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Biomedical subjects

Y Goda

Publications and source records attributed to Y Goda.

At least 91 records · Page 5Linked to original sources
PubMed1990

Antibodies to clathrin inhibit endocytosis but not recycling to the trans Golgi network in vitro.

Mannose 6-phosphate receptors carry newly synthesized lysosomal enzymes from the trans Golgi network (TGN) to prelysosomes and then return to the TGN to carry out another round of lysosomal enzyme delivery. Although clathrin-coated vesicles mediate the export of mannose 6-phosphate receptors from the TGN, nothing is known about the transport vesicles used to carry these receptors back to the TGN. Two different in vitro assays used in this study show that an antibody that interferes with clathrin assembly blocks receptor-mediated endocytosis of transferrin, but has no effect on the recycling of the 300-kilodalton mannose 6-phosphate receptor from prelysosomes to the TGN. These results suggest that the transport of mannose 6-phosphate receptors from prelysosomes to the TGN does not involve clathrin.

Animals↗
PubMed1990

[Increased fibrinolytic activity during surgery with cardiopulmonary bypass].

We studied blood coagulation and fibrinolysis in 19 patients during surgery with cardiopulmonary bypass (CPB). CPB was performed with a rotating pump and a membrane oxygenator. Heparinization was achieved with heparin 3 mg.kg-1 and the ACT value was kept above 400 seconds throughout the CPB. Heparin was neutralized by protamine at a ratio of 1:1-1.5 of the total amount of heparin. Blood was collected four times from an indwelling arterial line. We obtained the first sample immediately after induction of anesthesia, the second sample before heparinization, the third sample before protamine administration, and the fourth sample at the end of the operation. FPA, FPB beta 15-42, alpha 2PI-Pl-C, D-dimer, and the t-PA activity were measured. A statistically significant elevation of FPA was observed during the operation. FPB beta 15-42, alpha 2PI-Pl-C, and the D-dimer rose significantly immediately after the beginning of the CPB and these elevations continued until the end of the operation. The t-PA activity was elevated significantly only during the CPB. In conclusion, the t-PA is released from the endothelial cells during CPB by some undetermined mechanism (primary fibrinolysis). Then, plasmin is generated by the t-PA and this dissolves the fibrin clots formed by thrombin before the beginning of the CPB (secondary fibrinolysis). Enhanced fibrinolytic activity before and after the CPB is physiological secondary fibrinolysis.

Cardiopulmonary Bypass↗
PubMed1989

Cell-free systems to study vesicular transport along the secretory and endocytic pathways.

Proteins bound for the cell surface, lysosomes, and secretory storage granules share a common pathway of intracellular transport. After their synthesis and translocation into the endoplasmic reticulum, these proteins traverse the secretory pathway by a series of vesicular transfers. Similarly, nutrient and signaling molecules enter cells by endocytosis, and move through the endocytic pathway by passage from one membrane-bound compartment to another. Little is known about the mechanisms by which proteins are collected into transport vesicles, or how these vesicles form, identify their targets, and subsequently fuse with their target membranes. An important advance toward our understanding these processes has come from the establishment of cell-free systems that reconstitute vesicular transfers in vitro. It is now possible to measure, in vitro, the transport of proteins from the endoplasmic reticulum to the Golgi, between Golgi cisternae, and the formation of transport vesicles en route from the trans Golgi network to the cell surface. Along the endocytic pathway, cell-free systems are available to study clathrin-coated vesicle formation, early endosome fusion, and the fusion of late endosomes with lysosomes. Moreover, the selective movement of receptors between late endosomes and the trans Golgi network has also been reconstituted. The molecular mechanisms of vesicular transport are now amenable to elucidation.

Animals↗
PubMed1989

[Power spectral analysis of heart rate and peripheral blood flow variations during total spinal anesthesia].

We evaluated the effect of total spinal anesthesia (TSA) on the heart rate and peripheral blood flow variations to evaluate if TSA could influence these parameters as indicators of autonomic nervous function (ANF). Four patients with intractable pain were treated by TSA by administration of local anesthetics (lidocaine or mepivacaine) into the C7-Th1 vertebral interspace. Power spectrum of heart rate before TSA showed three peaks; low (LO-FR, 0.04-0.095 Hz), mid (MID-FR, 0.095-0.15Hz) and high frequency areas (HI-FR, 0.15-0.3Hz). Spectral peaks of LO-FR and MID-FR disappeared during TSA (P less than 0.001). HI-FR area decreased to 3.3% of the control level (P less than 0.001). Mean peripheral blood flow was changed to 59.9% of the control level (not significant). However, peripheral blood flow variations of LO-FR decreased to 11.3% of the control level (P less than 0.001) after TSA. Furthermore, the vagal discharge disappeared promptly after TSA in dog. These results suggest that TSA depresses the vagal activity as well as the sympathetic activity innervating the cardiovascular system and therefore, heart rate and peripheral blood flow variations are totally eliminated. Thus, we conclude that heart rate and peripheral blood flow variations can serve as valid markers of ANF activity.

Anesthesia, Spinal↗
PubMed1989

[Studies on coloring constituents in commercial madder color].

Two main coloring constituents in the commercial madder color were isolated and identified as ruberthric acid and lucidin-3-O-primeveroside. On quantitative analysis by high-performance liquid chromatography, the contents of ruberthric acid and lucidin-3-O-primeveroside in commercial madder color were determined 0.07% and 0.04%, respectively.

Anthraquinones↗
PubMed1989

[Distinction between sodium chlorite and sodium hypochlorite by ion-chromatography].

