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Biomedical subjects

R Doi

Publications and source records attributed to R Doi.

At least 109 records · Page 6Linked to original sources
PubMed1991

[A case of lead neuropathy--importance of subclinical entrapment of nerves in lead neuropathy].

The patient was a left handed 25-year-old man who had worked in a vinyl chloride resin factory since July 1987 using lead stearate as a stabilizer. During the two years preceding hospitalization, he had been admitted three times for colicky abdominal pain with constipation and nausea. Anemia and proteinuria without causative diseases were pointed out. Because of progressive muscle weakness of hands which began since January 1989, he was admitted to our neurologic clinic on October 2 1989. Neurological examination showed severe atrophy of both small hand muscles without sensory disturbances. Left hand was predominantly affected, especially in interossei muscles. Laboratory findings are as follows; RBC 3.25 million/cu.mm: Hb 9.7 g/dl:blood lead concentration 100 micrograms/dl: urinary coproporphyrin 4503 micrograms/l: urinary delta-ALA 138 mg/l: and urinary lead excretion after 1 g CaEDTA infusion: 3938 micrograms/day. Electromyography of extensor carpi radialis, flexor carpi ulnaris and opponens showed increased polyphasic, long duration MUPs. Electromyography of dorsal interossei showed fibrillation. Nerve conduction study showed mildly decreased motor and sensory conduction velocities and markedly reduced amplitude of compound muscle action potentials (CAMPs). Investigation by inching method revealed conduction block of left ulnar nerve across elbow. After CaEDTA chelating therapy, 1 g once a week, steady improvement of muscular weakness was observed within a few months. Serial nerve condition studies revealed constant recovery of nerve conduction velocities, amplitude of CMAPs and diminution of conduction block across the left elbow. Conduction block across left elbow without sensory disturbances implies that subclinical cubital tunnel syndrome might have existed in this patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Receptor binding of cholecystokinin analogues in isolated rat pancreatic acini.

The receptor binding of CCK analogues was determined in terms of the inhibition of [125I]CCK binding in isolated rat pancreatic acini. The inhibition curve produced by CCK-8 showed the same feature as that produced by synthetic human CCK-33. The relative potency values of CCK analogues to half-maximally inhibit specific CCK binding were calculated; CCK-8 was equal to human CCK-33, 3-fold stronger than natural porcine CCK-33 and 39, and 700-fold stronger than the unsulphated form of synthetic human CCK-33. Our data suggest that CCK-33, one of the longer molecular forms of CCK, is as important as CCK-8 in the mechanism of physiological actions of CCK.

Animals↗
PubMed1990

Effect of human epidermal growth factor (hEGF) on splanchnic circulation in dogs.

The effect of intravenous administration of human epidermal growth factor on the splanchnic blood flows was examined in anesthetized dogs, using an ultrasonic transit-time volume flow meter. Human epidermal growth factor (0.1, 0.5 and 1 microgram/kg) significantly increased blood flows in the portal vein (36.9 +/- 7.4% at 1 microgram/kg) and the superior mesenteric artery (49.0 +/- 16.8% at 1 microgram/kg). Systemic blood pressure monitored simultaneously was significantly decreased (8.4 +/- 1.2% at 1 microgram/kg). This study is the first to demonstrate that intravenous administration of epidermal growth factor increases the portal venous blood flow.

Animals↗
PubMed1990

Effect of synthetic human cholecystokinin-33 on pancreatic blood flow in dogs.

We have examined the effect of synthetic human cholecystokinin (CCK-33 and CCK-8) on pancreatic blood flow and protein output in anesthetized dogs. Human CCK-33 and CCK-8 increased pancreatic blood flow and protein output in a dose-related manner. There were no significant differences in increasing pancreatic blood flow between human CCK-33 and CCK-8, and increases in blood flow were closely related to the increase of the pancreatic enzyme secretion. L-364,718 (20 nmol/kg) caused a potent inhibition of CCK-stimulated pancreatic blood flow as well as protein output. The degree of inhibition by L-364,718 was dependent on the amount of CCK infused. This study demonstrates that increasing effect on pancreatic blood flow may be one of the biological actions of CCK mediated via CCK receptor. The CCK-33, one of longer molecular forms of CCK, is an important biological stimulator of pancreatic blood flow as well as of exocrine pancreatic secretion.

Animals↗
PubMed1990

Measurement of splanchnic circulation in dogs: changes induced by prostaglandin E1.

In seven anesthetized dogs the effects of intravenously administered prostaglandin E1 on mesenteric arterial and portal venous blood flows and pancreatic capillary blood flow were measured with a transit-time ultrasonic volume flowmeter and a laser Doppler flowmeter. Basal blood flow of the superior mesenteric artery and of the portal vein were 5.7 +/- 0.6 and 11.2 +/- 1.0 ml/min/kg, respectively. Prostaglandin E1 caused a dose-dependent increase in these blood flows. The maximal effect was observed at a dose of 1.0 microgram/kg, when the superior mesenteric arterial blood flow increased 117.9 +/- 3.2% and the portal venous blood flow increased 99.4 +/- 1.7%. Prostaglandin E1 produced an initial rapid increase, followed by a decrease in pancreatic capillary blood flow. The results indicate that the flowmeters used in the present study are widely available for the study of splanchnic circulation and may have a possibility for clinical application.

