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Biomedical subjects

H Satoh

Publications and source records attributed to H Satoh.

At least 235 records · Page 13Linked to original sources
PubMed1999

Retroperitoneal liposarcoma with combined well-differentiated and myxoid malignant fibrous histiocytoma-like myxoid areas.

To broaden the knowledge of myxoid morphology in liposarcoma, eight cases of unusual liposarcoma with combined well-differentiated and myxoid malignant fibrous histiocytoma (MFH)-like myxoid areas are reported. The tumors arose as huge retroperitoneal masses in elderly patients, except for one that occurred in the spermatic cord. Three cases had local recurrences, and one of the seven patients who were followed up had died of the tumor. Grossly, the tumors were mostly confluent and multinodular and showed a glistening myxoid appearance in variable proportions, which merged gradually into or were juxtaposed to yellow fatty or sclerotic whitish areas. Microscopically, in addition to areas of well-differentiated lipoma-like or sclerosing liposarcoma, all the tumors contained myxoid portions characterized by scattered multinucleated or bizarre giant cells and a prominent plexiform vascular pattern that resembled myxoid MFH or myxofibrosarcoma. The myxoid areas were associated with discernible lipogenesis. High-grade dedifferentiation was present in one tumor. Cytogenetically, in one case, the myxoid lesion had nonrandom chromosomal aberrations, such as ring and marker chromosomes, characteristic of a well-differentiated variant of liposarcoma. In a nested reverse transcription-polymerase chain reaction analysis using archival paraffin-embedded tissue, it was seen that none of the eight tumors with myxoid MFH-like features had TLS/FUS-CHOP fusion transcripts characteristic of myxoid and round cell liposarcomas. These clinicopathologic and molecular features suggest that the current myxoid tumors are more closely related to well-differentiated liposarcoma rather than to ordinary myxoid liposarcoma despite their unequivocal myxoid morphology. Missense point mutations of the p53 gene were detected in two (25%) cases by single-strand conformation polymorphism and sequence analyses. Immunohistochemical expressions of p53 and mdm2 were observed in 75% of the cases, in which immunoreactive tumor cells were seen more often in the myxoid MFH-like areas. Thus, altered p53 pathways, such as p53 gene mutation and mdm2-mediated inactivation of p53, may play a pathogenetic role in this form of tumor progression showing myxoid MFH-like morphology in liposarcoma, as has been suggested in dedifferentiated liposarcoma.

Aged↗
PubMed1999

Characteristics of blood pressure measured at home in the morning and in the evening: the Ohasama study.

OBJECTIVE: To determine the qualitative and quantitative differences of blood pressure measured at home (home measurement) in the morning versus the evening. METHODS: Of 3744 participants, aged 20 years or older in the Ohasama population, more than 14 home measurements in the morning and in the evening, respectively, were obtained in each of 1207 individuals (881 untreated, 56.1 +/- 11.4 years and 326 treated, 66.0 +/- 9.2 years). A casual/screening measurement was also obtained in these individuals. RESULTS: The home measurements in the morning were significantly higher than those in the evening. The bivariate linear regression analysis demonstrated that the difference between diastolic home measurement in the morning and that in the evening increased with an increase in diastolic home measurements. The multiple step-wise linear regression analysis, however, demonstrated that male sex, the use of antihypertensive medication, and SD of home measurements in individuals (blood pressure variability), but not level of home measurements, were positively associated with the difference between home measurement in the morning and that in the evening. The SD of home measurement in the evening in individuals was significantly larger than that in the morning, and the SD in treated individuals was significantly larger than that in untreated individuals. The correlations between casual and home measurements were moderate in untreated individuals (r = 0.509-0.567) but poor in treated subjects (r= 0.223-0.384). The correlations between home systolic measurements in the morning and in the evening were very close in both treated and untreated subjects (r = 0.814-0.902). The correlations between the SD of home measurements in the morning and in the evening were moderate in both treated and untreated individuals (r = 0.585-0.657). CONCLUSIONS: Qualitative and quantitative differences in home blood pressure measurement, due to the differential time of measurement, should be taken into consideration in clinical use of home blood pressure measurements.

Adult↗
PubMed1999

A maize glycine-rich protein is synthesized in the lateral root cap and accumulates in the mucilage.

