properties.

Ammonia↗
PubMed1990

Granulocyte colony-stimulating factor stimulates human mature neutrophilic granulocytes to produce interferon-alpha.

Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein hormone that specifically stimulates both production and functional activation of neutrophils, while interferon-alpha (IFN-alpha) is known to suppress myelopoiesis, including neutrophil production in vivo and in vitro. On a possibility that IFN-alpha may operate as one of the inhibitory feedback factors in neutropoiesis, we examined whether neutrophils produce IFN-alpha in response to G-CSF. Northern blot analysis showed that messenger RNA (mRNA) for human IFN-alpha 1 became detectable time-dependently in highly purified human neutrophils incubated with purified recombinant human G-CSF (rhG-CSF). But such transcription was not observed either in neutrophils incubated with other neutrophil activators, such as formyl-methionyl-leucyl-phenylalanine (fMLP) or lipopolysaccharides (LPS), or in blood mononuclear cells incubated with rhG-CSF. In addition, radioimmunoassay for human IFN-alpha showed that its levels in culture medium of the rhG-CSF-treated neutrophils rose markedly (up to approximately 100 IU/mL/1 x 10(7) cells) in a time-dependent way, compared with those of nonstimulated neutrophils. These findings suggest that the G-CSF/IFN-alpha system may participate in the feedback regulatory loop of neutropoiesis.

Blotting, Northern↗
PubMed1990

Estrogen regulates peptidylarginine deiminase levels in a rat pituitary cell line in culture.

A Nonidet P-40 extract of growth hormone-producing rat pituitary MtT/S cells was found to contain peptidylarginine deiminase (EC 3.5.3.15), which was indistinguishable from an enzyme preparation from rat muscle in Western immunoblotting and immunoprecipitation. This enzyme was immunocytochemically detected in the cytoplasm but was not secreted into the medium during the cultivation. When the cells were cultured for 2 days with various concentrations of 17 beta-estradiol (E2), the enzyme activity increased in a dose-dependent manner, reaching a maximum level (four- to fivefold higher than control) at about 10(-9) M. This increase in the enzyme activity was evident by 14 hr of culture and became relatively stable after 24 hr. It correlated well with the increase in the amount of the muscle type enzyme per cell as analyzed by Western immunoblotting. Estriol and a synthetic estrogen, diethylstilbestrol, also increased the enzyme activity, whereas testosterone, progesterone, and corticosterone were without effect. An antiestrogen, tamoxifen, which by itself was inactive, partially suppressed the effect of E2. Exposure of MtT/S cells for 14 hr to E2 increased incorporation of 35S-labeled amino acids into the immunoprecipitable peptidylarginine deiminase. This increase was dependent on the concentration of E2, attaining a maximum level (about tenfold higher than the control) at about 10(-9) M. These results indicate that estrogen effects the increase in peptidylarginine deiminase content in the pituitary cells by stimulating enzyme synthesis.

Amino Acids↗
PubMed1990

Reoperation for moyamoya disease refractory to encephalo-duro-arterio-synangiosis.

Three cases of Moyamoya disease successfully treated by reoperation are reported with special reference to the operative techniques in the second operation. These children first underwent encephalo-duro-arterio-synangiosis (EDAS). Because two of the three postoperative collateral formations through EDAS were either poor or not present at all and their symptoms remained. Encephalo-myo-synangiosis (EMS) was later added in the posterior frontal and/or parietal regions of the same side as the former EDAS. In the remaining one, the collaterals through EDAS were well formed but transient ischaemic attack (TIA) persisted in the lower limb. The collateral to the middle cerebral arterial (MCA) distribution, even though seemingly well formed, was not sufficient to obtain a complete subsidence of the symptoms. In this case encephalo-myo-arterio-synangiosis (EMAS) was later added to the antero-medial frontal region of the same side as the EDAS to form collaterals to the anterior cerebral arterial (ACA) distribution. In all three cases the angiograms after the second operation showed good formation of collaterals, and the symptoms subsided. The causes of poor collateral formation through EDAS and operative techniques for the additional operation for those cases refractory to EDAS are discussed.

Brain↗
PubMed1990

EMG power spectrum as a measure of muscular fatigue at different levels of contraction.

