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Biomedical subjects

A Ueda

Publications and source records attributed to A Ueda.

At least 91 records · Page 5Linked to original sources
PubMed1998

Prolonged suppressed thyroid-stimulating hormone levels in hyperthyroidism in a neonate born to a mother with Graves' disease.

We report here a case of neonatal hyperthyroidism born to a mother, whose pregnancy was complicated by poorly controlled Graves' disease. The patient demonstrated exophthalmos and marked goiter at birth, indicating the existence of thyrotoxicosis in utero. The mother's Graves' disease was well controlled in the third trimester, resulting in a slightly lower level of free thyroxine (FT4) in the umbilical cord blood serum; however, thyroid-stimulating hormone (TSH) was undetectable. Thyroid-stimulating hormone remained undetectable for 2 months, while FT4 levels varied in the course. This case suggests that severe and prolonged thyrotoxicosis in utero, due to poor control of pregnancy with Graves' disease, might induce unresponsiveness of the hypothalamo-pituitary system in the newborn.

Female↗
PubMed1998

Biosynthesis of methylguanidine in the hepatic peroxisomes and the effect of the induction of peroxisomal enzymes by clofibrate.

A state of peroxidation is one of the factors contributing to uremia. For example, we have reported that certain species of reactive oxygen, particularly the hydroxyl radical, play an important role in the biosynthesis of methylguanidine which contributes to toxicity in patients with uremia. However, it is uncertain which enzymes are involved in the synthesis of methylguanidine from creatinine. In this study, we attempt to show methylguanidine synthesis in the presence of peroxisomal enzymes that catalyze the beta-oxidation of fatty acids. In addition, we investigate the effect of clofibrate, which induces peroxisomal enzymes or glutathione peroxidase activity, on methylguanidine synthesis in the peroxisomal fraction. Male Wistar rats were fed with the chow containing 0.5% clofibrate to induce peroxisomal enzymes and control rats were fed with ordinary laboratory chow. Peroxisomal fractions were obtained from liver homogenates by centrifugation, and incubated with creatinine in 0.1 M potassium phosphate buffer pH 7.4 at 37 degrees C. Results show that methylguanidine is synthesized from creatinine concomitant with the synthesis of hydrogen peroxide from endogenous substrates in the peroxisomal fraction. This methylguanidine synthesis is inhibited by the addition of dimethylsulfoxide, glutathione, or sodium azide (p < 0.01). The rate of methylguanidine synthesis in clofibrate-treated rats was significantly less than that in control rats (p < 0.02). These results suggest that methylguanidine is synthesized in the peroxisomal fraction, and reactive oxygen species which are generated through this enzymatic reaction, participate in methylguanidine synthesis. Moreover, the induction of a scavenger system, especially glutathione peroxidase takes precedent over the generation of reactive oxygen species in peroxisomes treated with clofibrate.

Animals↗
PubMed1998

[An analysis on a relationship between perinatal mortality and live births of low birthweight, in Kumamoto Prefecture, 1968-1994].

The aims of this investigation were to describe the relationship between perinatal mortality rates and the proportions of live births among low birth weight (LBW) infants from 1968 to 1994, and to determine risk factors in infants of low birth weight. Using vital statistics from 1968 to 1994 of the Japanese government and the Kumamoto Prefecture and Maternal and Child Health Statistics of Japan from 1968 to 1995, perinatal deaths and live births of infants of low birth weight were studied according to national statistics criteria. In Japanese and Kumamoto Prefecture, there was an association between perinatal deaths and live births of LBW. The significant decline of perinatal mortality rates from 1968 to 1976, of which the fetal death ratio at 28 weeks and over mostly declined, was closely related to the decline of live births of LBW. In this period, the improvement of socioeconomic conditions and the comprehensive health care provided by the government contributed in improving perinatal mortality rates. From 1977 to 1988, the annual variation of Kumamoto was different from that of all Japan. Both perinatal mortality rates continued to decline due to a general decrease in early neonatal mortality rates. The number of Live births of LBW infants in Kumamoto prefecture increased in 1977 and once again started to decline in 1982. In 1977, the insufficient maternal-child health care and the increase of female workers contributed to increasing rates of live births of LBW. Advances in neonatal medicine contributed to the increase in survival rates of infants of LBW. Although, after 1982, the improvement of maternal-child health care and the perinatal care system contributed to the declining rates of live births of LBW. On the other hand, those rates in all Japan continued to gradually increase from 1977 to 1988. After 1989, perinatal mortality rates continued to decline, and live births of LBW continued to increase in both Kumamoto prefecture and all Japan. These results were contrary to the above results from 1968 to 1976. It was considered that medical advances in the care of pregnant women and neonates increased survival rates of the LBW. In future, the perinatal mortality rates will appear to approach a minimum constant, that is, a minimum of fetal death rates. It is important to reduce the number of LBW infants, particularly birthweight of 2000 g-2499 g, with maternal-child health care.

