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Biomedical subjects

S Ueda

Publications and source records attributed to S Ueda.

At least 757 records · Page 42Linked to original sources
PubMed1988

Characteristic structures of serotonin neuron system. An immunohistochemical study.

Since 1982, the authors have carried out intensive immunohistochemical studies on the distribution of serotonin neurons in the central nervous system and have reported the distinctive structures of these nerve cells. In the present study, two characteristic findings are described with special regard to the histophysiological significance: (1) direct innervation of the cerebral arteries by central serotonin neurons and (2) the perineuronal ivylike serotonin plexus.

Animals↗
PubMed1988

Multiple recombinational events in primate immunoglobulin epsilon and alpha genes suggest closer relationship of humans to chimpanzees than to gorillas.

Immunoglobulin epsilon and alpha genes of chimpanzee and gorilla were isolated and their structures were compared with their human counterparts. Multiple deletions and duplications seem to have happened in both genes during hominoid evolution; the chimpanzee had deleted the entire C epsilon 2 gene after its divergence. In addition, the length of the C alpha 1 hinge region of gorilla is distinct from those of chimpanzee and humans. Structural homology of the epsilon and alpha genes suggests that humans are evolutionarily closer to chimpanzees than to gorillas.

Animals↗
PubMed1988

Enzymatic determination of serum 12 alpha-hydroxy bile acid concentration with 12 alpha-hydroxysteroid dehydrogenase.

A simple colorimetric enzymatic assay for determination of serum 12 alpha-hydroxy bile acids was developed using 12 alpha-hydroxysteroid dehydrogenase (HSD). The enzymes were extracted from Bacillus sphaericus. The principle of the method is as follows: 12 alpha-hydroxy bile acids are converted to 12-oxo bile acids using 12 alpha-HSD with the conocomitant reduction of NAD to NADH, and then the hydrogen of the generated NADH is transferred by diaphorase to NTB to yield diformazan. Finally, the color of resultant diformazan was measured. The specificity and precision of this assay method were satisfactory. A linear relationship was noted between the amount of 12 alpha-hydroxy bile acids and the degree of absorbance in the range of 6.7 to 215 microM. The fasting values for serum 12 alpha-hydroxy bile acid in 10 patients with liver diseases ranged widely from 7.6 to 91.1 microM, and values obtained with this assay agreed closely with those obtained by gas-liquid chromatography (r = 0.94, p less than 0.001). The assay is convenient, rapid, and specific for the measurement of 12 alpha-hydroxy bile acid concentrations in the serum of patients with liver diseases.

Adult↗
PubMed1988

Inhibitory effects of prostaglandin E1 on T-cell mediated cytotoxicity against isolated mouse liver cells.

The effects of prostaglandin E1 on cell-mediated cytotoxicity against hepatocytes were investigated using an in vitro cytotoxic assay system. Isolated liver cells from normal C57BL/6 mice were used as the target cells, and effector cells were obtained from spleens of C57BL/6 mice in which experimental hepatitis had been induced by immunization with syngeneic liver antigens. In this assay system, spleen T cells adhering to nylon wool demonstrated a high cytotoxic activity against target liver cells. The cytotoxicity was markedly reduced by prostaglandin E1 at concentrations greater than 10(-7) M. Maximum suppressive activity was obtained when prostaglandin E1 was continuously present during the assay period. By contrast, indomethacin, a specific inhibitor of prostaglandin synthesis, enhanced the cytotoxic activity of effector cells. These data seem to indicate that exogenously added prostaglandin E1 has an inhibitory effect on cell-mediated cytotoxicity of effector spleen cells against target hepatocytes.

Alprostadil↗
PubMed1988

Cortical blindness caused by acute general cerebral swelling.

A 7-year-old girl who suffered from acute general cerebral swelling as a result of a traffic accident showed cortical blindness. Computed tomography (CT) scan on admission revealed marked slitlike ventricles and narrowing of the perimesencephalic cisterns, which indicated general cerebral swelling. While hospitalized, the patient developed transtentorial herniation twice on day 3, and CT scans at herniation episodes showed disappearance of the perimesencephalic cisterns. After recovery of consciousness, the patient showed cortical blindness, and during gradual recovery she showed pure alexia without agraphia. The visual evoked potentials at 8 weeks, 16 weeks, and 3 years 4 months after trauma showed normalization of the pattern, but revealed left occipital inactivity.

Acute Disease↗
PubMed1988

Pharmacokinetics of single and consecutive doses of cilazapril and its depressor effects in hypertensive patients with renal dysfunction.

The pharmacokinetic properties and antihypertensive effects of cilazapril, a long-acting converting enzyme inhibitor, were investigated in seven hypertensive patients with renal failure. Cilazapril 1.25 mg was given orally once a day for 5 or 8 days. Cilazapril induced a significant decrease in both systolic and diastolic blood pressures, and its antihypertensive effect was still present 24 hours after administration. Serum-converting enzyme activity was markedly suppressed for at least 24 hours. No significant differences were noted in plasma peak level and the area under the curve between the first and last days of treatment. These results suggest that cilazapril has a long-lasting effect and is a useful antihypertensive agent in controlling blood pressure in hypertensive patients with renal failure.

