Biomedical subjects

K Shinohara

Publications and source records attributed to K Shinohara.

At least 271 records · Page 15Linked to original sources

PubMed1990

Fine structure of unstained human chromosome fibres dried with no fixative as observed by X-ray contact microscopy.

X-ray contact microscopy was used to examine unstained human chromosomes dried without any fixative. This is the first report of the observation of single human chromosome fibres at high resolution without any modification(s) such as staining or fixation. The 'beads-on-a-string' structure was observed in stretched portions of chromosome fibres. The diameters of the thin filaments and small particles were 7-15 nm (mean +/- SD of 12.2 +/- 2.1 nm) and 16-69 nm (31.4 +/- 13.2 nm), respectively. These sizes correspond to those of fibres composed of nucleosomes (10-15 nm in diameter) and particle units (15-50 nm in diameter) called superbeads (unit structures composed of a multiple association of nucleosomes). These results are in good agreement with the current nucleosome and superbead model for chromosome fibre structure.

Chromosomes↗

PubMed1990

A novel human hepatoblastoma cell line (HuH-6KK) with rapid growth in serum-free medium without extracellular matrix.

A novel human hepatoblastoma cell line (HuH-6KK) with a high growth rate in a serum-free medium without extracellular matrix was developed from an original one, HuH-6 c15 (HuH). The original HuH cells (38 passages) did not proliferate well in RPMI 1640 medium containing 20% fetal calf serum (FCS). The HuH cells (HuH-6KK) with a high growth rate were selected by culturing them in an enriched RDF containing 20% FCS and 0.01% mucous polysaccharide (spirulinan) isolated from a blue-green alga, Spirulina subsalsa. The HuH-6KK cells showed a rapid growth in serum-free eRDF medium containing insulin, transferrin, ethanolamine, and selenite (eRDF-ITES medium) without fibronectin. The proliferation of the original HuH cells was also observed in the eRDF-ITES medium, but the growth was slow compared with the HuH-6KK cells. In the medium without ITES, the growth of the HuH-6KK and original HuH cells was slow. Among the ITES ingredients, insulin promoted the growth of HuH-6KK cells the most.

Blood↗

PubMed1990

Gamma interferon production and two-color fluorescence flow cytometry analysis of peripheral blood mononuclear cells in allogeneic bone marrow transplant recipients.

Gamma interferon (gamma-INF) production was studied and two-color fluorescence flow cytometry analysis was done on the peripheral blood mononuclear cells (PBMC) in allogeneic bone marrow transplant recipients. Gamma INF was not detected in any patients within a year after transplantation whether PBMC was stimulated with PHA or not. A year after transplantation, gamma-INF was produced in the normal level in the stimulated and unstimulated PBMC. The number of suppressor-inducer T cells (CD4+2H4+) was decreased and that of suppressor T cells (CD11+CD8+) was normal. The numbers of helper-inducer T cells (CD4+4B4+) and helper T cells (CD4+2H4-) were normal. The numbers of activated helper-inducer T cells (CD4+HLA-DR+) and suppressor-cytotoxic T cells (CD8+HLA-DR+) were elevated. In the NK cells, Leu7+ CD16-cells were elevated, whereas Leu7+CD16+ cells and Leu7-CD16+ cells were normal. Leu7+CD8+ cells were elevated. These results indicated immunodeficiency after transplantation.

Bone Marrow Transplantation↗

PubMed1990

[Aplastic anemia probably induced by allopurinol in a patient with renal insufficiency].

A rare case of aplastic anemia which was considered to be induced by allopurinol was reported. A 48-year-old female had suffered from urolithiasis and chronic renal insufficiency. She was administered allopurinol for hyperuricemia for 4 months, and subsequently developed severe pancytopenia and bone marrow suppression. After stopping of allopurinol administration, she was administered prednisolone but died of gastro-intestinal tract bleeding and sepsis on the 21th hospital day, without hematological recovery.

Allopurinol↗

PubMed1990

[Idiopathic autoimmune hemolytic anemia successfully treated with danazol].

A 50 year old female suffered from idiopathic autoimmune hemolytic anemia. She was initially treated with prednisolone, and anemia was improved moderately. However, maintenance of Hb value was difficult with the decreased dosage of prednisolone. She was subsequently administered danazol, and anemia was completely improved. It is worth to use danazol for the treatment of the patient of autoimmune hemolytic anemia who is refractory to prednisolone therapy.

