Biomedical subjects

S Miyashita

Publications and source records attributed to S Miyashita.

18 recordsLinked to original sources

PubMed1995

Expression of pS2 gene in rat brain.

We have previously shown that the expression of pS2 mRNA, which encodes a secreted 60-amino acid protein of unknown function, is widely distributed throughout the entire body of the mouse including the brain. We report herein that pS2 mRNA is also expressed in the brain and in peripheral tissues of rats. In adult rat brain, pS2 mRNA was predominantly expressed in hippocampus, followed by the cerebral cortex and cerebellum. The developmental expression of pS2 mRNA in hippocampus, which region is known to mature after birth, showed a clear peak in 1- or 3-day-old rats, then gradually decreased by 7 weeks after birth. In midbrain, the maturation of which occurs at an early developmental stage, pS2 mRNA level was retained at a low level from postnatal 1 day to week 7. These results suggest that pS2 protein plays an important role in the development of central nervous system.

Animals↗

PubMed1994

Effect of basic fibroblast growth factor on synthesis/secretion of pS2 protein by human breast cancer cells (MCF-7).

pS2 is an estrogen-induced mRNA species that was originally identified in the breast cancer cell line MCF-7. Exposure of the cells to basic fibroblast growth factor (bFGF) at the concentration of 10-100 ng/ml for 48-72 h resulted in a marked increase in the concentration of pS2 protein in the medium. The polymerase chain reaction with reverse transcriptase revealed that bFGF increased the amount of intracellular pS2 mRNA: immunocytochemical studies showed that exposure to the factor increased the amount of intracellular pS2 protein. Simultaneous addition of cycloheximide with bFGF completely abolished induction of pS2 protein, although it did not affect the induction of pS2 mRNA. Actinomycin D did not affect the stimulatory effect of bFGF on synthesis/secretion of pS2 protein. bFGF effectively abolished decay of the pS2 mRNA level caused by actinomycin D. These results suggest that the induction of the synthesis/secretion of pS2 protein by bFGF occurs at the post-transcriptional level, most probably due to the stabilization of pS2 mRNA. Another finding, that bFGF and estradiol have a synergistic effect on induction of pS2 protein, suggests the possibility that these two inducers act by a different but partly overlapping mechanism.

Breast Neoplasms↗

PubMed1994

pS2 gene especially expressed in the late G1/S phase of mouse astrocytes.

By the reverse transcription-polymerase chain reaction we investigated the localization of pS2 mRNA, which encodes a secreted polypeptide of 60 amino acids with unknown function, in the adult mouse. This method revealed that the expression of pS2 mRNA was not restricted to the stomach as previously reported but was also found in various other tissues such as brain, heart, spleen, and muscle. The pS2 mRNA was additionally detected in astrocytes cultured from the whole brain of the newborn mouse. The pS2 expression in these astrocytes increased with cell growth and sharply declined after the cells reached the stationary phase. In the cells synchronized by the serum deprivation-refeeding technique, the expression of pS2 mRNA was only found at late G1 and S phase. These results suggest that the transcripts of pS2 gene are widely distributed throughout the entire body of the mouse and that they play some important cell cycle-related role in these tissues.

Animals↗

PubMed1994

Estimation of pS2 protein level in human body fluids by a sensitive two-site enzyme immunoassay.

A sensitive two-site enzyme immunoassay (EIA) system was established for human pS2 protein, a small estrogen-inducible secretory protein of unknown function originally identified in MCF-7 human breast cancer cells. Our EIA system is based on the sandwiching of antigen between anti-recombinant (r) pS2 antibody IgG coated on a polystyrene plate and biotinylated anti-rpS2 antibody IgG. The amount of pS2 protein was quantified by measurement of the bound enzyme activity of subsequently added streptavidin-linked beta-D-galactosidase (beta-D-galactosidase, EC 3.2.1.23). pS2 protein purified from MCF-7 culture supernatants was detectable at a concentration as low as 3 pg/ml (corresponding to 60 fg/well). This EIA system revealed that the amount of pS2-like immunoreactivity (LI) in human urine was 13.6 ng/mg creatinine (median, n = 416) and that there was no correlation between the pS2-LI concentration in urine and sex or aging. pS2-LI levels in plasma and sera of the normal subjects were 392 pg/ml (median, n = 14) and 494 pg/ml (median, n = 12), respectively. The serum level of the patients with breast cancer (528 pg/ml; median, n = 67) was not statistically different from that of normal subjects, although high levels of pS2 protein in breast cancer tissues had been reported.

Antibody Specificity↗

PubMed1993

[Fulminant streptococcal infection and sudden death in a pregnant woman: a case report].

