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Biomedical subjects

T Nagata

Publications and source records attributed to T Nagata.

At least 487 records · Page 27Linked to original sources
PubMed1989

Isolation of an auxin-regulated gene cDNA expressed during the transition from G0 to S phase in tobacco mesophyll protoplasts.

A cDNA clone for an auxin-regulated gene was isolated from a tobacco mesophyll protoplast cDNA library by differential screening. Nucleotide, sequence analysis showed that the deduced product of the gene, which we have designated par, is hydrophilic and is composed of 220 amino acids. No significant homology to other known proteins was detected. The mRNA of the par gene is approximately 900 bases long and its accumulation was detected in cultured mesophyll protoplasts as early as 30 min after the addition of 2,4-dichlorophenoxyacetic acid to the culture medium. The par mRNA was not detected in leaves or freshly prepared protoplasts or in protoplasts in the absence of 2,4-dichlorophenoxyacetic acid. Expression of the par gene was detected at a low level in actively dividing BY-2 tobacco suspension culture cells. The conspicuous accumulation of par mRNA before the initiation of DNA synthesis in tobacco mesophyll protoplasts suggests that the par gene product could play a role in the initiation of meristematic activity in differentiated mesophyll cells.

Amino Acid Sequence↗
PubMed1989

Serum C-reactive protein in the early diagnosis of neonatal septicemia and bacterial meningitis.

The usefulness of serum C-reactive protein (CRP) in the early detection of neonatal infection was studied using a special laser nephelometric apparatus (CRP-1), by which CRP concentrations could be quickly determined in the nursery, with only a small amount of serum (20 microL). Initial serum CRP concentrations of samples obtained from 90 infants suspected to have sepsis and/or meningitis were evaluated. Of the 90 infants, 25 showed culture-proven septicemia and/or bacterial meningitis, while 18 were considered to be infectious based on clinical signs and positive sepsis work-up even though cultures were negative. 47 infants had negative cultures and sepsis work-up and showed a favorable clinical courses. Statistical analysis for the evaluation of serum CRP at the level of one mg/dL was performed. False negative CRP was demonstrated in seven of 25 infants with culture-proven sepsis and/or meningitis (28%) and in 4 of 18 infants with other infections (22%). On the other hand, seven of 47 (15%) non-infected infants showed false positive results. The specificity and sensitivity of serum CRP determination were 85% and 74%, respectively, for all patients, and 85% and 72%, respectively, for patients with sepsis and/or meningitis. The sensitivity varied with the pathogens. We conclude that, while the initial CRP values alone are unsatisfactory for deciding the need for antibiotic therapy, CRP is useful in the early detection of neonatal infections, and its measurement by this new equipment should available in the nursery.

C-Reactive Protein↗
PubMed1989

Genetic suppression of a dnaG mutation in Escherichia coli.

Escherichia coli strains with a temperature-sensitive mutation, dnaG2903, in the primase-encoding gene spontaneously reverted to the temperature-insensitive phenotype at a high frequency. Many of the reversions were caused by extragenic sdg suppressors. About 100 independently isolated sdg suppressors were analyzed. They fall into two classes. The sdgA mutations were genetically mapped very close to and upstream of the dnaG gene and were found to be cis dominant. DNA sequencing of two of them revealed that G----A and C----A base substitutions had occurred 43 and 62 bases, respectively, upstream of the dnaG start codon. This region represents a transcriptional terminator thought to contribute to control of dnaG gene expression. The other class of suppressor, sdgB, seemed to comprise mutant alleles in the rpoB gene coding for the beta subunit of RNA polymerase core enzyme. Some of them were initially isolated as rifampin-resistant mutants. Both the sdgA and sdgB suppressors were found to increase the transcriptional activity of dnaG. This finding and other observations led to the proposition that sdgA and sdgB suppress the phenotype caused by dnaG2903 by overproducing the mutated primase; the quantitative oversupply may compensate for the qualitative defect of the dnaG2903 primase. An alternative mechanism of suppression by sdgB is discussed.