Birth Weight↗
PubMed1998

Catalase catalyzes of peroxynitrite-mediated phenolic nitration.

Catalase catalyzed the peroxynitrite-mediated nitration of 4-hydroxyphenylacetic acid. The curve for the pH dependence of nitration was similar to that for the reaction between peroxynitrite and phenol. Cyanide, azide, and 3-amino-1,2,4-triazole inhibited the nitration in a dose-dependent way. When catalase was mixed with peroxynitrite, Compound I was detected as an intermediate. Because azide was an electron donor for the peroxidatic action of catalase, and because 3-amino-1,2,4-triazole inhibited catalase activity by binding with Compound I, peroxynitrite-mediated phenolic nitration was probably accompanied by Compound I formation. Both catalase and superoxide dismutase protected Escherichia coli from peroxynitrite toxicity.

Animals↗
PubMed1998

Left postpneumonectomy syndrome successfully treated with endobronchial stent.

We describe a case of left pneumothorax-induced left postpneumonectomy syndrome in the absence of anatomical anomalies developing at 10 years after the operation. We placed an endobronchial stent into the right truncus intermidius and the procedure resulted in recovery of the syndrome. We consider endobronchial stent placement as an effective treatment for postpneumonectomy syndrome, especially when surgical management is not feasible.

Aged↗
PubMed1998

Does electrical stimulation of the sciatic nerve prevent suspension-induced changes in rat hindlimb bones?

Osteoporosis due to mineral loss is a major health problem resulting from long-term spaceflight. The development of a suitable countermeasure is essential because an advanced decrease in bone density could be irreversible. Therefore the current study was performed to test our hypothesis that the loading of bones by electrical stimulation-induced muscle contraction may prevent the mineral loss caused by gravitational unloading and bone growth will be maintained. During 10 d of hindlimb suspension, electrical stimulation at 1, 50, or 100 Hz was administered through the left sciatic nerve at the gluteal region of rats with approximately 300 g body weight. The dry weight, mineral content, and mineral density in hindlimb bones were analyzed. The dry weight and mineral content of femur and tibia-fibula in hindlimb-suspended rats tended to be less than in the age-matched cage controls. However, these detrimental effects were prevented by stimulation at 50 and 100 Hz. A positive effect of stimulation was seen even in the nonstimulated limb, although greater effect was induced in the stimulated limb. It is suggested that loading by stimulation-induced muscle contraction at higher frequencies is beneficial for the maintenance of bone growth or the prevention of mineral loss, or both, during hindlimb suspension in rats.

Animals↗
PubMed1998

[Two cases of Churg-Strauss syndrome with impaired prognosis].

