Search PubMed⌕ Search

Biomedical subjects

S Miyake

Publications and source records attributed to S Miyake.

At least 271 records · Page 15Linked to original sources
PubMed1988

Plasma levels of human atrial natriuretic factor in patients treated by hemodialysis and continuous ambulatory peritoneal dialysis.

We measured plasma levels of immunoreactive human atrial natriuretic factor (ANF) in chronic renal failure patients treated by hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD). Predialysis plasma ANF was significantly higher in HD patients (271.8 +/- 173.4 pg/ml) as compared to CAPD patients (81.8 +/- 80.5 pg/ml) and healthy subjects (31.5 +/- 19.8 pg/ml). Plasma volume was higher in HD patients than in CAPD patients. Plasma ANF and plasma volume showed a significant positive correlation. In HD patients, high plasma ANF value decreased significantly to a value comparable with that of CAPD patients after each dialysis. The removal rates of ANF by HD and CAPD were comparable. Ultrafiltration corresponding to 2% of body weight without dialysis also reduced plasma ANF. Thus, the difference in plasma ANF values between HD and CAPD patients seems to be mostly due to the difference in plasma volume, indicating that plasma ANF is sensitive to volume status even in chronic dialysis patients.

Adult↗
PubMed1988

Effect of pre-exercise fructose ingestion on endurance performance in fed men.

Twelve trained males, in a fed state, were studied to examine the effect of pre-exercise fructose ingestion on endurance capacity during prolonged cycling exercise. Sixty minutes prior to exercise, subjects ingested either 60 or 85 g fructose or a sweet placebo. Mean exercise intensity initially required 62% of the maximal aerobic power and thereafter increased to elicit 72 and 81% of maximal aerobic power at 90 and 120 min of exercise, respectively. Exercise time (mean +/- SE) to exhaustion was significantly increased after fructose ingestion, as compared to placebo ingestion (145 +/- 4 vs 132 +/- 3 min, P less than 0.01). During the exercise, no differences were observed between both trials for oxygen uptake, heart rate, or perceived exertion. Serum glucose and insulin levels between both trials were not significantly different throughout the experiment. There were also no significant differences in serum-free fatty acids and glycerol levels as well as respiratory exchange ratio between fructose and placebo trials during the exercise. The results suggest that fructose ingestion is of benefit before prolonged exercise, because it provides a carbohydrate source to contracting muscles without transient hypoglycemia and a depression of fat utilization, and thereby delays the fatigue.

Adolescent↗
PubMed1988

Cardiovascular pharmacology of RS-1893, an orally active cardiotonic agent with arterial and venous vasodilator actions.

RS-1893, 2-[2-chloro-4-(2,3,4,5-tetrahydro-3-oxo-6-pyridazinyl)]-phenoxy-N- (2-(2-morpholinoethyl)-acetamide, is a newly synthesized compound whose structure is different from that of cardiac glycosides and beta-stimulants. The in vitro cardiotonic action of RS-1893 was about 3 times more potent than that of milrinone. This action is most likely due to inhibition of phosphodiesterase-III, as has been suggested for many other cardiotonic agents. In pentobarbital anesthetized dogs, RS-1893 (1-30 micrograms/kg, i.v.) produced dose dependent increases in left ventricular dP/dtmax and cardiac output and caused decreases in blood pressure and total peripheral resistance with a relatively small increase in heart rate. Central venous pressure decreased markedly, suggesting venous vasodilation. The in vivo cardiotonic action of RS-1893 was 3 times more potent than that of milrinone and was not affected in the presence of a large dose of propranolol. Oral administration of RS-1893 (0.03 and 0.1 mg/kg) also produced a dose-related increase in cardiac contractility in conscious beagles. The increase in LVdP/dtmax reached a maximum in 1-3 hr after administration and lasted for more than 8 hr. Thus, RS-1893 appeared to be an orally active cardiotonic agent with vasodilator properties, probably acting on both arterioles and veins.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1987

Effects of sucralfate, 15(R)15-methyl prostaglandin E2, and cimetidine on rat gastric mucosal damage induced by ethanol.

The efficacy of sucralfate, 15(R)15-methyl prostaglandin E2, and cimetidine in protecting against ethanol injury in rat stomachs was examined. Rats that had been fasted were pretreated intragastrically with either sucralfate 160 mg/kg, 15(R)15-methyl prostaglandin E2 16 micrograms/kg, cimetidine 100 mg/kg, or an equal amount of vehicle alone (control). One hour later, all rats received 1 ml of 99.5 percent ethanol orally and were killed 15 minutes or 24 hours later. Stomachs were removed, and mucosal damage was assessed macroscopically as well as by scanning electron microscopy. Pretreatment with either 15(R)15-methyl prostaglandin E2 or sucralfate significantly reduced the number and extent of ethanol-induced mucosal gastric lesions; pretreatment with cimetidine, however, failed to produce positive results. It is concluded that the abilities of 15(R)15-methyl prostaglandin E2 and sucralfate in protecting against ethanol injury are comparable.

Animals↗
PubMed1987

Selective use of the VHQ52 family in functional VH to DJH rearrangements in a B precursor cell line.

