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Biomedical subjects

A Hara

Publications and source records attributed to A Hara.

At least 649 records · Page 36Linked to original sources

Chemiluminescent immunoassay (CLIA) for salmon growth hormone (GH).

A highly sensitive and specific chemiluminescent immunoassay (CLIA) was developed for quantification of growth hormone (GH) in salmonid species. The CLIA for salmon GH was performed using the sandwich method with anti-GH IgG as the first antibody and chemiluminescent acridinium ester-labelled specific anti-GH F(ab')2 as the second antibody. The measurable range of salmon GH in the CLIA was 39-1250 pg/mL using a short assay (1 day) protocol and 3.9-125 pg/mL in a longer (2-day) assay. The dilution curve in the CLIA of serum from masu salmon (Oncorhynchus masou) was parallel to the standard curve of recombinant chum salmon (Oncorhynchus keta) GH. Seasonal changes of serum GH levels were measured in 1 year-old masu salmon cultivated in a pond from March to November. Their serum GH levels increased during smoltification from March to April, achieved a maximum level of 21 ng/mL in August, and then declined gradually to 11 ng/mL in October.

Animals↗

Immune complex transfer two-site chemiluminescent immunoassay for serum growth hormone in alevin chum salmon.

An immune complex transfer two-site chemiluminescent immunoassay (CLIA) for salmon growth hormone (GH) was developed to measure serum GH in alevin chum salmon (Oncorhynchus keta) using a chemiluminescent acridinium ester as a label. The immune complex transfer method dramatically reduced non-specifically bound of acridinium ester labelled antibody without a decrease in the specific binding. Consequently, we could detect lower levels of GH than achieved previously in a two-site CLIA for salmon GH. The detection limit of the assay was 7.8 fg/ml and the standard curve was linear up to 250 fg/ml. Coefficients of variation were 2.2-7.7% within-assay and 5.3-91% between-assay. We have developed a highly sensitive and reproducible GH method and applied it to measurement of GH in alevin chum salmon.

Acridines↗

Hepatic perfusion abnormalities in acute pancreatitis: CT appearance and clinical importance.

BACKGROUND: The purpose of the present study was to describe the computed tomography (CT) appearances of transient hepatic attenuation differences (THADs) in patients with acute pancreatitis and to discuss the mechanism of THAD. METHODS: Two-phase dynamic CT images of 28 patients with acute pancreatitis were reviewed. Among them, THAD was seen in nine patients. All patients underwent ultrasonography, and four patients with THAD underwent surgery. RESULTS: Three types of THAD (THAD adjacent to the gallbladder in five of 28 patients, THAD with left lobar distribution in three of 28, wedge-shaped THAD in one of 28) were seen on the two-phase dynamic CT scans of patients with acute pancreatitis. In five patients, THAD disappeared when acute pancreatitis had subsided. CONCLUSIONS: THAD in acute pancreatitis is probably caused by increased arterial blood flow attributable to the inflamed lobe of the liver or the inflamed gallbladder. THAD in acute pancreatitis should not be confused with primary liver abnormalities.

Acute Disease↗

A peculiar immunoglobulin M (IgM) identified in eggs of chum salmon (Oncorhynchus keta).

A protein reacting with antibody against chum salmon serum IgM was found in salmon egg yolk. The protein tentatively named IgM-like protein was partially purified from egg yolk extract by removal of euglobulin from the extract by dialysis against a low ionic strength buffer following DEAE ion-exchange chromatography. The IgM-like protein was antigenically identical with serum IgM, showing a complete fusion of precipitin line of the IgM-like protein with that of serum IgM on double immunodiffusion with antiserum IgM. The molecular weight of intact IgM-like protein was assessed by 3% SDS-PAGE to be 495 kDa, smaller than that of serum IgM (750 kDa). Upon 10% SDS-PAGE with mercaptane and subsequent Western blotting with antiserum IgM, the IgM-like protein separated into three components with molecular weights of 68 kDa, 51.5 kDa, and 23 kDa. The 68 kDa, the most minor component, and the 23 kDa, the smallest molecular weight component, were identified, respectively, as H and L chain in view of their molecular weights identical to those of serum IgM. The 51.5 kDa, the main component, was also identified as H chain, since it reacted with antiserum IgM absorbed with purified L chain. From these results, it was concluded that the IgM-like protein in egg yolk, having a lower molecular weight than that of serum IgM, consists of H chain of smaller molecular weight as well as H and L chain of ordinary molecular weight.

