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Biomedical subjects

Y Higashimoto

Publications and source records attributed to Y Higashimoto.

At least 19 recordsLinked to original sources
PubMed1992

Molecular cloning of rat glucose-dependent insulinotropic peptide (GIP).

A cDNA clone encoding glucose-dependent insulinotropic peptide (GIP) was identified that consisted of 34 bp of 5' untranslated sequence, an open reading frame of 432 bp and 115 bp in the 3' untranslated region. The deduced amino acid sequence revealed a 144 amino acid preprohormone consisting of a 43 amino acid N-terminal extension including a signal peptide, a 42 amino acid hormone, and a 59 amino acid C-terminal extension. Rat GIP differs from the human hormone by two amino acid substitutions: arginine for histidine at position 18 and leucine for isoleucine at position 40. A single mRNA from small intestine of approximately 800 bases was identified on Northern blot analysis in equivalent amounts in proximal and distal small intestine.

Amino Acid Sequence↗
PubMed1992

Inhibition of mouse alveolar macrophage production of tumor necrosis factor alpha by acute in vivo and in vitro exposure to tobacco smoke.

We investigated the effects of tobacco smoke exposure on the production of tumor necrosis factor alpha (TNF alpha) by alveolar macrophages (AM) in mice (C57BL/6). The results obtained are as follows: (1) In vivo tobacco smoke exposure caused a significant decrease in the production of TNF alpha by AM with the stimulation of lipopolysaccharide (LPS; control group: 19.32 +/- 5.52 U/ml, smoked group: 4.28 +/- 0.98 U/ml; p less than 0.05). (2) In vitro exposure of AM to tobacco smoke extracts (water-soluble extracts) also caused a decrease in the production of TNF alpha up to 93% of control with stimulation of LPS (p less than 0.05) without any decrease in cellular viability. We concluded that the production of TNF alpha by AM was impaired by smoking via direct action of the factors present in tobacco smoke.

Animals↗
PubMed1992

[Efficacy of magnetic resonance imaging in treatment of neuroblastoma].

Magnetic resonance imaging (MRI) was performed in 36 children with neuroblastoma at Chiba University from 1984 through 1989, and 29 patients of them were discussed about efficacy of MRI in treatment of neuroblastoma in this paper and the results were as follows. 1) MRI was difficult to differentiate tumor from normal kidney in the image intensity and was more efficient in determining the relationship of tumor to liver and to vascular structures. 2) MRI was better than CT in detecting the size and extent of tumor mass and in identifying lymph node spread using multiple planes. 3) MRI was more efficient than CT in defining displacement and encasement of renal vessels by tumor. It was useful to predict to reserve kidney before surgery. 4) MRI was useful to monitor tumor response to combined modalities of therapy. A favorable response was seen as a change in the image intensity in bone marrow metastases of neuroblastoma.

Adrenal Gland Neoplasms↗
PubMed1991

[A case of primary intrapulmonary benign schwannoma].

A case of primary intrapulmonary schwannoma was described. A 72-year-old man was admitted to our hospital because of dry cough. A chest radiograph showed partial atelectasis of the middle lobe, but computed tomogram of the chest revealed no tumor shadow. Bronchoscopy disclosed a pale-yellow uneven endobronchial wall of the right middle lobe bronchus. Transbronchial biopsy revealed benign schwannoma. Primary intrapulmonary schwannoma has been rarely reported.

Aged↗
PubMed1990

Purification of N-terminal hexapeptide of big gastrin from human urine.

We previously demonstrated that extremely high amounts of N-terminal big gastrin (G-34) fragments are excreted in human urine and three of them are N-terminal octa-, nona-, and decapeptide of G-34. Our subsequent examination revealed that there exists a considerable amount of another N-terminal G-34 fragment in urine, less hydrophobic than the three peptides. We purified this fragment from urine of an achlorhydric patient and determined the structure: less than Glu-Leu-Gly-Pro-Gln-Gly. The purification was carried out by Sep-Pak C18 cartridges, Sephadex G-25, and reverse phase HPLC. The structure was determined by a combination of amino acid analysis, amino acid sequence analysis, and mass spectral analysis. N-terminal hexapeptide of G-34 is the second richest component of urinary N-terminal G-34 fragments next to N-terminal octapeptide of G-34 in normal subjects.

