Search PubMed⌕ Search

Biomedical subjects

Y Abe

Publications and source records attributed to Y Abe.

At least 865 records · Page 48Linked to original sources
PubMed1988

Chlorinated organic compounds in urban air in Japan.

Air pollution by the principal chlorinated organic compounds chloroform, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene and tetrachloroethylene was investigated over a period of approximately 1 year at 15 sites in an urban area. Each compound was detected in the range from approximately 0.1 to several ppb; the concentrations of these compounds, with the exception of carbon tetrachloride, were higher than their global pollution levels. The concentrations of 1,1,1-trichloroethane and trichloroethylene especially were very high in the industrial regions, and the concentration of tetrachloroethylene was very high in the industrial and commercial regions. Concentrations were low in spring and summer and high in fall, winter and the rainy season. The correlation between the reciprocal of wind speed and concentrations was found to be subject to seasonal variations. Intake of chlorinated organic compounds by man from the air was estimated from the data to be larger than the allowable intakes determined by WHO and EPA for drinking water.

Air Pollutants↗
PubMed1988

Erythroid differentiation factor can modulate follicular granulosa cell functions.

The action of human erythroid differentiation factor (EDF) on the functions of rat granulosa cells cultured in a chemically defined medium was investigated. In the presence of FSH that induced LH receptor expression and progesterone synthesis during culture of the cells, EDF augmented both responses in a dose- and time-dependent manner. Unlike FSH, EDF itself did not have such an inducing effect at all. Furthermore, in the absence of FSH, EDF was found to strongly enhance the ability of granulosa cells to produce inhibin. Thus, EDF may play an important role in the regulation of granulosa cell function and differentiation during follicle development.

Animals↗
PubMed1988

A new autoantibody in patients with rheumatoid arthritis: characterization of the anti-HaT-1 antibody system.

A unique, new autoantibody, anti-HaT-1, has been identified in the serum of patients with rheumatoid arthritis (RA). Anti-HaT-1 antibody is predominantly IgM, and reacts by double immunodiffusion with HaT-1 antigen, an acidic protein in human and rat liver supernatant (MW approximately 150,000). It was detected in 9 of 38 patients with RA, 2 of 15 patients with RA and Sjögren's syndrome, and none of 92 patients with other connective tissue diseases, indicating that this autoantibody is highly specific for RA.

Antibody Specificity↗
PubMed1988

Regional coupling of blood flow and methionine uptake in an experimental tumor assessed with autoradiography.

Regional distribution of L-[methyl-14C] methionine (14C-MET) and 4-[18F] fluoro-antipyrine was compared using experimental rat tumors (AH109A) and a computerized autoradiogram image processor. Tissue distributions of the two tracers were found to be inhomogeneous in the tumor with nearly identical image patterns. Analysis of tissue radioactivities revealed that 82% of 14C-MET was derived from the acid insoluble fraction at 60 min after injection. The present study showed that 14C-MET uptake closely relates to tissue blood flow and may depend on its blood to tissue transport. Rapid incorporation of MET in the acid insoluble fraction implies that it is rapidly metabolized after transport into tumor tissue.

Animals↗
PubMed1988

Positron CT imaging of an impending stroke.

We present PET findings of a case of a transient ischemic attack which later progressed to cerebral infarction. Cerebral blood flow at the stroke focus in the right parietal cortex measured after a TIA attack and before stroke was as low as 24 ml/100 g/min with some increase in oxygen extraction fraction and blood volume. The condition was compatible with "misery perfusion". This case may be an example suggestive that the "misery perfusion sign" is a warning of impending stroke and its poor prognosis if left without appropriate treatments.

Aged↗
PubMed1988

Studies on the energy expenditure following surgical stress--(I. The effects of the severity of stress and the administration of nutrients).

