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Biomedical subjects

T Moriyama

Publications and source records attributed to T Moriyama.

At least 19 recordsLinked to original sources
PubMed1992

Spatio-temporal pattern of frequency representation in the auditory cortex of guinea pigs.

The spatio-temporal pattern of sound-evoked neural activity in the guinea pig auditory cortex was studied by optical recording with the aid of voltage-sensitive dye. Changes in light intensity induced by sounds at various frequencies and pressure levels were recorded with a 12 x 12 array of photodiodes. The amplitudes of the responses were displayed as sequential two-dimensional images. Tonotopical organization was found in two subdivisions of the auditory cortex, the anterior field (field A) and the dorsocaudal field (field DC). The frequency gradients in fields A and DC had a mirror-image relationship. This agrees with results obtained by the microelectrode technique. However, the tonotopic response observed in our study was transient. The focal activity that began in field A propagated in two directions; dorsally along the iso-frequency bands in field A, and caudally toward field DC. This suggests that the sound information processing initiates at field A, and its outputs are transferred to field DC, which is probably a hierarchically higher center.

Acoustic Stimulation↗
PubMed1992

cDNA cloning of rat LRP, a receptor like protein tyrosine phosphatase, and evidence for its gene regulation in cultured rat mesangial cells.

Protein tyrosine phosphatases (PTPases) are a family of enzymes that play a crucial role in the regulation of signal transduction mediated by reversible protein tyrosine phosphorylation. To understand the significance of PTPases in physiological and pathophysiological processes in the kidney, we isolated three cDNA segments encoding PTPases (LAR, LRP and a novel PTPase) from rat kidney by polymerase chain reaction (PCR). Using PCR product as a probe, we isolated a full-length cDNA of rat LRP. LRP cDNA encoded a single membrane spanning protein consisted of 796 amino acids, with two tandemly located intracellular PTPase domains. By Northern analysis, a ubiquitous pattern of LRP gene expression in rat tissues was demonstrated. In cultured rat mesangial cells, LRP mRNA was detected and the mRNA level was suppressed by either interleukin-1 or interleukin-6 treatment.

Amino Acid Sequence↗
PubMed1992

Protein degradation by the phosphoinositide-specific phospholipase C-alpha family from rat liver endoplasmic reticulum.

A 60-kDa protein homologous to phosphoinositide-specific phospholipase C-alpha was purified to apparent homogeneity on sodium dodecyl sulfate-polyacrylamide gel electrophoresis from the rough endoplasmic reticulum of rat liver through three sequential chromatographies on DEAE Toyopearl 650, AF-heparin Toyopearl 650M, and TSK gel G3000SW. The purified protein was monomeric, with an M(r) of 60,000. Eight types of protein were further separated from the 60-kDa protein and named ER60A-ER60H according to the order of their elution from a TSK gel DEAE-5PW column. They were essentially identical in terms of immunochemical properties and the NH2-terminal amino acid sequence. The partial amino acid sequence of ER60F showed homology to that of phosphoinositide-specific phospholipase C-alpha. ER60A-ER60H showed no phosphoinositide-specific phospholipase C activity. However, ER60A-ER60H catalyzed cleavage of themselves and the endoplasmic reticulum proteins protein disulfide-isomerase and calreticulin. Proteolytic degradation was inhibited by p-chloromercuribenzoate. These results indicate that ER60A-ER60H comprise a group of endoplasmic reticulum resident proteins and show thiol group-related proteolytic activity.

Amino Acid Sequence↗
PubMed1992

[Angiographic features of alveolar soft-part sarcoma].

The angiographic findings were analyzed in five patients with alveolar soft-part sarcoma. The angiographic appearance of the tumors was the same in all five cases: hypervascularity of the tumor including encasement, dilatation, tortuosity and displacement of feeding arteries, remarkable tumor stain and early venous filling. These angiographic findings are considered to be characteristic of alveolar soft-part sarcoma in the differential diagnosis of hypervascular soft tissue mass.