Blood Pressure↗
PubMed1988

Pharmacokinetics of single and consecutive doses of cilazapril and its depressor effects in patients with essential hypertension.

The pharmacokinetic properties and antihypertensive effects of cilazapril, a long-acting angiotensin-converting enzyme (ACE) inhibitor, were investigated in five patients with mild to moderate essential hypertension (mean age 57 years, mean serum creatinine 1.2 mg/dL, mean glomerular filtration rate 69 mL/min/1.73m2, mean blood pressure 158/94 mm Hg). All patients were hospitalized and placed on a constant sodium diet (7 g of NaCl/day) throughout the study. After an overnight fast, a 1.25-mg dose of cilazapril was given orally once a day for 5 or 8 days. On the first and last days of treatment, blood samples were taken and blood pressure was measured. All patients tolerated cilazapril with no untoward effects. Cilazapril induced a significant decrease in both systolic and diastolic blood pressure, and its antihypertensive effect was still present 24 hours after administration. Serum ACE activity was markedly suppressed for at least 24 hours. The peak plasma concentrations (Cmax) of cilazapril and its diacid were 117 and 24.6 ng/mL on the first treatment day, and 144 and 31.1 ng/mL on the last day. The area under the plasma concentration time curve (AUC) of cilazapril and its diacid were 408 and 227 ng.h/mL on the first day, and 501 and 305 ng.h/mL on the last day. In looking at the data gathered on the first and last treatment days, no significant differences were noted in Cmax and AUC values. These results suggest that cilazapril has a long-lasting effect and is a useful antihypertensive agent in controlling blood pressure in patients with mild to moderate essential hypertension.

Angiotensin II↗
PubMed1988

Identification of B-L antigens on reticular epithelial cells of the bursa of Fabricius.

We have established two monoclonal antibodies against B-L antigens (chicken Ia-like antigens). The specificity of the antibodies for B-L antigens was determined by two criteria, the cellular expression and the molecular structure of antigens with which they reacted. They reacted with antigens expressed on bursacytes, Con A-blast thymocytes, macrophages, and MDCC MSB1, but not with thymocytes and erythrocytes. In molecular basis, they recognized 64,000 dalton glycoprotein consisting of two polypeptides, 35,000 and 32,000 dalton, which bound non-covalently. To investigate the distribution of B-L antigens on non-lymphoid cells of the bursa of Fabricius, which were thought to play important roles in the differentiation of B cells, anti-B-L antigen and anti-chicken immunoglobulin (Ig) monoclonal antibodies were used. B-L antigen-positive cells were detected in both cortical and medullary areas, whereas Ig-positive lymphoid cells were confined to the medullary areas of normal chicken bursal follicles. In the bursal follicles of cyclophosphamide (CY)-treated chickens, lymphoid cells were depleted but epithelial cells remained intact. And B-L antigen-positive but Ig-negative cells were easily detected in the medullary areas of almost all follicles. These cells were identified to be reticular epithelial cells (REp cells) from the result of their keratin expression.

Animals↗
PubMed1988

Molecular basis for the spontaneous generation of colonization-defective mutants of Streptococcus mutans.

Spontaneous mutants of Streptococcus mutans GS-5 defective in sucrose-dependent colonization of smooth surfaces are generated at frequencies above the spontaneous mutation rate. Southern blot analysis of such mutants suggested rearrangement of the genes coding for glucosyltransferase (GTF) activity. Two strain GS-5 homologous tandem genes, gtfB and gtfC, coding for GTF-I and GTF-S activities respectively, were demonstrated to undergo recombination when introduced into recombination-proficient Escherichia coli transformants. However, the two genes were quite stable when transformed on a single DNA fragment into a recA mutant of E. coli. The DNA fragment coding for GTF activity from one S. mutans colonization-defective mutant, SP2, was isolated and shown also to have undergone recombination between the gtfB and gtfC genes, resulting in reduced GTF activity. These results are discussed relative to the in vivo generation of colonization-defective mutants in cultures of S. mutans.

Cloning, Molecular↗
PubMed1988

Immunohistochemical demonstration of serotonin-containing nerve fibers in the mammalian hippocampal formation.