The shift in the power spectrum resulting from a 5-7 min fatigue-inducing effort followed by a 1-2 min recovery period of two elbow flexors, the biceps brachii (BB) and the brachio-radialis (BR), was assessed using two variables, the mean frequency Fm and the median or central frequency Fmd. These two variables were calculated in pre- and post-fatigue conditions and following a brief recovery, at four levels, namely 20, 40, 60 and 80 per cent of maximum voluntary contraction (MVC). These were taken from a ramped isometric effort that is from 0 to 100 per cent MVC. The EMG activity of the two flexors was recorded with bipolar surface electrodes from a group of ten volunteers. Following muscle fatigue, induced with a maintained 60 per cent MVC isometric contraction, a statistically significant (p less than 0.05) shift towards the lower frequencies was observed for both Fm and Fmd for both muscles. Following a brief recovery, a shift towards the pre-fatigue higher frequencies was statistically significant (p less than 0.05). These two synergists responded to muscle fatigue and recovery similarly, as they both demonstrated parallel shifts in power spectrum. The power spectrum is consequently a reliable measure of muscular fatigue. It is also complementary to the net articular moment results.

Adult↗
PubMed1990

Spectrum of restrictive cardiomyopathy: report of the national survey in Japan.

This report describes clinical profiles and echocardiographic, hemodynamic, and histologic findings in 26 cases of idiopathic RCM based on the diagnostic criteria of (1) heart failure resulting from a stiff left ventricle, (2) normal LV size and systolic function, (3) absence of LV hypertrophy, and (4) cause or association unknown. There were 14 male and 12 female patients ranging in age from 5 to 63 years. Ten patients died during the mean follow-up period of 145 months, and five died of heart failure after 10 years. Three had a family history of HCM. Thromboembolism was observed in eight. Echocardiograms showed normal LV wall thickness and contraction. Hemodynamic characteristics included elevated biventricular filling pressures and a pulmonary wedge pressure that was usually higher than the right atrial pressure. Equalization of biventricular filling pressures was seen, however, in almost all patients with severe tricuspid regurgitation (seven of eight). The square root sign was seen in 50% in RV diastolic pressure tracings and 28% in LV tracings. This sign was observed in patients with elevated filling pressures. Interstitial fibrosis (22 of 23), endocardial thickening (13 of 23), and myofibrillar hypertrophy (10 of 23) were common histologic findings. Severe myocardial fiber disarray consistent with HCM was seen in four patients.

Adolescent↗
PubMed1990

Residual atrial septal perforation after percutaneous transvenous mitral commissurotomy with Inoue balloon catheter.

To estimate the incidence of residual atrial septal perforation (ASP) following percutaneous transvenous mitral commissurotomy (PTMC) with the Inoue balloon catheter and to examine the factors contributing to ASP, we studied 46 patients with mitral stenosis undergoing PTMC. Residual ASP was evaluated by Doppler color flow imaging 1 day after PTMC, and was detected in 7 out of 46 patients (15.2%). We examined the relationship between the development of ASP (ASP+) and the age of the patient, the left atrial dimension before PTMC, the mean pressure difference between left and right atrium after PTMC, and the duration of the procedure from atrial septal puncture by the Brockenbrough method to balloon inflation. There was a good correlation between the development of residual ASP and the duration of the procedure (ASP+, 51.0 +/- 34.0 minutes; without ASP, 24.6 +/- 16.2 minutes; p less than 0.01). However, there was no significant correlation between the development of ASP and other factors. In the follow-up study, ASP disappeared in four patients within 3 months. ASP persisted in two patients for 1 year after PTMC. However, the shunt in these two patients was clinically insignificant. These data suggest that residual ASP may depend on the duration of the procedure, and that most cases of ASP disappear within 1 year after PTMC.

Adult↗
PubMed1990

Two pediatric cases with occlusions of the ipsilateral internal carotid and posterior cerebral arteries associated with moyamoya vessels: "unilateral" moyamoya disease.

Two pediatric cases of unilateral Moyamoya disease are reported. The clinical symptoms and the findings of electroencephalography, angiography, and positron emission tomography in these cases were quite the same as those in the cases with bilateral involvement, which is typical of this disease. In both cases angiography demonstrated unilateral occlusion not only of the internal carotid artery but also of the posterior cerebral artery together with so-called Moyamoya vessels on the same side. Although infectious diseases were mentioned in the patients' histories, no obvious basic diseases related to the cerebrovascular occlusion were detected. We consider that these cases with unilateral involvement suggest the presence of unilateral Moyamoya disease without progression onto the opposite side.