Energy expenditure was studied in male Donryu rats, following two types of surgical stress, namely, laparotomy and burns. The rats with burns were subsequently fasted for 6 hours, by which time the resting metabolic expenditure (RME) became significantly decreased (84.3 +/- 9.5 per cent), as when compared to the pre-burn value (100 per cent), then increased 24 hours after the burn (132.9 +/- 10.1 per cent). The RME in burned rats receiving an intravenous infusion of electrolyte fluid, slightly increased 6 hours after the burn (109.0 +/- 15.8 per cent) and was almost identical to the RME in rats fed ad libitum for 24 hours after the burn. Rats with burns, that were given intravenous infusions of electrolytes and nutrients (TPN) already had a high RME value (134.6 +/- 7.0 per cent) 6 hours after the burn. In laparotomized rats fed ad libitum, no obvious changes in energy expenditure were observed 6 hours or 24 hours after the laparotomy, however, rats receiving TPN showed a moderately increased RME 6 hours after the laparotomy (113.9 +/- 3.4 per cent, p less than 0.05) which returned to the pre-stress level 24 hours post-operatively. These results confirmed that a phase of decreased RME (ebb phase), followed by a phase of increased RME were clearly observed after severe surgical stress, which indicated that appropriate treatments could shorten or extinguish the ebb phase.

Animals↗
PubMed1988

Urine human epidermal growth factor (hEGF) levels following surgery.

In order to investigate the contribution of growth factors in conditions of postoperative stress, we measured the blood and urine hEGF levels in patients with various surgical disorders. While the levels of serum and plasma hEGF did not change significantly after surgery, urine hEGF (u-hEGF) stayed at the base-level followed by a single peak within a postoperative period of two weeks. The peak day of u-hEGF in patients with more than 1000 ml of intraoperative bleeding was later than that in patients with bleeding of less than 1000 ml. In patients with postoperative renal failure or dysfunction, u-hEGF levels dropped and did not rise until the recovery of renal function. The changing pattern of u-hEGF levels was an indicator of operative bleeding volume and renal function.

Adolescent↗
PubMed1988

Studies on the energy expenditure following surgical stress (II. The correlation between energy expenditure and hormonal changes).

The correlation between energy expenditure and hormonal changes following surgical stress was studied using rats. Blood concentrations of catecholamine, insulin, corticosterone, glucagon, T3, and T4 were compared between the rats (IIa and IIb) in the ebb phase and those (III and IV) in the flow phase, 6 hours after being inflicted with a burn. Noradrenaline was higher, though not significantly, and glucagon was significantly higher in the latter groups than in the former groups. When glucagon was administered to the rats in the ebb phase, RME increased significantly. From these results, it is suggested that glucagon plays an important role in the transition from ebb phase to flow phase.

Animals↗
PubMed1988

Tumor uptake studies of D,L-[5-14C]ornithine and D,L-2-difluoromethyl [5-14C]ornithine.

The feasibility of D,L-[5-14C]ornithine ([14C]ornithine), a precursor for polyamine synthesis, and D,L-2-difluoromethyl[5-14C]ornithine ([14C]DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC) were investigated for tumor localization. As an animal model, mice bearing mammary carcinoma, FM3A, were used. After i.v. injection of [14C]ornithine accumulation of radioactivity was observed in the FM3A, in which 43% of the 14C radioactivity was measured in the polyamine pool and 41% in the amino acid pool at 60 min after injection. Tumor uptake of [14C]DFMO was relatively low but constant during 60 min after injection. At 60 min after injection, 11% of the 14C was present in the acid-precipitable fraction of the FM3A, which suggests the formation of an irreversible complex of [14C]DFMO with ODC. For both compounds rapid blood clearance and high tumor-to-organ ratios were observed. Our results indicate that in connection with an enhanced polyamine synthesis in the tumors, the compounds investigated have potential as tracers for tumor detection.

Animals↗
PubMed1988

Tumor uptake studies of S-adenosyl-L-[methyl-11C]methionine and L-[methyl-11C]methionine.