Base Sequence↗
PubMed1989

Effects of inhaled cadmium on breathing in the mouse.

Effects of intranasally administered cadmium (3.67 micrograms Cd approximately 36.7 mg per mouse) on breathing were investigated in mice under pentobarbital anesthesia. Cd levels found in the respiratory tract were dependent on the amount administered. Cd mainly caused degeneration and desquamation of the bronchial epithelium and pulmonary congestion, while the carrier solvent had no effects. On the other hand, the carrier solvent decreased respiratory frequency and enhanced its amplitude. These effects were absent 24 h later. However, Cd strongly affected respiration; frequency and amplitude were decreased and recovery at 24 h was not complete at the higher concentrations. These effects by Cd on respiration were dependent on the concentration of administered Cd and the Cd level in lung. Therefore, these results suggest that intranasally administered Cd has inhibitory effects on mouse respiration, perhaps owing to its acute toxicity to pulmonary tissues.

Administration, Inhalation↗
PubMed1989

Preventive effect of taurine against acute paraquat intoxication in beagles.

The continuous infusion of taurine markedly protected against paraquat (PQ)-induced oliguria in beagles. Pharmacokinetic studies revealed that taurine infusion increased the blood concentration of PQ and reduced the net content in the kidney and, to a lesser extent, in the lung. The excretion of PQ into the urine was unaltered. The infusion of glycine did not have such effects.

Animals↗
PubMed1989

[Evaluation of hydroxyapatite implants in human periodontal osseous defects].

In this clinical study we evaluated the use of hydroxyapatite ceramic (HAP) implant in conjunction with the surgical treatment of periodontal osseous defects. Fifty-five defects in 23 patients were treated and filled with HAP particles (BDHAP-101). At 6 months and 12 months after the placement of particles, the sites were evaluated by gingival margin heights, periodontal pocket depths, attachment levels, tooth mobility, the gingival index (GI), and radiographic analyses. Oral hygiene status was estimated by the plaque index (PlI). There were significant improvements with regard to probe depth, attachment level, tooth mobility, and GI. The radiographic analysis showed a similar density of the adjacent bone and the particles, suggesting excellent biocompatibility. There were no changes in PlI before or after the placement of implants.

Bone Resorption↗
PubMed1989

Biological significance of phospholipids in the rat stomach--from the viewpoint of electron microscopy.

The structures of gastric phospholipids (PLs) were further confirmed by employing an improved fixative and fixation method. PLs were detected on the free surface of superficial mucous epithelial cells and epithelial cells of the foveolar crypts. PLs were also detected inside superficial mucous cells and epithelial cells of the foveolar crypts. The gastric PLs were secreted through a merocrine-like mechanism. Apocrine-like secretion of PLs was also observed in some electron microscopic images. PLs were observed in the intercellular and intracellular secretory canaliculi of parietal cells and also in the rest of the parietal cytoplasm. The above findings indicated the localization of PLs on the surface of the gastric lumen and in the gastric mucosa, and suggested that, similar to gastric glycoproteins, gastric PLs play an important role in the gastric mucous barrier and mucosal barrier.

Animals↗
PubMed1989

Radioautographic study on the localization of an anti-allergic agent, tranilast, in the rat liver.

In order to demonstrate the localization associated with metabolism of an anti-allergic agent, Tranilast, in the liver, light microscopic radioautography of the liver was performed. Rats were administrated orally with 3H-Tranilast, and were sacrificed at 15 minutes to 24 hours after the administration. The livers were taken out and fixed, embedded and processed for light microscopic radioautography. 3H-Tranilast was absorbed rapidly, and the radioactivity in the liver increased and decreased within several hours. The number of radioautographic silver grains reached a maximum 3 hours after the administration. From 1 to 6 hours after the administration, the silver grains decreased from the portal area toward the central area. Seventy to 80% of all silver grains on the hepatocytes were retained in the cytoplasms of the hepatocytes at any experimental period. From these results, it was concluded that the localization of radioautographic silver grains was associated with Tranilast uptake of hepatocytes in each hepatic lobular compartment and that the metabolic process from uptake to excretion of Tranilast took part in the hepatocytes in each hepatic lobular compartment.

