Curative effect of zhuling polysaccharide injection in debilitated children with hypoimmunity.
Explore the source record for details and available documents.
Adjuvants, Immunologic↗
Biomedical subjects
L Yu
Publications and source records attributed to L Yu.
Correction of anemia in patients on continuous ambulatory peritoneal dialysis with subcutaneous recombinant erythropoietin twice a week: a long-term study.
Subcutaneous recombinant human erythropoietin (rHuEPO) was given for 12 months twice weekly to 10 patients on continuous ambulatory peritoneal dialysis (CAPD) with anemia (hemoglobin less than 9.0 mg/dl). All patients responded to a median weekly dose of between 37.5 to 100 (mean 55 to 105) units/kg and reached a target hemoglobin of 10-12 mg/dl in a mean of 11.7 weeks (range 5-24). Serum iron, iron saturation and ferritin were significantly lower and serum potassium was significantly higher than the pre-treatment level from 1 month onwards. Five patients without pre-treatment iron overload required oral iron supplement and 3 required oral potassium-binding resin. No significant change in other serum biochemical parameters was observed. Blood pressure remained stable during the treatment period but additional or increased dosage of antihypertensive drugs was required in 5 patients. Peritoneal small solute clearance and ultrafiltration and residual renal clearance did not change significantly after correction of anemia. The incidence of peritonitis and exit site infection was similarly unaffected. One patient developed a severe headache which was not associated with hypertension and responded to withdrawal of rHuEPO treatment. Most of the remaining patients showed improvement in subjective well-being. It was concluded that the subcutaneous route twice a week is a safe, convenient and cost-effective way to administer rHuEPO to patients on CAPD.
Adult↗
Estimation of sample size and assurance probability in library screening.
Explore the source record for details and available documents.
DNA, Recombinant↗
EPR characterization of the cytochrome b-c1 complex from Rhodobacter sphaeroides.
EPR characteristics of cytochrome c1, cytochromes b-565 and b-562, the iron-sulfur cluster, and an antimycin-sensitive ubisemiquinone radical of purified cytochrome b-c1 complex of Rhodobacter sphaeroides have been studied. The EPR specra of cytochrome c1 shows a signal at g = 3.36 flanked with shoulders. The oxidized form of cytochrome b-562 shows a broad EPR signal at g = 3.49, while oxidized cytochrome b-565 shows a signal at g = 3.76, similar to those of two b cytochromes in the mitochondrial complex. The distribution of cytochromes b-565 and b-562 in the isolated complex is 44 and 56%, respectively. Antimycin and 2,5-dibromo-3-methyl-6-isopropyl-1,4-benzoquinone (DBMIB) have little effect on the g = 3.76 signal, but they cause a slight downfield and upfield shifts of the g = 3.49 signal, respectively. 5-Undecyl-6-hydroxyl-4,7-dioxobenzothiazole (UHDBT) shifts the g = 3.49 signal downfield to g = 3.56 and sharpens the g = 3.76 signal slightly. Myxothiazol causes an upfield shift of both g = 3.49 and g = 3.76 signals. EPR characteristics of the reduced iron-sulfur cluster in bacterial cytochrome b-c1 complex are: gx = 1.8 with a small shoulder at g = 1.76, gy = 1.89 and gz = 2.02, similar to those observed with the mitochondrial enzyme. The gx = 1.8 signal decreased and the shoulder increased concurrently as the redox potential decreased, indicating that the environment of the iron-sulfur cluster is sensitive to the redox state of the complex. UHDBT sharpens the gz and and shifts it downfield from g = 2.02 to 2.03, and shifts gx upfield from g = 1.80 to 1.78. UHDBT also causes an upfield shift of gy but to a much lesser extent compared to the other two signals. Addition of DBMIB causes a downfield shift of the gy from 1.89 to 1.94 and broadens the gx signal with an upfield to g = 1.75. Myxothiazol and antimycin show little effect on the gy and gz signals, but they broaden and shift the gx signal upfield to g = 1.74. However, the myxothiazol effect is partially reversed by UHDBT. An antimycin-sensitive ubisemiquinone radical was detected in the cytochrome b-c1 complex. At pH 8.4, the antimycin-sensitive ubisemiquinone radical has a maximal concentration of 0.66 mol per mol complex at 100 mV.(ABSTRACT TRUNCATED AT 400 WORDS)
Antimycin A↗
The small molecular mass ubiquinone-binding protein (QPc-9.5 kDa) in mitochondrial ubiquinol-cytochrome c reductase: isolation, ubiquinone-binding domain, and immunoinhibition.
