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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 937 records · Page 52Linked to original sources
PubMed1992

[A study of plasma atrial natriuretic peptide, antidiuretic hormone and aldosterone levels in a series of patients with intracranial disease and hyponatremia].

For intracranial diseases, plasma atrial natriuretic peptide (ANP), antidiuretic hormone (ADH) and aldosterone were determined and their effects on the development of hyponatremia with central origin were studied. The subjects were 71 cases of intracranial diseases which were admitted to our hospital during a period of 1 year from March, 1989 to March, 1990. The diseases were broken down to subarachnoid hemorrhage 26 cases, hypertensive intracerebral hemorrhage 19 cases, head injury 12 cases, cerebral infarction 11 cases and 3 other cases. Serum-urine electrolytes, plasma ANP and ADH were determined in the acute stage on Day 1 to 4, in the hyponatremia stage on Day 5 to 14 and in the chronic stage on Day 15 downward. Hyponatremia was defined as the serum sodium level of 130 mEq/l or less. Cases evidently having other causes such as heart failure and renal insufficiency were excluded. In the normal control group of persons who were admitted to our hospital for a close checkup (n = 20), plasma ANP was 26.5 +/- 11.6 pg/ml (10-50); levels of 50 pg/ml or more were regarded as abnormally high. 1) Hyponatremia was found in 18 cases (25.4%), subarachnoid hemorrhage in 7 cases, hypertensive intracerebral hemorrhage in 4 cases, head injury in 5 cases and others in 2 cases. 2) The time of onset of hyponatremia was on the 8.3 hospital day. The duration was 7.2 days. The minimum serum sodium level was 124.6 mEq/l. 3) There was no significant change in the plasma aldosterone level at each stage.2+ Predicting development of hyponatremia from plasma ADH and ANP levels in the acute stage is difficult. Inadequate secretion of ANP rather than ADH appeared to be an important factor for the development of hyponatremia, but the plasma ANP level was not always abnormally high, so involvement of other sodium diuretic factors should also be kept in mind.

Adult↗
PubMed1992

[A successful surgical treatment of ascending aortic aneurysm, left common carotid artery aneurysm and left subclavian artery obstruction due to aortitis syndrome in active phase].

A 24-year-old female was admitted complaining of coldness of left upper extremity and pulsating tumor of the neck. She was diagnosed as ascending aortic aneurysm, left common carotid artery aneurysm and left subclavian artery obstruction due to aortitis syndrome on examinations. Although steroid treatment appeared to be effective in controlling inflammatory reaction, the left common carotid artery aneurysm increased in size and severe neck pain started. The risk of rupture was feared, and surgical intervention was carried out in spite of aortitis in active phase. The patient underwent surgery where aneurysmectomy and graft replacement for ascending aortic aneurysm, aneurysmectomy and graft replacement using autogenous saphenous vein for left common carotid artery aneurysm and bypass grafting for left subclavian artery obstruction were performed. The histology of resected specimens of aortic wall showed active aortitis. The postoperative course was uneventful and the patient was discharged on steroid.

Adult↗
PubMed1992

Comparison of EEG between nasopharyngeal and scalp leads with the aid of an automatic EEG analysis system.

We analyzed the EEG quantitatively with an automatic EEG analysis system, and introduced this system for investigation the relationship between the scalp EEG and nasopharyngeal EEG. The EEG was recorded from healthy volunteers by photic stimulation. We found that components of slow waves like delta and theta were more rich but alpha component was less in the nasopharyngeal EEG than in the scalp EEG. In the analysis of the rate of the appearance of each EEG wave using photic stimulus, a decrease of alpha 1 and an increase of theta 1 are observed in the scalp EEG while there are no specific changes of them in the nasopharyngeal and scalp EEGs. The nasopharyngeal EEG obtained from the vicinity of the base of the brain was thought to originate from the vicinity of the brain stem.

Adult↗
PubMed1991

Cancer cachexia syndrome developed in nude mice bearing melanoma cells producing leukemia-inhibitory factor.

