The selection and coexistence of a plural number of primitive tRNAs and the origin of the genetic code.
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Biological Evolution↗
Biomedical subjects
T Hamamoto
Publications and source records attributed to T Hamamoto.
Structures of the asparagine-linked sugar chains of human chorionic gonadotropin produced in choriocarcinoma. Appearance of triantennary sugar chains and unique biantennary sugar chains.
Human chorionic gonadotropin (hCG) highly purified from urine of the patient with choriocarcinoma contains four asparagine-linked sugar chains in one molecule. The sugar chains were quantitatively liberated as radioactive oligosaccharides from polypeptide portion by hydrazinolysis followed by N-acetylation and NaB3H4 reduction. The structures of these sugar chains were determined by the combination of sequential glycosidase digestion, periodate oxidation, and methylation analysis. As compared with the sugar chains of normal urinary and placental hCG reported previously, they include several prominent structural differences. More than 97% of the sugar chains of choriocarcinoma hCG was free from sialic acid, while the sugar chains of normal hCG were mostly sialylated. Choriocarcinoma hCG contains unusual biantennary complex-type sugar chains in addition to regular tri-, bi-, and monoantennary sugar chains. These sugar chains have two outer chains linked at the C-2 and C-4 positions of the same alpha-mannosyl residue of the trimannosyl core. Since normal hCG does not contain any triantennary sugar chains, occurrence of Gal beta 1 leads to 4GlcNAc beta 1 leads to 4Man alpha 1 leads to group is another characteristic feature of the sugar chains of choriocarcinoma hCG. The evidence that the monoantennary sugar chain of Man alpha 1 leads to 6(Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4(Fuc alpha 1 leads to 6)GlcNAc leads to Asn is not found in normal hCG and the sum total of fucosylated sugar chains is 50%, which is twice as much as normal hCG, indicated that fucosylation is also modified in choriocarcinoma tissue.
Adult↗
Heterogeneity of free alpha-subunit in term placenta.
Free alpha-subunit in normal term placenta was examined for molecular weight, electric charge and ability to combine with standard hCG-beta in comparison with extracellular free alpha-subunit and standard hCG-alpha dissociated from urinary hCG in vitro. The gel chromatography on Sephadex G-100 of the placental extract revealed three major immunoreactive hCG-alpha peaks, designated as P alpha-A (Kav = 0.32-0.46), P alpha-B (0.47-0.58) and P alpha-C (0.59-0.70), near the position of standard hCG-alpha. In the isoelectric focusing, while P alpha-A was mainly distributed over the acidic region, the major components of P alpha-B and P alpha-C were distributed over the basic region. Furthermore, in the combination study with standard hCG-beta, such a alpha-subunit with acidic pI scarcely showed any combining activity whereas alpha-subunit with basic pI revealed significant combining activity. These results suggest the following possibilities: that 1) the various size species of placental alpha-subunit may be responsible for the progressive glycosylation; 2) the small alpha-subunit with basic pI may combine with beta-subunit to form immunoreactive hCG; 3) the alpha-subunit, which has not associated with beta-subunit, may be converted to a large and incombinative form with acidic pI by further glycosylation, followed by secretion as a free alpha-subunit.
Chorionic Gonadotropin↗
Leptomycins A and B, new antifungal antibiotics. I. Taxonomy of the producing strain and their fermentation, purification and characterization.
A strain of Streptomyces was found to produce new antifungal antibiotics. The active compounds were purified and separated into two substances named leptomycin A and B by high performance liquid chromatography. The molecular formulae of leptomycins A and B are C32H46O6 and C33H48O6 respectively, and physicochemical and biological properties of them are very similar to each other. Leptomycins A and B exhibit strong inhibitory activity against Schizosaccharomyces and Mucor.
Antifungal Agents↗
Leptomycins A and B, new antifungal antibiotics. II. Structure elucidation.
The structures of new antifungal antibiotics, leptomycins A and B produced by Streptomyces sp. ATS1287 were determined as described below (Fig. 1) on the basis of their spectral and chemical character. Leptomycins have unique structures which belong to the unsaturated, branched-chain fatty acids with delta-lactone rings at the end.
Antifungal Agents↗
Endobronchial miconazole for pulmonary aspergilloma.
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Aspergillosis↗
Discordant pregnancy tests in detection of alpha-subunit--producing tumors.