Tumor accumulation of S-adenosyl-L-[methyl-11C]methionine ([11C]SAM) was investigated in mice bearing mammary carcinoma (FM3A) and in rats bearing ascitic hepatoma (AH109A). After injection of [11C]SAM the blood clearance of 11C radioactivity was rapid. The 11C level was relatively high in both tumors. The uptake ratios of tumor to organ increased with time in several organs, especially in brain and muscle. In FM3A tumor tissue the 11C was incorporated with time into the acid-precipitable fraction and 38% of the 11C was detected in this fraction at 60 min after injection. This fraction reflects the amount of 11C-methyl group transferred into macromolecules in tumor tissue. In AH109A-bearing rats the metabolisms of [11C]SAM and L-[methyl-11C]methionine ([11C]Met), in vivo precursor of SAM, were compared. Tumor uptake of [11C]SAM was about two thirds of that of [11C]Met at 20 min after injection. At this time, for the [11C]SAM 27 and 8% of the 11C in the AH109A tissue were detected in the acid-precipitable and the lipid fractions, respectively. The corresponding figures for [11C]Met were 61% and 2%. In the liver considerable amounts of 11C were observed in the lipid fraction for both tracers. These results show that [11C]SAM has potential as a tracer for tumor localization with positron emission tomography (PET) and suggest that in tumor studies combining [11C]Met and PET, it should be taken into account that the 11C-labeled methyl group of [11C]Met is not only incorporated into protein but also other macromolecules and lipids via [11C]SAM.

Animals↗
PubMed1988

The organic matrix of urinary uric acid crystals.

We have demonstrated that urinary uric acid crystals contain an organic matrix within the crystalline boundaries, morphologically similar to that of uric acid stones. Among several glycosaminoglycans in urine, heparan sulfate was almost exclusively identified in this matrix, as in that of uric acid stones. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed that several proteins in urine were incorporated in this matrix on a selective basis; two of which were albumin and Tamm-Horsfall mucoprotein. An affinity of uric acid or urate for selective urinary macromolecules in a liquid phase was supposed to be the origin of this matrix. But the proteins in the uric acid stone matrix were not separated by SDS-PAGE. Therefore we could not conclude whether the organic matrix of urinary uric acid crystals is similar to that of uric acid stones.

Crystallization↗
PubMed1988

Lipoxins A4 and B4: comparison of icosanoids having bronchoconstrictor and vasodilator actions but lacking platelet aggregatory activity.

Lipoxins A4 (LxA4) and B4 (LxB4), two lipoxygenase-generated icosanoids of arachidonic acid metabolism, were found to have a distinct biological profile. Both LxA4 and LxB4 slowly contracted pulmonary parenchymal strips isolated from guinea pigs, rabbits, and rats in a concentration-dependent manner over the range 0.1-1 microM. This bronchoconstrictor effect was not associated with release of peptide leukotrienes or thromboxane A2, nor was it blocked by lipoxygenase inhibitors or thromboxane receptor antagonists, suggesting it is a direct effect of lipoxins. However, the leukotriene D4 (LTD4) receptor antagonist LY-171883 reduced the LxA4 response, indicating that LTD4 and LxA4 may share the same receptor. LxA4 and LxB4 also exerted an endothelium-dependent vasorelaxation in guinea pig, rat, and, to a lesser extent, rabbit aortic vascular smooth muscle. In contrast to other vasoactive icosanoids, LxA4 and LxB4 failed to aggregate rat, rabbit, or guinea pig platelets or to inhibit ADP-induced aggregation. LxA4 also enhanced the release of liver lysosomal hydrolases in a liver large granule fraction, indicating a lysosomal labilizing action of LxA4. LxA4 and LxB4 share a similar biological profile. It is not clear yet whether the lipoxins could be mediators of circulatory or pulmonary disease states.

Animals↗
PubMed1988

Effect of changes in sodium balance on renin, angiotensinogen and atrial natriuretic factor messenger RNA levels in rats.

The expression of messenger (m)RNA for renin, angiotensinogen and atrial natriuretic factor (ANF) was investigated in rats on different sodium intakes. Messenger RNA was measured by a radiodensitometric hybridization assay. In the high-sodium state, renal renin mRNA decreased, but it increased in the low-sodium state. A further increase in renin mRNA was seen in the low-sodium state after captopril administration. Angiotensinogen mRNA levels in the liver, kidney and brain were altered by varying sodium intake. In the high-sodium state angiotensinogen mRNA decreased, but in the low-sodium state it increased. After treatment with captopril, angiotensinogen mRNA levels decreased in the liver and kidney. Angiotensinogen mRNA showed tissue specificity for expression, especially in the brain. Atrial ANF mRNA levels changed slightly with different levels of sodium intake.