We report two cases of Churg-Strauss syndrome with impaired prognosis. Case 1: A 58-year-old woman started to complain of progressive dysesthesia and muscle weakness of the lower extremities on February 6, 1992 and was admitted to our hospital eight days later. The eosinophil count was 1, 170/microliters and chest X-ray on admission revealed bilateral diffuse interstitial shadows. Necrosis of muscle fibers and significant infiltration of eosinophils into vessel walls were histopathologically demonstrated. Case 2: A 69-year-old woman was admitted to our hospital with productive cough and back pain. An expiratory wheeze was audible in all lung fields and bronchial asthma was diagnosed. Laboratory findings showed eosinophilia (8, 550/microliters), an IgE level of 16, 266 IU/ml and no positive data for allergic bronchopulmonary aspergillosis. A biopsy of subcutaneous nodules in the lower extremity revealed significant edema of vessel walls and infiltration eosinophils and lymphocytes. Churg-Strauss syndrome was diagnosed in both cases, and corticosteroid therapy was successful in alleviating eosinophilia. However, symptoms of vasculitis in case 1, including mononeuritis multiplex, did not improve, and cardiomyopathy in case 2 progressively worsened. Particularly in elderly patients, it is very important to make an early diagnosis and to initiate therapy that does not disturb quality of life, even for diseases generally regarded as having a good or fair prognosis.

Aged↗
PubMed1998

Adsorption of salivary proteins and serum proteins to titanium.

Titanium (Ti) is very effective as a dental implant material owing to its low toxicity and high biocompatibility. I carried out in vitro experiments on the adsorption of salivary proteins and serum proteins to Ti to better understand how this material reacts in the oral cavity. I found that when Ti that had adsorbed serum proteins was exposed to salivary proteins, there was an exchange of the proteins on the Ti surface. The same thing happened when Ti that had adsorbed salivary proteins was exposed to serum proteins. These results suggest that both human salivary proteins and serum proteins adsorb to Ti with different affinity, and that protein already adsorbed to Ti might mask binding sites for other proteins.

Adsorption↗
PubMed1998

[Orbital and stomach metastasis from invasive lobular breast carcinoma].

Orbital or ocular metastatic tumors may originate from breast cancer. Few studies have been made regarding their histopathological classification. A 71-year-old female noted a tumor in the right orbital region. She had had bilateral breast cancer 2 years before and gastric cancer 5 months before. Histopathology had shown stage II invasive ductal cancer (scirrhus) in the right breast and stage III invasive lobular cancer in the left. Signet-ring cells were present in the breast and gastric cancers. Biopsy of the right lower eyelid showed poorly differentiated adenocarcinoma with signet-ring cells. Indian file pattern, which is specific for invasive lobular cancer, was also present, suggesting that the orbital tumor had metastatized from the left breast cancer. Genetic analysis of the gastric cancer using polymerase chain reaction showed a mutation at exon 8 of the p53 tumor suppressor gene, indicating the cancer to be metastatic. These results led to the conclusion that invasive lobular cancer of the left breast was the primary lesion for the gastric and orbital metastases. This case also illustrates that signet-ring cells, which are usually seen in gastric cancer, may be present in invasive lobular breast cancer and in orbital metastasis.

Aged↗
PubMed1997

Radioimmunoassay for a novel lignan-related hypocholesterolemic agent, S-8921, in human plasma after high-performance liquid chromatography purification and in human urine after immunoaffinity extraction.

The novel compound methyl-1-(3,4-dimethoxyphenyl)-3-(3-ethylvaleryl)-4-hydroxy-6,7,8- trimethoxy-2-naphthoate (S-8921) has hypocholesterolemic activity in animals and is expected to exhibit a similar activity in human. Reversed-phase high-performance liquid chromatography (HPLC) separation followed by radioimmunoassay (RIA) for human plasma samples (HPLC-RIA) and immunoaffinity extraction (IAE) followed by RIA for human urine samples (IAE-RIA) were developed for investigation of S-8921 behavior in clinical studies. For the RIA, antisera from rabbit and a radioiodine-labelled S-8921 were prepared by immunizing a conjugate of S-8921 with bovine serum albumin and by the Bolton and Hunter method, respectively. HPLC-RIA using a semi-micro column was very sensitive, that is a 0.05 ng/ml limit of quantitation in human plasma, and specific for unchanged form of S-8921. IAE-RIA using a centrifugal filtration tube completely eliminated the matrix effect of human urine, and was very feasible. The limit of quantitation was 0.10 ng/ml. RIA detection following HPLC or IAE proved to be very useful for the pharmaceutical analysis of extremely low drug concentrations in body fluids.

