Altitude-dependent decrease in plasma fibronectin.
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Acute-Phase Proteins↗
Biomedical subjects
C Gruber
Publications and source records attributed to C Gruber.
Identification and functional expression of a receptor selectively recognizing parathyroid hormone, the PTH2 receptor.
We have identified a G-protein-coupled receptor specifically activated by parathyroid hormone, which we refer to as the PTH2 receptor. Parathyroid hormone (PTH) and parathyroid hormone-related peptide (PTHrP, hypercalcemia of malignancy factor) activate a previously identified PTH/PTHrP receptor, which has a widespread tissue distribution. The PTH2 receptor is much more selective in ligand recognition and appears to have a more specific tissue distribution. It is activated by PTH and not by PTHrP and is particularly abundant in the brain and pancreas.
Amino Acid Sequence↗
[Every-day-nursing with our patients' parents].
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Child↗
N-Acetylserotonin prevents the hypotension induced by bacterial lipopolysaccharides in the rat.
Nitric oxide is produced by the NO synthase, which catalyses the conversion of arginine to citrulline and NO using tetrahydrobiopterin as an essential cofactor. N-Acetylserotonin, an inhibitor of the tetrahydrobiopterin biosynthesis, given 30 min before bacterial lipopolysaccharide to anesthetized rats, inhibited both the decrease in blood pressure and the increase in nitrite plasma levels induced by lipopolysaccharide. Thus, during endotoxemia the availability of tetrahydrobiopterin appears to be essential for the activity of NO synthase.
Amino Acid Oxidoreductases↗
Exogenous nitric oxide stress on endothelial cells and macrophages.
Bovine endothelial cells (ECs, P1) and lipopolysaccharide/gamma-interferon-induced mouse macrophages (MMs) were incubated in the presence of SIN-1 and C 3754 (1 microM to 1 mM), sydnonimine metabolites of the antianginal predrugs molsidomine and pirsidomine, respectively up to 48 h. No change of the endogenous nitric oxide output from MMs and A23187- or adenosine triphosphate-stimulated ECs was found by means of the methemoglobin method. Data indicate that downregulation of the nitric oxide (NO) synthase is not obvious within the intact cells under exogenous NO stress supplied by high concentrations of the spontaneous NO donors. Cytosolic MM NO synthase extracts, however, revealed reduction in the enzymic [3H]arginine turnover to [3H]citrulline by SIN-1, but not by C 3786, the pharmacologically active metabolite of pirsidomine.
Amino Acid Oxidoreductases↗
Saccharomyces cerevisiae a- and alpha-agglutinin: characterization of their molecular interaction.
An O-glycosylated protein of approximately 18 kDa responsible for mating type specific agglutination has been isolated from Saccharomyces cerevisiae a cells, purified to homogeneity and via peptide sequences the gene was cloned by PCR. An open reading frame codes for a protein of 69 amino acids. A minimum of five serine and five threonine residues of the mature protein are glycosylated. alpha-Agglutinin is a highly N-glycosylated protein of approximately 250 kDa. Both purified agglutinins form a specific 1:1 complex in vitro. Pretreatment of alpha-agglutinin, but not of alpha-agglutinin, with diethylpyrocarbonate (DEPC) prevents formation of the complex; treatment of alpha-agglutinin in the presence of alpha-agglutinin protects the former from DEPC inactivation. By carboxy terminal shortening of the alpha-agglutinin gene and by replacing three of its eight histidyl residues by arginine, the active region of alpha-agglutinin for interaction with alpha-agglutinin has been defined. Neither the N- nor the O-linked saccharides of the two agglutinins seem to be essential for their interaction.
Base Sequence↗
[Organ- and species-specific properties of glucose-6-phosphate dehydrogenase and the effect of molsidomine].
Glucose-6-phosphate dehydrogenase (G-6-PDH) is the key enzyme of the pentose phosphate cycle and therefore regulates the synthesis of the nucleic acid constituent ribose-5-phosphate. At the same time the enzyme is coupled to the synthesis of reduced glutathione (GSH) which detoxifies electrophilic molecules (radicals) in the organism. Activity and stability of G-6-PDH and the influence of SIN 1--the active metabolite of molsidomine (Corvaton)--dithiothreitol (DTT) and NADP on these parameters were studied in enzyme preparations from different organs of the rat (liver, ethmoturbinates, blood) and from blood of mouse, guinea pig, rabbit, dog and man. The highest activity of G-6-PDH was measured in rat ethmoturbinates (69.26 +/- 5.91 mU/mg protein/min), the lowest in human blood (2.99 +/- 0.18 mU/mg protein/min). G-6-PDH of rat ethmoturbinates and of rat and dog blood was unstable and nearly completely inhibited by SIN 1. The enzyme of rat liver and of human, mouse, guinea pig and rabbit blood was stable and not influenced by SIN 1. These organ-and species-specific findings are discussed with respect to the toxicological actions of SIN 1.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
A rubella outbreak among dental students: description of the outbreak and analysis of control measures.
