Search PubMed⌕ Search

Biomedical subjects

R Nakamura

Publications and source records attributed to R Nakamura.

At least 415 records · Page 23Linked to original sources
PubMed1984

Reaction times of normal subjects and amputees with below-knee and above-knee prostheses during stepping.

Reaction times (RTs) of nine normal subjects and 11 amputees with prosthetic limbs were examined in standing posture and during stepping movement. There were significant differences of RTs between standing and stepping, and between the phases of the stepping cycle in both the normal subjects and the BK or AK amputees with prosthetic limbs. The attentional demand during stepping movement and the applicability of probe RT procedure to assess prosthetic limb were briefly discussed.

Adult↗
PubMed1984

[A case of thyroid carcinoma with temporal bone metastasis].

A 34-year-old female who had received left hemi-thyroidectomy because of carcinoma of the thyroid complained of progressive deafness 5 years postoperatively. A red pulsating tumor was found in her mid-ear; it was removed incompletely. The tumor was diagnosed as a glomus jugulare tumor. The patient died at age 47 due to tumor progression. Autopsy revealed a temporal bone tumor with brain invasion; histological examination confirmed it to be a metastasis from the thyroid carcinoma. Clinical and histological details of this rare case are reported and the relevant literature is reviewed.

Adult↗
PubMed1984

[A case with intramucosal carcinoma of the esophagus in widely expanding dysplasia--an autopsy case with simultaneous double-cancer of the esophagus and sigmoid colon].

Upon autopsy of a 67-year-old male who died of recurrence and metastasis from a carcinoma of the colon, early esophageal carcinoma was found. Diffuse slight thickening and longitudinal linear thinning with brownish discoloration were found in the esophageal mucosa. Upon microscopical examination, the esophageal epithelium showed mild dysplasia, severe dysplasia or intramucosal carcinoma. A diagram of the distribution of these lesions indicated that the carcinoma arose multicentrically in the lower two-third of the esophagus and always within, or adjacent to, the area of severe dysplasia.

Adenocarcinoma↗
PubMed1984

Congenital radio-ulnar synostosis.

Thirty-three patients with congenital radio-ulnar synostosis were examined. There was one familial predisposition. Chromosomal patterns were examined in seventeen patients and were normal. Bone maturation appeared normal. The radial deviation angle, in the patients whose distal radial epiphysis had closed, was elevated (Madelung's deformity). However, in the patients whose distal epiphysis maturation score was 8, it was not elevated. On the other hand, elongation of the ulna (plus variant) and/or dorsal dislocation of the distal end of the ulna was seen in early life. In terms of treatment, all attempts to divide the two bones failed. It was found that derotation of the nonwriting hand by an osteotomy through the proximal fusion mass was a useful procedure.

Adult↗
PubMed1983

Determination of a new antibacterial agent (AT-2266) and its metabolites in plasma and urine by high-performance liquid chromatography.

A high-performance liquid chromatographic method has been developed which enables accurate determination of a new synthetic antibacterial agent, AT-2266, and its metabolite, M-2, in plasma, and AT-2266 and its five metabolites, M-1, M-2, M-3, M-4 and M-5, in urine. AT-2266 is extracted as ethyl carbamate with chloroform containing 1% ethyl chloroformate and assayed on a liquid chromatograph equipped with an ultraviolet detector at 340 nm. Accurate determinations are possible over a concentration range of 0.1-10 micrograms/ml AT-2266 in plasma, and 1-500 micrograms/ml AT-2266 in urine. The coefficient of variation at the 2 micrograms/ml level of AT-2266 is 1.9% (n = 6). The minimum detectable concentrations of AT-2266 in plasma and urine are 0.01 micrograms/ml and 0.1 micrograms/ml, respectively, and those of other metabolites are similar to those of AT-2266. Plasma levels and urinary excretion of AT-2266 in a man following single oral administration (400 mg) have also been determined.

Anti-Infective Agents↗
PubMed1983

Ovomucoid and ovoinhibitor isolated from chicken egg white are immunologically cross-reactive.

Ovomucoid and ovoinhibitor were isolated from chicken egg white. Enzyme-linked immunosorbent assay (ELISA) and affinity chromatography of ovoinhibitor-coupled Sepharose 4B showed that about 25% of rabbit anti-ovomucoid antibody reacted with ovoinhibitor. Ovoinhibitor required about 1000 times the concentration of ovomucoid to give 50% inhibition of anti-ovomucoid antibody binding to ovoinhibitor in the plate-binding ELISA. These results suggested that ovoinhibitor possesses antigenic determinants which are conformationally homologous with those of ovomucoid and cross-react with anti-ovomucoid antibodies.

