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T Moriyama

Publications and source records attributed to T Moriyama.

At least 217 records · Page 12Linked to original sources
PubMed1990

Establishment of DDD/1-Mtv-2/Mtv-2, nu/nu and DDD/1-Mtv-2/Mtv-2, nu/+ mice: preliminary characterization in relation to MTV antigen expression and mammary tumorigenesis.

To investigate the effects of the T-cell deprivation on viral mammary tumorigenesis, two double congenic mouse strains of the DDD genetic background, DDD/1-Mtv-2/Mtv-2, nu/nu and DDD/1-Mtv-2/Mtv-2, nu/+, were produced by the cross between DDD/1-Mtv-2/Mtv-2 (DDD-Mtv-2) and DDD/1-nu/nu mice, followed by repeated intercross breedings. Expression of the mouse mammary tumor virus (MTV)-gp52 antigen was demonstrated in the mammary glands of mice from 14 days on, in both -nu/nu and -nu/+ females. Mammary gland development was comparable in both strains, but, the incidence of mammary cancer was lower in the T-cell-deprived mice.

Animals↗
PubMed1990

A method for assessing loss in milk yield due to subclinical mastitis.

A method for assessing the loss in quarter milk yield due to subclinical mastitis is proposed. It is based upon two indices calculated from quarter milk yields and results from the assessment of mastitis obtained by measurement of the electrical conductivity of milk. The results were obtained from the cows through repeated quarter-milkings during several months of lactation. The grade of abnormality of a quarter with subclinical mastitis was expressed by the first index, the mean quarter difference of electrical conductivity of milk produced by the quarter (mQdEC, 25 degrees C). The reduction in milk yield of a quarter presumed to be due to subclinical mastitis was expressed by another index, the quarter yield ratio, R, which is that percentage of normal milk yield produced by a quarter with mastitis. Examination of the relationship between these two indices showed that subclinical mastitis caused a reduction in milk yield in the affected quarters. From the linear regression, it was found that approximately 3% reduction in quarter milk yield occurred for every 1 X 10(-4)S/cm increase in the mQdEC of the quarter with presumed subclinical mastitis.

Animals↗
PubMed1990

Purification of polymeric phospholipase Cs from human platelets.

Two types of cytosolic phospholipase C specific for phosphoinositides were purified from human platelets. The molecular masses of the purified enzymes were 440 and 290 kDa. These enzymes were concluded to be respectively a trimer and a dimer of homologous 146 kDa polypeptides. The 146 kDa polypeptide may be an immunologically novel isozyme among the 140-150 kDa PLC isozymes. Both enzymes hydrolyzed phosphatidylinositol and phosphatidylinositol 4,5-bisphosphate in a Ca2(+)-dependent manner.

Blood Platelets↗
PubMed1990

Identification of immunoreactive pancreatic stone protein in pancreatic stone, pancreatic tissue, and pancreatic juice.

We first examined whether pancreatic stone protein (PSP) was present in pancreatic stone and normal pancreatic tissue. By using HPLC and Western blotting, a protein of Mr 13.5 kDa that reacted with monoclonal antibody against PSP was detected as a major component in EDTA-soluble fractions of pancreatic stone. In an in vitro experiment, this protein dose-dependently suppressed CaCO3 precipitation. PSP was immunohistochemically stained in the acinar cells of normal pancreatic tissue. Based on these findings, it seemed that PSP in pancreatic stone is probably a physiological secretory protein of the pancreas. We subsequently examined immunoreactive PSP in normal pancreatic juice by the Western blotting method. In all of the specimens, the band for immunoreactive PSP in pancreatic juice was found to correspond to 13.5 kDa, which thus agreed with that of purified PSP from a stone.

Blotting, Western↗
PubMed1990

Anaplastic ependymoma of the spinal cord in childhood. A case report.

We report a 6-year-old girl with anaplastic ependymoma probably originating in the region of the conus medullaris and probably spreading retrogradely to the region of the interventricular foramen (Monro) through the cerebrospinal fluid (CSF). Since ependymoma of the spinal cord rarely occurs in children, and retrograde spreading is extremely rare, the histological features and mechanism of metastasis of the tumor are discussed.

Child↗
PubMed1990

Detection of specific mRNAs in single nephron segments by use of the polymerase chain reaction.