From February to April 1982, rubella was diagnosed in 17 Washington University dental students. The affected students represented 4.8% of all dental students and 21% of susceptible students. Because a high likelihood of rubella transmission was perceived, three adjacent university hospitals undertook an emergency program to ensure immunity to rubella in all personnel. The program reached 84.6% of all target personnel, but only 36% of physicians (p less than 0.001). We estimated that the program increased the level of rubella immunity from 92.2% to 98.1%, at a total cost of $140,274 of which $29,990 was in excess of ordinary expenditures. Our experience indicates that schools training health professionals face the possibility of rubella outbreaks unless they ensure rubella immunity in all students. The experience also supports the value of ongoing programs to ensure rubella immunity in hospital personnel. Without such programs, hospitals may be forced to undertake emergency programs that are likely to be disruptive and expensive and may have relatively little immediate measurable impact.
Antibodies, Viral↗
Nucleotide sequence of the G protein gene of human respiratory syncytial virus reveals an unusual type of viral membrane protein.
The major surface glycoprotein (G) of human respiratory syncytial (RS) virus has an estimated mature Mr of 84,000-90,000. Among a library of cDNA clones prepared from RS virus mRNAs, we identified clones that hybridized to a message that encoded a Mr 36,000 polypeptide that was specifically immunoprecipitated with anti-G antiserum. The amino acid sequence of the G protein backbone was determined by nucleotide sequence analysis of several of the cDNA clones. It contains a combination of structural features that make it unique among the known viral glycoproteins. The G mRNA is 918 nucleotides long and contains a single major open reading frame that encodes a polypeptide having 298 amino acid residues with a Mr of 32,587, a finding consistent with the Mr 36,000 estimate for the in vitro translation product of the G mRNA. This suggests that greater than 50% of the molecular weight of the mature glycoprotein may be contributed by carbohydrate. Glycosylation of G is largely resistant to tunicamycin, an inhibitor of the attachment of N-linked oligosaccharides, suggesting that the majority of the carbohydrate residues are attached via O-glycosidic bonds. In accordance with this, serine and threonine residues, the acceptor sites for O-linked oligosaccharides, comprise 30.6% of the total amino acid composition. There are also four potential acceptor sites for N-linked oligosaccharides. The amino acid sequence lacks both an NH2-terminal hydrophobic signal sequence and a COOH-terminal hydrophobic region. Instead, a strongly hydrophobic region is located between amino acid residues 38 and 66. This region may serve as both the signal to insert the nascent polypeptide through the membrane and as the membrane anchor site.
Amino Acid Sequence↗
Respiratory syncytial virus polypeptides. IV. The oligosaccharides of the glycoproteins.
The cell-associated glycoproteins of respiratory syncytial (RS) virus included GP1 (90K), VP70 (70K), VGP48 (48K) and GP26 (26K). Although present in infected cells, there was no VP70 in purified virus. Trypsin treatment of infected cells removed 80 to 90% of VP70 as well as its products VGP48 and GP26. This suggested that most of the VP70 in the cell is located on the plasma membrane. The glycoproteins of purified RS virus (GP1, VGP48 and GP26) contain mannose, galactose and fucose as well as glucosamine, but the quantity of mannose in GP1 is low when compared to that of the other three sugars. The effects that follow the treatment of infected cells with the glycosylation inhibitors tunicamycin and monensin, and the treatment of the immunoprecipitated product of pulse-chase experiments with endonuclease H demonstrated that VP70 and its products contained N-linked oligosaccharides, and that the oligosaccharides of the mature VGP48 subunit were of the complex type, while GP1 contained both N- and O-linked oligosaccharides. The non-glycosylated forms of VP70 and GP1 have estimated mol. wt. of 50K and 33K respectively. Therefore, the carbohydrate contribution to the mol. wt. of VP70 and GP1, as determined by PAGE, was equivalent to 20K for the former and 57K for the latter. The majority of the GP1 oligosaccharides were O-linked, a form of sugar linkage not previously found among paramyxoviruses.