Anemia, Hemolytic, Autoimmune↗

PubMed1989

Embryonic and postnatal development of N-(1-[2-thienyl]cyclohexyl)[3H]piperidine binding sites in rat forebrain homogenates and slices.

The development of N-(1-[2-thienyl]-cyclohexyl)[3H]piperidine [( 3H]TCP) binding to phencyclidine (PCP) receptors in both brain homogenates and slices has been investigated in the rat. The specific binding sites for [3H]TCP in the homogenate were already detected at prenatal stages and steadily increased after birth. A similar developmental pattern was seen in the autoradiography of the [3H]TCP binding to the brain slice in which the distribution of the binding in the young is more homogeneous than that in adult. There was an increase in the Bmax without changes in the Kd of the [3H]TCP binding and there was no change in inhibition of the binding by TCP, PCP and D-(-)-2-amino-5-phosphonovalerate during postnatal maturation. These findings suggest an increase in the density with no change in the affinity of PCP receptors and the absence of a change in the interaction between the PCP and N-methyl-D-aspartate receptors in the developing rat forebrain.

Aging↗

PubMed1989

Expression and processing of cyanobacterial Mn-stabilizing protein in Escherichia coli.

The woxA gene of cyanobacterium Anacystis nidulans R2, which encodes the precursor of the Mn-stabilizing protein involved in photosynthetic water oxidation, was found to be expressed in Escherichia coli. The 30-kDa expression product was indistinguishable from the authentic mature protein on SDS/PAGE. Upon fractionation of E. coli cells, the expression product was co-precipitated with the membrane fraction, which is consistent with the water-insoluble nature of the authentic mature protein. Analysis of the amino-terminal amino acid sequence of the product revealed that it is identical to the sequence from the 28th residue of the precursor, indicating that the precursor is processed in E. coli. The expression product was digested by trypsinization of E. coli spheroplasts, but not by that of intact cells. This observation suggests that the product is secreted from the cytoplasmic membrane, but not from the outer membrane. The occurrence of both processing and secretion suggests that a signal peptidase of E. coli can recognize the structure for translocation across the thylakoid membrane. Comparison of the signal sequence and the presequence of sweet potato sporamin A suggests that the processing enzymes of the thylakoid membrane and endoplasmic reticulum possess a common substrate specificity.

Amino Acid Sequence↗

PubMed1989

Ontogeny of strychnine-insensitive [3H]glycine binding sites in rat forebrain.

The specific binding sites for strychnine-insensitive [3H]glycine were already demonstrable at prenatal stages and had increased to the adult level by postnatal day (PN) 10. This ontogenic increase was found to be due to an augmentation of Bmax without changes in kd of the [3H]glycine binding. Moreover, there was no shift in inhibition of the binding due to glycine, D-serine, L-serine and HA-966 (1-hydroxy-3-amino-pyrrolid-2-one) after birth. These findings are consistent with the view that there is an increase in density in the absence of the glycine recognition site associated with N-methyl-D-aspartate receptor/ion channel complex in rat forebrain during ontogenic development.

Animals↗

PubMed1989

Macrophage-mediated N-nitrosation of thioproline and proline.

Thioproline (Thiazolidine-4-carboxylic acid) and proline were nitrosated by stimulated mouse macrophages in vitro. A macrophage cell line (J774.1, 1.0 x 10(6)/well, 1 ml) was incubated with Escherichia coli lipopolysaccharide, interferon-gamma and thioproline (5 mM) or proline (5 mM). After 72 hr incubation at 37 degrees C, 4 microM N-nitrosothioproline was produced. The amount of N-nitrosoproline was much lower than that of N-nitrosothioproline. Thioproline and proline inhibited the formation of carcinogenic N-nitrosomorpholine. N-nitrosothioproline and N-nitrosoproline are found as major N-nitroso compounds in human urine. Macrophage mediated N-nitrosation may contribute to the formation of these N-nitrosamino acids in the human body.

Animals↗

PubMed1989

The appearance of prostate cancer on transrectal ultrasonography: correlation of imaging and pathological examinations.