A case of fulminant streptococcal infection occurring in a 28-year-old pregnant female is reported. She initially developed pharyngitis and high fever during the 33rd week of gestation. This was treated with oral piperacillin for two days with temporary amelioration. Recurrence of high fever, however, was noted shortly thereafter, which was followed by stillbirth of twin babies, and subsequent development of refractory hypotension and demise of the mother. Autopsy revealed presence of numerous cocci and fibrin thrombi in systemic circulation, and this was thought to be the immediate cause of her death. The causative organism was identified as Streptococcus pyogenes, M3, T3, and was found to be producing streptococcal pyrogenic exotoxin A in vitro. The underlying mechanism for this serious infection remains unknown.

Adult↗

PubMed1993

[A three-dimensional reconstruction of the temporal bone by the helical scanning CT and its clinical application].

The current availability of 3 dimensional (3-D) imaging from Computed Tomography (CT) has yielded new anatomical information and pre-and postoperative evaluations. However, little discussion as to the 3-D structural image of the temporal bone has been reported because conventional CT does provide sufficient data to produce such images. The Helical scanning CT gathers continuous and multiple slice image data since it consists of an X-ray tube that continuously rotates around the patient while the patient moves continuously into the CT scanner. Thus, application of the Helical scanning CT has made it possible to reconstruct 3-D images of the minute and complicated structure of the temporal bone. We evaluated 3-D images from 9 typical cases, examined from February to October 1992. As a result, we found that the 3-D images reconstructed with this system are useful for evaluation of the postoperative state of tympanoplasty, the diagnosis of anomalies of the bony labyrinth, and examining the extent of bone destruction induced by trauma, cholesteatoma, etc.

Adolescent↗

PubMed1991

Novel epoxysuccinyl peptides. Selective inhibitors of cathepsin B, in vitro.

A series of new epoxysuccinyl peptides were designed and synthesized to develop a specific inhibitor of cathepsin B. Of these compounds, N-(L-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-isoleucyl-L-proli ne (compound CA-030) and N-(L-3-trans-propylcarbamoyloxirane-2-carbonyl)-L-isoleucyl-L-prol ine (compound CA-074) were the most potent and specific inhibitors of cathepsin B in vitro. The carboxyl group of proline and the ethyl ester group or the n-propylamide group in the oxirane ring were necessary, the ethyl ester group or the n-propylamide group being particularly effective for distinguishing cathepsin B from other cysteine proteinases such as cathepsins L and H, and calpains.

Animals↗

PubMed1990

Linear plasmid DNAs of the plant pathogenic fungus Rhizoctonia solani with unique terminal structures.

Three linear DNA plasmids were found in isolate RI-64 of anastomosis group 4 (AG-4) of Rhizoctonia solani. These plasmids, designated pRS64-1, -2, and -3, possessed the same size of 2.7 kb. Restriction mapping and Southern hybridization analysis of pRS64-1, -2, and -3 revealed the presence of homologous regions at both termini. The plasmid DNAs were resistant to both 3'-exonuclease and 5'-exonuclease even after treatment with proteinase K or alkali. The length of both terminal fragments that were generated by restriction endonuclease digestion was doubled under the denaturation condition, indicating that the linear plasmid DNAs have hairpin loops at both termini. Southern blotting analysis of total DNA showed the presence of two types of dimeric forms of pRS64 DNA. One is a head-to-head dimer and the other is a tail-to-tail dimer. The role of these unique DNA structures in replication of the plasmids is discussed.

Base Sequence↗

PubMed1987

[Clinical use of autologous frozen blood in the surgery of three esophageal cancer patients].

Autologous frozen blood transfusion (AFBT) has advantages both of autologous and frozen blood transfusion. In AFBT there are no remarkable adverse effects which often emerge after usual heterologous blood transfusion. As a rule, four hundred milliliters of blood were drawn twice from patients and reserved as autologous frozen blood (AFB) preoperatively. It is supposed that radical operation of esophageal cancer using only AFB is difficult to perform because of various kinds of preoperative risks. In this paper three cases of radical esophageal cancer operations, in which only AFBT were used are reported. Pre- and postoperative liver functions were uneventful. RBC counts, Hb and Hct dropped after drawing blood and did not recover until the day of operation. Postoperatively, they deteriorated further but recovered to initial values without any specific treatment within 5 months after operation. Pre- and postoperative PaO2 values of AFBT were not different from those of the usual blood transfusion. Thus using only AFBT, esophageal cancer operations were performed without any disadvantageous effects.

Blood Preservation↗

PubMed1978