The root cap functions in the perception of gravity, the protection of the root apical meristem, and facilitation of the passage of roots through the soil, but the genes involved in these functions are poorly understood. Here we report the isolation of a root-specific gene from the cap of maize (Zea mays L.) primary root by cDNA subtraction and differential screening. The gene zmGRP4 (Z. mays glycine rich protein 4) encodes a member of the glycine-rich proteins with a putative signal peptide at the amino terminus. The deduced molecular mass of mature zmGRP4 is 14.4 kD. In situ-hybridization analysis has shown zmGRP4 to be strongly expressed in the lateral root cap and weakly expressed in the root epidermis. A polyclonal antibody raised against recombinant zmGRP4 detected a protein of 36 kD in the insoluble protein fraction extracted from the root tip and the root proper, indicating posttranslational modification(s) of zmGRP4. Immunohistochemical analysis showed the accumulation of zmGRP4 in the mucilage that covers the root tip. These results indicate that lateral root-cap cells secrete modified zmGRP4 into the mucilage to which the protein may contribute to its characteristic physical properties.

Amino Acid Sequence↗
PubMed1999

The starch-debranching enzymes isoamylase and pullulanase are both involved in amylopectin biosynthesis in rice endosperm

The activities of the two types of starch debranching enzymes, isoamylase and pullulanase, were greatly reduced in endosperms of allelic sugary-1 mutants of rice (Oryza sativa), with the decrease more pronounced for isoamylase than for pullulanase. However, the decrease in isoamylase activity was not related to the magnitude of the sugary phenotype (the proportion of the phytoglycogen region of the endosperm), as observed with pullulanase. In the moderately mutated line EM-5, the pullulanase activity was markedly lower in the phytoglycogen region than in the starch region, and isoamylase activity was extremely low or completely lost in the whole endosperm tissue. These results suggest that both debranching enzymes are involved in amylopectin biosynthesis in rice endosperm. We presume that isoamylase plays a predominant role in amylopectin synthesis, but pullulanase is also essential or can compensate for the role of isoamylase in the construction of the amylopectin multiple-cluster structure. It is highly possible that isoamylase was modified in some sugary-1 mutants such as EM-273 and EM-5, since it was present in significant and trace amounts, respectively, in these mutants but was apparently inactive. The results show that the Sugary-1 gene encodes the isoamylase gene of the rice genome.

Journal Article↗
PubMed1999

Analyses of spatial distributions of sulfate-reducing bacteria and their activity in aerobic wastewater biofilms.

The vertical distribution of sulfate-reducing bacteria (SRB) in aerobic wastewater biofilms grown on rotating disk reactors was investigated by fluorescent in situ hybridization (FISH) with 16S rRNA-targeted oligonucleotide probes. To correlate the vertical distribution of SRB populations with their activity, the microprofiles of O(2), H(2)S, NO(2)(-), NO(3)(-), NH(4)(+), and pH were measured with microelectrodes. In addition, a cross-evaluation of the FISH and microelectrode analyses was performed by comparing them with culture-based approaches and biogeochemical measurements. In situ hybridization revealed that a relatively high abundance of the probe SRB385-stained cells (approximately 10(9) to 10(10) cells per cm(3) of biofilm) were evenly distributed throughout the biofilm, even in the oxic surface. The probe SRB660-stained Desulfobulbus spp. were found to be numerically important members of SRB populations (approximately 10(8) to 10(9) cells per cm(3)). The result of microelectrode measurements showed that a high sulfate-reducing activity was found in a narrow anaerobic zone located about 150 to 300 microm below the biofilm surface and above which an intensive sulfide oxidation zone was found. The biogeochemical measurements showed that elemental sulfur (S(0)) was an important intermediate of the sulfide reoxidation in such thin wastewater biofilms (approximately 1,500 microm), which accounted for about 75% of the total S pool in the biofilm. The contribution of an internal Fe-sulfur cycle to the overall sulfur cycle in aerobic wastewater biofilms was insignificant (less than 1%) due to the relatively high sulfate reduction rate.

Aerobiosis↗
PubMed1999

In situ analysis of nitrifying biofilms as determined by in situ hybridization and the use of microelectrodes.

We investigated the in situ spatial organization of ammonia-oxidizing and nitrite-oxidizing bacteria in domestic wastewater biofilms and autotrophic nitrifying biofilms by using microsensors and fluorescent in situ hybridization (FISH) performed with 16S rRNA-targeted oligonucleotide probes. The combination of these techniques made it possible to relate in situ microbial activity directly to the occurrence of nitrifying bacterial populations. In situ hybridization revealed that bacteria belonging to the genus Nitrosomonas were the numerically dominant ammonia-oxidizing bacteria in both types of biofilms. Bacteria belonging to the genus Nitrobacter were not detected; instead, Nitrospira-like bacteria were the main nitrite-oxidizing bacteria in both types of biofilms. Nitrospira-like cells formed irregularly shaped aggregates consisting of small microcolonies, which clustered around the clusters of ammonia oxidizers. Whereas most of the ammonia-oxidizing bacteria were present throughout the biofilms, the nitrite-oxidizing bacteria were restricted to the active nitrite-oxidizing zones, which were in the inner parts of the biofilms. Microelectrode measurements showed that the active ammonia-oxidizing zone was located in the outer part of a biofilm, whereas the active nitrite-oxidizing zone was located just below the ammonia-oxidizing zone and overlapped the location of nitrite-oxidizing bacteria, as determined by FISH.