Preoperative transrectal ultrasonograms in 70 patients who underwent radical prostatectomy were compared retrospectively to the histological features of whole mount sections of the surgical specimens. In 42 cases (60 per cent) the tumor could be appreciated as a hypoechoic area on the sonogram. In only 1 case did the tumor appear as a hyperechoic area. In the other 27 cases (39 per cent) the tumor was isoechoic and could not be distinguished clearly from the surrounding tissue. The smallest tumor visualized sonographically measured 4.4 mm. in diameter in the surgical specimen. There was a statistically significant correlation among tumor echogenicity, the actual tumor size and the Gleason grade. Although there was a linear correlation between the size (maximum diameter) of the tumor measured by ultrasound and that determined from the histological sections, ultrasonography generally underestimated the size of the tumor, with the maximum diameter measured sonographically being approximately 4.8 mm. smaller than the diameter measured in the whole mount sections. Of 25 nonpalpable (stage A) tumors 9 (36 per cent) were visualized on ultrasound, while of 45 palpable (stage B) tumors 11 (21 per cent) were not. Although most clinically recognized tumors can be appreciated sonographically, the tumors that are visualized tend to be larger, less well differentiated and palpable. These features favor the use of sonography to stage and monitor established prostate cancers, and suggest that tumors detected by sonography in an early detection program are likely to be clinically important cancers.

Aged↗

PubMed1989

[Differential effects of isoflurane and nitrous oxide on cerebral blood flow, metabolism and electrocorticogram after incomplete cerebral ischemia in the rat].

Differential effects of isoflurane (ISOF) and N2O on cerebral blood flow, metabolism and electrocorticogram (ECoG) were examined in rats subjected to 15 min-incomplete cerebral ischemia. In the first study, regional cerebral blood flow (rCBF) and ECoG were measured during and after ischemia. In the second study, local cerebral blood flow (LCBF) and glucose utilization (LCGU) were determined at 60 min after reperfusion. In the N2O group, rCBF in both the cerebral cortex and hippocampus decreased significantly to less than 10% of the pre-ischemic value during ischemia, and it increased to 170% at 10 min after reperfusion. The ECoG became flat during ischemia and reappeared at 21 min after reperfusion. In the ISOF group, rCBF decreased significantly to 25% during ischemia and returned to the preischemic value after reperfusion. The ECoG became flat during ischemia and reappeared at 14 min. In the N2O group, LCBFs decreased significantly to 40-50% of the pre-ischemic values in the forebrain. LCGUs decreased significantly to 30-50% in all structures of the forebrain. In the ISOF group, LCBFs decreased significantly to 60-80% in the forebrain, but were not different in other structures. LCGUs did not differ from pre-ischemic values in all structures except for in the thalamus and habenula. These results may indicate cerebral protective effects of ISOF on incomplete cerebral ischemia in rats.

Animals↗

PubMed1989

The arterial pulse analyzer as a potential replacement for manual pulse palpation in Oriental medicine.

Application of the arterial pulse analyzer now makes it possible to automatically diagnose such geriatric disorders as arteriosclerosis by using simple electrocardiograms and radial, carotid and posterior tibial artery pressure pulse wave charts. If the arterial pulse analyzer is adopted for use in Oriental medical clinics, there will no longer be a need for manual pulse palpation. In brief, applying the arterial pulse analyzer to the 8 key pulses of Oriental medicine yields the following results: 1) 'Slow' or 'rapid' pulses can be defined by the S-S interval (almost identical to the R-R interval of the ECG). 2) 'Slippery' or 'hesitant' pulses can be defined by the S-P time and the Dh/Ch% (P time & Incisura) ratio. 3) 'Floating' or 'submerged' pulses can be defined by the Ph/Ch% (pressure pulse wave to height) ratio. 4) 'Scattered' or 'moderate' pulses can be defined by the S-C- time (E time). Thus, by employing the arterial pulse analyzer, subjectivity problems inherent in the manual pulse palpation used by Oriental medicine for over 1500 years can be analyzed objectively.

Arteriosclerosis↗

PubMed1989

[Research on aseptic condition of root canals after endodontic treatment].

Fifty infected root canals were examined whether they had been in aseptic condition or not after endodontic treatment. PLADIA was used for the examination of bacteriologic culture. Twenty eight cases were positive, 22 cases were negative, and the percentage of positive was 56%. Of the anterior teeth, 13 cases were positive in 23 cases (57%), In the posterior teeth, 15 cases were positive in 27 cases (56%), 5 cases were positive in 17 cases (29%) with clinical symptoms before treatment, 23 cases were positive in 33 cases (70%) without clinical symptoms before treatment. These results showed that the treated root canals which had been well adapted to root canal filling by clinical symptoms had a high percentage of positive of bacteriological culture.

Bacteria↗

PubMed1989

[Investigated reports of tooth fractures cases from November, 1986 to September, 1988].