The small molecular mass ubiquinone-binding protein (QPc-9.5 kDa) was purified to homogeneity from 3-azido-2-methyl-5-methoxy-6-(3,7-dimethyl[3H]octyl)-1,4-benzoquinol+ ++- labeled bovine heart mitochondrial ubiquinol-cytochrome c reductase. The N-terminal amino acid sequence of the isolated protein is Gly-Arg-Gln-Phe-Gly-His-Leu-Thr-Arg-Val-Arg-His-, which is identical with that of a Mr = 9500 protein in the reductase [Borchart et al. (1986) FEBS Lett. 200, 81-86]. A ubiquinone-binding peptide was prepared from [3H]azidoubiquinol-labeled QPc-9.5 kDa protein by trypsin digestion followed by HPLC separation. The partial N-terminal amino acid sequence of this peptide, Val-Ala-Pro-Pro-Phe-Val-Ala-Phe-Tyr-Leu-, corresponds to amino acid residues 48-57 in the reported Mr = 9500 protein. According to the proposed structural model for the Mr = 9500 protein, the azido-Q-labeled peptide is located in the membrane on the matrix side. These results confirm our previous assessment that the Mr = 13,400 subunit is not the small molecular weight Q-binding protein. Purified antibodies against QPc-9.5 kDa have a high titer with isolated QPc-9.5 kDa protein and complexes that contain it. Although antibodies against QPc-9.5 kDa do not inhibit intact succinate- and ubiquinol-cytochrome c reductases, a decrease of 85% and 20% in restoration of succinate- and ubiquinol-cytochrome c reductases, respectively, is observed when delipidated succinate- or ubiquinol-cytochrome reductases are incubated with antibodies prior to reconstitution with ubiquinone and phospholipid, indicating that epitopes at the catalytic site of QPc-9.5 kDa are buried in the phospholipid environment.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗
A time-saving method for screening cDNA or genomic libraries.
Explore the source record for details and available documents.
DNA↗
Pineal transduction. Adrenergic----cyclic AMP-dependent phosphorylation of cytoplasmic 33-kDa protein (MEKA) which binds beta gamma-complex of transducin.
Adrenergic regulation of phosphorylation of pineal proteins was studied. Norepinephrine treatment of intact pinealocytes incubated with 32Pi enhanced phosphorylation of a 33-kDa phosphoprotein (33PP). The effect of NE was rapid, sustained, and appeared to be mediated by a beta-adrenergic----cyclic AMP mechanism. Studies using broken cell preparations revealed that 33PP was phosphorylated by cyclic AMP-dependent protein kinase (PKA). It was also possible to demonstrate PKA-dependent phosphorylation of the 33-kDa protein in cytosol from rat retina and in cow and sheep pineal glands. Two-dimensional polyacrylamide gel electrophoresis revealed that 33PP is acidic (pI congruent to 4.5), appears to exist as two isoforms with slightly different charge, and has the same mobility as the retinal 33-kDa PKA substrate. Immunological analysis indicated 33PP in both tissues is a previously reported 33-kDa protein (MEKA); this protein is a PKA substrate which has been reported to form a cytoplasmic complex with the beta gamma complex of transducin. Consistent with this, it was possible to identify the beta-subunit in pineal cytoplasm and in the same congruent to 70-kDa gel permeation fraction which contained the 33-kDa protein identified as MEKA. Thus, it appears possible that MEKA is present in pineal cytoplasm in a 70-kDa complex with G beta gamma, as is the case in retina. The finding of MEKA in the pineal makes it the latest addition to a family of retinal/pineal proteins which are thought to have evolved from a common ancestral photochemical transduction system.