Animals↗
PubMed1983

An increase in high-molecular weight renin substrate associated with estrogenic hypertension.

We have previously reported that estrogens have the potential to induce new forms of renin substrate in addition to elevating the major circulating form of this protein. One of these estrogen-induced forms had a molecular weight in excess of 150,000. In this study we have compared the plasma concentration of the high-molecular-weight renin substrate in normotensive women receiving estrogen therapy and women with estrogenic hypertension. A statistically significant elevation of this protein was associated with estrogenic hypertension and normotensive pregnant women at term. This form of renin substrate differed from the major form with respect to electrophoretic mobility, isoelectric point, and immunologic cross-reactivity. In addition, kinetic analysis indicated that this high-molecular-weight substrate has a significantly higher affinity for the enzyme renin than the major circulating form (Km = 1800 +/- 290 versus 3520 +/- 260 ng angiotensin I equivalents/ml). These results suggest that in addition to renin substrate concentration, substrate composition may play an important role in blood pressure regulation.

Adult↗
PubMed1983

Ecological studies of Yersinia enterocolitica. I. Dissemination of Y. enterocolitica in pigs.

Pigs were examined on five farms for carrier status of Yersinia enterocolitica. Yersinia enterocolitica biovar 4, serovar 3, phagovar VIII was isolated consistently from the feces of fattening pigs on one farm and sporadically from those of similar pigs on the other farms and of sows on all five farms, during a one-year period of weekly surveys. Seasonal variation was not a feature of fattening pigs on a highly contaminated farm. In other pigs, however, the organisms were not isolated during the summer months. On a highly contaminated farm, the organisms were excreted in the feces of 8 to 15-week-old pigs within 1-3 weeks of entering pens which were thought to be contaminated with the organisms. On a detailed observation of natural infection of Y. enterocolitica in eight pigs, the organism appeared in the pigs' feces within 2-7 weeks of them being moved to a pen which had been washed thoroughly after becoming contaminated, by a previous group of pigs, with feces containing 10(5) viable organisms per g. Thus, Y. enterocolitica is apparently transmitted from infected feces or picked up from the floor of a contaminated pen, and the regular schedule of pig movement among the pens is an important factor in the spread of Y. enterocolitica within a piggery. Intestinal colonization continues for a long time and does not occur by re-infection. The organisms were not isolated from eight pigs at the time of slaughter, and their serum O-agglutinin titers were 1/40 or less. Thus, circulating antibody may not inhibit intestinal colonization by Y. enterocolitica.

Age Factors↗
PubMed1983

Blocking effect of trypsin associated with ovomucoid on the antibody binding to ovomucoid.

Ovomucoid-trypsin association complex was prepared by incubating chicken egg white ovomucoid with bovine trypsin. The reactivity of ovomucoid-trypsin complex was investigated by immunodiffusion, quantitative precipitation and enzyme-linked immunosorbent assay (ELISA). It was demonstrated that the association of trypsin with ovomucoid hindered the binding of the specific antibody at some antigenic sites of ovomucoid by lowering the antibody-binding affinity of these sites. The anti-ovomucoid antiserum was absorbed with ovomucoid-trypsin complex, and non-absorbed antibody was collected by immunoaffinity chromatography of ovomucoid-coupled Sepharose 4B. The antibody blocked the trypsin-inhibitory activity of ovomucoid in a molar ratio (antibody/ovomucoid) of about 1.2:1. The findings suggested that at least one antigenic site is located near the reactive site of trypsin inhibition (Arg89 decreases Ala90) of ovomucoid.

Animals↗
PubMed1983

Effect of metoclopramide on the secretion of aldosterone and other adrenocortical steroids.

The aim of this study was to determine the effect of metoclopramide, a dopamine antagonist, on the secretion of aldosterone and other adrenocortical steroids in normal subjects. An i.v. bolus injection of 10 mg of metoclopramide significantly increased the plasma PRL, plasma aldosterone and 18-hydroxycorticosterone, but the plasma renin activity, plasma deoxycorticosterone, corticosterone and cortisol remained unchanged. The changes in plasma aldosterone induced by metoclopramide were significantly correlated with the basal levels of plasma aldosterone and renin activity. These results suggest that the response of plasma aldosterone to metoclopramide in normal subjects is influenced by the basal activity of renin-angiotensin-aldosterone system and the late step of aldosterone synthesis is stimulated by metoclopramide.