We have developed a procedure to detect specific mRNAs in single renal nephron segments. This approach combines microdissection, reverse transcription (RT) of the target mRNA, and amplification of the resulting cDNA using the polymerase chain reaction (PCR). After microdissection, the sample is placed in a tube where it is permeabilized and where all reactions are performed directly without the need for isolation of the RNA. Our model target was the mRNA for aldose reductase. This enzyme catalyzes the conversion of glucose to sorbitol. Its expression is modulated by changes in extracellular osmolality in the renal medulla. RT-PCR of inner medullary collecting duct (1 mm) and glomeruli (6-10) yielded a product of the predicted length (670 base pairs) defined by the PCR primers. Its identity was confirmed by a specific oligonucleotide probe that differed from the primers. RT-PCR of proximal tubules (1 mm) resulted in no aldose reductase-specific amplification product. RT-PCR is generally applicable for measuring specific gene expression in single nephron segments or small numbers of cultured cells. Utility, limitations, and refinements of this approach are discussed.

Aldehyde Reductase↗
PubMed1990

Factors affecting the ratio of different organic osmolytes in renal medullary cells.

Renal medullary cells contain high concentrations of sorbitol, inositol, glycerophosphorylcholine (GPC), and betaine, which balance the variably high osmolality of extracellular NaCl. We found that PAP-HT25 (rabbit renal medullary) cells in tissue culture increase their content of all four when medium osmolality is increased by adding NaCl and urea. However, this requires that betaine be added to medium in addition to customary constituents. Some factors affecting the mix of organic osmolytes in these cells during hypertonicity are as follows. 1) Urea in medium increases cell GPC and tends to decrease others, particularly betaine. 2) With small increases in medium NaCl, intracellular inositol is highest, whereas sorbitol predominates with large NaCl increases. 3) When osmolality is suddenly decreased, these four organic osmolytes exit rapidly from cells, but in differing relative amounts (betaine much greater than sorbitol greater than inositol much greater than GPC). 4) Altering cell betaine levels (by varying betaine in medium) causes reciprocal changes in cell sorbitol (by affecting aldose reductase activity) and vice versa, whereas inositol and GPC are less affected. 5) Raising medium glucose concentration (from which sorbitol is synthesized) increases cell sorbitol and decreases cell inositol and betaine. 6) Decreasing the amount of GPC in cells (by removing choline from medium) causes small changes in betaine and sorbitol, but not in inositol. Changing the amount of inositol does not affect the others. Similar interrelations may operate in vivo to vary the mix of organic osmolytes in renal medulla.

Animals↗
PubMed1990

Bacteriological examination of fissure plaques from seriously mentally retarded adults.

The microfloras of fissure plaque samples removed from a total of 23 seriously mentally retarded adults, resident in two institutions, were examined and compared with the fissure microfloras found in 17 control subjects who were employees in both institutions. The samples were collected from both an intact fissure and a fissure with brown-stained defective enamel surface of the premolars of the lower jaw. Mutans streptococci, selected with MSB medium, were recovered from only one of the defective fissures of 13 patients who became retarded younger than 2 years of age, whereas 14 defective fissures of 17 controls harbored mutans streptococci. Four of 8 patients who became retarded older than 3 years of age harbored mutans streptococci. Lactobacilli were infrequently recovered from both patients and controls. The results are discussed in terms of the microbiological aspect of caries development in adults who became mentally retarded when young.

Adult↗
PubMed1990

Apolipoprotein E phenotyping from plasma by isoelectric focusing and immunoblotting.

A method for apolipoprotein (apo) E phenotyping directly from plasma by isoelectric focusing (IEF) and immunoblotting was confirmed. Ten microliters plasma were delipidated. IEF in 5% polyacrylamide flat gel with 6.4 mol/l urea and 2.8% pharmalyte (PH 4-6.5) was carried out at 3,000 V for 1 hr. Seventeen samples were applied per one flat gel, and IEF of two flat gels was made. Then, Western blotting on nitrocellulose membrane was done at 75 V for 3 hr. Immunostaining was performed using goat-anti-human apo E as first antibody and biotinylated anti-goat IgG as second antibody, and 4-chlorodel-1-naphthol as a substrate. In approximately 5% of the samples, we had difficulty in discriminating between homozygotes and heterozygotes (i.e., apo E3/3 and apo E3/2, or apo E4/4 and apo E4/3) because of equally strong sialated band, but this problem was solved by sialidase treatment of plasma before delipidation. As a result, six apo E phenotypes were clearly demonstrated. Apo E phenotyping of 34 samples could be made simultaneously in 2 days. It is concluded that the polyacrylamide gel IEF and immunoblotting method is useful for apo E phenotyping if it is made up for by sialidase treatment.

