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Biomedical subjects

S Naruse

Publications and source records attributed to S Naruse.

At least 163 records · Page 9Linked to original sources
PubMed1992

Enzyme immunoassay and immunochemical characterization of pancreatic stone protein in human serum.

Monoclonal antibodies were raised against human pancreatic stone protein (PSP) and used for one-step enzyme immunoassay (EIA). PSP-S2-5 was employed as the standard in the assay. The assay's measurable range was 25-1,500 ng/ml and within run coefficient of variation was 3.7-6.4%. Analytical recovery of the assay was 101.5 +/- 5.65% (mean +/- SD). The results of experiments in which serum was fractionated by Mono S (cation exchange chromatography) suggested that most of immunoreactive material in human serum is PSP-S2-5. The EIA offers simple, rapid, and specific analysis of serum PSP level for clinical diagnosis.

Antibodies, Monoclonal↗
PubMed1992

Effect and distribution of intravenously injected 125I-endothelin-1 in rat kidney and lung examined by electron microscopic radioautography.

The morphological effect of endothelin-1 (ET-1) and the distribution of endothelin-binding sites on the kidney and lung was investigated ultrastructually by intravenous injection of [125I]-ET-1 into rats. About 10% decrease of the diameter of glomeruli was observed at 10 min after the injections of ET-1 or [125I]-ET-1 (1.3-2.4 nmole/kg). When localization of [125I]-ET-1 in the kidney was examined by light and electron microscopic radioautography, silver grains were preferably localized on the fenestrated endothelial cells of glomeruli and peritubular capillary endothelial cells. Some grains were also localized on the interdigitating processes of urinary tubules. Quantitative analysis of silver grains in the glomeruli showed that 83% of grains were located on the fenestrated endothelial cells, 12% on the podocytes of visceral cells, and 5% on mesangial cells at 10 min. After 60 min, 50% of silver grains were incorporated into the cytoplasm of fenestrated endothelial cells. In contrast to glomeruli, silver grains were rare on the arteries and large arterioles. However, a few silver grains were often observed on the smooth muscle cells of small arterioles (8-20 microns in diameter). In the lung, 70% of silver grains were located on the alveolar capillary endothelial cells. These results indicate the abundance of ET receptors on the glomerular fenestrated endothelium, peritubular fenestrated endothelium and alveolar capillary endothelium.

Animals↗
PubMed1992

Binding of 125I-endothelin-1 to fat-storing cells in rat liver revealed by electron microscopic radioautography.

Localization of intravenously injected [125I]-endothelin-1 was examined in rat liver by light and electron microscopic radioautography. At 10 min after injection, silver grains were localized along the sinusoidal wall, i.e., mostly on the thin processes of fat-storing cells and sinusoidal endothelial cells, and also on the Kupffer cells and the microvilli of hepatocytes. About 35% of the total silver grains were located on the processes of fat-storing cells at 10 min. The grain density (number of silver grains/cell area) of fat-storing cells was three-fold that of Kupffer cells, and 18-fold that of hepatocytes. At 60 min, 60% of the total grains were observed on the fat-storing cells, though the value of grain density was not changed. Silver grains were internalized into the cytoplasm of fat-storing cells and often associated with multivesicular bodies. In contrast, the grain density of endothelial cells and Kupffer cells decreased with time. These results indicate that hepatic fat-storing cells have a considerable number of endothelin-binding sites, and incorporate bound endothelin into cytoplasm.

Animals↗
PubMed1992

Peritoneal absorption of pancreatic enzymes in dogs.

To elucidate peritoneal absorption of pancreatic enzymes, plasma levels of amylase, lipase, and trypsinogen were measured after the intraperitoneal injection of 10 ml human pancreatic juice in dogs. Plasma pancreatic amylase, lipase, and trypsinogen were determined using the immunoassay specific to the corresponding human pancreatic enzyme to exclude cross-reaction with the endogenous enzyme activities of the canine plasma. Plasma immunoreactivity of human amylase persistently rose during 24 h after the injection, whereas elevation of plasma amylase enzyme activity become significant only at 24 h. Increase of plasma lipase was not remarkable. Significant increase of the immunoreactivity was observed only at 24 h but there was no significant increase of the enzyme activity during this period. Plasma trypsinogen immunoreactivity peaked at 2 h remained significantly elevated during 24 h. The transperitoneal absorption of pancreatic enzymes in dogs was confirmed using intraperitoneal injection of human pancreatic juice combined with immunoassay specific to human pancreatic enzymes.

Amylases↗
PubMed1992

Molecular form of pancreatic elastase 1 in human plasma.

