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Biomedical subjects

K Maeda

Publications and source records attributed to K Maeda.

At least 883 records · Page 49Linked to original sources
PubMed1993

Urinary trehalase activity in chronic glomerulonephritis.

To determine the diagnostic role of urinary trehalase in chronic glomerular disease, urinary trehalase activity and other urinary markers such as N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), alkaline phosphatase (ALP), gamma-glutamyltranspeptidase (gamma-GTP), lactate dehydrogenase (LDH), lysozyme and beta 2-microglobulin (BMG) were measured in patients with chronic glomerulonephritis, nephrotic syndrome and chronic renal failure. Urinary trehalase activity was significantly increased in chronic glomerular disease, especially nephrotic syndrome, as compared with that in the healthy subjects. The highest incidence of elevated excretion was observed for trehalase with 52% in chronic glomerular disease, followed by NAG. Urinary trehalase activities in the patients were significantly correlated with the urinary levels of protein, NAG and AAP and total score of tubular damage, but not correlated with urinary levels of BMG or lysozyme. In patients with chronic glomerulonephritis and nephrotic syndrome, there was no significant difference in urinary trehalase activities between with and without hematuria. These results indicate that in some patients with chronic glomerular disease, there is tubular involvement as substantiated by elevation of the other urinary enzymes and BMG. Urinary trehalase is elevated more often in these types of disease than other markers of tubular damage.

Acetylglucosaminidase↗
PubMed1993

Effect of hemodialysis on plasma levels of vasoactive peptides: endothelin, calcitonin gene-related peptide and human atrial natriuretic peptide.

To determine the role of vasoactive peptides such as endothelin (ET), calcitonin gene-related peptide (CGRP) and human atrial natriuretic peptide (hANP) in the regulation of blood pressure in uremic patients, and to determine the effect of various types of dialyzer membranes on hemodialysis (HD)-induced changes in plasma levels of such peptides, plasma ET, CGRP and hANP were measured in HD patients and patients on continuous ambulatory peritoneal dialysis (CAPD). Plasma levels of ET, CGRP, and hANP were significantly higher in HD and CAPD patients than in healthy subjects. There were no significant differences in plasma levels of ET, CGRP, and hANP between hypertensive and normotensive HD patients, and no significant correlation was observed between HD-induced changes in plasma levels and changes in blood pressure. Plasma levels of ET decreased when HD was performed using high-flux membranes, such as polyacrylonitrile (PAN), polymethyl methacrylate (PMMA) and cellulose triacetate (CTA), but did not decrease using a saponified cellulose (SC) membrane. Plasma levels of CGRP decreased in the case of PAN, but increased significantly with PMMA and showed no change with SC and CTA. Plasma levels of hANP decreased in all types of dialyzer membranes due to decreased secretion. These results indicate that the effect of HD on plasma levels of ET and CGRP, but not hANP, depends on the type of dialyzer membrane used.

Atrial Natriuretic Factor↗
PubMed1993

beta 2-Microglobulin modified with advanced glycation end products is a major component of hemodialysis-associated amyloidosis.

beta 2-Microglobulin (beta 2M) is a major constituent of amyloid fibrils in hemodialysis-associated amyloidosis, a complication of long-term hemodialysis patients. Amyloid fibril proteins were isolated from connective tissues forming carpal tunnels in hemodialysis patients with carpal tunnel syndrome. Two-dimensional polyacrylamide gel electrophoresis and Western blotting demonstrated that most of the beta 2M forming amyloid fibrils exhibited a more acidic pI value than normal beta 2M. This acidic beta 2M was also found in a small fraction of beta 2M in sera and urine from these patients, whereas heterogeneity was not observed in healthy individuals. We purified acidic and normal beta 2M from the urine of long-term hemodialysis patients and compared their physicochemical and immunochemical properties. Acidic beta 2M, but not normal beta 2M, was brown in color and fluoresced, both of which are characteristics of advanced glycation end products (AGEs) of the Maillard reaction. Immunochemical studies showed that acidic beta 2M reacted with anti-AGE antibody and also with an antibody against an Amadori product, an early product of the Maillard reaction, but normal beta 2M did not react with either antibody. Incubating normal beta 2M with glucose in vitro resulted in a shift to a more acidic pI, generation of fluorescence, and immunoreactivity to the anti-AGE antibody. The beta 2M forming amyloid fibrils also reacted with anti-AGE antibody. These data provided evidence that AGE-modified beta 2M is a dominant constituent of the amyloid deposits in hemodialysis-associated amyloidosis.

