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Biomedical subjects

A Shigematsu

Publications and source records attributed to A Shigematsu.

At least 109 records · Page 6Linked to original sources
PubMed1992

[Autoradiography for drug metabolism and pharmacokinetics study].

Since Ullberg presented a macroautoradiograph showing the distribution of 35S-benzylpenicillin in rats by use of a commercial X-ray film in 1954, anything besides X-ray film has never been used for macroautoradiography. In the minireview a new type of radiation sensor, "Imaging Plate" (IP), is introduced as a useful sensor as a sensor that is more useful than previous ones. The IP is a photo-stimulable phosphor that can trap and store the radiation energy quantitatively. About 100 times higher sensitivity than any of ordinary X-ray films and very precise quantitativeness are demonstrated by many results reported recently. Simple procedures are herein presented with a few demonstrative examples of macro- and microautoradiography.

Animals↗
PubMed1992

[Plasma levels of alpha-human atrial natriuretic peptide, renin activity and angiotensin II in partial hepatectomy].

Plasma levels of alpha-human atrial natriuretic peptide (alpha-hANP), renin activity and angiotensin II were studied in 17 patients undergoing partial hepatectomy. Central venous pressure (CVP), heart rate (HR), mean arterial pressure (MAP) and the serum sodium concentration (Na), which affect plasma ANP levels, were measured during the operation. At 90 minutes after the surgical incision, plasma alpha-hANP levels increased significantly from 38.6 +/- 4.02 pg.ml-1 to 62.7 +/- 8.24 pg.ml-1, but the changes in plasma alpha-hANP levels during the surgery were within normal levels. Plasma alpha-hANP levels were not related to changes in CVP, HR and Na. At 90 minutes after the incision when plasma alpha-hANP levels were elevated, plasma renin activity, angiotensin II and MAP also increased significantly. Therefore, we believe that activation of the sympathetic nervous system by surgical stimulation is one of the causes of the elevation of alpha-hANP levels during the operation. The increase in plasma alpha-hANP levels, however, was lower than those of the plasma renin activity and angiotensin II. Our results suggest that surgical stimulation acts to retain sodium and water in patients during partial hepatectomy.

Angiotensin II↗
PubMed1991

Temporal distribution of retinoic acid and cellular retinoic acid-binding protein (CRABP) in the fetal hamster.

The temporal relationship between the distribution of retinoic acid, a known human and rodent teratogen, and that of cellular retinoic acid-binding protein (CRABP) was investigated from Day 11 to Day 14 of hamster prenatal development. The 11,12-(3)H2 and 15(-14C) forms of all-trans-retinoic acid were used for quantitative distribution studies and autoradiography, respectively, and were evaluated 15 min after a single intravenous injection. Radioactivity was detected in all fetal tissues examined (brain, liver, heart, spinal cord, limb, and skin), and at Day 14, approximately 66% of the total radioactivity was present as parent all-trans-retinoic acid. High concentrations of total radioactivity were observed by autoradiography in the midbrain and hindbrain (mesencephalon, metencephalon, and myelencephalon) and spinal cord, but not in the forebrain. At the earliest time studied, limb buds showed relatively high concentrations of radioactivity. Levels of radioactivity were also high in portions of the developing face, nose, and tongue. Immunohistochemical analyses indicated that the amount of CRABP in Day 14 tissues was the highest in spinal cord followed by limb and skin; heart and liver contained only relatively small amounts of this protein. From Day 11 to Day 14, the amount of CRABP, as measured by high-performance size-exclusion liquid chromatography, in the whole body decreased as gestation progressed. Microscopic immunohistochemical localization of CRABP found the highest concentration in the ventral midbrain and in the ventral and lateral sides of the hindbrain and spinal cord; CRABP was also abundant in tongue, limb, and skin. The distribution of CRABP-positive cells in the central nervous system was similar to the distribution of retinoic acid. The data presented here indicate that fetal CRABP appears to play a role in differential accumulation of retinoic acid in certain structures of the developing hamster. The patterns of tissue retinoid and CRABP distribution observed here are consistent with the patterns of congenital malformations induced by prenatal retinoid exposure.

