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Biomedical subjects

S Himeno

Publications and source records attributed to S Himeno.

At least 73 records · Page 4Linked to original sources

Changes in plasma active renin and prorenin after endoscopic retrograde pancreatography.

Plasma active renin, total renin (active renin plus prorenin) and immunoreactive trypsin were measured simultaneously before and after endoscopic retrograde pancreatography (ERP) in 9 subjects suspected of having pancreatic or biliary disease. After ERP, their plasma immunoreactive trypsin level increased significantly (p less than 0.02) from 12.4 +/- 1.5 to 163 +/- 57 ng/ml (means +/- SEM), while their plasma renin activity, total renin activity and ratio of active renin to total renin did not change. Individual values for the ratio of active renin to total renin correlated significantly (p less than 0.01) with those for immunoreactive trypsin in the basal condition (before ERP), but not after ERP. These results suggest that plasma trypsin is involved in activation of prorenin to active renin in the basal condition, and that ERP-induced increase in plasma trypsin has no effect on activation of prorenin.

Blood Pressure↗

Marked secretion of pyruvate in human duodenal juice stimulated with pancreozymin or secretin.

Pyruvate and lactate in duodenal aspirates were investigated to determine whether they are excreted from human pancreas as substrates for alkaline secretion as is bicarbonate. Secretion of these acids was compared with that of another organic acid, citrate, which is thought to be excreted in close relationship to digestive enzymes. All acids were assayed in the fluid obtained from 11 subjects without pancreatic diseases, before and after sequential intravenous injections of 1 unit/kg pancreozymin and 1 unit/kg secretin. Pyruvate concentrations were markedly increased by each stimulation, especially by secretin, and the cumulative excretions of pyruvate and bicarbonate after secretin stimulation were significantly correlated among the subjects. In contrast, lactate concentrations, although high just after administration of pancreozymin, declined to a considerable extent following each injection, rather similar to those of protein or citrate. These data suggest that pyruvate may be secreted from human pancreatic duct cells similar to bicarbonate secretion through mechanisms related to alkaline secretion.

Adult↗

Prostaglandin D2 diminishes transmucosal potential difference in rat colonic mucosa in vitro in contrast to the increasing effect of prostaglandin E1.

The effect of Prostaglandin D2 (PGD2) on ion transport was investigated in the rat colon in vitro. Ion transport across the intestinal mucosa was estimated by transmucosal potential difference (PD) and short circuit current (Isc) in the Ussing chamber. PGD2 added to the serosal reservoir induced a sustained reduction in PD and Isc at the concentration of higher than 10(-7)M, producing the maximal decrease at 10(-5)M. PGD2 at 10(-5)M completely blocked the increase in PD elicited by prostaglandin E1 (PGE1), theophylline, dibutyryl cAMP or serotonin. Adenylate cyclase activity was determined in the colonic mucosal homogenates after addition of PGD2 and PGE1. Treatment with PGD2 or PGE1 caused a significant increase in the enzyme activity. Combined treatment with both prostaglandins induced no more increase than that elicited by PGE1 alone. These results suggest that PGD2 has an anti-secretory effect on the rat colon and it may regulate the ion transport process through other mechanism than the modification of cyclic AMP concentration in mucosal cells.

Adenylyl Cyclases↗

Lunch induces an increase in the plasma prolactin concentration, but not vasoactive intestinal peptides or cholecystokinin.

Ingestion of lunch is known to be associated with acute release of prolactin (PRL). The neuroendocrine mechanism of this release was examined by measuring changes in serum vasoactive intestinal peptides (VIP) and cholecystokinin (CCK) after the noon meal in six normal men. The serum PRL concentration was significantly increased (40% above the level before lunch) from 30 min to 1 h 45 min after beginning to eat. However, the ingestion of lunch had no remarkable effects on the plasma immunoreactive concentration of VIP and CCK. Thus the changes in the plasma concentration of these two gut-brain peptides did not coincided with acute PRL release after ingestion of lunch, suggesting either that these two gut-brain peptides are probably not involved in PRL release after lunch, or that the level of these two gut-brain peptides in the general circulation may not represent that in the hypophyseal portal plasma.

Adult↗

Plasma cholecystokinin-octapeptide like immunoreactivity in patients with hepatic cirrhosis.