Ammonia↗
PubMed1999

Clustered adenine/thymine stretches are essential for function of a fission yeast replication origin.

We have determined functional elements required for autonomous replication of the Schizosaccharomyces pombe ars2004 that acts as an intrinsic chromosomal replication origin. Internal deletion analysis of a 940-bp fragment (ars2004M) showed three regions, I to III, to be required for autonomously replicating sequence (ARS) activity. Eight-base-pair substitutions in the 40-bp region I, composed of arrays of adenines on a DNA strand, resulted in a great reduction of ARS activity. Substitutions of region I with synthetic sequences showed that no specific sequence but rather repeats of three or more consecutive adenines or thymines, without interruption by guanine or cytosine, are required for the ARS activity. The 65-bp region III contains 11 repeats of the AAAAT sequence, while the 165-bp region II has short adenine or thymine stretches and a guanine- and cytosine-rich region which enhances ARS activity. All three regions in ars2004M can be replaced with 40-bp poly(dA/dT) fragments without reduction of ARS activity. Although spacer regions in the ars2004M enhance ARS activity, all could be deleted when an 40-bp poly(dA/dT) fragment was added in place of region I. Our results suggest that the origin activity of fission yeast replicators depends on the number of adenine/thymine stretches, the extent of their clustering, and presence of certain replication-enhancing elements.

AT Rich Sequence↗
PubMed1999

Bioavailability and diuretic effect after administration of retarded capsules of bumetanide in human subjects.

Retarded capsules containing 1 mg bumetanide (BN) were prepared and their in vivo absorption and diuretic effect after oral administration in human subjects were studied. For comparison, commercially available tablets of BN (rapid effect) were administered orally. The mean value of the area under the plasma concentration time curve (AUC) after administration of retarded capsules was about one half that of the tablets. The mean maximum plasma concentration (Cmax) and the mean maximum urinary excretion rate of BN after administration of retarded capsules were also about one half compared to those of the tablets. Cumulative urinary volumes for 24 h, however, were not significantly different between retarded capsules and tablets. Peak times for the urinary excretion rate of BN, urine flow rate and the Cmax after administration of retarded capsules were significantly delayed compared to those of tablets. Clockwise hysteresis relationships between the urine flow rate and plasma concentration or urinary excretion rate of BN were observed after administration of retarded capsules. From these studies, retarded capsules of BN possessed a mild diuresis and its diuretic effect was maintained for a few hours after administration.

Administration, Oral↗
PubMed1999

Relationships among blood pressures obtained using different measurement methods in the general population of Ohasama, Japan.

To examine the relationships between casual, ambulatory and home blood pressure measurements in the general population, these measurements were obtained in 1,695 of 3,744 subjects aged 20 yr or older in Ohasama, Japan. Of these 1,695 subjects, 1,207 measured their home blood pressure more than 14 times in each of the morning and evening (881 untreated subjects including normotensives and untreated hypertensives, 56.4 +/- 11.5 yr of age; 326 treated subjects, 66.0 +/- 9.2 yr of age). We analyzed data in these 1,207 subjects, examining the distribution of each measurement, the relationships among measurements, and the factors affecting the blood pressure differences among the measurements. For systolic pressure, the casual measurement was the highest among the methods examined. The daytime ambulatory measurement was significantly higher than morning and evening home measurements. Morning home measurements were significantly higher than those in the evening. For diastolic pressure, however, the morning home measurement was the highest among the methods examined. Short-term pressure variability (standard deviation and variation coefficient of ambulatory measurements) was greater than long-term pressure variability (standard deviation and variation coefficient of home measurements). The pressure variability in treated subjects was greater than that in untreated subjects. The correlation between casual pressure and the other pressures was not as strong (r<0.567). Among the relationships between ambulatory and home measurements, the strongest correlation was observed between the 24-h ambulatory measurement and the morning home measurement (r=0.738) in untreated subjects. The morning home measurement was highly correlated with the evening home measurement (r>0.814). The differences among the methods examined were affected by blood pressure level and age. It should be noted that in elderly and treated subjects, blood pressure measurement using one method does not necessarily correlate with that obtained using the other methods. This information is useful for the estimation of the value of one type of blood pressure measurement from values obtained with other methods.