Animals↗
Cloning and sequencing of a cDNA encoding the Rieske iron-sulfur protein of bovine heart mitochondrial ubiquinol-cytochrome c reductase.
Two cDNA clones encoding bovine heart mitochondrial Rieske iron-sulfur protein were obtained by immunological screening of a bovine heart cDNA expression library in lambda gt11 with antiserum directed against Rieske iron-sulfur protein isolated from bovine heart mitochondrial ubiquinol-cytochrome c reductase. The cDNA inserts were 1005 and 1100 base pairs with an open reading frame of 807 base pairs which encoded a 196-amino acid mature Rieske iron-sulfur protein and a 73-amino acid presequence. The amino acid sequence of Rieske iron-sulfur protein deduced from nucleotide sequencing is the same as that obtained from protein sequencing except at residues #73 and #191 which are Ser and Asp instead of Ala and Gly, respectively.
Amino Acid Sequence↗
Effect of substituents of the benzoquinone ring on electron-transfer activities of ubiquinone derivatives.
The effect of substituents on the 1,4-benzoquinone ring of ubiquinone on its electron-transfer activity in the bovine heart mitochondrial succinate-cytochrome c reductase region is studied by using synthetic ubiquinone derivatives that have a decyl (or geranyl) side-chain at the 6-position and various arrangements of methyl, methoxy and hydrogen in the 2, 3 and 5 positions of the benzoquinone ring. The reduction of quinone derivatives by succinate is measured with succinate-ubiquinone reductase and with succinate-cytochrome c reductase. Oxidation of quinol derivatives is measured with ubiquinol-cytochrome c reductase. The electron-transfer efficacy of quinone derivatives is compared to that of 2,3-dimethoxy-5-methyl-6-decyl-1,4-benzoquinone. When quinone derivatives are used as the electron acceptor for succinate-ubiquinone reductase, the methyl group at the 5-position is less important than are the methoxy groups at the 2- and 3-positions. Replacing the 5-methyl group with hydrogen causes a slight increase in activity. However, replacing one or both of 2- and 3-methoxy groups with a methyl completely abolishes electron-acceptor activity. Replacing the 3-methoxy group with hydrogen results in a complete loss of electron-acceptor activity, while replacing the 2-methoxy with hydrogen results in an activity decrease by 70%, suggesting that the methoxy group at the 3-position is more specific than that at the 2-position. The structural requirements for quinol derivatives to be oxidized by ubiquinol-cytochrome c reductase are less strict. All 1,4-benzoquinol derivatives examined show partial activity when used as electron donors for ubiquinol-cytochrome c reductase. Derivatives that possess one unsubstituted position at 2, 3 or 5, with a decyl group at the 6-position, show substrate inhibition at high concentrations. Such substrate inhibition is not observed when fully substituted derivatives are used. The structural requirements for quinone derivatives to be reduced by succinate-cytochrome c reductase are less specific than those for succinate-ubiquinone reductase. Replacing one or both of the 2- and 3-methoxy groups with a methyl and keeping the 5-position unsubstituted (plastoquinone derivatives) yields derivatives with no acceptor activity for succinate-Q reductase. However, these derivatives are reducible by succinate in the presence of succinate-cytochrome c reductase. This reduction is antimycin-sensitive and requires endogenous ubiquinone, suggesting that these (plastoquinone) derivatives can only accept electrons from the ubisemiquinone radical at the Qi site of ubiquinol-cytochrome c reductase, and cannot accept electrons from the QPs of succinate-ubiquinone reductase.
Benzoquinones↗
The interaction of phospholipase A2 with phospholipid analogues and inhibitors.