Apolipoproteins E↗
PubMed1990

Vibration-induced white finger and auditory susceptibility to noise exposure.

It is well known that there are wide individual variations in the susceptibility of human hearing to noise exposure. The hearing of male forest workers were examined with vibration-induced white finger (VWF) as an indicator of noise susceptibility of hearing. The results were as follows: 1. Hearing losses at 4 and 8 kHz in subjects with VWF were greater than those of unaffected men in a matched pair case-control study allowing for confounding due to differences of age and noise exposure. 2. The hearing loss at 4 kHz on the ipsilateral side of the hand with VWF was greater than the loss on the contralateral side in subjects with VWF in one hand. 3. The hearing loss at 4 kHz in subjects with VWF progressed more rapidly during a five-year follow-up period than the loss in men with no history of VWF. These results indicate that the hearing of subjects with VWF was more vulnerable to noise than the hearing of subjects without VWF. It was suggested that a pathological change causing VWF, such as enhanced vasoconstriction due to elevated sympathetic nervous tone, could also cause this additional auditory vulnerability to noise exposure.

Adult↗
PubMed1990

Serogrouping of oral Streptococcus intermedius.

Employing twenty fresh oral isolates of Streptococcus intermedius, studies were carried out to characterize serological relations among the isolates and also between the isolates and the strains of bacterial species closely related to S. intermedius. The Rantz-Randall extracts from the cells were used as antigens. The anti-rabbit serum raised against S. intermedius ATCC 27335T reacted with the cell extracts from only three strains of the isolates, which were designated serogroup I strains. The other isolates were classified into four serogroups, I, III, IV, and V, which specifically reacted with the cell extracts from the homologous serogroup strains. However, the serogroup II antiserum formed in immunodiffusion a common precipitin line between the extracts from the cells of serogroups II and I. The serogroups I, III, IV, and V antisera reacted with none of the extracts from the bacterial cells closely related to S. intermedius, which included Streptococcus anginosus ATCC 33397T, Streptococcus constellatus ATCC 27823T, three NCTC strains of "Streptococcus milleri," and three ATCC strains of Streptococcus MG. The precipitin line formed by the homologous reaction of the serogroup II antiserum was found to be a reaction of identity with that formed by the extract from "S. milleri" NCTC 10708. Conversely, the antiserum against NCTC 10708 strain did not react with the cell extracts of serogroup II.

Animals↗
PubMed1990

[Three cases of alveolar soft part sarcoma and MRI findings].

Three cases of alveolar soft part sarcoma were reported with characteristic MRI findings. On MRI findings, slightly higher signal intensity than muscles on T1 weighted image and remarkably high signal intensity on T2 weighted image were thought to be characteristic of alveolar soft part sarcoma.

Adult↗
PubMed1989

Molecular pathogenesis of hepatocellular carcinoma in hepatitis B virus transgenic mice.

Transgenic mice that overproduce the hepatitis B virus large envelope polypeptide and accumulate toxic quantities of hepatitis B surface antigen (HBsAg) within the hepatocyte develop severe, prolonged hepatocellular injury that initiates a programmed response within the liver, characterized by inflammation, regenerative hyperplasia, transcriptional deregulation, and aneuploidy. This response inexorably progresses to neoplasia. The incidence of hepatocellular carcinoma in this model corresponds to the frequency, severity, and age of onset of liver cell injury, which itself corresponds to the intrahepatic concentration of HBsAg and is influenced by genetic background and sex. Thus, the inappropriate expression of a single structural viral gene is sufficient to cause malignant transformation in this model. These results suggest that severe, prolonged cellular injury induces a preneoplastic proliferative response that fosters secondary genetic events that program the cell for unrestrained growth.

Aging↗
PubMed1989

Osmotic regulation of aldose reductase protein synthesis in renal medullary cells.