Ectopic production of isolated alpha-subunit of glycoprotein hormones was detected in a 32-year-old Japanese woman with metastatic lung tumor by a discordance in the immunologic pregnancy tests for native human chorionic gonadotropin (hCG) assays. Quantitative discrepancy of titrations among different types of pregnancy tests, ie, competitive (hemagglutination or latexagglutination inhibition) and noncompetitive (hemagglutination or latexagglutination) reactions, was also confirmed experimentally using a highly purified ectopic alpha-subunit from the patient's urine. Thus the discrepancy between the 2 types of assay systems was due, at least partly, to a cross-reaction of high concentrations (20,000 ng/ml) of ectopically secreted free alpha-subunit of glycoprotein hormones.
Adult↗
Sialographic study in patients with and without antibodies to Sjögren's syndrome A (Ro).
Antibodies to Sjögren's syndrome A (SS-A) (Ro) antigen were detected in 13 of 16 (81%) patients with sicca alone and 18 of 34 (54%) patients with systemic lupus erythematosus (SLE). Antibodies to Sjögren's syndrome B (SS-B) (La, Ha) antigen were detected in 7 of 16 (44%) patients with sicca alone. These percentages were statistically higher than those in other types of connective tissue diseases. There were no direct correlations between titers of antibodies to SS-A (Ro) and severity of sialographic abnormalities in 35 patients with Sjögren's syndrome (SS). However comparison of a total of 20 sialograms obtained from patients with antibodies to SS-A (Ro) showed more advanced changes than in a total of 36 sialograms from patients without antibodies to SS-A (Ro) in systemic lupus erythematosus, mixed connective tissue disease, progressive systemic sclerosis and rheumatoid arthritis. These results suggested that antibody to SS-A (Ro) may be a good indicator of subclinical SS.
Adult↗
[Autopsy case of progressive systemic sclerosis(PSS) associated with rapidly progressive glomerulonephritis(RPGN) and diffuse intra-alveolar pulmonary hemorrhage--differentiation from Goodpasture's syndrome].
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Anti-Glomerular Basement Membrane Disease↗
[The response of free alpha-subunit of glycoprotein hormones to LH-RH administration (author's transl)].
The responses of immunoreactive free alpha-subunit of glycoprotein hormones to LH-RH administration were studied in normal men and women, and in patients with hypergonadotropic hypogonadism, hypogonadotropic hypogonadism, trophoblastic disease and isolated ectopic alpha-subunit producing tumor. In patients with hypergonadotropic hypergonadism, basal levels of serum alpha-subunit were elevated and the responses to LH-RH were also excessive compared to those of normal men and women. Conversely, in hypogonadotropic hypogonadism, basal levels of alpha-subunit were significantly low and its response to LH-RH was barely detectable. The response of alpha-subunit to constant intravenous infusion of LH-RH (1 microgram/kg/h) was studied in 4 normal men. Both LH and alpha-subunit revealed biphasic patterns of elevation. Its releasing pattern suggests the possibility that two pools of gonadotropin are involved in the production and secretion of alpha-subunit. In patients with trophoblastic disease secreting low levels of hCG (18 mIU/ml), the responses of alpha-subunit as well as pituitary gonadotropin to LH-RH were normal. However, in cases of high concentrations of hCG (1000 mIU/ml), the responses of alpha-subunit and gonadotropin were suppressed. After the administration of LH-RH to a patient with an isolated ectopic alpha-subunit producing tumor, the serum concentration of pituitary gonadotropin increased within the normal range, although that of alpha-subunit did not show a significant change. These results suggest that the production of alpha-subunit by tumors may be autonomous in contrast with a regulatory production in the pituitary.
Adult↗
Net adenosine triphosphate synthesis driven by an external electric field in rat liver mitochondria.
Rat liver mitochondria irradiated with external electric pulses (760 V/cm, 30 ms, rectangular) catalyzed net ATP synthesis of 0.055 nmol/mg protein/pulse. The amount of ATP synthesized increased on increasing the number, voltage and duration of the electric pulses. There was no apparent threshold voltage or duration for ATP synthesis in the ranges tested (0-760 V/cm and 0.05-30 ms). The energy applied to the mitochondrial membrane within a much shorter time than the turnover time of H+-ATPase must be stored in the membrane until it is utilized for ATP synthesis. Synthesis of ATP was inhibited by the specific H+-ATPase inhibitor aurovertin and by high concentrations of uncouplers. The energy transfer inhibitors oligomycin and dicyclohexylcarbodiimide had no effect on synthesis of ATP in mitochondria by electric pulses, but inhibited oxidative phosphorylation under the same conditions. In contrast to the pulse-driven ATP synthesis in subchloroplast particles, that in intact mitochondria required hexokinase-glucose, higher ADP concentration, lower osmolarity and protection against the pH effect of the electrodes.