In order to study the molecular forms of immunoreactive pancreatic elastase 1 (IRE) in human plasma, we investigated the characteristics of proelastase 1, elastase 1, and their alpha 1-protease inhibitor (alpha 1-PI) complexes on anion-exchange (Mono Q) chromatography, gel (Superose 12) chromatography, and enzyme immunoassay systems with monoclonal antielastase 1 antibodies of different affinities for alpha 1-PI-elastase 1 and alpha 1-PI-proelastase 1 complexes. The rate of complex formation between proelastase 1 and alpha 1-PI was dependent on temperature of incubation and concentration of alpha 1-PI. At 37 degrees C, 90% of proelastase 1 was bound to alpha 1-PI during 2 h of incubation of purified human proelastase 1 with human alpha 1-PI. Similar results were also obtained by 2 h of incubation of proelastase 1 with human plasma at 37 degrees C. Therefore, under physiological conditions, neither free proelastase 1 nor elastase 1 can be detected in the human blood stream, and most IRE exists as the complex of proelastase 1 with alpha 1-PI in human plasma.

Chromatography, Ion Exchange↗
PubMed1992

The effect of pituitary adenylate cyclase activating polypeptide (PACAP) on exocrine pancreatic secretion in dogs.

The effect of new hypothalamic peptides, PACAP38 and PACAP27, on exocrine pancreatic secretion was studied in five conscious dogs each with a chronic gastric fistula and a Thomas duodenal fistula. The intravenous injections of PACAP38 and PACAP27 (2.5-100 pmol/kg) induced dose-related increases in pancreatic fluid, bicarbonate, and protein secretion. The potency of PACAP27 was equal to that of VIP but was only 1/100 that of secretin; PACAP38 was less active (less than 1/10) than PACAP27. PACAP38 and PACAP27, in contrast to secretin and VIP, stimulated protein secretion; the potency of the former was about 1/10 that of the latter. The peak response to PACAP27 was about 44% of the maximal response to CCK8. Pancreatic protein secretion, but not fluid and bicarbonate secretion, in response to PACAP38 and PACAP27 was significantly (p less than 0.05) reduced by atropine. It is concluded that PACAP has a VIP-like action on pancreatic fluid and bicarbonate secretion in conscious dogs, but differs from VIP in stimulating protein secretion via a cholinergic mechanism.

Amino Acid Sequence↗
PubMed1992

Interdigestive gastric blood flow: the relation to motor and secretory activities in conscious dogs.

Blood flow in the left gastric artery was measured with an electromagnetic flowmeter in nine conscious beagle dogs. In the fasting state gastric motility and secretion exhibited periodical changes with an average cycle interval of 115.4 +/- 9.7 min. During a quiescent period, when gastric motility and secretion were minimal, the mean blood flow was stable at 33.9 +/- 3.8 ml/min. During the contracting phase each peristaltic contraction was coupled with a rapid fall and rise in blood flow (from 10.5 +/- 1.9 ml/min below to 21.2 +/- 3.8 ml/min above the precontraction levels) in 20-30 s. In addition there was a sustained elevation in blood flow (58.6 +/- 6.4 ml/min at the peak) lasting for 29.1 +/- 2.8 min. The onset of sustained blood flow elevation was preceded by that of motility in 63% of the cycles. In 23% of the cycles blood flow started to rise before the contracting phase began. Pepsin peaks coincided with blood flow peaks in two dogs and preceded the latter in the others. Feeding abolished periodic increases in motility and blood flow. It is concluded that left gastric arterial blood flow is not steady but exhibits dynamic changes in phase with periodic motor and secretory activities of the stomach in fasting conscious dogs.

Animals↗
PubMed1992

[Mutations of amyloid precursor protein in early-onset familial Alzheimer's disease].

Genetic linkage studies of familial Alzheimer's disease (FAD) have suggested that some form of early-onset FAD is linked to proximal long arm of chromosome 21. It has been also suggested that some form of late-onset FAD is linked to long arm of chromosome 19. Goate et al have identified a mis-sense mutation (Val to Ile) in exon 17 of the amyloid precursor protein (APP) gene in 2 of 16 early-onset FAD families, and have shown that the FAD locus in an FAD family is tightly linked to the mis-sense mutation. To determine if the mis-sense mutation is observed in different ethnic origine, we have studied some early-onset FAD families. Two early-onset FAD families showed the existence of the mutation. As the mutation has been identified in different ethnic origine and the mutation has not been observed in normal individuals, it strengthen hypothesis that the mutation is pathogenic. Recently, Val to Phe and Val to Gly mutations have been also identified at the same codon (Codon 717) of the APP gene.

Alzheimer Disease↗
PubMed1991

[The clinical application of multi-voxel 1H-CSI (chemical shift imaging) in brain tumors].

The 1H-Chemical shift imaging (CSI) method was developed and applied to reveal the metabolic changes in brain tumors. In the tumor, the decrease of NAA and the increase of lactate were observed by the CSI. These changes were more remarkable in the malignant tumors than in the benign tumors. The lactate was also observed in the tissue surrounding the tumors, which was supposed to be produced in the brain with hypoperfusion condition or to be leaked out from the tumor. The 1H-CSI has an advantage to demonstrate the pathophysiological changes in a wide area of the brain.

Aspartic Acid↗
PubMed1991

[Detection of A-P shunt by MR angiography].