Adult↗
PubMed1992

Treatment of hepatocellular carcinoma associated with advanced cirrhosis by transcatheter arterial chemoembolization using autologous blood clot: a preliminary report.

Twenty-two patients with hepatocellular carcinoma were treated by a new method of transcatheter arterial chemoembolization using an autologous blood clot as an embolizing agent. All had underlying advanced cirrhosis (14 Child's class B and 8 Child's class C patients). The median follow-up interval was 11 mo (range = 2 to 30 mo). The results of the treatment were compared with those of conventional chemoembolization using gelatin sponge particles for 19 Child's class B patients as historical controls. The survival rate for Child's class B patients treated by the new procedure estimated by the Kaplan-Meier method was 100% at 2 yr, whereas the survival rate for Child's class B patients treated by conventional chemoembolization was 89% at 1 yr and 72% at 2 yr. The survival rate for Child's class C patients was 75% at 1 yr and 50% at 2 yr. Side effects such as pyrexia of more than 38 degrees C or an elevation of the serum bilirubin level of more than 1.5-fold were less common in patients treated by the new method than in those treated by conventional chemoembolization, and thus the new procedure could be performed even for Child's class C patients. The autologous blood clot did not collapse the hepatic arteries even when the embolization was performed repeatedly, and thus fine collateral vessels feeding recurrent hepatocellular carcinoma did not develop. The results suggest that the new chemoembolization using an autologous blood clot is a promising therapeutic procedure in the management of hepatocellular carcinoma associated with advanced cirrhosis.

Aged↗
PubMed1992

Osteogenesis associated with bone gla protein gene expression in diffusion chambers by bone marrow cells with demineralized bone matrix.

Diffusion chambers with rat bone marrow cells and demineralized bone matrix (DBM) were implanted subcutaneously to syngeneic 8-week-old rats and were harvested every week 3-7 weeks after implantation, and histochemical examination, determination of alkaline phosphatase activity, total calcium and phosphorus, the bone-specific vitamin K-dependent gla-containing protein (BGP) content, and detection of BGP mRNA relative to mineralization were performed. Alkaline phosphatase in diffusion chamber implants reached the highest activity at 4 weeks and then decreased. Calcium and phosphorus deposits occurred at 4 weeks after implantation and were followed by marked increases until 7 weeks, which was comparable to the accumulation of BGP. The BGP gene within the diffusion chambers began to be expressed at 5 weeks, and its expression increased markedly at 7 weeks after implantation. At 4-5 weeks after implantation, new bone adjacent to the membrane filters and cartilage toward the center of the diffusion chamber were observed histochemically. Light microscopic and immunohistologic examinations of chambers with marrow cells and DBM revealed production of mineralized matrices, typical of bone characterized by the appearance of BGP and mineralized nodules. In contrast, bone marrow cells alone did not show extensive bone formation and yielded very low values for these biochemical parameters. The present experiments demonstrate the potential of bone marrow cells and DBM to produce not only cartilage formation but also membranous bone formation associated with increasing expression of BGP mRNA during the later stages of bone formation, as well as a marked accumulation of BGP.

Alkaline Phosphatase↗
PubMed1992

Biochemical and histological sequences of membranous ossification in ectopic site.

Porous hydroxyapatite ceramics alone (control) and ceramics combined with rat marrow cells were implanted subcutaneously in the back of syngeneic rats and harvested 1-8 weeks after implantation. The ceramics were examined biochemically and histologically. Alkaline phosphatase activity in the marrow cell/ceramic composites began to increase at 2 weeks and achieved a peak at 4 weeks, followed by a gradual decrease. Bone gla protein contents in the composites began to increase at 3 weeks and steadily increased as time passed. Histologically, osteoblastic cells were detected at 2 weeks and obvious de novo bone together with active osteoblasts began to appear at 3 weeks in the composites. The process was membranous ossification without cartilage formation and was observed in the pores of the composites. The pore areas occupied by bone increased as time passed. In contrast, ceramics alone did not show any bone formation and contained traces of these biochemical parameters. These results indicated that the biochemical sequences correlate with the histological sequences in the heterotopic membranous ossification.