Animals↗
PubMed1990

Chronological development of the fetal stomach assessed using real-time ultrasound.

To elucidate processes involved in the developing fetal stomach in utero, we examined chronological changes in maximum longitudinal and anteroposterior gastric dimensions in 618 fetuses from 16 to 41 weeks of gestation, using real-time ultrasound. Three statistically critical points were evident at 26-27, 32-33, and 36-37 weeks of gestation. Both dimensions increased from 16-17 to 26-27 weeks, remained fairly constant between 26-27 and 32-33 weeks, increased again from 32-33 to 36-37 weeks, and then decreased from 36-37 weeks onwards. These findings suggest that there are four different phases underlying the development of gastric function in the human fetus, corresponding to the time-periods divided by the three critical points of gestational age.

Embryonic and Fetal Development↗
PubMed1990

Three different mRNAs encoding human granulocyte colony-stimulating factor receptor.

Three cDNAs for the human granulocyte colony-stimulating factor (G-CSF) receptor were isolated from the cDNA libraries of human U937 leukemia cells and placenta by using a murine G-CSF receptor cDNA as the probe. The human G-CSF receptor containing 813 amino acids had a marked homology (62.5%) with its murine counterpart and consisted of extracellular, transmembrane, and cytoplasmic domains. The WSXWS motif found in members of the newly identified growth factor receptor family was also present in the extracellular domain of the human G-CSF receptor. Expression of the cloned cDNA in monkey COS cells gave rise to a protein that could specifically bind G-CSF with a high affinity (Kd, 550 pM). Two other classes of the human G-CSF receptor were also identified, one of which had a deletion of the transmembrane domain and seemed to encode a secreted, soluble receptor. The third class of the G-CSF receptor contained a 27-amino acid insertion in the cytoplasmic domain and was highly expressed in placenta.

Amino Acid Sequence↗
PubMed1990

Cerebral aspergillosis after burr-hole surgery for chronic subdural hematoma: case report.

We report a case of aspergillosis in the subdural space and frontal lobe in an 83-year-old man. The clinical course simulated that of a brain tumor. The source for the infection was considered to be the previous burr-hole surgery for chronic subdural hematoma, which was performed 2.5 years before the onset of symptoms. The patient was treated by removal of the abscess and granuloma. The clinical features and treatment of aspergillosis after neurosurgical procedures are discussed.

Aged↗
PubMed1990

Neuronal migration anomalies causing extensive ventricular indentation.

Neuronal migration disorders include various anomalies of the brain, and cortical heterotopia is the most common type. In this report, we present the radiological findings of two adults with unusually large cortical heterotopia associated with fused-lip schizencephaly that caused extensive ventricular indentation. The lesion showed density on a computed tomographic scan and signal intensity on a magnetic resonance imaging scan similar to normal gray matter. Perifocal edema, contrast enhancement, and calcification were not seen. An abnormally decreased volume of the ipsilateral cerebral hemisphere, the presence of adjacent microgyri, and deep fissures that contained blood vessels were also characteristic findings, indicating abnormal development. Knowledge of this entity is important in differentiating true intracerebral neoplasms.

Adult↗
PubMed1990

Regulatory elements responsible for inducible expression of the granulocyte colony-stimulating factor gene in macrophages.

Granulocyte colony-stimulating factor (G-CSF) plays an essential role in granulopoiesis during bacterial infection. Macrophages produce G-CSF in response to bacterial endotoxins such as lipopolysaccharide (LPS). To elucidate the mechanism of the induction of G-CSF gene in macrophages or macrophage-monocytes, we have examined regulatory cis elements in the promoter of mouse G-CSF gene. Analyses of linker-scanning and internal deletion mutants of the G-CSF promoter by the chloramphenicol acetyltransferase assay have indicated that at least three regulatory elements are indispensable for the LPS-induced expression of the G-CSF gene in macrophages. When one of the three elements was reiterated and placed upstream of the TATA box of the G-CSF promoter, it mediated inducibility as a tissue-specific and orientation-independent enhancer. Although this element contains a conserved NF-kappa B-like binding site, the gel retardation assay and DNA footprint analysis with nuclear extracts from macrophage cell lines demonstrated that nuclear proteins bind to the DNA sequence downstream of the NF-kappa B-like element, but not to the conserved element itself. The DNA sequence of the binding site was found to have some similarities to the LPS-responsive element which was recently identified in the promoter of the mouse class II major histocompatibility gene.

Animals↗