The distributional pattern of serotonin-immunoreactive nerve fibers in the hippocampal formation of six different mammalian species (rat, chipmunk, hamster, cat, dog and monkey) was studied in detail by means of a modified peroxidase-antiperoxidase immunohistochemical method, using a specific serotonin antiserum. Furthermore, the density of varicosities distributed in each layer of the hippocampus was semiquantitatively analyzed. In all species investigated, the routes of serotonin fibers entering the hippocampal formation were found to be almost the same. These fibers were extensively distributed throughout the hippocampal formation, and had a characteristic arrangement corresponding to the laminar structure of this region. A dense innervation by varicose serotonin fibers was found in the stratum lacunosum-moleculare, but a few serotonin fibers were also distributed in the stratum lucidum of the CA2 and CA3 fields. The stratum pyramidale and the granule cell layer of the dentate gyrus contained a small number of serotonin fibers. The concentration and the direction of serotonin fibers were different in each area of each animal. Two peculiar observations should be stressed: (1) in the rat, the strata oriens and radiatum of CA2 and CA3 as well as the stratum lacunosum-moleculare displayed abundant serotonin fibers; (2) in the dog, abundant serotonin fibers were diffusely distributed in the CA1 field except for the stratum pyramidale and the most dense concentration of serotonin fibers was seen in the stratum oriens of CA3. The present study provides a morphological basis for further study of the functional significance of serotonin in the limbic system.

Animals↗
PubMed1988

Role of sodium and renal prostaglandin E2 in the maintenance of hypertension in the chronic phase of two-kidney one-clip renovascular hypertension in rabbits.

To study the role of sodium and renal prostaglandin E2 in the chronic phase of two-kidney one-clip renovascular hypertension, urinary excretion rates of sodium and prostaglandin E2 were measured in rabbits with hypertension induced by left renal artery constriction during alteration in sodium intake. The arterial blood pressure, the increasing rate of body weight and sodium balance during alteration in sodium intake were directly proportional to the amount of sodium intake in the hypertensive rabbits, but not in the control ones. Plasma renin activity and plasma aldosterone concentration, which had no significant difference between hypertensive and control rabbits, were inversely proportional to the amount of sodium intake in both rabbits. Urinary excretion rates of sodium in the clipped kidneys of the hypertensive rabbits were significantly lower than the control values in all dietary regimens (p less than 0.01). Urinary excretion rates of sodium in the nonclipped kidneys were not significantly higher and in the total kidneys were significantly lower than the corresponding control values during sodium load (p less than 0.01). Urinary excretion rates of prostaglandin E2 were inversely proportional to the amount of sodium intake in both groups. Urinary excretion rates of prostaglandin E2 in the clipped kidneys were significantly lower than the control values in all dietary regimens (p less than 0.001). Urinary excretion rates of prostaglandin E2 in the nonclipped kidneys were significantly higher during sodium restriction (p less than 0.01) but not during sodium load than the control values. Furthermore, urinary excretion rates of prostaglandin E2 in the total kidneys were significantly lower than the control values in all dietary regimens (p less than 0.01). These results suggest that two-kidney one-clip renovascular hypertension in rabbits seems to be partly sodium-dependent in the chronic phase because the nonclipped kidney fails to excrete sodium sufficiently. There may also be disorders of renal prostaglandin E2 metabolism influencing these disorders of sodium in the nonclipped kidneys.

Animals↗
PubMed1988

Differential action of nerve growth factor, cyclic AMP and neurotropin on PC12h cells.

Nerve growth factor (NGF) induced the activities of acetylcholinesterase (AChE) and Na+,K+-ATPase concomitant with neurite outgrowth in PC12h cells, while dibutyryl cyclic AMP (DBcAMP) caused the induction of AChE activity and neurite outgrowth but not Na+,K+-ATPase activity. A nonproteinaceous extract isolated from the inflamed skin of rabbits inoculated with vaccinia virus (Neurotropin) induced neurite outgrowth and cell surface change similar to NGF without affecting AChE activity. The results suggest that NGF, DBcAMP and Neurotropin act on PC12h cells through different mechanisms.

Acetylcholinesterase↗
PubMed1988

[Effects of omeprazole and famotidine on (H+-K+) ATPase and acid secretion in rabbit gastric glands].

Effects of omeprazole, an anti-ulcer drug, on (H+-K+) ATPase activity and gastric acid secretion in a gastric mucosal gland preparation from rabbits were investigated. The mode of action of the substance was compared with famotidine, and H2 antagonist, by examining the effects of both drugs on the (H+-K+) ATPase of the rabbit gastric mucosa and on gastric acid secretion from the isolated rabbit gastric glands. Optimal assay conditions for (H+-K+) ATPase activity differed slightly from that reported for pig gastric mucosa, and they were pH 7.0, 2 mM of MgCl2 and 50 mM of KCl. Omeprazole dose-dependently inhibited the enzyme activity with an IC50 of 4.2 microM, whereas famotidine was not inhibitory even at the highest concentration of 100 microM. Acid secretion in the glands was determined by measuring accumulation of 14C-aminopyrine. Omeprazole and famotidine showed almost the same inhibitory effect against histamine-stimulated gastric secretion, and their IC50 values were 0.35 microM. Omeprazole inhibited dibutyryl cyclic AMP-stimulated gastric acid secretion, but famotidine was not inhibitory even at the highest concentration of 100 microM. The reason for this difference was that (H+-K+) ATPase activity is linked to the final step of acid secretion. From these results, omeprazole can be expected to be useful for the treatment of peptic ulcer disease.

Adenosine Triphosphatases↗