Animals↗
PubMed1991

Electrochemical detection of viable bacteria in urine and antibiotic selection.

An electrode system consisting of a basal-plane pyrolytic graphite (BPG) electrode and a porous nitrocellulose membrane filter to trap bacteria was used for the detection of bacteria in urine. The peak current of a cyclic voltammogram increased with increasing initial cell concentration of Escherichia coli in urine. Urine containing from 5 x 10(2) to 5 x 10(5) cells ml-1 was measured with this system. The susceptibility of bacteria to various antibiotics was also determined from the peak current. The minimum inhibitory concentration values obtained by the electrochemical method were in good agreement with those obtained by the conventional method.

Anti-Bacterial Agents↗
PubMed1991

Enhancement of lipopolysaccharide-induced tumor necrosis factor production in mice by carrageenan pretreatment.

Tumor necrosis factor (TNF) is a cytokine which mediates endotoxin shock and causes multiple organ damage. It is thought that macrophage (MP) activation is necessary to increase lipopolysaccharide (LPS)-induced TNF production and lethality. Carrageenan (CAR) is sulfated polygalactose which destroys MP; it is used as a MP blocker. We found that CAR pretreatment can increase both endotoxin-induced TNF production and the mortality rate in mice. The ddY mice (7 to 8 weeks old) were injected intraperitoneally with CAR (5-mg dose) and challenged intravenously with LPS 24 h later. Without CAR pretreatment, LPS doses of less than 10 micrograms did not induce TNF in sera. After pretreatment, however, about 3 x 10(3) to 4 x 10(4) U of TNF per ml was produced after LPS injection at doses of 0.1 to 10 micrograms, respectively. TNF production was significantly increased by CAR pretreatment at LPS doses of more than 10 micrograms. CAR pretreatment rendered the mice more sensitive to the lethal effect of LPS; 50% lethal doses of LPS in CAR-pretreated mice and nonpretreated mice were 26.9 and 227 micrograms, respectively. The mortality of the two groups was significantly different at doses of 50, 100, and 200 micrograms of LPS. CAR increased LPS-induced TNF production and mortality within 2 h, much earlier than MP activators, which needed at least 4 days. Our results made clear that TNF production is enhanced not only by a MP activator but also by a MP blocker.

Animals↗
PubMed1990

The changes in arterial keton bodies during upper abdominal surgery.

The relationship between the arterial keton body ratio (AKBR: acetoacetate/Beta-hydroxybutyrate) and the plasma hormone activities were studied under a general anesthesia using enflurane group (group G) and a GO + Epidural group (group E) with continuous glucose loading (10 g.hr(-1)) during partial gastrectomy. In both groups, the AKBR increased significantly during the operation. The plasma insulin activity was significantly positively correlated with the AKBR and it was negatively correlated with log (Beta-hydroxybutyrate) in both groups. We could not find any significant difference of the AKBR between group G and group E. Our results indicate that the plasma insulin activity affects the arterial keton body ratio and that the AKBR must be evaluated considering the plasma hormone activity, especially insulin activity during the operation.

Journal Article↗
PubMed1990

[Mesenteric hematoma; a pediatric case].

A 3-Year-old girl was admitted to National Beppu Hospital due to abdominal mass. US examination revealed cystic mass with multiple scattered nonreverberatory echoes in right upper abdomen. CT examination revealed almost homogeneous mass (29-31 H.U.) with a few internal components (36-42 H.U.). US and CT were useful methods for diagnosis of mesenteric hematoma.

Child, Preschool↗
PubMed1990

[Clinical study of arterial ketone body ratio (ACAC/beta-OHCS) during hepatectomy].