Amyloidosis↗
PubMed1993

[Effects of selenium on the glycolysis and gluconeogenesis system in rat liver].

We studied the effect of selenium on the glycolysis and gluconeogenesis system in the rat liver. Significant decreases in glucose level in the serum were observed from the 4th day after daily intraperitoneal (i.p.) administration of selenite (173 micrograms/kg, 78.9 micrograms/kg of selenium base equivalent). Selenium was also effective in reducing a precursor of gluconeogenesis, lactate, alanine or glycerol, in the serum. Moreover, there were significant decreases in the activities of pyruvate carboxylase and glucose-6-phosphatase, a rate-limiting enzyme of gluconeogenesis, in the liver of selenium-treated rates. On the contrary, the activities of glycokinase and phosphofructokinase, a rate-limiting enzyme of glycolysis, in the liver of rat treated with selenium significantly increased in comparison with the control group. These data, therefore, indicated that the hypoglycemic effect of selenium might be due to the acceleration of glucose metabolism and the inhibition of glucose synthesis in the liver, suggesting a decrease in a source of precursor supply for the gluconeogenesis.

Alanine↗
PubMed1993

Nucleotide sequence of the glycoprotein C (gC) homologous gene of Marek's disease virus (MDV) serotype 2 and comparison of gC homologous genes among three serotypes of MDV.

The sequence analysis of the genomic region of Marek's disease virus (MDV) serotype 2 (MDV2) which had homology with the gene encoding MDV serotype 1 (MDV1) homologue of glycoprotein C (gC) of herpes simplex virus revealed that there was a single open reading frame (ORF) capable of encoding 479 amino acids. The predicted protein from this ORF had strong hydrophobic regions in both the amino and carboxyl termini and several potential N-linked glycosylation sites, as seen in those from the ORFs of MDV1 and MDV serotype 3 (MDV3 = herpesvirus of turkeys (HVT)) gC homologues. By northern-blot analysis using a DNA fragment located in the MDV2 gC homologue ORF as a probe, 3.6 and 1.9 kb RNA transcripts were identified in MDV2-infected cells. When the alignment of amino acid sequences of the gC homologous genes of three MDV serotypes were compared, the homology between MDV1 and MDV2 and that between MDV1 and HVT showed about 76% identity, whereas that between MDV2 and HVT was about 70% identity. These results suggested a possibility that the evolutionary distance between MDV1 and MDV2 and between MDV1 and HVT is shorter than that between MDV2 and HVT.

Amino Acid Sequence↗
PubMed1993

Expression and localization of a major lysosomal membrane sialoglycoprotein (LGP107) in plasma membranes of rat osteoblasts and osteocytes.

The immunocytochemical localization of a major lysosomal membrane sialoglycoprotein with a molecular mass of 107 kDa, which was designated as LGP107, was investigated in osteoblast lineage cells involved in osteoclastic bone resorption using specific polyclonal antibody against LGP107. Osteoclastic bone resorption was induced by transplantation of parathyroid glands. In control experiments, no immunoreaction product for LGP107 was recognized in osteoblasts and osteocytes. Strong immunoreaction products for LGP107 occurred on the plasma membranes in the osteoblasts and osteocytes prior to the appearance of osteoclasts one day after transplantation of the parathyroid glands. Furthermore, two days after induction, strong diaminobenzidine reactions were also observed on the plasma membranes in the osteoblastic cells adjacent to the active osteoclasts. These data suggest that LGP107 in osteoblastic cells and osteocytes may play an important role in cell-recognition and/or cell-adhesion, and that LGP107 may be involved in osteoblastic degradation of the osteoid as well as exposure of the bone surface.

Animals↗
PubMed1993

Usefulness of a simple device to measure aural canal temperature.

In patients with spinal cord injury, rectal temperature is difficult to use as body temperature due to impairment such as defecation disturbance. We developed an earphone type device to measure aural canal temperature that can be also used during exercise in patients with spinal cord injury and evaluated its usefulness. The subjects consisted of 11 healthy male students. They exercised for 30 minutes using an ergometer until the heart rate increased to 150-160 bpm. Aural canal temperature, rectal temperature, and non-contact tympanic membrane temperature were measured before, during, and after exercise. This device for the measurement of aural canal temperature was produced by cutting the tip of a commercially available earphone and connecting a thermocouple wire to it. This device is very small and causes no discomfort even during long wearing or inconvenience during exercise. The aural canal temperature obtained in this study was very stable compared with the rectal temperature or non-contact tympanic membrane temperature and thus may be useful for monitoring body temperature.