Alprostadil↗
PubMed1990

Training effects on blood zinc levels in humans.

Effects of physical training on fasting erythrocyte and plasma zinc distributions were studied on seven previously sedentary male students. The training consisted of running over 5 km, 6 times/week for 10 weeks. Maximum aerobic capacity (VO2max) and 12 min walk-run performance increased significantly (p less than 0.01) after training. The erythrocyte concentrations of total zinc and of zinc derived from carbonic anhydrase I (CA-I) rose significantly (p less than 0.05) after training, whereas no such effects were noted in CA-II-derived zinc, Cu2Zn2 superoxide dismutase-derived zinc, and other zinc. On the other hand, no effect of training was found in total or alpha 2-macroglobulin-bound zinc in plasma, although albumin-bound zinc concentration declined significantly (p less than 0.05). Following the training period, however, the response to a VO2max test of the van Beaumont quotient (J Appl Physiol 1973;34:102-6) for total plasma zinc had decreased significantly (p less than 0.05), suggesting a relative reduction of the circulating exchangeable zinc. In addition, there were significant (p less than 0.05) decreases in plasma iron and ferritin concentrations after training, indicating latent iron deficiency anemia. These results may suggest that the changes in CA-I-derived zinc and/or albumin-bound zinc portend zinc deficiency during running training and that sports anemia precedes hypozincemia in athletes.

Adolescent↗
PubMed1989

Effect of synthetic physalaemin on splanchnic circulation in dogs.

Physalaemin has been reported as one of the most potent vasodilator and hypotensive peptides (1-4). In spite of these studies, however, the effect of the peptide on splanchnic circulation is not known precisely. In the present study, the effect of synthetic physalaemin on superior mesenteric arterial blood flow, portal venous blood flow and pancreatic capillary blood flow was investigated in dogs. Dose dependent increases of superior mesenteric arterial blood flow and portal venous blood flow were induced in response to physalaemin (0.1-10.0 ng/kg). Superior mesenteric arterial blood flow and portal venous blood flow attained maximal increases of 77 +/- 8.9% and 70 +/- 8.6%, respectively, at a dose of 5 ng/kg. Physalaemin caused a dose-related decrease in systemic arterial blood pressure. Pancreatic capillary blood flow did not show significant change with the administration of physalaemin. These data suggest that physalaemin may play some physiological roles in the regulation of splanchnic circulation.

Amino Acid Sequence↗
PubMed1988

Role of sulphated tyrosine residue in influencing the biologic activity of human cholecystokinin-33.

To evaluate the role of the sulphated tyrosine residue in position 27 in human cholecystokinin-33, parallel bioassay of the sulphated form of human cholecystokinin-33 and the unsulphated form of human cholecystokinin-33 was performed on the pancreatic protein secretion. Both peptides increased the protein output in a dose-related manner. However, the sulphated form possessed a considerably higher activity than the sulphated form. The relative potency of the unsulphated human cholecystokinin-33 compared to that of the sulphated human cholecystokinin-33 (taken as 1.0) was 0.08. From the results, it was suggested that the sulphated tyrosine may play an important role in controlling the activity of the longer molecular forms as well as that of the smaller forms of cholecystokinin.

Animals↗
PubMed1988

Effect of synthetic human cholecystokinin-33 on exocrine pancreas.

Synthetic human cholecystokinin-33 was first evaluated with respect to the biological activity on the pancreatic protein secretion. Human cholecystokinin-33 increased pancreatic protein secretion in a dose-related manner. The relative molar potency of this substance compared to that of synthetic cholecystokinin-8 (taken as 1.0) was 0.92. This study supports the concept that longer molecular forms of cholecystokinin are quantitatively important mediators of biological action of cholecystokinin on the pancreas.

Animals↗
PubMed1988

Effects of intravenous ethanol on hepatic and pancreatic blood flow in dogs.

Changes in hepatic and pancreatic blood flow in response to ethanol infusion were determined simultaneously and continuously in anesthetized dogs, using a transit-time ultrasonic flowmeter and a laser-Doppler flowmeter. In addition, the effect of intravenous ethanol on exocrine pancreatic secretion was investigated. With a background infusion of secretin, ethanol (1.3 g/kg body wt) was infused intravenously over a 40-min period. Ethanol infusion significantly increased blood flow in the common hepatic artery (by 49%, at the time of the cessation of ethanol infusion), and this increased flow was maintained for 60 min after the cessation of ethanol infusion. In contrast, blood flow in the portal vein was not altered significantly by ethanol. Pancreatic blood flow and secretion showed no significant difference from those seen in the controls. Our data suggest that intravenous ethanol induces a redistribution of the splanchnic blood flow. The increased hepatic arterial flow seen in response to ethanol may play an important role in preventing ethanol-induced hypoxic liver damage.

Animals↗
PubMed1988

Methods of removing external metal contamination from hair samples for environmental monitoring.