Researching the actual condition of tooth fractures, clinical records and X-ray photographs of 2717 patients, visited P.D.I. Dental Clinic from November, 1986 to September, 1988 were investigated statistically. 174 cases were tooth fractures in 2717 patients. The frequency rate of tooth fractures at an early age was low, increased from the latter half of the 30s and was highest at the latter half of the 50s accounted for over 10%, and decreased from the 60s. In the upper anterior teeth, the crown fractures caused by traumatic factors, at an early age showed a high proportion, and in the lower anterior the tooth fractures were rare. In the posterior the root fractures of non-vital teeth attributed to dental treatment at the middle and advanced age indicated a high proportion. In the case of tooth restored with metalcore and bridge, the proportion of the root fractures were high, the metalcore, was used in 63%, and in the bridge in 27% of the root fractures.

Adult↗

PubMed1989

[Influence of surface properties on the bending strength of OPTEC porcelain].

Influence of properties on bending strength of OPTEC porcelain, an experiment on four-point bending test was studied using four kinds of specimens (5 X 3 X 20) made of OPTEC porcelain (INCISAL) each of which was surface-treated; (1) glaze firing (no treatment) (2) polishing by emery paper #150 (3) polishing by alumina powder (0.3 microns) (4) glaze firing after polishing by emery paper #150 The test specimens were immersed in distilled water maintained at 37 +/- 1 degrees C broken into four-point bending at 1.0 mm/min, and their bending jig had on inner and outer span of 5 mm and 15 mm. The specimens graze fired after polishing had the highest bending strength, of 914 kg/km2, those polished with alumina powder, 831 kg/cm2, those graze 763 kg/cm2, and those polished with emery paper 705 kg/cm2. In conclusion, the bending strength of the porcelain was decreased by the surface roughness.

Dental Porcelain↗

PubMed1989

Malignant mixed mesodermal tumour of the peritoneum with a complete response to cyclophosphamide.

We treated a 66-year-old Japanese woman with malignant mixed mesodermal tumour of the heterologous type arising from the paracolic peritoneum. The tumour contained heterologous elements in the form of cartilage in addition to carcinosarcomatous areas. This is the third case of malignant mixed mesodermal tumours originating from the peritoneum to be documented in the literature. A complete resection of the tumour was carried out but multiple lymph nodes metastases in the left neck occurred 5 months later. Cyclophosphamide in doses of 150 mg daily by mouth was initiated, with the result of a complete regression of the malignant lesions. She died of myocardial infarction 21 months after surgery.

Aged↗

PubMed1989

Modulation of striatal serotonin metabolism by baclofen, a gamma-aminobutyric acidB receptor agonist.

Intraperitoneal (i.p.) administration of racemic baclofen (10-40 mg/kg), a gamma aminobutyric acidB (GABAB) Receptor agonist, increased striatal and hippocampal 5-hydroxytryptophan (5-HTP) accumulation after inhibition of L-aromatic amino acid decarboxylase. The baclofen-induced increment of 5-HTP accumulation in the striatum showed a much greater magnitude and longer duration than that in the hippocampus. In contrast, systemic application of baclofen (10-40 mg/kg, i.p.) failed to modify the rate of serotonin (5-HT) disappearance during inhibition of tryptophan hydroxylase in the striatum and hippocampus. Acute cerebral hemitransection decreased striatal 5-HTP accumulation and completely blocked the ability of baclofen to enhance 5-HT synthesis in the striatum. Furthermore, there were no changes in striatal 5-HTP accumulation after intrastriatal infusion of baclofen and GABA. These findings suggested that systemically applied baclofen facilitates in vivo 5-HT synthesis in the striatum via primarily stimulating GABAB receptors located in the extra-striatal area(s).

Animals↗

PubMed1989

Ontogeny of amino acids related to excitatory amino acidergic transmission in the rat forebrain.

Developmental changes in the concentration of putative amino acid neurotransmitters were investigated in the forebrain of prenatal and postnatal rats. Glutamate and aspartate, which interact with three-typed agonist sites of excitatory amino acid receptors, decreased until birth and then increased with maturation. Agonists for strychnine-insensitive glycine sites, i.e., glycine, serine and alanine, showed progressive decreases in the postnatal period. Although alanine rapidly decreased in preterm, there was no change in glycine and serine contents in this period. These developmental patterns of the compounds related to EAA transmission differed from those of inhibitory amino acid transmitters. GABA showed a steady increase during ontogeny. Taurine increased until birth and then decreased to the adult level. These results suggested that the ontogenic profile for EAA is different from that for the glycine receptor agonists and that other inhibitory amino acid transmitters develop with patterns different from those of amino acids related to EAAergic transmission.

Amino Acids↗