Magnetic Resonance Angiography using a time-of-flight method was performed on two cases with arterial-portal shunting (A-P shunt). Each case was examined both with and without presaturation applied above the diaphragms. Signal intensity in the portal vein on these cases decreased with presaturation. This presaturation normally eliminates signal from inflowing spins in the artery but never effect on that in portal vein. Therefore the decrease of signal intensity in the portal vein with presaturation indicates the arterial inflow to the portal vein.

Arteriovenous Fistula↗
PubMed1991

Effect of anaerobic metabolic changes on the creatine kinase reaction in frog muscle studied by 31P saturation transfer NMR.

The effect of anaerobic metabolic changes on the flux of the creatine kinase reaction in bullfrog skeletal muscle was evaluated by 31P saturation transfer NMR. During an anaerobic time course the reduction ratio (M+/M0) of the phosphocreatine signal and the spin-lattice relaxation time measured in the presence of saturating irradiation at the ATP gamma-phosphate resonance were decreased; however, the intrinsic spin-lattice relaxation time of phosphocreatine was constant (4 s). The pseudo-first-order rate constant for the forward reaction of creatine kinase (i.e., phosphocreatine to ATP) was increased during the time course, accompanied by a decrease in phosphocreatine concentration and an intracellular acidification. However, the flux was constant (4 mmol.kg-1 wet wt.s-1) over the anaerobic time course. The fluxes analysed in several locations along the fibers, which were simultaneously measured by means of the one-dimensional chemical shift imaging technique, were almost the same along the entire length of the fibers. These results indicate that the creatine kinase reaction is at equilibrium along the entire length of the frog muscle fibers.

Anaerobiosis↗
PubMed1991

Localization of [125I]endothelin-1 in rat tissues observed by electron-microscopic radioautography.

[125I]Endothelin-1 (ET-1) was administered intravenously into rats, and binding sites in various tissues were examined by electron-microscopic radioautography. Labeling was observed predominantly on the glomerular fenestrated endothelial cells of kidney, alveolar capillary endothelial cells of lung, fat-storing cells in the sinusoids of liver, and subepithelial myofibroblasts of the small intestine. At first, silver grains were observed mostly on the plasmalemma of these cells and with time translocated into the cytoplasm of these cells. Myofibroblasts of the small intestine were cultured to study the cellular effects of ET. By fura-2 fluorescence method, transient increase and oscillation of intracellular Ca2+ level were observed in the cultured myofibroblasts following the application of ET-1 or endothelin-3 (ET-3). These results suggest that ET induces diverse physiological reactions in specific cells of various tissues.

Animals↗
PubMed1991

Effects of atrial natriuretic peptide on ischemic brain edema in rats evaluated by proton magnetic resonance method.

We examined the effect of atrial natriuretic peptide on cerebral edema in 96 rats. Forty-four rats were given 30 (n = 11), 120 (n = 26), or 150 (n = 7) micrograms/kg of the peptide intravenously over 24 hours after occlusion of the left middle cerebral artery to induce cerebral ischemia. We then measured the brain water content, the brain sodium and potassium contents, the in vitro proton nuclear magnetic resonance longitudinal (T1) and transverse (T2) relaxation times, and the area of the edematous regions. Compared with saline treatment (n = 39), peptide treatment decreased the brain water content in a dose-dependent manner and decreased the brain sodium content significantly (p less than 0.05). Peptide treatment also suppressed the lengthening of both T1 and T2 in edematous tissue (p less than 0.05 and p less than 0.01, respectively) and reduced the area of the edematous regions observed by magnetic resonance imaging (p less than 0.01). Atrial natriuretic peptide appears to have a pharmacological effect on ischemic brain edema, possibly by suppressing the elevation of water content through regulation of electrolyte transport in the brain.

Animals↗
PubMed1991

[The application of in vivo diffusion weighted magnetic resonance imaging to intracranial disorders].

We have developed a magnetic resonance (MR) spin echo method to obtain diffusion weighted imaging using motion-probing gradient (MPG) pulses in one or three orthogonal directions before and after a 180 degree pulse. Phantom models containing water and acetone, normal volunteers and patients with brain tumors, brain edema and infarction were examined. Experimental models of brain edema including triethyltin intoxication and cold injuries were also examined in Wistar rats. MRI was performed at a 1.0-T clinical machine or a 4.7-T experimental machine using spin echo pulse sequences with or without additional MPGs on one or three orthogonal axes. The one direction method was useful to define diffusion anisotropy of myelinated axonal fibers in white matter. Faster diffusion was detected in the white matter parallel to the direction of MPGs. On the other hand, slower diffusion was detected perpendicular to the direction of MPGs because the myelin sheath restricted water diffusion. The three orthogonal gradients method was useful to demonstrate the difference in the diffusion coefficients in various diseases due to its larger total gradient strength. The clear distinction between the cytotoxic edema, which revealed slower diffusion, and the vasogenic edema, which revealed faster diffusion, was demonstrated in the experimental models using diffusion weighted image. In the clinical cases, faster diffusion was demonstrated in the brain tumor and perifocal vasogenic edema, which was in agreement with the results in the experimental models of rats. Brain tumors such as low grade astrocytoma with microcysts and perifocal vasogenic edema have very wide extracellular space.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