Melanoma-derived lipoprotein lipase inhibitor (MLPLI) is a factor purified from the conditioned medium of a human melanoma cell line, SEKI, which induced severe cachexia in tumor-bearing nude mice. Amino acid sequencing revealed that the amino-terminal portion was identical to that of leukemia-inhibitory factor (LIF). To determine whether MLPLI is actually LIF, the expression of LIF mRNA was examined in the SEKI melanoma cell line. Northern blot analyses revealed that the cell line displayed an intense hybridizable band with a molecular size of 3.8 kilobases, suggesting that MLPLI is identical to LIF. The relationship between the development of the cancer cachexia syndrome and the expression of LIF mRNA was examined in four melanoma xenografts, SEKI, G361, A375 and MEWO, in nude mice. SEKI- and G361-bearing nude mice developed cancer cachexia syndrome, and their body weights decreased by the 25th day after the transplantation to 73.6% and 73.8% of the control, respectively. A375- and MEWO-bearing nude mice, however, did not develop the syndrome. Northern blot analyses revealed that G361 as well as SEKI expressed a large amount of LIF mRNA, but A375 and MEWO did not, suggesting a close relationship between the expression of LIF mRNA and the development of the syndrome. These data support the concept that MLPLI, or LIF, plays an important role in the development of the cancer cachexia syndrome observed in melanoma-bearing nude mice.

Animals↗
PubMed1991

Effects of site-directed removal of N-glycosylation sites in human erythropoietin on its production and biological properties.

Erythropoietin (Epo) has three N-linked sugar chains. Codons for asparagine at N-glycosylation sites in genomic human Epo DNA were replaced with those for glutamine. The wild-type Epo gene and seven mutants that lacked N-glycosylation sites in every possible combination were introduced into baby hamster-kidney cells. To study the role of the N-linked sugars in Epo biosynthesis, Epo protein expressed transiently was measured by an enzyme-linked immunoassay. The elimination of all three N-glycosylation sites decreased Epo production to 10% of that of the wild-type Epo. Wild-type and mutant Epos produced by stably transfected cells were partially purified to investigate their properties. Removal of N-glycosylation sites changed affinity of Epo to the receptor. The in vitro activity of Epo that lost all N-glycosylation sites was comparable with that of the wild-type Epo, while the in vivo activity severely decreased. These results indicate that N-linked sugars of Epo have two major functions; N-linked sugars are important for 1) proper biosynthesis and/or secretion and 2) expression of the in vivo activity probably by enhancing survival in the circulation. N-Linked sugars of Epo affect binding affinity of the ligand to the receptor but do not play a key role in expression of the in vitro activity.

Base Sequence↗
PubMed1991

Genes encoding peroxisomal enzymes are not necessarily assigned on the same chromosome of an n-alkane-utilizable yeast Candida tropicalis.

We have resolved eight chromosomal bands from an n-alkane-assimilating yeast, Candida tropicalis pK 233, by using contour-clamped homogeneous electric field gel electrophoresis (CHEF). From the results of hybridization of DNA probes of yeast peroxisomal enzymes--catalase, acyl-CoA oxidase, carnitine acetyltransferase, isocitrate lyase, malate synthase, acetoacetyl-CoA thiolase, and 3-ketoacyl-CoA thiolase--to Southern transfers of CHEF gels, these genes were proven not necessarily to be located on the same chromosome. This fact shows that the genes encoding the enzymes tested were not distributed to be cistronic, although simultaneous and inducible synthesis of peroxisomal enzymes occurred in harmony with the proliferation of peroxisomes, suggesting that their co-ordinated expression might be mainly regulated by certain trans-acting factors.

Alkanes↗
PubMed1991

Postresection autopsy findings in patients with cancer of the main hepatic duct junction.

Extensive resection of the bile ducts combined with hepatic resection is the procedure of choice for carcinoma of the main hepatic duct junction. Currently this procedure is done without great risk, and increasing long-term survival is now the issue. For this purpose, it is necessary to elucidate the biologic properties of the cancer to take reasonable measures. Autopsy findings of patients who died of recurrence may offer a reliable guide. Autopsy findings were studied in 14 patients: eight who had undergone curative resection and six who had received noncurative resection. Cancer recurred at the liver hilum with invasion into adjacent organs. Peritoneal dissemination and lymph node metastases were infrequent. These were common findings in both curative and noncurative resection groups. Cancer cells in the connective tissue of the hepatoduodenal ligament may play a major role in recurrence.

Adenocarcinoma↗
PubMed1991

12-Deoxyphorbol 13-isobutyrate contracts isolated rat thoracic arteries.