Animals↗

Lens reconstruction after mature cataract in SCR rat.

PURPOSE: To conduct a long-term observation study of SCR rats that had developed a mature cataract at 11 weeks of age at 3-month intervals until the rats were 12 months old. METHODS: Lenses of 15 rats were examined with both light and electron microscopes. RESULTS: At 12 weeks, opacity was observed in the perinuclear zone and the cortical intermediate layer. Liquefaction of the posterior subcapsular area and regression of cortical superficial fibers were also observed at this stage. Epithelial cells at the anterior polar area were multilayered. At 12 months, the lens recovered as a result of the regenerated lens fibers in the intermediate layer and the cortical superficial layer, although the opacity remained in the perinuclear zone. The multilayered cellular structure in the center of the epithelium returned to its original monolayer form. However, the equatorial epithelial cells became vacuolated and swollen with age, showing regression from the bow region. CONCLUSIONS: These results suggest that the decrease of opacity in SCR rats is merely a temporary phenomenon that reflects the differentiating and metabolizing functions of the epithelial cells. With initiation of epithelial regression, the regeneration of the lens fibers ceased, suggesting that further decrease in opacity was no longer possible.

Animals↗

Spared flow tract within the mural thrombus of an aortic aneurysm: its pathogenesis and clinical importance.

The purpose of this case report is to determine the unique pathogenesis of a "spared flow tract" through a thick mural thrombus of an aortic aneurysm mimicking the penetrating or dissecting tract of an impending or acute rupture of an abdominal aortic aneurysm (AAA) and to discuss its clinical importance. Three blood flow tracts (i.e., spared flow tracts) penetrating to aortic major branches (inferior mesenteric arteries in two and left renal artery in one) through thick mural thrombi of three aortic aneurysms were found on thin section spiral CT scans. Histopathological examination revealed that the tracts were formed by thrombi and partially covered with endothelial cells. In conclusion, spared flow tracts may be pathways continuing to the aortic major branches through thick mural thrombi of aortic aneurysms and are spared from thrombogenesis because of relatively high blood flows. Their pathogenesis is definitely different from penetrating or dissecting tracts within mural thrombi of ruptured AAAs. Spared flow tracts should not be misinterpreted as penetrating or dissecting tracts of impending or acute rupture.

Acute Disease↗

Molecular cloning of a gene encoding acid alpha-glucosidase from Tetrahymena pyriformis.

Lysosomal acid alpha-glucosidase is essential for the degradation of glycogen to glucose in lysosomes. The ciliated protozoan Tetrahymena pyriformis secretes acid alpha-glucosidase into its culture medium. We have earlier reported the purification and characterization of acid alpha-glucosidase from T. pyriformis. The exact molecular mechanism of secretion of this enzyme has not yet been clarified. In the present study we have isolated a full length cDNA clone encoding acid alpha-glucosidase from T. pyriformis. The isolated clone (3019 bp) contained an open reading frame encoding 923 amino acids, and has an estimated molecular mass of 104 kDa. Northern blot analysis revealed that the isolated cDNA hybridized to a 2.8-kb mRNA transcript. N-terminal amino acids after the first methionine fulfilled the requirement of a signal peptide. The deduced amino acid sequence contains the amino acid sequences determined of several peptides derived from the purified enzyme, and was found to have 34% identity and 45% similarity with that of human lysosomal enzyme, with 75% identity in the 16 amino acids at the proposed active site.