Renal medullary cells are normally exposed to high extracellular NaCl as part of the urinary concentrating mechanism. They react to this stress by accumulating sorbitol and other organic osmolytes. PAP-HT25, a line of epithelial cells derived from rabbit renal inner medulla, expresses this response. In hypertonic medium, these cells accumulate large amounts of sorbitol. There is a large increase in the amount of aldose reductase, which catalyzes production of sorbitol from glucose. The purpose of the present study was to investigate whether the aldose reductase protein increases because of faster synthesis or slower degradation. We measured the rate of synthesis and degradation of aldose reductase protein by pulse-chase with [35S]methionine, followed by immunoprecipitation with specific antiserum and autoradiography. The protein synthesis rate was 6 times greater in cells grown in hypertonic (500 mosmol/kg) medium, than in those grown in normal (300 mosmol/kg) medium. When control cells were switched to hypertonic medium, the synthesis rate increased 15-fold by 24 h, then decreased to 11-fold after 48 h. In contrast, synthesis rate continued to increase past 24 h when accumulation of sorbitol was prevented by inhibiting aldose reductase activity with Tolrestat. Thus, there is a feedback mechanism by which cellular sorbitol accumulation inhibits aldose reductase protein synthesis. Degradation of aldose reductase protein was slow (only about 25% in 3 days) and was not affected by osmolality. Thus, the osmoregulatory increase in aldose reductase protein is due to an increase in its synthesis rate and not to any change in its degradation.

Aldehyde Reductase↗
PubMed1989

Decrease in the fluidity of brush-border membrane vesicles induced by gentamicin. A spin-labeling study.

In our previous paper (Horio et al., Biochim Biophys Acta 858: 153-160, 1986), we reported that the addition of gentamicin in vitro to rabbit renal brush-border membrane vesicles decreases the apparent Vmax of Na+-dependent D-glucose transport without affecting the apparent Km. In the present study, we investigated the effects of gentamicin on the physical state of spin-labeled rabbit renal brush-border membranes, using electron spin resonance spectrometry. Brush-border membrane vesicles were prepared from outer cortex (mainly contains early proximal tubule) and outer medulla (containing primarily late proximal tubule), and the gentamicin toxicities in both preparations were compared. Significant decreases were observed in the membrane fluidity of 5 mM gentamicin-treated brush-border membranes. The fluidity of outer cortical brush-border membranes was affected at both 25 degrees and 35 degrees, whereas that of outer medullary membranes was affected only at 35 degrees. Two different stearic acid spin labels revealed that gentamicin affected the fluidity only in the superficial region of the membranes. We also demonstrated that the gentamicin-induced decreases in Na+-dependent D-glucose transport and in the membrane fluidity were recovered by washing gentamicin-treated brush-border membranes. We suggest that gentamicin binds to the superficial region of brush-border membranes and inhibits Na+-dependent D-glucose transport across brush-border membranes through the decrease in the membrane fluidity.

Animals↗
PubMed1989

Direct inhibition of contractile apparatus by analogues of amiloride in the smooth muscle of guinea-pig taenia caecum and chicken gizzard.

The relaxant effects of amiloride and its analogues, benzamil, 5-(N,N-diethyl)-amiloride (DEAM) and 5-(N-ethyl-N-isopropyl)-amiloride (EIAM), were investigated using smooth muscle of guinea-pig taenia caeci and chicken gizzard. High K+-induced contractions of intact taenia and gizzard were inhibited by these compounds (1-100 microM) with the order of potency; benzamil greater than or equal to EIAM greater than DEAM greater than amiloride. Contractions of permealized taenia and gizzard were also inhibited by these compounds at concentrations 8-35 times higher than those needed to inhibit the contractions of intact tissues. These compounds inhibited 20 K myosin light chain (MLC) phosphorylation at the concentrations needed to inhibit the contraction in the permealized muscles. Calmodulin (CaM) activity, as monitored by erythrocyte membrane (Ca2+ + Mg2+)-ATPase and phosphodiesterase activities, was inhibited by DEAM and EIAM at similar concentrations as those to inhibit the MLC phosphorylation. Benzamil also inhibited CaM activity at concentrations 4-8 times higher than those required to inhibit MLC phosphorylation. However, amiloride failed to inhibit CaM activity. Among these compounds, amiloride and benzamil inhibited Ca2+/CaM-independent MLC phosphorylation due to trypsin-treated MLC kinase. Taenia tissue gradually accumulated these compounds and the tissue/medium ratio exceeded 3.5-17 after a 3-hr incubation period. These results indicate that amiloride and its analogues inhibit smooth muscle contraction mainly by the direct inhibition of MLC phosphorylation. The inhibitory effect of amiloride may be attributable to the inhibition of MLC kinase, whereas the inhibitory effect of DEAM and EIAM may largely be attributable to the inhibition of CaM. Benzamil may inhibit contraction by the inhibition of both MLC kinase and CaM. Differences in the drug-sensitivity between intact and permealized tissues may be attributable to the difference in drug accumulation by the cell.

Amiloride↗