The vasocontractile effect of 12-deoxyphorbol 13-isobutyrate (DPB), an activator of protein kinase C (PKC), was studied to clarify the mechanism of the vascontractile response elicited by activation of PKC. DPB induced both a sustained increase in intracellular Ca2+ levels and contraction in isolated rat thoracic artery. For a given increase in intracellular Ca2+ levels. DPB induced a greater contraction than high K+ or ionomycin. In Ca(2+)-free media, DPB induced concentration-dependent contraction with a slow rate of rise without causing detectable changes in intracellular Ca2+ levels. The DPB-induced contractions in Ca(2+)-free media were less inhibited by the inhibitors of calmodulin or myosin light chain kinase than ionomycin-induced contractions in normal media were. These results indicate that activation of PKC might increase the Ca2+ sensitivity of contractile elements due to mechanisms not associated with the Ca(2+)-calmodulin pathway.

Animals↗
PubMed1991

Significance of int-2/hst-1 coamplification as a prognostic factor in patients with esophageal squamous carcinoma.

The correlation between the clinical outcome in patients with esophageal squamous cell carcinoma and coamplification of the proto-oncogenes int-2 and hst-1, which are partially homologous to angiogenesis-inducing fibroblast growth factor, was analyzed retrospectively. Coamplification of these genes was examined by slot-blot hybridization using DNAs extracted from formalin-fixed and paraffin-embedded blocks of tissues. These tissues were obtained from 107 patients with esophageal squamous cell carcinoma who had undergone radical surgery. Int-2/hst-1 coamplification greater than 3-fold was observed in the primary tumors of 30 of 107 cases (28%), and in the metastatic lymph nodes of 12 of 40 cases (30%). The cumulative survival rate of patients with int-2/hst-1 coamplification in the primary tumors was significantly lower than that of the patients without coamplification (P less than 0.001), and there were no significant differences between the clinicopathological backgrounds of the 2 groups. Int-2/hst-1 coamplification was also significantly correlated with a high incidence of eventual metastasis in distant organs in these patients. These results suggest that int-2/hst-1 coamplification is a new biological indicator of prognosis and distant organ metastasis in patients with esophageal squamous cell carcinoma.

Carcinoma, Squamous Cell↗
PubMed1991

Antimicrobial and anti-plaque activity of N'-alkyl-N-(2-aminoethyl)piperidine against dental plaque bacteria.

Five N'-alkyl-N-(2-aminoethyl)piperidines were synthesized and their in vitro antimicrobial activities were tested against four micro-organisms related to dental caries (Streptococcus mutans, S. sobrinus, Actinomyces viscosus, and A. naeslundii) which are known to be implicated in dental caries. The tetradecyl and hexadecyl derivatives possessed good bacteriostatic activity. Some derivatives exhibited a rapid bactericidal effect against S. mutans and S. sobrinus in aqueous solution. These compounds also possessed surfactant properties and anti-plaque activity.

Actinomyces↗
PubMed1991

High level expression of isocitrate lyase gene of n-alkane-utilizing yeast Candida tropicalis in Saccharomyces cerevisiae.

The genomic DNA of peroxisomal isocitrate lyase (ICL) isolated from an n-alkane-assimilating yeast, Candida tropicalis, was truncated to utilize the original open reading frame under the control of the GAL7 promoter and was expressed in Saccharomyces cerevisiae. The recombinant ICL was synthesized as a functionally active enzyme with a specific activity similar to the enzyme purified from C. tropicalis, and was accounted for approximately 30% of the total extractable proteins in the yeast cells. This recombinant enzyme was easily purified to homogeneity. N-Terminal amino acid sequence, molecular masses of native form and subunit, amino acid composition, peptide maps, and kinetic parameters of the recombinant ICL were essentially the same as those of ICL purified from C. tropicalis. From these facts, S. cerevisiae was suggested to be an excellent micro-organism to highly express the genes encoding peroxisomal proteins of C. tropicalis.

Amino Acid Sequence↗
PubMed1991

Effects of dietary calcium, magnesium and phosphorus on the formation of struvite stones in the urinary tract of rats.

After feeding various diets we studied the effects of dietary calcium, magnesium and phosphorus on the formation of struvite stones in rats with urinary tract infections, and also studied the effects of the administration of vitamin D3 and aluminium gel on stone formation. A low-magnesium diet decreased urinary magnesium and prevented stone formation, but a medium-calcium diet did not significantly decrease stone weight. A high-calcium diet decreased urinary phosphorus and inhibited stone formation. A high-calcium and high-phosphorus diet decreased urinary excretion of magnesium and inhibited stone formation. Although the administration of vitamin D3 did not inhibit stone formation, aluminium gel decreased the urinary level of phosphorus and prevented stone formation. A marked decrease in urinary magnesium and/or phosphorus may prevent struvite stone formation in rats with urinary tract infections.

Aluminum↗