Adolescent↗
PubMed1993

[Relationship between aging and hydroxyproline content of serum in human being].

The authors have studied the effects of physical exercise on extracellular substances of several tissues in animals. Hydroxyproline (Hyp) exist in the form of peptide and the free state in blood. It is generally thought that Hyp in blood derived from the decomposition of collagen in tissue. To clarify the influence on collagen metabolism due to aging and exercise training, we attempted to see the changes of Hyp content of serum before and after exercise in human being. Subjects were 51 adult aged 20 to 74 years, and 10 nonathletes and 51 athletes, aged 18 to 22 years. The Hyp content in serum was measured by woessner's method. The Hyp content of serum decreased with age. This fact suggests that the formation of intramolecular and intermolecular cross-links in collagen of tissue is accelerated by aging. And there is a possibility that the proportion of insoluble collagen increased in tissue of aged human being. Before the exercise, Hyp content of serum in athlete was lower than that in nonathletes. Hyp content of serum increased remarkably after the exercise in athlete. These results suggest that the collagen metabolism may be accelerated by continuous exercise training.

Adolescent↗
PubMed1993

Spontaneous submucosal dissection of the esophagus.

A 41-year-old woman was found to have had spontaneous submucosal dissection of the esophagus by esophagoscopy. Food ingestion was postulated to have been an initiating factor in this instance. Conservative therapy was sufficient in this case. Patients who complain of sore throat with retrosternal pain and an obstructed sensation on swallowing or mild hematemesis should be examined by esophagoscopy for evidence of this disorder.

Adult↗
PubMed1993

Pineocytoma with intratumoral hemorrhage following ventriculoperitoneal shunt--case report.

A 58-year-old female with pineocytoma developed intratumoral hemorrhage after ventriculoperitoneal shunting for hydrocephalus. Neurological examination revealed Parinaud's sign and papilledema. Computed tomography and magnetic resonance (MR) imaging revealed a pineal neoplasm and obstructive hydrocephalus. Serum and cerebrospinal fluid levels of human chorionic gonadotropin, alpha-fetoprotein, carcinoembryonic antigen, and placental alkaline phosphatase were negative or within normal limits. MR images after the ventriculoperitoneal shunting disclosed intratumoral hemorrhage and markedly smaller ventricles. The tumor was totally removed via the occipital transtentorial approach and was diagnosed histologically as a pineocytoma with astrocytic differentiation. The tumor probably shifted away from the surrounding structures following the marked reduction in ventricular size after ventriculoperitoneal shunting, resulting in changed venous circulation in the tumor and the formation of intratumoral hematoma.

Brain↗
PubMed1993

Vitamin E is an important factor in T cell differentiation in thymus of F344 rats.

The effect of vitamin E (dl-alpha-tocopheryl acetate) on T cell differentiation in thymus of F344 rats was examined in this study. The rats were divided into three groups: vitamin E-free, regular and high vitamin E groups and fed a diet containing various levels of vitamin E (0, 50, and 585 mg/kg diet) for 7 weeks. The number of thymocytes was significantly lower in the vitamin E-free group relative to the regular group. Although the proportions of both CD4+CD8- and CD4-CD8+ T cells in thymocytes were significantly greater in the high vitamin E group, the proportion of CD4+CD8- T cells inversely decreased in vitamin E-free group compared to that of the regular group. The ratio of CD4+CD8-/CD4-CD8+ T cells increased in the high vitamin E group (p < 0.01) and significantly decreased in the vitamin E-free group (p < 0.001) compared to that of the regular group. Although the marked changes of T cell subsets were not seen in peripheral blood lymphocytes (PBL), the ratio of CD4+CD8-/CD4-CD8+ T cells was significantly lower in the vitamin E-free group and significantly greater in the high vitamin E group compared to that of the regular group. Production of interleukin (IL) 2 by thymocytes following the stimulation with Con A for 48 h increased about threefold in the high vitamin E group compared to the regular group. Conversely, thymocytes from rats fed the vitamin E-free diet showed a significant decrease of IL2 production compared to that of the regular group. Prostaglandin E2 (PGE2) production from thymocytes was significantly lower in the high vitamin E group compared to that of the regular group, whereas thymocytes of rats fed the vitamin E-free diet showed a significant increase of PGE2 production compared to that of rats fed the regular diet. Furthermore, in vitro addition of indomethacin provided a restoration of IL2 production from thymocytes of rats fed the vitamin E-free diet to the level of rats fed the regular diet. These results suggest that vitamin E plays an important role in T cell differentiation in thymus, which may be related to the action of vitamin E as antioxidant.