Achlorhydria↗
PubMed1990

NH2-terminal big gastrin immunoreactivity in human urine.

The concentrations and molecular forms of urinary and plasma gastrin from normal subjects were studied by radioimmunoassays using two region-specific antisera. Urinary concentration of NH2-terminal big gastrin (G-34) immunoreactivity was several hundred times as great as that of COOH-terminal gastrin immunoreactivity. Fractionation of urine extract showed a broad giant peak of NH2-terminal G-34 immunoreactivity (gastrin fragments "U") eluting in a later position than G-34(1-17) by Sephadex G-50 column chromatography. HPLC revealed that urinary NH2-terminal G-34 immunoreactivity was composed of four fragments including G-34(1-8), G-34(1-9), and G-34(1-10). Sephadex G-50 column chromatography of plasma extract revealed two or three peaks of NH2-terminal G-34 immunoreactivity, and a major peak eluted in the same position as urinary gastrin fragments "U". These results and data on renal clearances suggest that most of all gastrin fragments "U" in plasma are excreted in urine without renal reabsorption, whereas almost all of plasma COOH-terminal gastrin peptides including G-34 and little gastrin (G-17) are removed and metabolized in the kidney.

Adult↗
PubMed1990

Temporal profiles of urinary excretion of NH2-terminal big gastrin immunoreactivity in humans.

We studied the temporal profile of urinary NH2-terminal big gastrin immunoreactivity (NT G-34-IR) excretion in order to evaluate the dynamics of gastrin secretion. The temporal profile of urinary NT G-34-IR excretion in normal subjects represented three peaks corresponding to each meal. In contrast, the profile in antrectomized patients and patients under total parenteral nutrition (TPN) represented a flat pattern. Urinary NT G-34-IR excretions during fasting 2-h periods in antrectomized patients and TPN patients were about one-sixth and one-third, respectively, of basal NT G-34-IR excretion in normal subjects (53.1 +/- 13.9 pmol/h). Total urinary NT G-34-IR excretion during 24 h both in antrectomized patients (220 +/- 35 pmol/24 h) and TPN patients (390 +/- 68 pmol/24 h) was also significantly lower than in normal subjects (1985 +/- 403 pmol/24 h). The present study showed that the main source of urinary NT G-34-IR is the gastric antrum, that the main factor fluctuating its excretion is food intake, and that long-term TPN reduces basal gastrin secretion. Urinary NT G-34-IR would be a useful indicator for total gastrin secretion.

Adult↗
PubMed1990

[Usefulness of demand oxygen delivery system for patients with chronic respiratory failure due to mainly tuberculosis sequelae].

To evaluate the usefulness of a new oxymatic conserver, Demand Oxygen Delivery System (DODS), we compared DODS breathing with Standard steady flow (SF) breathing in thirteen subjects with chronic respiratory failure due to mainly tuberculosis sequelae. The value of the DODS (Oxymatic) is that it delivers oxygen only during early inspiration, so as to minimize loss from delivery during expiratory phase. Improvement of SaO2, measured by BIOX 3740, and PaO2 were observed at rest and on exercise. The oxygen consumption ratio of the DODS to the SF method was between 0.5 and 0.3, favoring the DODS over the SF method. In some patients DODS hardly ran at rest. But no problems are observed during exercise. The results indicate the effectiveness of DODS in advancement of quality of life patients with chronic respiratory failure.

Aged↗
PubMed1990

A possible indicator of urinary NH2-terminal big gastrin immunoreactivity for gastrin secretion.