Administration, Oral↗
PubMed1989

Platelet vasopressin receptor in patients with chronic renal failure.

The vasopressin binding to intact platelet from patients with chronic renal failure (CRF) was investigated in relation to the abnormalities in platelet aggregation. The immunoreactive arginine vasopressin (AVP) in platelet-free plasma (PFP) but not in platelets was significantly higher in non-dialyzed patients with CRF than in normal subjects. Binding studies using [3H]AVP demonstrated a decreased number of binding sites (Bmax) on platelets from patients with CRF compared to normal controls with no significant difference in affinity (Ka). A significant diminution of the maximal percentage aggregation with AVP was found in patients with CRF. An inverse relation between Bmax and the PFP AVP levels and a highly significant relation between Bmax and the maximal percentage aggregation with AVP in patients with CRF and normal controls were observed. At 4 weeks after the introduction of hemodialysis in patients with CRF, the PFP AVP levels decreased and Bmax increased significantly, and the maximal percentage aggregation tended to increase. The present findings suggest that a reduced number of AVP receptors on platelets might account for decreased platelet aggregation with AVP, and the elevated plasma AVP levels might induce a down-regulation of the AVP receptor number on platelets in patients with CRF.

Adult↗
PubMed1989

[The assessment of the safety of vacuum extraction deliveries under routine epidural block].

To assess the safety of vacuum extraction (V.E.) deliveries under continuous lumbar epidural block (E.B.) with Bupivacain, the modified Krebs score in CTG, Apgar score, cord arterial blood acid-base balance, hypoxanthine, CPK, CPK-BB, Neuron specific enolase and c-AMP were examined. A total of 74 full term oxytocin-induced labors were divided into three groups: A) 21 cases by V.E. under E.B., B) 34 cases under E.B. only, and C) 19 cases without V.E. or E.B. There was no difference in age, gestational weeks in the three groups. However, the incidence of primiparas was highest in group A. Though CTG showed a temporary low Krebs score in group A within 30 minutes after the initiation of E.B., it was found that there was no significant difference between the three groups 30 minutes before parturition. The apgar score, cord arterial blood pH, PO2 and B.E. were also found to be similar in all three groups. Among various kinds of substances in the cord blood, both CPK-BB and c-AMP showed a striking rise in group A, compared to groups B and C. Therefore, the use of V.E. under E.B. might be hazardous to the well-being of the newborn infant.

Accident Prevention↗
PubMed1988

Expression of H-2K and H-2D genes by PYS-2 teratocarcinoma cells.

The parietal yolk-sac carcinoma cell line PYS-2, which has been described to synthesize a trace amount of H-2 antigens, was shown to express low levels of Kb- and/or Db-specific antigens by flow cytometric analysis. Further studies of H-2 cDNA clones from PYS-2 cDNA library revealed 8 out of 10 clones were identified as classical H-2Kb and 2 were H-2Db, which confirmed the result from the immunofluorescent analysis. However, we have not isolated Qa, Tla or other embryonic class I cDNAs from our PYS-2 library.

Animals↗
PubMed1988

Sensitive determination of diazepam and N-desmethyldiazepam in human material using capillary gas chromatography-mass spectrometry.

A reliable and sensitive capillary gas chromatographic-mass spectrometric method was developed for the detection and determination of diazepam and its major metabolite, N-desmethyldiazepam, in human material. Medazepam served as the internal standard. Quantitative determination was achieved using mass fragmentography with selected ions of m/z 256 for diazepam and m/z 242 for N-desmethyldiazepam and medazepam. The limit of detection was 1 ng/g and the recoveries were 98.54 +/- 3.95% for diazepam and 98.66 +/- 6.48% for N-desmethyldiazepam. The calibration graph was linear over the concentration range from 1.0 ng/g to 1.0 microgram/g for diazepam and N-desmethyldiazepam. Using this method, trace amounts of diazepam and N-desmethyldiazepam were detected in the tissues of an autopsied individual.