Anticholesteremic Agents↗
PubMed1997

Transcriptional regulation of the human monocyte chemoattractant protein-1 gene. Cooperation of two NF-kappaB sites and NF-kappaB/Rel subunit specificity.

Human monocyte chemoattractant protein-1 (human MCP-1) mRNA accumulated in THP-1 cells 2 h after lipopolysaccharide (LPS) stimulation. DNase I footprinting revealed that LPS stimulation induced protein binding to the two closely located NF-kappaB sites, A1 and A2. By electrophoretic gel mobility shift assay and supershift assay, the binding of (p65)2, c-Rel/p65, p50/p65, and p50/c-Rel to the A2 oligonucleotide probe was detected after LPS stimulation. In contrast, 12-o-tetradecanoylphorbol 13-acetate did not induce a significant amount of MCP-1 mRNA in THP-1 cells 2 h after stimulation, and only p50/p65 bound to the A2 probe. trans-Activity of each NF-kappaB/Rel dimer was investigated by transfecting P19 cells with p65, p50, and/or c-Rel expression vectors, and a luciferase construct containing the enhancer region of the human MCP-1 gene. Expression of recombinant p65 or p65 and c-Rel resulted in elevated luciferase activities, indicating that (p65)2 and c-Rel/p65 had trans-activity. The binding of (p65)2 and/or c-Rel/p65 to the A2 probe was also detected from 12-o-tetradecanoylphorbol 13-acetate-stimulated HeLa, HOS, and A172 cells in which expression of MCP-1 mRNA was elevated. Finally, the role of the A1 site was investigated. Both (p65)2 and c-Rel/p65 bound to the A1 probe by electrophoretic mobility shift assay and a mutation in the A1 or A2 site resulted in a loss of the enhancer activity. These results suggest that the binding of (p65)2 and c-Rel/p65 to the A1 and A2 sites of this gene is important for the tissue- and stimulus-specific transcription of the human MCP-1 gene.

Base Sequence↗
PubMed1997

Antioxidant activity of polyphenolics in diets. Rate constants of reactions of chlorogenic acid and caffeic acid with reactive species of oxygen and nitrogen.

Phenolic non-flavonoid compounds in diets, such as chlorogenic acid and caffeic acid are widely recognized to be antioxidants. However, it is not known how these phenolics scavenge reactive species of oxygen and nitrogen. We determined the rate constants of the reactions between the phenolics with superoxide and hydroxyl radical with a pulse radiolysis. The second-order rate constants of the reactions of chlorogenic acid with superoxide and hydroxyl radical were 1.67 +/- 0.14 x 10(6) M(-1) s(-1) and 3.34 +/- 0.19 x 10(9) M(-1) s(-1), respectively, while those of caffeic acid with superoxide and hydroxyl radical were 0.96 +/- 0.01 x 10(6) M(-1) s(-1) and 3.24 +/- 0.12 x 10(9) M(-1) s(-1), respectively. By scavenging peroxy radical chlorogenic acid inhibited the initiation of chain lipid peroxidations by organic free radical. The second-order rate constant of the reaction of chlorogenic acid with peroxy radical was estimated to be 1.28 +/- 0.11 x 10(5) M(-1) s(-1). Chlorogenic acid was rapidly oxidized by peroxynitrite in concentration- and pH-dependent manners and its rate constant was determined to be 1.6 +/- 0.7 x 10(5) M(-1) s(-1), using competitive inhibitions by glutathione and methionine.

Antioxidants↗
PubMed1997

A novel nonenzymatic pathway for the generation of nitric oxide by the reaction of hydrogen peroxide and D- or L-arginine.

Nitric oxide (NO) is a biologically active molecule known to be enzymatically synthesized from L-arginine in the presence of NO synthetase (NOS). In this study, we demonstrate a novel non-enzymatic pathway for NO synthesis involving hydrogen peroxide and D- or L-arginine. We employed two measures of NO generation. The first consists in the demonstration of the oxidative metabolites of NO (NO2 + NO3 = NOx) and the second is the confirmatory finding of chemiluminescence derived from NO. The results show that NOx increases in the incubation mixture containing hydrogen peroxide coupled with D-arginine, L-arginine, L-canavanine, and even the NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). However, chemiluminescence was detected only from the reactions of hydrogen peroxide and D- or L-arginine and was diminished by the addition of carboxy-2-phenyl-4, 4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (PTIO), a specific scavenger of NO, confirming NO generation in the reaction.