Molecular forms of cholecystokinin (CCK) in the peripheral circulation were studied in normal subjects and cirrhotic patients. Fractionation of plasma extract collected 20 min after intraduodenal infusion of fat revealed four major peaks by Sephadex G-50 column chromatography in normal subjects. Peak I eluted at a position similar to CCK-33, peaks II and III eluted between CCK-33 and CCK-14, and peak IV eluted between CCK-14 and CCK-8. In cirrhotic patients, there was a prominent peak (peak V) eluted at a position similar to CCK-8, in addition to those four peaks. These findings are consistent with the previous observations of hepatic elimination of CCK-8, and suggest that smaller forms of CCK similar in size to CCK-8 are not major forms of CCK in plasma in normal subjects but circulate substantially in cirrhotic patients.

Cholecystokinin↗

Effect of synthetic trypsin inhibitor on plasma immunoreactive cholecystokinin in rats.

A sensitive and specific radioimmunoassay system for rat plasma cholecystokinin (CCK) was employed to study the effect of trypsin inhibitor on plasma CCK levels. Feeding the trypsin inhibitor, FOY-305 200 mg/kg, to rats for 10 days stimulated the pancreatic growth. However, there was no significant difference in fasting plasma concentrations and duodenal contents of CCK and secretin. On the other hand, acute ingestion of same dosage of FOY-305 caused a marked (20-fold) and sustained elevation of plasma CCK levels. The principal form of circulating CCK was CCK-22 like on Sephadex G-50, in contrast to that of the cerebrum and duodenum where CCK-8 like form, or CCK-8 and CCK-22 like forms were main components, respectively. A significant rise in plasma levels of immunoreactive secretin was also found. These results suggest that the pancreatic growth observed by feeding the trypsin inhibitor to rats is caused by an excessive amount of CCK in conjunction with secretin.

Animals↗

Revision of consensus sequence of human Alu repeats--a review.

Nucleotide sequences of 50 human Alu repeats and their flanking regions are presented together with the consensus sequence based on the literature and our findings. The results indicate the need for some revisions of the Alu consensus sequence published by Deininger et al. (1981). Most nucleotide substitutions among the Alu members are transitions, rather than transversions. The Alu sequence seems to consist of 'conserved' regions and 'variable' regions. The conserved regions consist of a 25-bp region between nt positions 23 and 47 and a 16-bp region between nt positions 245 and 260. The 16-bp region corresponds to the region of 7SL RNA that is claimed to fold and become paired with the internal promoter sequence. Two A-rich regions, one located at the right end of the first monomer and the other at the right end of the second monomer, are variable. No defined property was found with direct repeats flanking the Alu repeats.

Base Sequence↗

Transient hyperphagia after sodium selenite injection in mice.

Injection (s.c.) of Na2SeO3 (SS, 20-30 mumol/kg) into male mice initiated eating, which began about 20 min after injection and continued for about 3 h. This initiation effect was observed for mice of different ages and at different times of the day. Other findings of this study were: (1) early morning injection (30 mumol/kg) caused increased food intake, as examined by gastric content 3 h after injection, compared to daytime injection; and (2) SS-induced transient hyperphagia was observed at ambient temperatures of 10 and 22 degrees C, but not at 37 degrees C. This paper discusses these results in relation to SS-induced hypothermia.

Animals↗

Mercury-selenium interaction in workers exposed to elemental mercury vapor.

Mercury (Hg) and selenium (Se) levels were determined for erythrocytes, plasma and urine of 25 male and 29 female workers exposed to elemental mercury (Hgo) vapor. Interrelationship between the Hg levels and the Se levels was examined by the correlational analysis and the stepwise regression analysis. Indicators of Se status (erythrocyte Se levels, plasma Se levels and urinary Se levels) were closely intercorrelated; similarly, indicators of exposure to Hgo vapor (erythrocyte inorganic Hg levels, plasma Hg levels and urinary Hg levels) were significantly intercorrelated. Since plasma Hg level was one of the significant independent variables in determining the erythrocyte Se and plasma Se levels, Hgo vapor exposure was thought likely to influence the Se metabolism in workers. None of the Se status indicators were significant as determinants of the indicators of Hgo vapor exposure.

Adult↗

Elemental composition of ancient Japanese bones.