18-Hydroxycorticosterone↗
PubMed1983

Insulin binding sites in various segments of the rabbit nephron.

Insulin binds specifically to basolateral renal cortical membranes and modifies tubular electrolyte transport, but the target sites of this hormone in the nephron have not been identified. Using a microassay that permits measurement of hormone binding in discrete tubule segments we have determined the binding sites of 125I-insulin along the rabbit nephron. Assays were performed under conditions that minimize insulin degradation, and specific binding was measured as the difference between 125I-insulin bound in the presence or absence of excess (10(-5) M) unlabeled hormone. Insulin monoiodinated in position A14 was used in all assays. Specific insulin binding (attomol . cm-1 +/- SE) was highest in the distal convoluted tubule (180.5 +/- 15.0) and medullary thick ascending limb of Henle's loop (132.9 +/- 14.6), followed by the proximal convoluted and straight tubule. When expressed per milligram protein, insulin binding capacity was highest along the entire thick ascending limb (medullary and cortical portions) and the distal convoluted tubule, i.e., the "diluting segment" (congruent to 10(-13) mol . mg protein-1), and was lower (congruent to 4 X 10(-14) mol . mg protein-1), and remarkably similar, in all other nephron segments. Binding specificity was verified in competition studies with unlabeled insulin, insulin analogues (proinsulin and desoctapeptide insulin), and unrelated hormones (glucagon, 1-34 parathyroid hormone, prolactin, follicle-stimulating hormone). In addition, serum containing antiinsulin receptor antibody from two patients with type B insulin resistance syndrome markedly inhibited insulin binding to isolated tubules. Whether calculated per unit tubule length or protein content, insulin binding is highest in the thick ascending limb and the distal convoluted tubule, the same nephron sites where a regulatory role in sodium transport has been postulated for this hormone.

Animals↗
PubMed1983

Purification and some properties of neuraminidase isolated from the culture medium of oral bacterium Streptococcus mitis ATCC 9811.

Neuraminidase acting on the salivary bacterial agglutinating factor was isolated and purified from the culture medium of Streptococcus mitis ATCC 9811. The molecular weight and the isoelectric point of the enzyme were determined to be 42,000 and a pH of 4.6, respectively. The enzyme showed high activity against human glycoprotein substrates, especially the salivary bacterial agglutinating factor.

Electrophoresis, Polyacrylamide Gel↗
PubMed1983

Effects of porcine gastrin-releasing peptide on amylase release, 2-deoxyglucose uptake, and alpha-aminoisobutyric acid uptake in mouse pancreatic acini.

The effects of synthetic porcine gastrin-releasing peptide (pGRP), a recently isolated gut hormone, were studied in isolated mouse pancreatic acini. pGRP was found to exert direct effects on amylase release, 2-deoxyglucose ( [3H] 2DG) uptake, and alpha-aminoisobutyric acid (AIB) uptake. The stimulatory effect of pGRP on amylase release was significant at 100 pM, and maximal at 1 nM. Higher concentrations of pGRP exerted a smaller stimulatory effect on amylase release. pGRP also increased [3H]2DG uptake, exerting a detectable effect at 300 pM, and a maximal effect at 30 nM. In contrast to its stimulatory effect on amylase release and [3H]2DG uptake, pGRP inhibited AIB uptake. A significant inhibitory effect on AIB uptake occurred at 100 pM, and a maximal inhibitory effect occurred at 3 nM. Dose-response curves of pGRP for amylase release and AIB uptake were found to be biphasic. Bombesin was also found to stimulate amylase release with a biphasic dose-response curve in mouse acini. Both cholecystokinin (CCK) octapeptide and the cholinergic analog carbachol exerted similar effects in isolated mouse acini. However, the effects of pGRP were not inhibited by either dibutyryl cyclic guanosine 3',5'-monophosphate or atropine, whereas the effects of CCK octapeptide were inhibited by dibutyryl cyclic guanosine 3',5'-monophosphate and the effects of carbachol were inhibited by atropine. These results indicate that pGRP can mimic the biological effects of CCK and acetylcholine, but that its actions are probably mediated via a separate class of receptors in mouse acini.

Aminoisobutyric Acids↗