A series of structurally modified phospholipids have been used to delineate the structural features involved in the interaction between cobra venom (Naja naja naja) phospholipase A2 and its substrate. Special emphasis has been placed on sn-2 amide analogues of the phospholipids. These studies have led to a very potent, reversible phospholipase A2 inhibitor. A six-step synthesis of this compound, 1-palmitylthio-2-palmitoylamino-1,2-dideoxy-sn-glycero-3- phosphorylethanolamine (thioether amide-PE), was developed. Other analogues studied included 1-palmitylthio-2-palmitoylamino-1,2-dideox-sn- glycero-3-phosphorylcholine, 1-palmityl-2-palmitoylamino-2- deoxy-sn-glycero-3-phosphorylcholine, 1-palmitoyl-2-palmitoylamino-2-deoxy-sn-glycero-3- phosphorylcholine, 1-palmitylthio- 2([(tetradecyloxy)carbonyl]amino)-1,2-dideoxy-sn-glycero-3- phosphorylcholine, 1-palmitoyl- 2([(octadecylylamino)carbonyl]amino)-2-deoxy-sn-glycero-3- phosphorylcholine, and sphingomyelin. Inhibition studies used the well defined Triton X-100 mixed micelle system and the spectroscopic thio assay. The phospholipid analogues showed varying degrees of inhibition. The best inhibitor was the thioether amide-PE which had an IC50 of 0.45 microM. In contrast, sphingomyelin, a natural phospholipid that resembles the amide analogues, did not inhibit but rather activated phosphatidylcholine hydrolysis. This systematic study of phospholipase A2 inhibition led to the following conclusions about phospholipid-phospholipase A2 interactions: (i) sn-2 amide analogues bind tighter than natural phospholipids, presumably because the amide forms a hydrogen bond with the water molecule in the enzyme active site, stabilizing its binding. (ii) Inhibitor analogues containing the ethanolamine polar head group appear to be more potent inhibitors than those containing the choline group. This difference in potency may be due solely to the fact that the cobra venom phospholipase A2 is activated by choline-containing phospholipids. Thus, choline-containing non-hydrolyzable analogues both inhibit and activate this enzyme. Both of these effects must be taken into account when studying phosphatidylcholine inhibitors of the cobra venom enzyme. (iii) The potency of inhibition of these analogues is significantly enhanced by increasing the hydrophobicity of the sn-1 functional group.(ABSTRACT TRUNCATED AT 400 WORDS)
Binding Sites↗
Isolated CNS involvement in Ewing's sarcoma.
Ewing's sarcoma, an uncommon malignant neoplasm of bone, represents about 10% of all the malignant primary bone tumors. The assumption that subclinical metastases are already present in patients with apparently localized tumor indicates the need for systemic therapy as an integral part of primary treatment. The usual sites of metastases are the lungs and skeletal system. Central nervous system (CNS) involvement is rare and is usually seen only in disseminated and fairly advanced disease. We report two patients in whom, after aggressive adjuvant chemotherapy, disease developed in the CNS without local recurrence. In one patient, meningeal involvement with malignant cells was identifiable in the cerebrospinal fluid; in the second patient, who presented with a space-occupying lesion, a diagnosis of arachnoid involvement was made histologically.
Adolescent↗
Qualitative and quantitative comparison of gallbladder proteins from patients with and without cholesterol gallstones.
Amino acid analysis and protein electrophoretic techniques were used to determine whether qualitative and quantitative gallbladder protein abnormalities exist in patients with cholesterol gallstones in Inner Mongolia. Gallbladder bile osmotic pressure measurement was determined and correlations were sought between the protein concentration and osmotic pressure of gallbladder bile. Protein concentrations and bile osmolality were higher in patients with cholesterol gallstones than in controls without biliary tract disease. A correlation between the protein concentration and osmotic pressure was found in gallbladder patients but not in controls (patients: r = 0.83, P less than 0.05; controls: r = 0.74, P less than 0.1).
Amino Acids↗
[The study on genome size of leptospires].
Determination of genome size is very important in genetic studies and the molecular cloning of leptospires. With pulsed field gel electrophoresis (PFGE), which can be used in the analysis of large DNA molecules, we studied the genome size of leptospires and analysed it with rare cutter restrict endonuclease Not I. The PFGE system used was CHEF-DR II which produced parallel bands in agarose gel. The results showed that the genome size of leptospires was 2000kb and there was no dramatic difference between the 5 strains of 2 genus leptospira. Rare cutter Not I digestion of genome DNA of leptospira resulted in 11 bands and its bands pattern was quite different from that of E. coli, S. choleraesuis, S. typhimurium, and S. dysenteriae genome DNA. It is thought that more information can be obtained about leptospiral DNA with PFGE technique.