Adenosine Diphosphate↗
The characterization of alpha-subunit of glycoprotein hormone produced by undifferentiated carcinoma.
The glycoprotein hormone alpha-subunit was extracted and purified from the urine of a patient with undifferentiated carcinoma producing isolated alpha-subunit. Its final specific immunoactivity was 0.92 (mg alpha-subunit/mg protein). The alpha-subunit exhibited virtually identical immunoantigenicity to hCG-alpha antiserum with standard hCG-alpha. The molecular weight of the alpha-subunit determined by gel chromatography on Sephadex G-100 was greater than that of standard hCG-alpha dissociated by urea in vitro. By SDS disc electrophoresis, however, the alpha-subunit moved faster than hCG-alpha separated by mercaptoethanol reduction. The amino acid composition of the alpha-subunit was quite similar to that of standard hCG-alpha. In the isoelectric focusing, the major components of the alpha-subunit from undifferentiated carcinoma and the alpha-subunit from urine of normal pregnant women (third trimester) were distributed over the range from pH 3.5 to 6.0, while standard hCG-alpha was distributed in the fractions ranging from pH 6.0 to 8.0. The result of a combination study in vitro indicated that both alpha-subunits from undifferentiated carcinoma and from urine of normal pregnant women did not actively combine with hCG-beta. These results suggest that the alpha-subunit secreted by undifferentiated carcinoma is virtually identical with standard hCG-alpha as the protein moiety but differs in regard to carbohydrate moiety, and also suggest that the excess of alpha-subunit, which is not associated with beta-subunit, may have undergone some intracellular modification, and consequently, the electric charge of the freely secreted alpha-subunit changes and it no longer has the ability to combine with the beta-subunit.
Adult↗
Eicosapolyenoic acids of serum lipids of Japanese islanders with low incidence of cardiovascular diseases.
Japanese are unique among the peoples of developed countries in having a high intake of eicosapentaenoic acid (C 20:5) from fresh fish and this may in part contribute to their low incidence of cardiovascular diseases. Mass spectroscopic analyses of eicosapolyenoic acids (C20:3, C20:4 and C20:5) were carried out on the serum of aged persons living on Kohama island in Okinawa and known to have the lowest incidence of cardiovascular diseases in Japan. All but 4 of the 77 persons examined (73.94 +/- 7.81 years old) led active fishing-farming lives. The total amount of eicosapolyenoic acids in the serum of persons on Kohama island (46.77 +/- 7.46 mg/100 ml) was higher (p less than 0.001) than that in people on mainland Japan, owing to the higher intake of fresh fish (147.7 g/day). A positive correlation (p less than 0.01) was found between serum C 20:5 concentration (6.82 +/- 2.54 mg/100 ml) and high density lipoprotein concentration (55.38 +/- 13.83 mg/100 ml). In addition, there were positive correlations (p less than 0.01) between serum C 20:3 concentration (6.58 +/- 1.61 mg/100 ml) and total cholesterol (188.60 +/- 32.30 mg/100 ml), and triglyceride and skinfold thickness. The blood pressure level (p less than 0.01), incidence of abnormal ECG (p less than 0.05), and salt intake (6.2-8.3 g/day) estimated from urinalysis, were all lower than the average figures for Japanese of similar ages. No persons examined showed Q-wave on ECG. The percentage of smokers and drinkers were similar for Kohama island and mainland Japan.
Activities of Daily Living↗
[Discordance of competitive and non-competitive pregnancy tests for human chorionic gonadotropin, as related to alpha subunit producing tumor (author's transl)].