Asparagine↗
Respiratory syncytial virus polypeptides. V. The kinetics of glycoprotein synthesis.
The cell-associated glycoproteins of respiratory syncytial virus included GP1 (90K), VP70 (70K), VGP48 (48K) and GP26 (26K). The time course of virus protein synthesis in HeLa cells revealed that the nucleocapsid protein (VPN41) was the first to appear at 11 h post-infection followed by the appearance of the other viral proteins at 16 h post-infection. Pulse-chase experiments with [3H]leucine or [35S]methionine demonstrated that the precursor for VGP48 and GP26 was an uncleaved protein of 70K (VP70) which required at least 30 min to chase into its final products, while the precursor for GP1 was a glycoprotein of 46K, and also required at least 30 min to chase into GP1. Trypsin treatment of monensin-treated infected cells suggested that VP70 can be cleaved intracellularly into its products VGP48 and GP26.
Electrophoresis, Polyacrylamide Gel↗
Wound healing accelerated by Staphylococcus aureus.
While comparing the effects on wound healing of a heated scalpel with those of the cold scalpel, we discovered that inoculation of rat skin incisions with a strain of Staphylococcus aureus dramatically accelerated the gain in wound strength. The accelerating effect was evident four days postoperatively, was maximal at seven to ten days, and was still present at 28 days. The accelerating effect was correlated with the number of S aureus organisms introduced into the wound, and was found in conventional rats and rats germ free up to the time of monocontamination with S aureus. There was no evidence of infection on gross examination; on histologic examination an occasional microabscess was seen in some rats. There may be both local and systemic mechanisms underlying the S aureus accelerating effect. Seven strains of S aureus with varying characteristics demonstrated the wound-healing accelerating effect. In sharp contrast, Staphylococcus epidermidis (three strains), Staphylococcus hominis (one strain), and Pseudomonas aeruginosa (two strains) did not show this effect. The increases in wound healing due to S aureus were substantially greater than reported previously for any nutritional supplement, drug, or other chemical or physical agent.
Animals↗
Respiratory syncytial virus polypeptides. III. The envelope-associated proteins.
Four proteins, GP1, VGP48, GP26 and VPM27, are associated with the envelope of respiratory syncytial (RS) virus. The status of GP1 has been uncertain, because a cellular glycoprotein migrates at the same position when Laemmli's discontinuous buffer system is used for PAGE, and because BSC-1 cells infected with the RSN-2 strain of RS virus appear not to contain GP1. However, additional evidence suggests that GP1 is a viral structural protein. (i) It is removed from cells by trypsin, while the cellular glycoprotein is not; (ii) it is separated from the cellular glycoprotein when the infected cells are analysed by neutral SDS-PAGE; (iii) it is present in the purified RSN-2 strain of RS virus produced by BSC-1 cells; (iv) it is also present in the purified Long strain of RS virus produced by either human or monkey cells. When purified Long strain virus is analysed by PAGE under non-reducing conditions, the glycoproteins VGP48 and GP26 migrate together, and VPM27 separates into two proteins, which one-dimensional peptide mapping suggests are not different proteins. These observations suggest that VGP48 and GP26 exist in the virion as a single molecule joined by disulphide bonds, and so resemble a paramyxovirus fusion protein, and that probably there are two forms of VPM27 which differ in either position or number of disulphide bonds.
Electrophoresis, Polyacrylamide Gel↗
Medroxyprogesterone acetate and homozygous sickle-cell disease.
The haematological and clinical effects of medroxyprogesterone acetate in homozygous sickle-cell (SS) disease were assessed in a 2-year controlled crossover trial completed by 23 patients. Haematological indices remained steady during the placebo phase, but during the medroxyprogesterone-acetate phase fetal haemoglobin, total haemoglobin, red-cell mass, and red-cell survival rose significantly, and reticulocytes, irreversibly-sickled-cell counts, and total bilirubin fell significantly. Painful crises were significantly less frequent during the medroxyprogesterone-acetate than the placebo phase. These results are compatible with an inhibition of in-vivo sickling in patients with SS disease during medroxyprogesterone-acetate treatment. The mechanisms of such an effect require further study.
Adult↗
A hemostatic scalpel for burn debridement.
