Nucleotide sequence of the aceB gene encoding malate synthase A in Escherichia coli.
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Amino Acid Sequence↗
Biomedical subjects
K A Ward
Publications and source records attributed to K A Ward.
Nucleotide sequence of the aceB gene encoding malate synthase A in Escherichia coli.
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Amino Acid Sequence↗
Effect of galactose on systemic hemodynamics and blood flow rate in normal and tumor tissues in rats.
The effect of galactose on systemic hemodynamics and blood flow rate of Walker 256 carcinomas and several normal tissues of unanesthetized, unrestrained female Sprague-Dawley rats was measured, using the radioactive microsphere technique, prior to and at 30 and 60 min after galactose administration (6 g/kg body weight, i.v.). Whereas heart rate remained unchanged following injection, cardiac output (CO) and cardiac index decreased by 35% (P less than 0.05). Mean arterial pressure immediately decreased during the injection but then increased reaching a value 10% (P less than 0.05) above the baseline 30 min following injection. Stroke volume (SV) decreased by 30% (P less than 0.05) and total peripheral resistance increased by 65% (P less than 0.05). Redistribution of blood flow, expressed as %CO, among normal tissues was seen to the brain, kidneys, liver, jejunum, and hindlimb muscle and away from the pancreas, stomach, and skin. Changes in %CO to the spleen, colon, forelimb muscle, and peritumor tissue were not significant. Blood flow rate in most normal tissues either decreased or remained constant following injection. An exception was in the liver where blood flow significantly increased. Blood flow significantly decreased in the tumor (approximately 60%) and this reduction in blood flow was larger than the reduction in CO. These results suggest that (a) the effect of galactose on systemic hemodynamics and blood flow rate are similar to those produced by glucose; (b) reduction in blood flow rate in tumors is due to both systemic and local effects; and (c) changes in blood flow to normal tissues should not be disregarded when using galactose in combination with hyperthermia and/or chemotherapy for cancer treatment.
Animals↗
Decrease in canine endocardial and epicardial electrogram voltages with exercise: implications for pacemaker sensing.
Individuals with permanently implanted pacemakers who have normal sensing and pacing at rest may demonstrate abnormalities, particularly of atrial sensing, with exercise. Exercise is known to cause changes in the surface electrocardiographic voltages. The purpose of this study was to evaluate changes in endocardial and epicardial voltages during exercise in canines with permanently implanted pacing leads similar to those permanently implanted in humans with pacemakers. Six adult mongrel dogs were equipped with transvenous atrial and ventricular endocardial bipolar screw-in leads from a jugular venosection, and with atrial and ventricular bipolar stab-on leads from a left thoracotomy. Exercise was performed at one week following implantation and at weekly intervals for a total of 4 weeks. The animals were studied at rest and at a single workload of 3 miles per hour at a 30% elevation. Unfiltered electrograms were recorded with a VR-12 Electronics-for-Medicine photographic recorder. The mean decreases of electrograms with exercise from resting voltage were: 15% for atrial endocardial unipolar leads; 11% for atrial endocardial bipolar leads; 4% for atrial epicardial unipolar leads; 15% for atrial epicardial bipolar leads; 8% for ventricular endocardial unipolar leads; 18% for ventricular endocardial bipolar leads; 0.1% for ventricular epicardial unipolar leads and 5% for ventricular epicardial bipolar leads.
Animals↗
DNA sequences of the cysK regions of Salmonella typhimurium and Escherichia coli and linkage of the cysK regions to ptsH.
Nucleotide sequences of the cysK regions of Salmonella typhimurium and Escherichia coli have been determined. A total of 3,812 and 2,595 nucleotides were sequenced from S. typhimurium and E. coli, respectively. Open reading frames of 323 codons were found in both species and were identified as those of cysK by comparison of deduced amino acid sequences with amino- and carboxyl-terminal amino acid analyses of the S. typhimurium cysK gene product O-acetylserine (thiol)-lyase A. The two cysK DNA sequences were 85% identical, and the deduced amino acid sequences were 96% identical. The major transcription initiation sites for cysK were found to be virtually identical in the two organisms, by using primer extension and S1 nuclease protection techniques. The -35 region corresponding to the major transcription start site was TTCCCC in S. typhimurium and TTCCGC in E. coli. The deviation of these sequences from the consensus sequence TTGACA may reflect the fact that cysK is subject to positive control and requires the cysB regulatory protein for expression. Sequences downstream of cysK were found to include ptsH and a portion of ptsI, thus establishing the exact relationship of cysK with these two genes. A 290-codon open reading frame, which may represent the cysZ gene, was identified upstream of cysK.
Amino Acid Sequence↗
Herpes simplex-specific IgG subclass response in herpetic keratitis.