Aged↗
PubMed1988

Requirement of the Escherichia coli dnaA gene function for integrative suppression of dnaA mutations by plasmid R 100-1.

The phenotype of Escherichia coli dnaA missense and nonsense mutations was integratively suppressed by plasmid R100-1. The suppressed strains, however, could not survive when the dnaA function was totally inactivated. This was demonstrated by the inability of replacing the dnaA allele in the suppressed strain by a dnaA::Tn10 insertion using phage P1-mediated transduction. When the intact dnaA+ allele was additionally supplied by a specialized transducing phage, lambda imm21 dnaA+, which integrated at the att lambda site on the E. coli chromosome, then the dnaA::Tn10 insertion, together with a delta oriC deletion, were able to be introduced into the suppressed strain. Thus, the mechanisms of dnaA function for oriC and for the replication origin of R100-1 may not be quite the same.

Bacterial Proteins↗
PubMed1988

Estimation of lipid concentrations on thin-layer plates by densitometry of transparent copies.

A relatively simple procedure for the quantitative estimation of phospholipids resolved on thin-layer plates has been developed. After resolution in an appropriate solvent, the lipids are visualized by staining with iodine, ninhydrin, or molybdate and then photocopied onto transparent sheets with a standard office copy machine. The density of each spot on the photocopy, measured with a simple silicon cell area densitometer, is a direct function of each lipid applied to the plate over at least a six- to eightfold range in concentration. Under controlled conditions the staining and photocopying steps are quite reproducible. Known concentrations of the choline, ethanolamine, serine, and inositol derivatives of L-alpha-phosphatidic acid applied either separately or as mixtures can be determined essentially quantitatively (100 +/- 5%) by this procedure following their resolution on the thin-layer plates.

Animals↗
PubMed1988

TRH test and DST in schizoaffective mania, mania, and schizophrenia.

The thyrotropin-releasing hormone (TRH) test and the Dexamethasone Suppression Test (DST) were given to 10 patients who met Research Diagnostic Criteria (RDC) for schizoaffective disorder, manic type, 9 who met the criteria for mania, and 27 who met the criteria for schizophrenia. A blunted thyrotropin (TSH) response to TRH was observed in 3 of the 10 schizoaffective manics, 4 of the 9 manics, and 3 of the 27 schizophrenics. Nonsuppression on the DST was observed in 5 of the 10 schizoaffective manics, 2 of the 9 manics, and 2 of 22 schizophrenics. The schizoaffective manic and the manic patients had similar rates of TSH blunting and DST nonsuppression, and these were significantly higher than the rates in the schizophrenic patients. This difference was not attributable to baseline TSH and cortisol levels or to neuroleptic treatment. It is suggested that patients with RDC schizoaffective mania and mania have more disturbance in the hypothalamic-pituitary adrenal and thyroid axes than patients with schizophrenia.

Antipsychotic Agents↗
PubMed1988

Prevalence of binge-eating and bulimia among adolescent women in Japan.

This study examined by questionnaire the prevalence of binge-eating and bulimia among 220 women at a school of nursing and 236 women at a junior college, all from 18 to 21 years old, in two different areas of Japan. Binge-eating more than once a week was found in 14 (6.5%) of the nursing school students and 21 (9.1%) of the college women. Self-induced vomiting and use of purgatives were found in 19 (8.7%) and 12 (5.5%) of the nursing school students, and 19 (8.1%) and 9 (3.8%) of the college women, respectively. The difference between these two groups was not significant. The prevalence of binge-eating more than once a week, together with self-induced vomiting or purgative use, was 3.6% in the nursing school students, 2.1% in the college women, and 2.9% in the total sample. These women appeared to meet both DSM-III criteria for bulimia and Russell's criteria for bulimia nervosa.

Adolescent↗