We studied excision of burns with a new heated scalpel. The disposable blade resemble conventional scalpel blades, except that their edges can be heated and the temperature controlled within narrow limits. The control mechanism compensates "instantaneously" for varying losses of heat depending on the vascularity of the tissues and rate of cutting. Cutting is done by the blade's sharp edge and hemostasis results from direct transfer of heat; no electric currents are generated in the tissues. The blades can be fashioned in variety of shapes and sizes, including those suitable for tangential excisions. The heated scalpel allows excision of third-degree burns in pigs and humans with much smaller loss of blood than when the usual cold surgical scalpel is used. Skin grafts applied immediately after excisions with the heated scalpel had excellent rates of success, similar to those of grafts applied immediately after excisions with the cold scalpel.
Animals↗
Burn sepsis: bacterial interference with Pseudomonas aeruginosa.
The pathogenicity of several strains of Pseudomonas aeruginosa for burned rats (3 degrees scald burns, 20% body surface) following topical application of the bacteria to the burn within 1 hour after burning was established. Following this, it was demonstrated that purposeful infection of such 3 degrees scald burns of rats by a strain of Ps. aeruginosa of low virulence (JB-77) protects the rats from the lethal effect of subsequent (48-hour) topical contamination of the burn by a highly virulent strain of Ps. aeruginosa (VA-134) (p less than 0.001). This finding was confirmed in a similar experiment beginning with germfree rats. When the challenge with the highly virulent Ps. aeruginosa strain was 24 hours (rather than 48 hours) after the burning and topical contamination of the burn with the low virulence strain of Ps. aeruginosa, there was little protection (p N.S.). When burned rats were given the low virulence strain of Ps. aeruginosa by gavage right after burning, there was not protection to subsequent (48 hours) challenge by topical application of the highly virulent strain of Ps. aeruginosa to the burn (11/12 vs 12/12 dying). Our finding that purposeful infection of a 3 degrees burn of rats (conventional and also germfree) by a strain of Ps. aeruginosa of low virulence protects from the lethal effect of subsequent (48-hour) topical contamination of the burn by a highly virulent strain of Ps. aeruginosa is due, we believe, to direct bacterial interference between the two strains of pseudomonas.
Animals↗
Chemical debridement of burns: mercaptans.
Experiments were conducted using non-enzymatic chemical agents (with emphasis on certain mercaptans), alone, in conjunction with enzymatic agents and/or other nonenzymatic chemicals for debridement of burns. Both in vitro (rats, pigs, humans) and in vivo (rats, pigs) tests were carried out. N-acetylcysteine, penicillamine and cysteine ethyl ester in low to moderate concentrations accelerate the debriding action of bromelain (an enzymatic preparation from pineapple stems) and in higher concentrations, N-acetylcysteine and penicillamine (cysteine ethyl ester was not tested) cause ready separation of the burn eschar from the underlying tissue before solubilization of the eschar is complete (rat) or has occurred (pig). Debridement of 3 degree burns of rats is complete within 4-6 hours; the take of immediately applied syngeneic skin grafts is complete and permanent. This is first time rapid debridement of 3 degree burns permitting immediate successful skin grafting has been accomplished with known defined chemicals. In pigs there is softening of the 3 degree burn eschar by N-acetylcysteine but little, if any, dissolution of the eschar. However, mechanical separation of the eschar from the underlying tissue is accomplished readily with a wooden throat stick with no bleeding. There is a change in color of the superficial layer of the underlying subcutaneous tissue from yellow-light brown to dark brown-black. The debrided areas begin to granulate promptly. The healing of deep dermal burns of pigs is hastened by the application of N-acetylcysteine for a day (beginning 24 hours after burning) while the healing of moderately deep dermal burns is not modified. Unburned skin is not damaged. There is no apparent systemic toxicity associated with the use of N-acetylcysteine for debridement of 10-15% b.s.a. 3 degree burns of rats or 15-20% b.s.a. 3 degree burns of pigs. Major emphasis has been on N-acetylcysteine because of the potential adverse secondary effect of penicillamine and cysteine ethyl ester; N-acetylcysteine is readily metabolized. The use of a keratolytic agent prior to the application of N-acetylcysteine hastens the latter's action. Sulfamylon and sulfadiazine can be used with N-acetylcysteine without interfering with its debriding action. The effects of the mercaptans are likely due largely to their ability to depolymerize connective tissue proteoglycans and proteins, especially at the interface between living and dead tissue.
Acetylcysteine↗
Chemical debridement of burns with N-acetylcysteine.
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Acetylcysteine↗