Amino Acids↗
PubMed1997

The immunosuppressive effect of fresh allogeneic bone graft in mice.

We investigated the immunosuppressive effect of fresh bone allografts after donor specific spleen cell transfusion in mice. Allografts from major histocompatibility complex incompatible mice were performed one week after the transfusion. Cellular and humoral immune responses were recorded by measuring alloreactive cytotoxic T-lymphocyte activity and antibody activity. Survival in days of a second set skin graft was measured for determining clinical immunity. Alloreactive cytotoxic T-lymphocyte activity was stimulated at 17 days (10 days after bone grafting) and then suppressed at 31 days (24 days after bone grafting). The survival of the second set skin graft was not diminished at this time. This outcome indicates that the spleen cell stimulated cellular immune response was suppressed after fresh bone allografts, suggesting that these allografts have an immunosuppressive effect and induce immunosuppressive actions.

Animals↗
PubMed1997

Thiobarbituric acid reactive substances are increased in the subcutaneous fat tissue of patients with end-stage renal disease.

BACKGROUND: Patients with end-stage renal disease are thought to be in a highly peroxidative state, based on studies showing decreased serum antioxidant activity and increased peroxidative products. In this study we confirm these findings by examining lipid peroxidation in subcutaneous fat tissue in uraemia. SUBJECTS AND METHODS: Twenty-seven subcutaneous fat samples were taken from patients with end-stage renal disease when they underwent intervention for arteriovenous fistula for haemodialyis or for catheter insertion for continuous ambulatory peritoneal dialysis. The control samples were taken from 11 patients with normal renal function and without any history of renal disease who had surgical interventions. Lipid peroxides were measured as thiobarbituric acid reactive substance. RESULTS: The concentration of thiobarbituric acid reactive substances in subcutaneous fat tissue in the patients with end-stage renal disease is 1.223 +/- 0.636 nmol/mg fat tissue (mean +/- SD) whereas the level in the control group is 0.097 +/- 0.054 nmol/mg fat tissue. A comparison of the two groups by Student's t test revealed a highly significant difference (P < 0.001). CONCLUSIONS: This study supports the finding of a severe peroxidative state in patients with end-stage renal disease.

Adipose Tissue↗
PubMed1997

[Investigation of bone mineral distribution in Japanese using dual-energy X-ray absorptiometry].

To investigate bone mineral distribution in humans, the authors conducted a cross-sectional survey of, and performed bone-density measurements on, 1,310 healthy Japanese ranging in age 5 to 85 years. Eight hundred fifty-eight of the subjects were female, and 452 were male. Arm, leg, and spine bone mineral content (BMC) and bone mineral density (BMD) were assessed by dual-energy X-ray absorptiometry (DXA), and the subjects were divided into 5-year age groups. BMD showed increases with skeletal growth until reaching a peak at 15 to 19 years in females, and 25 to 29 for males. For both sexes the fastest growth to maturity in terms of bone mass values was in the late 20s. Females, though, had higher arm, leg, and spine remodeling rates than males. In premenopausal women no changes in arm, leg or spine BMC and BMD were observed. Postmenopausal women showed an overall reduction in bone mass, most noticeably in the spine. After menopause, women had about 10 years of accelerated loss (1.46%/year). Vertebral BMD values were similar for men and women (1.10 +/- 0.20g/cm2 for males vs. 1.09 +/- 0.14g/cm2 for females, p > 0.05). BMC values were significantly higher in males, and males at all times had a higher arm and leg BMD. There were no significant value differences in either sex for left and right leg BMC and BMD; however, from the age of 15, right arm values were significantly higher likely due to right handedness. For both sexes the order of BMC and BMD was leg, spine, and arm.

Absorptiometry, Photon↗