The measurement of the local IgG response in ocular Herpes simplex virus infection presents particular problems due to the difficulty in obtaining sufficient tear samples and the possible transudation of IgG from the serum to the inflamed eye. Using specific monoclonal antibodies to Human IgG subclasses in an enzyme-linked immunoabsorbant assay (ELISA) the local IgG antibody response in Herpes simplex keratitis was analysed. All serum samples from patients and controls contained quantifiable levels of HSV specific IgG1 and IgG4 antibody. Comparison of serum antibody levels with tear levels for patients showed that HSV specific IgG1 serum concentrations were 16.1 fold or more higher than in tears, whereas IgG4 concentrations were only 6.5 fold higher in serum than in tears. This difference was not apparent in the control group. Radioimmunoprecipitation assay of 35S-methionine labelled HSV antigens revealed only minor differences in the protein profiles produced by immunoprecipitation using serum or tear antibody. These results suggest a role for IgG4 antibodies in mucosal immunity in the eye as has been suggested for the mucosal surface of the lung.
Antibodies, Viral↗
The isolation and characterisation of the ovine growth hormone gene.
The ovine growth hormone gene has been isolated and sequenced, together with about 1 kbp of DNA flanking each end of the gene. The structure of the gene is similar to that found for other growth hormone genes, particularly the bovine gene, and has a primary transcript of 1792 bp, with five exons, and with intron sizes of 264 bp, 231 bp, 227 bp and 273 bp. The gene is flanked by artiodactyl-specific middle-repetitive DNA, consisting mainly of elements belonging to the 'C-A3' family of repeated DNA. A previously unreported sequence has been found, which we have named an 'E' element.
Amino Acid Sequence↗
Characterization of two mouse myeloma X sheep lymphocyte cell lines secreting sheep antibody.
Two mouse X sheep interspecific cell hybrids were obtained by fusing mouse myeloma cell line Sp2/O. Ag14 with sheep lymphocytes obtained from a lymph node antigenically stimulated with azo-benzene arsonate-ovalbumin (ABA-ova). The interspecific cell lines were characterized using immunochemical, karyotypic and molecular DNA techniques. Both cell lines secreted sheep IgG1 antibody specific for the ABA haptenic determinant. Karyotypic analysis revealed that cell lines 4.11 and 11.9 had modal chromosome numbers of 91 and 106, respectively. Although C-banded spreads confirmed that fusion between sheep and mouse cells had occurred, it was not possible to differentiate sheep from mouse chromosomes. However, DNA hybridization techniques showed that each line contained sheep repetitive sequence DNA. It was calculated that cell line 11.9 contained 17640 copies while cell line 4.11 contained 734 copies of the previously characterized sheep satellite DNA.
Animals↗
Tear and serum antibody levels in ocular herpetic infection: diagnostic precision of secretory IgA.
A sensitive enzyme linked immunosorbent assay (ELISA) was developed to evaluate the potential of herpes simplex virus (HSV) specific antibodies in the diagnosis of herpetic eye infection. The presence of HSV specific secretory IgA (sIgA) in tears was found to be diagnostic of infection. However, serum and tear HSV specific IgG and IgA were not considered reliable indicators of active infection.
Antibodies, Viral↗
The use of exercise testing in children to evaluate abnormalities of pacemaker function not apparent at rest.
The purpose of this study was to evaluate the use of exercise testing in identifying abnormalities of pacemaker function and in confirming set parameters not apparent at rest in children with implanted atrial synchronous physiologic pacemakers. Maximal exercise tests were performed on 24 children (15 boys, 9 girls) from 4.5 to 18 years of age (median = 15) with physiologic pacemakers. The lower rate limit was observed before or following testing in 19 of 24 cases. In each case this correlated with the set lower rate limit. The upper rate limit was reached in 10 of 24 cases and was found to be lower than that programmed in one case in which a long atrial refractory period had limited the upper rate limit. Six children reached the maximum upper rate limit to which their pacemaker could be programmed. No abnormalities of atrial capture or ventricular capture occurred during exercise testing. Ventricular sensing was normal in each case. Atrial sensing was observed to be normal in 15 of the 24 cases. Two patients had decreased atrial sensing with exercise. Reversion to the "noise rate" due to myopotential inhibition was found in seven other cases. Subsequent tests on two of these children showed normal sensing.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Antigenic and structural variation in the major nucleocapsid protein of respiratory syncytial virus.
Antigenic and structural variation in the major nucleocapsid protein, VPN41, from different strains of respiratory syncytial (RS) virus was observed using a combination of monoclonal antibodies and two-dimensional peptide mapping. Limited trypsin treatment of intact nucleocapsids produced two peptide fragments Mr 27K and Mr 14K. Two monoclonal antibodies, N1 and N2, reactive with primary sequence epitopes located on intact nucleocapsids also reacted with either the 27K fragment (N2) or the 14K fragment (N1). Competitive radioimmunoassay studies using N1 and N2 antibodies revealed two discrete antigenic groups among the seven human strains of RS virus examined. A bovine strain of RS virus, although antigenically similar to the human strain of RS virus, was placed in a separate group. Two-dimensional peptide mapping of 125I-labelled VPN41 purified by SDS-PAGE revealed extensive structural homology between all strains. However, several unique tryptic/chymotryptic peptides supported the grouping obtained with the monoclonal antibodies.