The changes in arterial ketone body ratio (acetoacetate/beta-hydroxybutyrate) were investigated in 7 patients undergoing hepatectomy under epidural anesthesia with nitrous oxide and oxygen. The plasma levels of glucose, insulin, glucagon, lactate, pyruvate and non-esterified free fatty acid (NEFA) were measured during the operation. The plasma level of insulin activity increased significantly during surgery. The secretory capability of insulin against glucose load was relatively preserved. Arterial ketone body ratio also increased during the operation. The plasma insulin activity was positively correlated significantly with the arterial ketone body ratio (Y = 0.98 + 0.76X; r = 0.76). Both lactate and pyruvate increased significantly during surgery. No remarkable changes of L/P ratio reflecting the redox state in cytoplasma were found in both groups. Our results suggest that the quantity of glucose load and insulin activity should be considered when arterial ketone body ratio is measured during the operation.

Aged↗
PubMed1990

[The effect of glucose loading on changes in ketone and glucose metabolism during gastrectomy].

Plasma glucose, insulin, glucagon, free fatty acid, ketone body, lactate and pyruvate were measured in 14 patients undergoing gastrectomy under general anesthesia with nitrous oxide and oxygen. Lactated ringer solution with glucose load (10 g.hr-1) was administered in seven patients [glucose loading group: Glucose (+)] and the other seven patients received only lactated ringer solution [glucose free group: Glucose (-)]. Blood glucose increased significantly in both groups, but a significant difference appeared between Glucose (+) and Glucose (-). Plasma insulin activity and IRI/BS ratio increased in Glucose (+) and a significant difference was found between the two groups. No remarkable change in plasma glucagon level was found in both groups. Free fatty acid and ketone bodies (acetoacetate, beta-hydroxybutyrate) decreased significantly in Glucose (+), but they increased significantly in Glucose (-) and significant differences were found between the two groups. The rate of changes of beta-hydroxybutyrate was consistently higher than that of acetoacetate. Lactate and pyruvate increased significantly in both groups. These results suggest that continuous glucose loading may facilitate insulin release from the pancreas and suppress the hyperketonemia and hyperlipidemia during partial gastrectomy.

Blood Glucose↗
PubMed1989

Detection of rat basophilic leukemia by cyclic voltammetry for monitoring allergic reaction.

Electrochemical detection of the rat basophilic leukemia (RBL-1) cells has been carried out by applying cyclic voltammetry. The detection system consists of a basal plane pyrolytic graphite electrode and a porous nitrocellulose membrane filter to trap RBL-1 cells. When the potential of the graphite electrode was run in the range of 0-1.0 V vs SCE, RBL-1 cells gave peak currents at 0.34 V vs SCE as well as 0.65 V vs SCE. There is a linear relationship between the peak current at 0.34 V vs SCE and the cell numbers of RBL-1. In the range of (0.4-2.0) X 10(5) cells. The peak current of RBL-1 cells was attributed to serotonin. When dinitrophenylated bovine serum albumin (DNP-BSA) as a model allergen was added to RBL-1 cells sensitized with anti-DNP IgE, the peak current decreased because of the degranulation of RBL-1 cells leading to serotonin release. On the other hand, RBL-1 cells sensitized with anti-DNP IgE did not respond to egg white, pollens, house dust, and milk.

Allergens↗
PubMed1989

Spontaneous regression of primary malignant lymphoma of the stomach in two nontreated Japanese.

Two patients with primary malignant lymphoma underwent spontaneous regression. One was a 40-year-old woman with a large ulcerating tumor on the greater curvature of the gastric antrum. This tumor shrank spontaneously, leaving only a small shallow ulcer. The resected specimen showed a minute focus of malignant lymphoma in the ulcer base. The other was a 73-year-old man who had a tumor with central ulceration on the posterior wall of the gastric antrum. Endoscopic biopsy revealed a malignant lymphoma. This tumor disappeared 60 days later. The patient refused surgery and remains well with no evidence of recurrent disease at this writing, 44 months later. Although there have been several case reports of spontaneous regression, partial or complete, of gastric malignant lymphoma, our cases seem to be the ones best proven.

Adult↗
PubMed1989

[Spinal anesthesia of only one lower extremity with hypobaric tetracaine].