Excavated bones (rib) obtained from 50 sites in Japan were measured by ICP atomic emission spectrometry and atomic absorption spectrometry for concentration of 19 elements, including Al, B, Ca, Cd, Cr, Co, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, V and Zn. One hundred and forty-one specimens were classified into five groups according to Japanese prehistoric and historic eras (Jomon, Yayoi, Kofun, Kamakura and Muromachi, and Edo). The elements, with concentrations which showed no significant change with era were Al, B and Cr. Average concentrations of Ca were in the range 2-2.5 X 10(-1) g g-1 and those of P ranged from 1.1 to 1.3 X 10(-1) g g-1, indicating a well-preserved bone mineral matrix. The Ca/P ratio (mol/mol) was lowest in the Edo group--1.48 as compared with 1.54-1.66 in the other groups. Among the elements which showed changes with era were Pb, Fe, Co and Mn, all of which showed remarkably elevated concentrations in the Edo group. In addition to this unique elemental composition of Edo bones, samples from the Kofun era showed a completely different composition from those of other periods, i.e. they had the highest concentrations of Cd, Zn and Mg, and the lowest concentrations of Cu, K, Ni and Sr. The cause of the elevated Pb concentration in Edo bones is discussed in relation to human activities which may have led to environmental Pb pollution.

Bone and Bones↗

The relationship of the increased level of metallothionein with heavy metal levels in the tissue of the harbor seal (Phoca vitulina).

The relationship between age, heavy metal levels, and a heavy-metal binding protein, metallothionein (MT), in the liver and kidney of the harbor seal (Phoca vitulina) was studied. The cadmium (Cd) level in the liver and the Cd, inorganic mercury (I-Hg), and zinc (Zn) levels in the kidney were increased with body length, suggesting an age-related accumulation of these metals. The MT levels determined by an MT radioimmunoassay showed concentrations of 240 +/- 139 micrograms/g in the liver and 343 +/- 219 micrograms/g in the kidney. These MT levels were shown to be correlated with age. The statistically significant relationship of the MT levels with the levels of Cd and Zn in the liver and those of Cd, Zn, and I-Hg in the kidney suggested that the protein is responsible for the sequestration of these metals as already observed in terrestrial animals.

Animals↗

Expression of human gastrin gene in normal and gastrinoma tissues.

The complete sequence of the human gastrin gene is reported here. This gene consists of three exons. Nine Alu family sequences are found within the gene and in the surrounding region. S1 mapping study showed that the transcription of gastrin gene starts at 60, 57, or 55 bp upstream from the 3' end of the first exon. The mechanism of mRNA synthesis in a gastrinoma tissue was studied to clarify the ectopic production of gastrin. It was found that mRNA synthesis starts from the same three transcriptional start points. Southern blotting profiles for normal gastric antrum and gastrinoma DNA were indistinguishable from each other within the 18-kb region containing the gastrin gene, showing that no genomic rearrangements are associated with the gastrinoma formation. Thus, the overproduction of gastrin in this tumor is likely to be due to an aberrant expression control system of the cell, rather than a change in the control region of the gastrin gene.

Amino Acid Sequence↗

Secretion of pyruvate and lactate in pancreatic juice induced by acetazolamide or secretin.

In vivo studies using pentobarbital sodium-anesthesized dogs were performed to investigate whether a transport pathway for pyruvate and lactate is present in the exocrine pancreas. Concentrations of both acids were measured in peripheral blood and pancreatic juice before and after intravenous 15-min administration of 2.25 mmol/kg DL-lactate, superimposed on continuous intravenous infusion of 3 U X kg-1 X h-1 secretin. The concentration ratio of lactate to pyruvate in pancreatic juice was found to be approximately 1, a lower value than found in other tissues or body fluids. D-lactate, not detected in either blood or juice during basal periods, rapidly appeared in both fluids in parallel with the physiological isomer L-lactate, after the infusion of DL-lactate. Further addition of acetazolamide or a high dose of secretin caused a marked secretory response of pyruvate and lactate with no increase in juice bicarbonate levels. We conclude that these acids can be transported from blood to lumen when the transmembrane pH gradient across the duct cell membranes is augmented by stimulants via a proton pump mechanism involving a CO2-HCO3-buffer system.

Acetazolamide↗