AT11-2, an Abelson virus-transformed cell line has DJH complexes on both chromosomes and is able to form functional variable region genes by the joins of VH genes to the DJH complexes during culture. Therefore we examined which VH gene family was used in functional VH to DJH recombinations in AT11-2. Surprisingly, of 32 independent functional VH to DJH recombinational events in AT11-2, 31 events used the VH segments of the VHQ52 family, and the remaining one used the VH segment of the VH7183 family. Thus, we describe here the first B precursor cell line that almost selectively uses the VHQ52 family in functional VH to DJH rearrangements. The selective use of the VHQ52 family in this B precursor cell line strongly indicates nonrandom use of VH gene families, and the existence of a stage at which the VHQ52 family is preferentially used during the normal development of early pre-B cells and has important implications for understanding the ontogeny of VH repertoire development. Furthermore, this cell line should prove extremely valuable in further studies of this kind.

Animals↗
PubMed1987

Start of mu-chain production by the further two-step rearrangements of immunoglobulin heavy chain genes on one chromosome from a DJH/DJH configuration in an Abelson virus-transformed cell line: evidence of secondary DJH complex formation.

A variant was selected from an Abelson virus-transformed cell line with identifiable and distinguishable DJH rearrangements on both chromosomes. Southern blotting experiments suggested that this variant resulted from a secondary DJH complex formation accompanied with the deletion of one of the DJH rearrangements on the same chromosome. Furthermore, this variant started making mu-chains by the further functional join of a VH gene to the secondarily formed DJH complex. Thus, we describe here the first evidence of a secondary DJH complex formation.

Abelson murine leukemia virus↗
PubMed1987

Effects of hypoglycaemia on early embryogenesis in rat embryo organ culture.

As congenital malformations may be caused by perturbations of glycolytic flux on early embryogenesis [16], effects of hypoglycaemia were investigated by using rat embryo organ culture. Nine and one-half day old rat embryos were grown in vitro for 48 h (day 9 1/2 to 11 1/2) in the presence of hypoglycaemic serum for different hours during the culture period. Hypoglycaemic serum was obtained from rats given insulin intraperitoneally. On exposure to hypoglycaemic serum during the first 24 h of culture (day 9 1/2 to 10 1/2), embryos showed marked growth retardation and had increased frequencies of neural lesions (42.7% versus 0%, p less than 0.01), in contrast to hypoglycaemic exposure during the second 24 h of culture (day 10 1/2 to 11 1/2), where only minor growth retardation and low frequencies of neural lesions (2.4% versus 0%, NS) were seen. Even exposure to hypoglycaemic serum for a relatively short period (8 h) during the first 24 h of culture resulted in neural lesions at the frequency of 9.3-13.3%. The embryos exposed to hypoglycaemia demonstrated decreased glucose uptake and lactic acid formation, indicating decreased energy production via glycolysis that constitutes the principal energy pathway at this stage of embryonic development. These results suggest that hypoglycaemia during critical periods of embryogenesis has adverse effects on the development of the embryo and these effects might be mediated through metabolic interruption of embryogenesis.

Animals↗
PubMed1987

Differentiation of an Abelson virus-transformed immature B precursor cell line under the expression of tyrosine kinase activity of v-abl oncogene product.

The expression of v-abl oncogene during the in vitro differentiation of an Abelson-virus-transformed immature B precursor cell line from immunoglobulin-null to intracytoplasmic mu-positive cells and further to intracytoplasmic gamma 2b-positive cells was examined. The results showed no significant alteration in the amounts and tyrosine kinase activity of v-abl oncogene product during differentiation, indicating that B cell differentiation processes are independent of v-abl functions.

Abelson murine leukemia virus↗
PubMed1987

Introducing the concept of a corporate culture to the hospital setting.

The hospital industry is undergoing radical changes. To keep pace with the ever increasing demands for improved productivity and performance, hospitals are attempting to operate like businesses. This article examines one hospital's attempts at establishing a culture focused on excellence in its occupational therapy department. Guidelines are offered for creating positive cultures in other hospital settings.

Attitude of Health Personnel↗
PubMed1987

Effect of a new H2-blocker, famotidine, in reflux esophagitis among severely handicapped children.

Vomiting, hematemesis, and esophagitis resulting from gastroesophageal reflux or hiatal hernia are frequently observed in severely handicapped children. This study was conducted to determine whether the use of a new H2-antagonist, famotidine, could prevent recurrence of reflux esophagitis among such children. Seventeen severely handicapped, bedridden children admitted to a children's medical center between April 1985 and September 1986 were studied. All had vomiting or hematemesis as a main symptom, and the cause of esophagitis was suggested to be gastroesophageal reflux in 13 cases and hiatal hernia in four. Six had been previously treated with cimetidine or other drugs or a combination thereof without relief. Famotidine was administered at about 1 to 2 mg/kg/day, two times daily to patients weighing more than 10 kg and three times daily to those weighing less than 10 kg. In 13 cases, famotidine was administered intravenously for between seven and ten days and then given orally, while the rest were given the drug orally from the outset. The following results were obtained: (1) improvement was seen within seven days after start of famotidine treatment, and reduction of vomiting or hematemesis or both was reached within two weeks in 70% of cases and within three weeks in 94%; (2) famotidine was markedly effective in 29% and moderately effective in 41%; in no case was the drug ineffective; (3) no side effects were observed; five patients had transient, mild elevation of SGOT . SGPT, but this was not attributable to the drug.

Adolescent↗