Animals↗
Viewbox: relapsing polychondritis with aortic insufficiency.
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Adult↗
Mammalian keratin gene families: organisation of genes coding for the B2 high-sulphur proteins of sheep wool.
We have isolated two genomic clones containing three B2 high-sulphur keratin genes from a sheep genomic library constructed in Charon 4A. These genes do not contain intervening sequences. Two genes, encoding the B2A and B2D proteins are closely linked in the genome, being separated by 1.9 kb, and are transcribed in the same direction. Although there is extensive sequence conservation in the 5' non-coding and coding regions, the 3' non-coding regions diverge both in length and sequence. Within the 5' non-coding region adjacent to the initiating AUG there is a highly conserved 18 bp sequence which is also present in another gene coding for a member of a different, unrelated high-sulphur keratin family. In the B2A-B2D intergene region, tightly linked to the B2D gene, there is a putative, divergently transcribed gene.
Amino Acid Sequence↗
Antibodies to respiratory syncytial virus polypeptides and their significance in human infection.
The human antibody response to respiratory syncytial (RS) virus infection was investigated using radioimmunoprecipitation analysis (RIPA). A total of nine RS virus-specific proteins, VP200, VGP95, VP68, VGP48, VPN41, VP35, VP27, VP23 and VGP20 were identified by comparing 35S- or 3H-labelled extracts of infected and uninfected HEp-2 cells, and by radioimmunoprecipitation using a hyperimmune human serum. Three glycopeptides, VGP95, VGP48 and VGP20, were identified by incorporation of [3H]glucosamine, and two of these (VGP48 and VGP20) were assumed to be part of a single disulphide-bonded polypeptide since they were precipitated by a monoclonal antibody raised against a surface protein. Human serum antibodies to three major RS virus proteins, VGP95, VGP48/VGP20 and VPN41 were measured by RIPA using radioiodinated RS virus antigens. Sera from a group of mothers whose babies escaped RS virus infection during a local epidemic showed increased antibody levels to VPN41 when compared to sera from mothers whose babies had become infected with RS virus within the first 6 months of life. In infants who remained uninfected with RS virus during the first 12 months of life the maternal gift of antibody decayed to about 50% at 3 months with traces of antibodies detected in a few sera at 12 months. The antibody levels detected in the sera of infants less than 3 months old convalescent from primary RS virus infection did not exceed the mean levels present in the serum of uninfected babies. Infants between the ages of 6 and 12 months were able to mount an IgG response to VPN41 and VGP48 but, unlike adults and older children, a particularly striking finding was their failure to produce antibodies to VGP95.
Animals↗
The development of a cell-substrate attachment system in a euglenoid flagellate.
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Acid Phosphatase↗
The isolation of wool keratin messenger RNA from sheep.
A method for the isolation of polysomal RNA from plucked wool follicle tissue is described. When translated in a reticulocyte lysate cell-free system, the products encoded by the RNA are electrophoretically identical to the low-sulfur and high-sulfur wool keratins. Since non-keratin translation products were not detected, the keratin mRNA species appear to be the predominant messenger component of the polysomal RNA. Sucrose gradient fractionation of the polysomal RNA gave rise to 2 discrete peaks of keratin mRNA, with mean sizes of 21S and 11S. The 21S fraction coded for the low-sulfur and larger high-sulfur wool keratins, while the 11S fraction coded for proteins smaller than about 20000 daltons, possibly the high-tyrosine keratins and smaller high-sulfur keratins. The keratin mRNA can be separated from the bulk ribosomal RNA by oligo(dT) cellulose chromatography, and hence is presumed to contain a terminal poly(rA) tract.
Animals↗
Studies on the in vitro metabolism of [3H]cortisol and [3H]oestradiol by sheep skin and wool roots.
The in vitro metabolism of [3H]cortisol, [3H]cortisone and [3H]estradiol-17 beta by adult sheep skin and wool follicle tissue (wool roots) was examined. The main metabolic product of the incubation of [3H]cortisol with sheep skin was [3H]cortisone, and the conversion was reversible. Wool roots were unable to carry out detectable interconversion, nor did this tissue give rise to other significant metabolites. Sheep skin and wool roots both rapidly converted [3H]oestradiol-17 beta to [3H]oestrone and the conversion could be carried out by follicle and non-follicle skin structures. It is suggested that sheep skin contains both 11 beta- and 17 beta-hydroxysteroid dehydrogenases, but that wool follicles contain only the latter enzyme.
Animals↗