For spinal anesthesia of only one lower extremity, effect factors, assumed to influence the level of anesthesia including the degree of head-down position of the patients during injection, the volume of the drug and the rate of its injection, are studied using 0.2% hypobaric tetracaine solution in water. Seventy-two patients having the surgery of one lower extremity were divided into 7 groups according to the difference in the degree of head-down position (0, 2 and 5 degrees), in the volume (3, 5 and 7 ml) and the rate (0.2, 0.1 and 0.05 ml.s-1) of injection of tetracaine solution. Patients, in lateral position with the operative side up during injection and 20 minutes after injection, were checked for the level of hypesthesia and analgesia on both operative side and non-operative side. Except 2 groups of the patients who were in horizontal position during injection or who are injected with 7 ml of tetracaine solution all at once, the upper level of analgesia in the operative side is well controlled at T10, although in some patients the additional injection of small amount of tetracaine solution was needed. In these patients, the analgesic level in the non-operative side is restricted within S level, and HR and BP changes were very slight. The rate of injection had no effect on the analgesic level on both operative side and non-operative side.

Adolescent↗
PubMed1988

Endoscopic diagnosis of lymphangioma of the small intestine.

In three patients with lymphangioma of the small intestine, the preoperative diagnosis of lymphangioma was made by endoscopy with biopsy and radiology. A typical endoscopic finding was an elevated polypoid tumor, yellowish-white to tan. The surface was smooth, often with white specks, and could be impressed by touching lightly with biopsy forceps. Endoscopic examination revealed satellite lesions not detected radiologically. Lymphangioma has heretofore been successfully diagnosed preoperatively by endoscopy in the duodenum. This report of accurate preoperative diagnoses of lymphangioma in the small intestine, other than the duodenum, using endoscopy, may be the first to be documented.

Aged↗
PubMed1987

Clinical study of glucose metabolism during partial gastrectomy--comparison between epidural and general anesthesia.

Plasma glucose, insulin, glucagon, growth hormone (GH) and cyclic-AMP (C-AMP) were measured in 14 patients undergoing partial gastrectomy under 5 g/hr glucose loading. Seven patients received general anesthesia (GOF; Group G) and the other seven, GO + epidural anesthesia (analgesia Th4-L1; Group E). Blood glucose increased in both groups, although it remained consistently lower in Group E than in Group G. Serum IRI and IRI/glucose ratio appeared consistently higher in Group E than in Group G and a significant difference was found between the two groups at the early period of surgery. The changes in plasma glucagon and GH were found independent of those in glucose. Cyclic-AMP was also consistently higher in Group G than in Group E and a significant difference was observed at the end of anesthesia. These results suggest that epidural anesthesia with 5 g/hr glucose loading may facilitate insulin release from the islet and peripheral blood uptake particularly during the early period of surgery while many other factors such as GH, cortisol and vagal stimulation seemed to be involved in the later period of surgery.

Journal Article↗
PubMed1987

Increased arachidonic acid composition of phospholipids in colonic mucosa from patients with active ulcerative colitis.

The long chain fatty acid composition of phospholipids in colonic mucosa was determined by high performance liquid chromatography in nine patients with active ulcerative colitis and eight healthy controls. The arachidonic acid composition was 12.5 +/- 1.4 mol % (mean +/- 2 SEM) in the inflamed colonic mucosa from the patients with active ulcerative colitis and 6.8 +/- 1.2 mol % in the intact mucosa from healthy controls (p less than 0.001). In the inflamed colonic mucosa, oleic acid and palmitoleic acid were concomitantly decreased (p less than 0.001 and p less than 0.02, respectively), while docosahexaenoic acid was increased (p less than 0.05). Histopathological examination showed that there was a three fold increase in the cell density of inflammatory infiltrate in the lamina propria of the inflamed colonic mucosa (p less than 0.001). The cell density of inflammatory infiltrate correlated with the arachidonic acid composition of phospholipids in colonic mucosa (r = 0.89, p less than 0.005). These findings indicate that inflammation alters the long chain fatty acid composition of phospholipids in colonic mucosa. The observed increase in the arachidonic acid composition of phospholipids in inflamed colonic mucosa may contribute to the enhanced arachidonic acid metabolism in patients with active ulcerative colitis.

Adolescent↗