Alkaline Phosphatase↗
PubMed1992

Aerobic capacity of forestry workers and physical demands of forestry operations.

The present study aimed at evaluating the aerobic capacities of forestry workers and the physical demands of their occupation. A submaximal cycle ergometer test was conducted on 22 male forestry workers and 15 male sedentary office workers aged 40-59 years. The slope of the regression line of heart rates on given exercise intensities was significantly smaller in the forestry workers than in the office workers. The mean heart rate of the forestry workers was 9 beats.min-1 less than that of the office workers at the initial exercise intensity of 50 W. This difference increased to 25 beats.min-1 at 175 W. For 6 of the 22 forestry workers, heart rates were recorded continuously during a usual workday. The metabolic rates, as multiples of basal metabolic rate (in met) of various forestry activities were estimated from the average heart rate during the activity of interest and a predicted maximal oxygen consumption of the subject obtained from a submaximal cycle ergometer test. The mean energy expenditure was 4.5 met with a range of 3.3-6.3 met for an average of 509 min at a worksite. These results indicated that the forestry workers had high aerobic capacities and this was ascribed to the high physical demands of their occupation.

Adult↗
PubMed1992

Decrease in bone strength of cadmium-treated young and old rats.

A decrease in mechanical strength of bones was observed both in young and old rats for long periods of administration of cadmium. Young (3-week-old) female rats were given 0 (control), 5 and 10 ppm cadmium in drinking water, respectively, for 20 weeks. Old (18-month-old) female rats were given 0 (control) and 40 ppm cadmium in drinking water, respectively, for 7 months. The compression strengths of bones of young rats which were given 10 ppm cadmium, and those of old rats which were given 40 ppm cadmium, significantly decreased at the distal end portion of femur. Cadmium contents in bones in the 10 ppm and 40 ppm groups were about 110 and 210 ng/g dry weight, respectively. The present result confirmed that cadmium has a lesional effect on the mechanical strength of bone at the concentration of 100-200 ng/g in dry weight of bone, for both young and old rats.

Aging↗
PubMed1992

Detection of xenogeneic anti-idiotypic antibodies specific to murine monoclonal antibody 17-1A in patients with gastrointestinal cancer.

Murine monoclonal antibody (MoAb) 17-1A, which reacts with an adenocarcinoma-associated antigen, has recently been utilized in a phase I clinical trial for patients with gastrointestinal tract cancers in Japan. In order to analyze anti-idiotypic (Id) antibodies to murine MoAb 17-1A in the sera of these cancer patients, we established a simple and specific assay. In a modified sandwich assay, normal mouse sera were utilized for neutralization of rat antimouse immunoglobulin (Ig) antibodies and reduction of their nonspecific effects. When the modified sandwich assay was applied to the sera of patients who had been treated with MoAb 17-1A, anti-Id antibodies were induced in 53% of 13 cancer patients with gastrointestinal cancers at 3-4 weeks after infusion of MoAb.

Animals↗
PubMed1992

Invasion of Streptococcus mutans, Streptococcus intermedius and Propionibacterium acnes into the teeth of gnotobiotic rats.

Germ-free rats, fed a modified cariogenic diet 2000 with a reduced sucrose content of 25%, were inoculated with a strain of Streptococcus mutans, Streptococcus intermedius or Propionibacterium acnes, respectively. After 100 days on the diet, the rats were sacrificed. Microscopic examination of stained decalcified tooth sections revealed marked destruction of the outer zones of the dentin infected with S. mutans. The destruction was closely associated with the formation of glucan-mediated large aggregates of S. mutans. The aggregates, however, were rarely formed in the deep zones of the infected dentin. Inoculation with S. intermedius and P. acnes had little effect on the microscopic outline of the decalcified tooth sections. However, the staining behavior of the sections with Mallory's method, Alcian blue-PAS and silver was like that of the tooth sections infected with S. mutans, even in the central and inner zones of the dentin. The histochemical alterations of the deep zones of the dentin induced by the three infected bacteria appeared to be due to their proteolytic rather than to their acidogenic activities.