Animals↗
PubMed1993

Ultrasound in fetal diagnosis and therapy.

Ultrasonic diagnosis is indispensable in perinatal medicine. The applications are; 1) diagnosis of early pregnancy, 2) diagnosis of fetal life, 3) diagnosis of pregnancy weeks by fetal crown rump length, 4) evaluation of fetal growth by biparietal diameter, femur length, abdominal size, or estimated fetal weight, 5) detection of early abnormalities in blighted ovum, fetal death, hydatidiform mole, ectopic pregnancy, etc., 6) diagnosis of fetal anomalies, e.g. anencephaly, hydrocephaly, neck hygraoma, diaphragmatic hernia, congenital heart disease, intestinal obstruction, renal anomalies, obstructive uropathy, etc., 7) diagnosis of fetal diseases, e.g. hydrops fetalis, 8) diagnosis of placenta previa, hydramnios, oligohydramnios, cord coiling, excessive cord twisting, 9) detection and prediction of fetal compromise by fetal and uterine blood flow velocity wave forms, 10) further precise diagnosis by transvaginal sonography, 11) interventional ultrasound in genetic diagnosis with amniocentesis and chorionic villi sampling, fetal blood sampling with cordocentesis, 12) detection of fetal hypoxia by ultrasonic fetal monitor, fetal actocardiogram, and ultrasonic Doppler flowmetry.

Female↗
PubMed1993

[Immunological aspects of asthmatic children in remission].

Allergen-activated T cells secrete several kinds of bioactive lymphokines such as IL2, IL3, IL4, IL5 and IFN-gamma. They function as helpers in IgE production involved in immediate type hypersensitivity and/or effector cells in delayed type hypersensitivity in allergic patients. The acquisition of interleukin 2 (IL2) responsiveness by specific antigen-stimulated cells is generally an essential event for the induction of specific immunological phenomena. To investigate the immunological changes in asthmatic children in remission, the induction of IL2-responsiveness and production by Df (Dermatophagoides farinae)-stimulated patient lymphocytes, and Df-induced IFN-gamma production by patient lymphocytes were evaluated. The patients were divided into 3 groups. The remission group (I) consisted of those patients who had had no or only a few asthmatic attacks for more than 2 years without medication. The group of active asthma were divided into 2 groups according to attack frequency and severity (II, partial remission; III, active asthma). IL2 responsiveness and production by Df-stimulated lymphocytes from group II and III were increased. As symptoms improved, the extent of the response subsided to a level comparable to that of normal individuals (group III). IFN-gamma production by Df-stimulated lymphocytes from patients with active asthma was lower than that of normal lymphocytes. In contrast, lymphocytes from patients in complete remission group (I) induced far greater IFN-gamma generation than those from normal and group II and III patients in a Df antigen-dependent manner, which might downregulate Df-induced hyperreactivity for Df-mediated allergic response.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[Relationship among aromatase activity, estrogen receptor and progesterone receptor in ovarian tumors from postmenopausal women].

Aromatase activity, as well as steroid receptors, has been demonstrated in ovarian tumors. Aromatase activity was detected in 35 tumors (81%), PR in 21 tumors (49%) and ER in 13 tumors (30%) out of 43 ovarian tumors (27 benign, 14 malignant and 2 granulosa cell tumors). Moreover, immunohistochemical study demonstrated aromatase cytochrome P-450 (P-450arom) in the tumor tissues. Aromatase activity was significantly greater in PR-positive tumors than in PR-negative tumors (p < 0.002). There was a positive correlation between aromatase activity and the PR level (rs = 0.490, p < 0.001). Thirteen of 14 (93%) malignant tumors showed negative PR with low aromatase activity. However, the presence of ER was not correlated with aromatase activity or the presence of PR. There was a positive correlation among serum levels of estradiol, estrone, androstenedione and testosterone, whereas the serum steroid levels were not correlated with aromatase activity, the PR or ER of ovarian tumors. These results suggest that aromatase activity is correlated with PR in ovarian tumors of postmenopausal women.

Adult↗