Angiotensinogen↗
PubMed1988

Effects of calcium and ouabain on the release of atrial natriuretic factor.

In order to examine the role of calcium in the secretory process of atrial natriuretic factor (ANF), we studied the effects of hypercalcaemia and ouabain on the plasma concentration of immunoreactive ANF, and the effect of calcium on immunoreactive ANF release from isolated rat atria. Anaesthetized dogs were treated with CaCl2 infusion, ouabain or phenylephrine injection. With CaCl2 infusion, serum calcium and plasma immunoreactive ANF respectively increased to three and four times their basal levels. Ouabain increased plasma immunoreactive ANF to two and a half times the initial level. Neither CaCl2 nor ouabain produced any effect on right atrial pressure and heart rate, but they both significantly increased arterial pressure. Phenylephrine caused a greater increase in arterial pressure than both CaCl2 and ouabain. However, there was no significant increase in plasma immunoreactive ANF. Moreover, calcium stimulated the release of immunoreactive ANF from isolated rat atria. These results suggest that the calcium may play a key role in the secretory process of ANF.

Animals↗
PubMed1988

Sodium balance effects on renin, angiotensinogen, and atrial natriuretic polypeptide mRNA levels.

The expressions of the renin, angiotensinogen, and atrial natriuretic polypeptide (ANP) genes were studied in rats with varying sodium intakes. mRNAs for angiotensinogen and renin were measured by a sensitive radiodensitometric hybridization assay. ANP mRNA was determined by a dot-blot hybridization assay. In the high-sodium state, plasma renin concentration (PRC), renal renin concentration (RRC), and renal renin mRNA decreased by 88, 90, and 75%, respectively. In the low-sodium state, PRC, RRC, and renin mRNA increased 17-fold, 2.5-fold, and 4.5-fold, respectively. With captopril treatment during sodium depletion, PRC and renin mRNA increased 144-fold and 17.1-fold, respectively, and RRC increased 4.2-fold. The angiotensinogen mRNA level in the liver and kidney decreased in the high-sodium and increased in the low-sodium state to similar extents. Captopril treatment decreased angiotensinogen mRNA in both organs by about half. Plasma ANP and ANP mRNA decreased in the low- compared with the high-sodium state, whereas atrial ANP content was unaltered in both low- and high-sodium states. These results demonstrate that sodium intake affects the expression of the renin and angiotensinogen genes and slightly alters the expression of ANP gene.

Aldosterone↗
PubMed1988

Effects of hypercalcemia and ouabain on plasma atrial natriuretic polypeptide in anesthetized dogs.

For the purpose of examining the role of calcium ion in the secretory process of atrial natriuretic polypeptide (ANP), we studied the effects of hypercalcemia and ouabain on plasma concentration of immunoreactive ANP (irANP). Pentobarbital sodium-anesthetized dogs were treated with calcium chloride infusion (0.136 mmol.kg-1.min-1, 10 min) or ouabain injection (30 micrograms/kg), and plasma irANP concentration, right atrial pressure, mean arterial pressure, heart rate, and serum calcium concentration were measured. To evaluate the effect of rising arterial pressure, plasma irANP concentration was also measured in dogs treated with phenylephrine hydrochloride (10 micrograms/kg). With calcium chloride infusion, serum calcium concentration and plasma irANP concentration, respectively, increased to about three times and about four times their basal levels. This increase of plasma irANP concentration was not attenuated by pretreatment with adrenoceptor blockers. Ouabain increased plasma irANP concentration to approximately 2.5 times the initial level. Neither calcium chloride nor ouabain produced any effect on right atrial pressure and heart rate, but both significantly increased mean atrial pressure. Phenylephrine caused a greater increase in mean arterial pressure than both calcium chloride and ouabain. However, there was no significant increase in plasma irANP concentration. These results suggest that the calcium ion may play a key role in the secretory process of ANP.

Anesthesia, General↗