A new method to distinguish between sodium chlorite and sodium hypochlorite by ion-chromatography is described. Under the operating condition (TSK-gel DEAE-5PW glass column 8.0 mm ID x 7.5 cm with an aqueous solution containing 20 mM sodium carbonate, 10 mM sodium hydroxide and 4 mM ethylenediamine) and electrochemical detector (Toso EC-8000, -200 mV, Ag-electrode), chlorite and hypochlorite anions were clearly separated and detected and the retention times (tR) were 6.0 and 4.6 min, respectively.

Chlorides↗
PubMed1988

Participation of microsomal aldehyde reductase in long-chain fatty alcohol synthesis in the rat brain.

The participation of microsomal aldehyde reductase in long-chain fatty alcohol synthesis in the rat brain was examined. A reaction mixture of [1-14C]hexadecanoic acid with brain microsomes and NADPH formed two radioactive products having the same mobilities as pure hexadecanal (RF 0.61) and hexadecanol (RF 0.22), respectively, on TLC plates. The product of the RF 0.61 spot was further identified as hexadecanal using gas-liquid chromatography after methylation and TLC of its reduced product with LiAlH4 and semicarbazide. The ratio of hexadecanal to hexadecanol varied from 0.4 to 1.2 under the present experimental conditions. When solubilized rat brain microsomes were applied to a Sepharose 4B column coupled with the rabbit antibody raised against rat liver microsomal NADPH-cytochrome-c reductase, which reacts with aldehyde reductase from rat brain, the eluted fraction ceased to form [14C]hexadecanol but continued to form [14C]hexadecanal from [14C]hexadecanoic acid. These results strongly indicate that hexadecanal is the intermediate in the synthesis of hexadecanol from hexadecanoic acid in rat brain microsomes with the participation of microsomal aldehyde reductase.

Alcohol Oxidoreductases↗
PubMed1988

Selective recycling of the mannose 6-phosphate/IGF-II receptor to the trans Golgi network in vitro.

Mannose 6-phosphate receptors carry soluble lysosomal enzymes from the trans Golgi network (TGN) to prelysosomes, and then return to the TGN for another round of lysosomal enzyme sorting. We describe here a complementation scheme that detects the vesicular transport of the 300 kd mannose 6-phosphate/IGF-II receptor from prelysosomes to the TGN in cell extracts. In vitro transport displays the same selectivity observed in living cells in that the transferrin receptor traverses to the TGN at a much lower rate than mannose 6-phosphate receptors. Furthermore, recycling of mannose 6-phosphate/IGF-II receptors to the TGN requires GTP hydrolysis and can be distinguished biochemically from the constitutive transport of proteins between Golgi cisternae by its resistance to the weak base, primaquine.

Animals↗
PubMed1988

Clinical evaluation of continuous venous oxygen saturation monitoring during anesthesia.

Clinical evaluation of continuous SvO2 monitoring during anesthesia was made in 14 surgical patients utilizing a fiberoptic reflectometry system combined with a pulmonary artery flow-directed balloon catheter. On-line values for SvO2 by the system were closely related to those obtained in vitro from a Radiometer ABL-300. There was a good correlation between changes of in vivo SvO2 and corresponding changes in cardiac index. We also observed that there was a significant correlation between SvO2 and oxygen extraction ratio. Our data indicate that continuous SvO2 monitoring during anesthesia can provide on-line information not only about hemodynamic state but also on oxygen transport.

Adult↗
PubMed1986

Characterization of microsomal NADPH-dependent aldehyde reductase from rat brain.

An NADPH-dependent aldehyde reductase was purified from rat brain microsomes to electrophoretic homogeneity. The purified enzyme had a molecular weight of 75,000 and reduced long chain fatty aldehydes such as octanal and hexadecanal with higher affinity (Km values of 0.21 mM and 0.03 mM, respectively) than for various artificial carbonyl compounds such as p-nitrobenzaldehyde and p-nitroacetophenone (Km values of 0.31 mM and 1.4 mM, respectively). The purified microsomal aldehyde reductase also showed NADPH-cytochrome c reductase activity, and it could not be distinguished from NADPH-cytochrome c reductase in molecular weight (75,000), chromatographic behavior, electrophoretic mobility, or immunological properties. The solubilized microsomal fraction treated with steapsin lost the reductase activity for hexadecanal but not that for cytochrome c. These results suggest that the aldehyde reductase in brain microsomes is identical to NADPH-cytochrome c reductase and that a hydrophobic portion of the NADPH-cytochrome c reductase is required for the reduction of hexadecanal.

Alcohol Oxidoreductases↗
PubMed1985

Efficient modification of E. coli RNA polymerase in vitro by the N gene transcription antitermination protein of bacteriophage lambda.

The N gene protein of bacteriophage lambda prevents termination of transcription by E. coli RNA polymerase. We describe here the conditions of a cell-free reaction system in which pure N stimulates net transcription up to tenfold and therefore nearly stoichiometrically modifies transcribing RNA polymerase molecules. The reaction contains micrococcal nuclease-treated S100 extract derived from E. coli and a plasmid template DNA containing the lambda early promoter PL, the N utilization site nutL, and the Rho-dependent terminator tL1. Stimulation by N in this system is specific and biologically relevant since it is absent with vector pBR322 DNA and with extracts derived from E. coli strains bearing the nusA1 and nusE71 mutations known to block N function in vivo. We use the system to provide further evidence that ribosomes are not necessary for N function and to demonstrate the direct involvement in N function of the NusA protein of E. coli.

Ammonia↗