Urinary and plasma gastrin immunoreactivities in normal subjects were studied by radioimmunoassays using three region-specific antisera. Urinary excretion of NH2-terminal big gastrin immunoreactivity (NT G-34-IR) in the fasting state (0.79 +/- 0.17 pmol/kg/h, mean +/- SE) was several hundred times as much as that of either COOH-terminal gastrin or gastrin/cholecystokinin immunoreactivity. Urinary NT G-34-IR increased significantly after feeding, and correlated closely with integrated plasma NT G-34-IR. Renal clearance of NT G-34-IR was 62.4 +/- 7.9 ml/min and about one hundred times greater than that of any other gastrin immunoreactivities, indicating that there exist different catabolic pathways of gastrin peptides in the kidney. Gel filtration of urine extract revealed that a single giant peak of NT G-34-IR eluted in a later position than NH2-terminal heptadecapeptide of big gastrin. These results suggest that most of plasma NT G-34-IR is excreted in urine, and urinary excretion of NT G-34-IR reflects well-integrated plasma NT G-34-IR. Therefore, urinary NT G-34-IR may serve as a feasible indicator for gastrin secretion.

Adult↗
PubMed1989

Purification and structural determination of urinary NH2-terminal big gastrin fragments.

We previously demonstrated that there existed extremely abundant NH2-terminal big gastrin immunoreactivity (NT G-34-IR) in human urine. This report describes the purification and sequence of NT G-34-IR from the urine of an achlorhydric patient. The purification was carried out by a combination of Sep-Pak C18 cartridges, Sephadex G-25, and HPLC steps using a radioimmunoassay specific for NH2-terminus of G-34 and ultraviolet absorption at 214 nm as monitors. Three peptides were isolated. The amino acid analysis, mass spectrometry, and sequence analysis confirmed the structures of urinary NT G-34 fragments being less than Glu-Leu-Gly-Pro-Gln-Gly-Pro-Pro, less than Glu-Leu-Gly-Pro-Gln-Gly- Pro-Pro-His, and less than Glu- Leu-Gly-Pro-Gln-Gly-Pro-Pro-His-Leu. NH2-terminal octapeptide of G-34 was the main component of urinary NT G-34-IR.

Achlorhydria↗
PubMed1988

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↗
PubMed1987

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↗
PubMed1985

Changes in serum levels of pancreatic isoamylase, lipase, trypsin, and elastase 1 after endoscopic retrograde pancreatography.

To compare the behavior of pancreatic enzymes in the circulation, serum levels of pancreatic isoamylase activity, lipase activity, immunoreactive trypsin (IRT), and immunoreactive elastase 1 (IRE) were measured in the same serum samples taken serially from 29 subjects undergoing endoscopic retrograde pancreatography (ERP). A striking correlation between the maximal increments of serum pancreatic enzyme levels after ERP and the degrees of opacification of pancreatic duct system was observed, except in 6 subjects with chronic pancreatitis. In 13 out of 19 subjects whose main pancreatic duct (MPD) and branches were opacified, serum pancreatic enzyme levels reached a peak within 2 hours after ERP and decreased thereafter. The mean maximal rise of serum levels of lipase, IRT, pancreatic isoamylase, and IRE in the 13 subjects was 32, 21, 10, and 4 times the basal value, respectively. A delay of peaking in serum levels of pancreatic isoamylase and IRE as compared with those of lipase and IRT was observed in the 13 subjects. The mean disappearance half-time of serum lipase, IRT, pancreatic isoamylase, and IRE in the 13 subjects was 2.8, 4.6, 8.0 and 16.0 hours, respectively.

Adolescent↗
PubMed1985

Marked prolongation in disappearance half-time of plasma cholecystokinin-octapeptide in patients with hepatic cirrhosis.

For exploration on the elimination of cholecystokinin from the circulation, the disappearance half-time of cholecystokinin-octapeptide was estimated with cholecystokinin specific radioimmunoassay in normal subjects and patients with chronic renal failure and with hepatic cirrhosis. With a brief infusion of 30.4 ng/kg of cholecystokinin-octapeptide for 2 min, plasma cholecystokinin level rose from 16.1 +/- 3.6 pg/ml (mean +/- SE) to 216.5 +/- 6.1 pg/ml at 3 min after starting infusion, and decreased rapidly in a single exponential fashion for 10 min in hepatic cirrhosis. The disappearance half-time of cholecystokinin-octapeptide in patients with hepatic cirrhosis was 2.45 +/- 0.07 min, and it was significantly longer than that in normal subjects (1.30 +/- 0.07) or patients with chronic renal failure (1.70 +/- 0.11). These findings suggest that the liver plays a major role in cholecystokinin-octapeptide elimination in humans.

Adult↗