Animals↗
PubMed1992

Calcium channel blocker-like action of reserpine in smooth muscle.

The effect of reserpine on vascular and intestinal smooth muscles was examined. In these muscles, reserpine inhibited the high K(+)-induced contraction, and this inhibitory effect was antagonized by the increase in external Ca2+ concentration and also by a Ca2+ channel activator, Bay k8644. In rabbit aorta, increases in cytosolic Ca2+ level and muscle tension due to high K+ were inhibited in parallel by reserpine. These results suggest that reserpine inhibits L-type Ca2+ channels to inhibit smooth muscle contraction.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1992

Butyrolactols A and B, new antifungal antibiotics. Taxonomy, isolation, physico-chemical properties, structure and biological activity.

New antifungal antibiotics, butyrolactols A and B, have been isolated from the culture broth of Streptomyces rochei S785-16. They are novel type of molecules containing a common 2,3-dihydroxybutyrolactone nucleus substituted with a different long hydroxyalkyl side chain. Butyrolactol A showed good antifungal activity against Aspergillus fumigatus and Trichophyton mentagrophytes, and moderately inhibited the growth of yeasts.

4-Butyrolactone↗
PubMed1992

New antiviral antibiotics, cycloviracins B1 and B2. II. Structure determination.

The structures of novel antiviral antibiotics, cycloviracins B1 and B2 have been determined by means of chemical and spectroscopic methods including 2D NMR correlation spectroscopy. The antibiotics are unique macrocyclic diesters consisting of two D-glucoses, three 2-O-methyl-D-glucoses and two (C24 and C26) hydroxy fatty acids.

Actinomycetales↗
PubMed1992

A quantitative method for LDH, MDH and albumin levels in tears with ocular surface toxicity scored by Draize criteria in rabbit eyes.

We have established a quantitative method for evaluation of ocular surface lesions on the basis of lactate dehydrogenase (LDH) activity, malate dehydrogenase (MDH) activity, and albumin levels in rabbit tears. Lesions were produced with solutions of 0.005-0.02% benzalkonium chloride (BAK), 0.01-0.03% chlorhexidine digluconate (CHX), and 0.01-0.03% polyhexamethylene biguanide hydrochloride (PHMB), all of which are widely used in topical ophthalmic preparations. Two drops of test solution were instilled 15 times into rabbit eyes at 5 minute intervals. Sixty minutes after 0.02% BAK instillation, tear LDH activity increased from 1,840 U/L (without instillation) to 26,100 U/L, and concomitantly tear albumin levels rose from 0.11 mg/mL (without instillation) to 9.48 mg/mL. Instillation of 0.03% CHX and 0.03% PHMB caused smaller increases in LDH and MDH activity and albumin tear levels. LDH activity and albumin levels in tears were significantly correlated with the degree of total ocular surface lesions in both cornea and conjunctiva as observed by slit lamp biomicroscopy quantified using a modified Draize score. Based on the results of this study, we believe that LDH activity and albumin level in tears can be used as objective indicators for the quantitative evaluation of ocular surface lesions on both cornea and conjunctiva following application of topical ophthalmic preparations containing cytotoxic preservatives in animals and man.

Albumins↗
PubMed1992

[A case of hyperalphalipoproteinemia with complete deficiency of cholesteryl ester transfer activity].

A 68-year-old male patient with benign hypertension shows high levels of high density lipoprotein cholesterol (HDL-C) of 171 mg/dl. The serum total cholesterol was 240 mg/dl. An abnormal slow alpha band and polydisperse low density lipoprotein (LDL) bands were detected by agarose gel and polyacrylamide gel electrophoresis. The slow alpha band was considered as an apo E-rich HDL. A peak of large HDL particle and a peak of abnormal high-molecular-LDL particle were observed in the patient's serum by gel permeation high performance liquid chromatography. Cholesteryl ester transfer activity (CETA) of the patient's serum was completely deficient (0.0%/10 microliters/18 hr). From these results, it is strongly suggested that patient's hyper-HDL-cholesterolemia caused by a complete deficiency of CETA.

Aged↗