Cloning, Molecular↗
[Monoclonal antibodies against human type IV collagen: preparation and its application in IgA nephropathy].
In the present experiment, BALB/C mice were immunized with type IV collagen from human placenta, afterwards the mouse spleen cells were fused with mouse myeloma line P3 U1. As a result 4 hybridoma cell lines secreting monoclonal antibody against type IV collagen were developed successfully. McAb produced was verified to be isotype of IgG1 and unique as their specificity and purity are concerned. On Western blotting it bound to 120 KD, 95 KD and 60 KD of alpha 1 chain fragments of collagen IV. IF studies of renal biopsy specimen from 38 IgA nephropathy patient were made using this McAb to testify its characterization. Interestingly, it was found that its deposition within glomeruli corresponded to the distribution of collagen IV in general, but varied a great deal in different cases, depending on the presence, severity and extent of mesangial proliferation, sclerosis, crescent formation and tubulo-interstitial lesion. This fact might reflect that collagen IV contents of renal glomeruli in IgA nephropathy patients have developed certain changes either qualitatively or quantitatively, and it might serve as a marker to predict the severity and prognosis of this disease.
Animals↗
Pharmacological and molecular evidence that the contractile response to serotonin in rat stomach fundus is not mediated by activation of the 5-hydroxytryptamine1C receptor.
The receptor mediating contraction in response to serotonin in the rat stomach fundus has not been characterized in light of the currently acceptable serotonergic receptor classification scheme. Several biochemical and pharmacological approaches to a characterization of this receptor have demonstrated nonidentity with the 5-hydroxytryptamine2 (5HT2), 5HT3, 5HT1A, and 5HT1B receptors, as defined by radiolabeled ligand binding studies in brain cortical membranes. Although there have been reports suggesting that the receptor in the rat stomach fundus may be analogous to the 5HT1C receptor, other pharmacological and biochemical studies have not been consistent with this idea. The present study utilized high affinity ligands for the 5HT1C receptor and the recently derived 5HT1C receptor cDNA clone to provide a more definitive approach to the examination of the relationship between the 5HT1C receptor and the serotonergic contractile receptor in the rat stomach fundus. Using three ligands with high affinity at the 5HT1C receptor, LY53857, ritanserin, and SCH23390, the contractile response to serotonin was inhibited by all three ligands. However, inhibition did not appear competitive nor was the inhibitory potency of these ligands consistent with their affinity at 5HT1C binding sites in brain cortical membranes. We further showed that SCH23390, unlike LY53857 and ritanserin, was also a partial agonist, producing a maximal contraction that was approximately 50% of the maximal response to serotonin in the rat stomach fundus. Thus, the use of these ligands did not support the contention that the receptor mediating serotonin-induced contractions in the rat stomach is identical to the 5HT1C receptor. In more definitive studies using a 5HT1C receptor cDNA probe, we were unable to detect hybridization of the probe with any mRNA species from the rat stomach fundus, whereas the 5HT1C receptor cDNA probe did hybridize to the 5HT1C receptor mRNA in rat brain. Because the cathepsin-D cDNA probe hybridized equally in rat brain and stomach fundus, ensuring the integrity of the RNA preparation from both tissues, the absence of measurable quantities of the 5HT1C receptor mRNA in the rat stomach was probe specific and not an artifact. Furthermore, primers specific for the rat 5HT1C receptor sequence did not detect significant levels of receptor mRNA in rat fundus, although the target sequence was amplified a minimum of 10(5)-fold in a polymerase chain reaction. These studies do not support the contention that the receptor mediating contractile responses to serotonin in the rat stomach fundus is identical to the 5HT1C receptor.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Functional expression of the yeast alpha-factor receptor in Xenopus oocytes.