Adult↗
PubMed1999

Novel techniques for in vivo hemolysis studies in guinea pigs.

The in vivo toxic-hemolytic studies using small experimental animals are complicated by difficulties in preventing hemolysis during repeated collection of blood specimens and in measuring hemoglobin concentration in small amounts of plasma sample. To solve these problems we tried to develope the new techniques for the in vivo hemolysis studies using guinea pigs. The hemolysis accident was minimized to 2.75 mg/dl by collecting the blood directly into heparinized microhematocrit tubes by small longitudinal incision in the auricular artery. The hemoglobin in a small amount of sample (10 microliters) was determined by the new analytical system using a microflow spectrophotometer with a modified cyanmethemoglobin method. The standard curve of the hemoglobin concentration in the system revealed a line of Y = 1.8X + 0.79 (r = 0.999), CV < 1% with a minimum detectable concentration of 1.25 mg/dl. By using the new techniques, it was found that the plasma hemoglobin concentration in normal animals were 7.27 +/- 0.44 mg/dl (mean +/- S.E.). The in vivo hemolytic activity of saponin was observed dose-dependently at doses of 30-50 mg/kg, i.v. in the guinea pigs. It is concluded that the present techniques are useful for in vivo hemolytic studies in small experimental animals such as guinea pigs.

Animals↗
PubMed1999

The hemolytic activity of bracken extracts in guinea pigs.

This study was conducted to elucidate the hemolytic activity of a new toxic substance in bracken fern. A crude extract (CE) was prepared from the methanol extracts of bracken by the column chromatography. When the CE was injected subcutaneously in guinea pigs, the hemoglobinuria and hemolysis were observed within 6 hr, and 3 days later edema and hemorrhages in the urinary bladder were observed. The CE was then fractionated by high performance liquid chromatography (HPLC), and three (HF, BF and CF) of the fractions showed the toxic activities in guinea pigs. The HF caused the hemolysis, whereas both the BF and the CF caused the hemorrhagic cystitis without any hemolytic activities. The HF was further fractionated by the HPLC, resulting of the 3 fractions (HF-I, II and III). The hemolysis was caused only with the HF-II, and HF-II as well as HF did not cause the hemorrhagic cystitis. HPLC analysis revealed that both BF and CF contains braxin B and braxin C, respectively, and both HF and HF-II do not contain braxin A, B or C. These facts suggest that bracken fern contains a new toxic substance (hemolysin) which induces the acute hemolysis in guinea pigs.

Animals↗
PubMed1999

The effect of prenatal methylmercury exposure on the GSH level and lipid peroxidation in the fetal brain and placenta of mice.

Effect of prenatal exposure to methylmercury (MeHg) on the glutathione (GSH) levels and lipid peroxidation in the fetal brain was examined. Pregnant ICR mice were injected with 3 mgHg/kg of MeHg on gestational day 12, 13 and 14 (G12-14). On the G14 or G17, the fetal brains were removed and their GSH levels and thiobarbituric acid-reactive substances (TBARS) levels were determined. On the G17, GSH level of MeHg-treated fetal brain was significantly higher than that of the control brain; the TBARS level showed the similar trend but the difference was not significant. These results indicated that the prenatal MeHg treatment disturbed the normal GSH level in the fetal brain and warranted further investigation on the significance of this GSH perturbation.

Animals↗
PubMed1999

Daily response of blood pressure to day-to-day variation of urinary sodium to potassium ratio.

The relationship between blood pressure and urinary sodium-to-potassium (Na/K) ratio was assessed in eight healthy men, none of whom used antihypertensive medications. Blood pressure and urinary sodium and potassium concentrations were measured for 11 to 33 days without any dietary restriction. For two of the eight subjects, the urinary Na/K ratio significantly correlated with systolic blood pressure (r=0.70 and 0.45, respectively), and in one of the two subjects, the urinary ratio also positively correlated with diastolic blood pressure (r=0.72). In the others, no relationship between the ratio and blood pressure was observed (r=-0.24 to 0.26). The results indicate that, in some individuals, the daily variation of urinary Na/K ratio is closely correlated with day-to-day changes in blood pressure level, and suggest that the urinary Na/K ratio is useful in the management of the daily sodium and potassium intake balance of hypertensive patients who need to restrict salt intake.

Adult↗