Human exposure to trace elements has become a major environmental issue with the growing industrialization and urbanization around the world. Hair samples are the most conveniently obtainable biopsy material and they have been identified as good indicators of the metal pollution in an environment. For their effective use, however, it is necessary to exclude the effect of external contamination of the hair surface by metals. The present investigation compares the different methods of washing hair samples prior to further treatment for elemental analysis. Deionized water, solvents (acetone, ether and carbon tetrachloride), non-ionic detergent, ionic detergent (sodium lauryl sulfate), chelating agent (EDTA-2Na), ultrasonics and combinations of these agents were used in the experiments. EDTA was found to be the most suitable of these washing agents for removing external contaminant metals. Further elucidation, however, is needed before a standard method of hair washing can be established.

Copper↗
PubMed1988

A study of the sources of external metal contamination of hair.

Sources of external metal contamination of hair were examined experimentally by exposing hair samples to soil, hot water from a water boiler for domestic use and household dust and fumes in a kitchen. Copper concentration in the hair increased markedly only when the hair was exposed to hot water from the boiler. Iron concentration in the hair increased markedly after exposure to wet soil, and increased slightly after exposure to hot water from the boiler. There was a slight decrease in zinc in the hair after exposure to wet or moist soil, and a significant increase after exposure to hot water from the boiler. When the hair was exposed to household dust and fumes, zinc showed a slight increase but copper and iron showed no change at all. The experiments with soil demonstrated the importance of water in the movement of iron from soil to hair and the role played in this process by biological factors such as soil bacteria.

Adolescent↗
PubMed1988

Effects of synthetic human gastric inhibitory polypeptide on splanchnic circulation in dogs.

Changes in blood flow in the celiac artery, superior mesenteric artery, and pancreas in response to an intravenous injection of synthetic human gastric inhibitory polypeptide (GIP) were determined simultaneously and continuously in anesthetized dogs, using a transit-time ultrasonic flowmeter and a laser-Doppler flowmeter. Injection of GIP significantly increased superior mesenteric arterial flow in a dose-related manner (by 9%, 43%, and 139% at 30 s after an injection at the doses of 3, 50, and 800 pmol/kg, respectively). In contrast, celiac arterial flow was not significantly altered by GIP at any of the three doses. Calculated vascular resistance in the superior mesenteric artery decreased after GIP infusion, whereas that in the celiac artery was not changed by GIP. Pancreatic blood flow decreased significantly after GIP injection at the doses of 50 and 800 pmol/kg (by 11% and 17%, respectively). Our data indicate that there is a substantial difference in the hemodynamic responses to GIP among splanchnic organs, and suggest that GIP acts specifically on the mesenteric vasculature.

Animals↗
PubMed1988

Simultaneous measurement of hepatic arterial and portal venous flows by transit time ultrasonic volume flowmetry.

Simultaneous measurement of the hepatic artery and the portal vein was performed successfully upon 15 anesthetized patients during abdominal operations with the use of transit time ultrasonic volume flowmeter. The hepatic arterial flow, portal venous flow and total hepatic flow were 267.3 +/- 21.2, 746.4 +/- 41.3 and 1,010.7 +/- 52.7 milliliters per minute, respectively. The ratio of hepatic arterial flow to portal venous flow was 0.36 +/- 0.03. Temporary occlusion of the portal vein resulted in a significant increase in hepatic arterial flow (23.6 +/- 4.3 per cent, p less than 0.01), whereas temporary occlusion of the hepatic artery did not alter portal venous flow significantly. Occlusion of the common hepatic artery induced a significant decrease in hepatic arterial flow (p less than 0.05), but did not alter portal venous flow significantly. The results of this approach had useful clinical meanings in one patient in whom the Appleby's operation was performed in which sufficient hepatic arterial flow was needed after the common hepatic artery was ligated. Data are presented for hepatic circulation measured by transit time ultrasonic volume flowmeter, which is a good device to use to assess portal venous flow as well as hepatic arterial flow with reproducibility and stability.

Adult↗
PubMed1988

[Study on splanchnic circulation: measurement of the liver blood flow].

In anesthetized patients during abdominal surgery, hepatic artery and portal vein flows were measured simultaneously utilizing an ultrasonic transit-time volume flowmeter. The total hepatic blood flow was 994.6 +/- 52.4 ml/min. The hepatic artery flow and the portal vein flow were 260.0 +/- 23.8 ml/min and 730.8 +/- 41.3 ml/min, respectively. The ratio of hepatic artery flow to portal vein flow was 0.37 +/- 0.04. A significant increase in hepatic artery flow (p less than 0.01) followed portal vein occlusion, whereas no significant change was observed in portal vein flow after hepatic artery occlusion. Common hepatic artery occlusion resulted in a significant decrease in hepatic artery flow (p less than 0.05), but no significant change was observed in portal vein flow. The present study firstly demonstrated that ultrasonic transit-time volume flowmeter is a device to quantitatively assess hepatic artery and portal vein flows with good reproducibility and stability in human subjects. This easy and simple technique seemed to have wide clinical application to abdominal surgery and would have a promising in studying splanchnic blood flows in various situations such as in cases of hepatectomy and portal hypertension.

Adult↗