The STE2 gene of the yeast Saccharomyces cerevisiae encodes a 431-residue polypeptide that has been shown by chemical cross-linking and genetic studies to be a component of the receptor for the peptide mating pheromone, alpha-factor. To demonstrate directly that the ligand binding site of the alpha-factor receptor is comprised solely of the STE2 gene product, the STE2 protein was expressed in Xenopus oocytes. Oocytes microinjected with synthetic STE2 mRNA displayed specific surface binding for 35S-labeled alpha-factor (up to 40 sites/micron2/ng RNA). Oocytes injected with either STE2 antisense RNA or heterologous receptor mRNA (nicotinic acetylcholine receptor alpha, beta, gamma, and delta subunit mRNAs) showed no binding activity (indistinguishable from uninjected control oocytes). The apparent KD (7 nM) of the alpha-factor binding sites expressed on the oocyte surface, determined by competition binding studies, agreed with the values reported for intact yeast cells and yeast plasma membrane fractions. These findings demonstrate that the STE2 gene product is the only yeast polypeptide required for biogenesis of a functional alpha-factor receptor. Electrophysiological measurements indicated that the membrane conductance of oocytes injected with STE2 mRNA, or with both STE2 and GPA1 (encoding a yeast G protein alpha-subunit) mRNAs, did not change and was not affected by pheromone binding. Thus, the alpha-factor receptor, like mammalian G protein-coupled receptors, apparently lacks activity as an intrinsic or ligand-gated ion channel. This report is the first instance in which a membrane-bound receptor from a unicellular eukaryote has been expressed in a vertebrate cell.
Animals↗
The Rhodospirillum rubrum cytochrome bc1 complex: peptide composition, prosthetic group content and quinone binding.
A cytochrome bc1 complex, essentially free of bacteriochlorophyll, has been purified from the photosynthetic purple non-sulfur bacterium Rhodospirillum rubrum. The complex catalyzes electron flow from quinol to cytochrome c (turnover number = 75 s-1) that is inhibited by low concentrations of antimycin A and myxothiazol. The complex contains only three peptide subunits: cytochrome b (Mr = 35,000); cytochrome c1 (Mr = 31,000) and the Rieske iron-sulfur protein (Mr = 22,400). Em values (pH 7.4) were measured for cytochrome c1 (+320 mV) and the two hemes of cytochrome b (-33 and -90 mV). Electron flow from quinol to cytochrome c is inhibited when the complex is pre-illuminated in the presence of a ubiquinone photoaffinity analog (azido-Q). During illumination, the azido-Q becomes covalently attached to the cytochrome b peptide and, to a lesser extent, to cytochrome c1.
Affinity Labels↗
Daily use of smokeless tobacco: systemic effects.
STUDY OBJECTIVE: To compare exposure to nicotine and related cardiovascular effects as well as urinary mutagenicity (a potential marker of systemic absorption of carcinogenic compounds) during use of oral snuff, chewing tobacco, and cigarettes, as desired. DESIGN: Crossover sequential treatments, balanced-order experimental study. SETTING: Clinical research center. PARTICIPANTS: Eight healthy men who regularly smoked cigarettes and had previous experience with the use of both oral snuff and chewing tobacco. INTERVENTIONS: Four 3- or 4-day blocks during which participants used oral snuff, chewing tobacco, and cigarettes as desired, or abstained from all tobacco. Concentrations of nicotine and cotinine (the primary metabolite of nicotine), cardiovascular effects, and urine sodium, catecholamine and mutagenicity were measured over 24 hours at the end of each treatment block. MEASUREMENTS AND MAIN RESULTS: Circadian exposure to nicotine and cardiovascular effects, including urinary catecholamine excretion, were similar for all forms of tobacco use. Urine sodium excretion was greater while using smokeless tobacco than while smoking, probably due to absorption of sodium from the smokeless tobacco. Urine mutagenicity was markedly increased while smoking cigarettes and tended to be increased (P less than 0.10) while chewing tobacco but not while using oral snuff. CONCLUSIONS: Systemic absorption of nicotine, sodium, and carcinogenic chemicals from smokeless tobacco may cause or aggravate human illness in addition to the known adverse effects on the oral cavity.
Adult↗