Ectopic production of isolated alpha subunit of glycoprotein hormones(s) in 32-year-old woman with metastatic lung tumor was first detected by a discordance in the immunological pregnancy tests for native human chorionic gonadotropin (hCG). Quantitative discrepancy of titrations among different types of pregnancy test kit, that i, competitive (hemagglutination or latex agglutination inhibition) and non-competitive (hemagglutination or latex agglutination) reactions, was also confirmed by the experimental study using highly purified ectopic alpha-subunit from the patient's urine. Thus, the discrepancy among the two types of assay systems was due by crossreaction of high concentrations (20,000 ng/ml) of ectopically secreted alpha-subunit of glycoprotein hormone(s). We report herein the typical behavior of immunological assay systems for native hCG in determining immunoreactive free hCG-alpha and stress the diagnostic value of the discordance observed in these assay systems.
Adult↗
[Biological and biochemical properties of human chorionic gonadotropin from urine of patients with hydatidiform mole and its radioimmunoassay (author's transl)].
Human chorionic gonadotropin (hCG) was extracted and purified from the urine of four patients with hydatidiform mole. The immunological activities of the hCG-hydatidiform mole by hCG radioimmunoassay (RIA) ranged from 9,380 to 9,700 IU/mg, and the biological activities measured by the immature rat ovarian weight method ranged from 7,250 to 7,780 IU/mg. The results of the amino acid compositions of all the hCG-hydatidiform moles were practically identical with those of hCG-normal pregnancies. The carbohydrate moiety of the hCG-hydatidiform mole was also suspected to be almost similar to that of hCG-normal pregnancies by the results of their in vitro and in vivo biological activities. It was demonstrated that hCG-hydatidiform mole was composed of alpha and beta subunits (similar to a hCG-normal pregnancy) when hCG-hydatidiform mole was separated into subunits by SDS disc electrophoresis after treatment with mercaptoethanol. The RIA system of hCG-hydatidiform mole can be established. The concentrations of hCG in sera of normal pregnant women and patients with trophoblastic diseases assayed by hCG-hydatidiform mole RIA were equivalent to those obtained by a standard hCG RIA. Hence, a standard hCG-immunoassay method used in the management of hCG is concerned.
Adult↗
pH dependence of H+ conduction through the membrane moiety of the H+-ATPase (F0 . F1) and effects of tyrosyl residue modification.
A convenient and reliable method to measure passive H+-translocating activity (H+ conductivity) was developed; vesicles reconstituted from the membrane moiety (F0) of H+-ATPase (F0 . F1) and soybean phospholipids were loaded with KCl by a freeze-thaw-sonication procedure and the rate of H+ uptake caused by the K+ diffusion potential upon addition of valinomycin was followed with a pH meter. Of the methods tested, a dialysis method using cholate plus deoxycholate gave the best results for reconstitution. Using this method, H+ conductivity of the membrane moiety of H+-ATPase from a thermophilic bacterium PS3 (TF0) was analyzed. Dependence of H+ conductivity of TF0 on H+ concentration fitted a Michaelis-Menten equation showing a Vmax of 31.3 microgram ion/min . mg of TF0 and a Km of 0.095 microgram ion/liter. Upon modification of a tyrosyl residue of TF0 with iodine, the Km value shifted to 0.71 microgram ion/liter, while the Vmax remained constant. These results were interpreted as indicating that a single tyrosyl residue in N,N'-dicyclohexylcarbodiimide-binding proteolipid of TF0 plays an important role as an H+ donor in the the rate-limiting step of H+ permeation through TF0. TF1, the catalytic moiety of H+-ATPase from the thermophilic bacterium PS3, blocked H+ conduction through TF0. A 1:1 stoichiometry of TF1 and TF0 was found in ATP-dependent membrane potential generation as well as H+ conduction.
Adenosine Triphosphatases↗
[A case of mixed connective tissue disease in childhood with symptoms of juvenile rheumatoid arthritis (author's transl)].
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Adolescent↗
Response of adrenal efferent nerve activity to noxious stimulation of the skin.
The effect of pinching the various segmental skin areas (neck, forepaw, lower chest, abdomen, thigh, hindpaw) on adrenal sympathetic efferent nerve activity which contributes to secretion of adrenal medullary hormones was examined in anesthetized rats. In the spinal cord-intact animal, pinching the lower chest, abdomen, forepaw or hindpaw produced a large reflex increase in efferent nerve activity. The response to pinching neck or thigh was small. In the spinalized animal, pinching the lower chest or abdomen produced a great response, but pinching the other skin areas including forepaw, hindpaw, neck, thigh produced little response. It is suggested that the potent segmental organization of the cutaneo-adrenal nerve reflex within the spinal cord is modified into a generalized pattern by the supraspinal structure.
Adrenal Medulla↗