Amino Acid Sequence↗

Measurement and calculation of neutron leakage from a medical electron accelerator.

The leakage neutron spectra and dose equivalent were systematically measured in the irradiation field, treatment room, maze, and outside the shielding door at the microtron medical electron accelerator facility of the National Cancer Center, Tokyo. For these measurements, we used two types of multimoderator neutron spectrometers (Bonner spheres containing indium activation detectors and 3He detector), an aluminum activation detector, and a commercially available neutron rem counter. The measured results were compared with the combined calculation of the one-dimensional ANISN and two-dimensional DOT3.5 discrete ordinates transport codes. The calculation was performed by using a measured source spectrum in the irradiation field and by computer modeling of the maze entrance. The calculation indicated good agreement in spectral shape and agreement with experiment within a factor of 2 in absolute dose-equivalent values. This transport calculation was systematically repeated for different geometrical and material parameters, and simple analytical formulas and their parameters applicable for shielding design of a medical electron accelerator facility were obtained in general form.

Fast Neutrons↗

Studies on the activation and molecular weight of inactive renin in human plasma.

The mechanism of activation of inactive renin was studied in normal human plasma. The molecular weight of active renin and those of inactive renin before and after activation were analyzed by sephadex gel filtration. Active renin of human plasma had a molecular weight of 48,000 +/- 1000. Trypsin treatment and cold treatment activated inactive renin of a molecular weight of 54,000 +/- 1000. The inactive renin apparently did not change its molecular weight after activation. "Cryoactivation" of inactive renin was possible only when whole plasma was used. When the whole plasma was fractionated by gel filtration, cryoactivation was not observed in any of the fractions. Cryoactivation requires certain plasma factor(s) contained in some fractions. Plasma kallikrein is likely to be a major factor required for the cryoactivation of inactive renin, whereas some other factors may also participate in this mechanism.

Cold Temperature↗

Activation and reinactivation of inactive renin in normal human plasma.

Various facets of activation of inactive renin by acidification or cold exposure were investigated in normal human plasma. The acid activation obtained by titration was usually less than that by dialysis method, but varied from 41% to 122% of the latter. The acid phase of acid activation accounted for about 70% of the total activation achieved by the combined effects of the acid and alkaline phases on the average, and was not affected by any of the inhibitors for serine, thiol or carboxyl protease, whereas serine protease inhibitors suppressed the activation of both renin and plasma kallikrein in the alkaline phase of acid activation. A different mode of plasma kallikrein activation suggested some difference in the mechanism between the alkaline phase of acid activation and the cryoactivation. A part of cryoactivation of renin was independent of the action of plasma kallikrein. The renin activated by either acidification or cold exposure without concomitant activation of plasma kallikrein was reinactivated by the removal of pH and temperature, but recovered by repeating acidification or cold exposure. When active plasma kallikrein had been produced, it activated inactive renin irreversibly. It appears unlikely that irreversible activation of inactive renin is taking place in the normal circulation where practically no active plasma kallikrein is present.

Acid-Base Equilibrium↗

Asymptomatic normotensive primary aldosteronism. Case report.

We report a case of primary aldosteronism in a 30-year-old woman without hypertension or any other characteristic symptoms. The condition was first suspected by hypokalemia (2.6 mEq/liter), which was incidentally found by routine checkup. There was evidence of suppressed plasma renin activity (PRA) and elevated plasma aldosterone levels. However, the blood pressure never reached a hypertensive level, and the circulating blood volume was within a normal range. A functioning right adrenal tumor was diagnosed by adrenal scintigraphy, computerized x-ray tomography, and adrenal venography. Adrenal venous catheterization suggested an aldosteronoma, which was confirmed by lateralized hypersecretion of aldosterone. After removal of the benign adenoma, the biochemical abnormalities were corrected, yet the blood pressure remained much the same. Hypertension is not necessarily a sign of primary aldosteronism.

Adenoma↗