The social costs of unemployment: implications for social support.
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Adult↗
Biomedical subjects
T Atkinson
Publications and source records attributed to T Atkinson.
Enzyme-based salicylate estimation.
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Humans↗
In vitro studies on the fibrinolytic, thrombolytic and fibrinogenolytic properties of a tissue plasminogen activator from guinea pig keratocytes.
The fibrinolytic and thrombolytic properties of a tissue plasminogen activator (tPA) purified from the conditioned medium of an established guinea pig keratocyte (GPK) cell line were investigated in in vitro systems and compared with urokinase. Using the fibrin clot lysis assay, GPK activator appears to be similar to human melanoma tPA and not to human urokinase. GPK activator also caused negligible fibrinogen breakdown, when incubated with human plasma at 37 degrees C over 23 hr. Urokinase on the other hand caused significant fibrinogenolysis, under similar conditions. Comparison of the lysis of plasma clots by GPK activator and human urokinase have shown that GPK activator was a much more effective fibrinolytic agent than urokinase, especially at lower concentrations (less than 50 IU/ml). Studies on the thrombolytic effect of GPK activator on the lysis of aged and cross-linked whole human blood clots and plasma clots hanging in artificially circulating human plasma suggest that GPK activator can lyse both these types of clots equally well. The lysis is dose dependent, attaining complete lysis within 3-6 hr with the concentration of GPK activator in the range of 1-5 micrograms/ml plasma. It is concluded that GPK activator has a higher fibrinolytic and thrombolytic activity and lower fibrinogenolytic activity than urokinase.
Animals↗
Purification and properties of plasminogen activators from epithelial cells.
Two epithelial plasminogen activators were purified from the serum-free conditioned medium of guinea pig keratocytes (GPK) and human breast epithelial (BEB) cells in culture. The cells were cultured on Cytodex 3 microcarrier beads in Eagles' minimum essential medium. The purification procedure was essentially as described by Rijken and Collen (1981) [J. Biol. Chem. 265, 7035-7041]. The specific activities of the purified GPK and BEB activators were 12500 and 6000 IU/mg. Unlike other tissue activators, both the epithelial activators had an isoelectric point of approximately 4.7 +/- 0.2. Pure enzymes were shown to be homogeneous by dodecyl sulphate/polyacrylamide gel electrophoresis with an apparent molecular mass of 62 +/- 2 kDa under reducing conditions. Immunological experiments have shown that both the activators are different from urokinase and do not cross react with anti-urokinase antibodies. Both GPK and BEB activators bound tightly to fibrin clots in vitro. Preliminary N-terminal sequence results indicate that both the epithelial activators appear to be similar to one another but different from melanoma and other tissue activators. These findings indicate that the plasminogen activators secreted by epithelial cells represent a unique and different class of tissue plasminogen activator.
Amino Acid Sequence↗
Nucleotide sequence of the thymidylate synthetase gene (thyP3) from the Bacillus subtilis phage phi 3T.
The thyP3 gene, encoding thymidylate synthetase, from the Bacillus subtilis phage phi 3T has been cloned and the nucleotide sequence determined. The derived amino acid sequence indicates a subunit Mr of 32 748. The primary amino acid sequence is compared with the sequences of the analogous proteins specified by Escherichia coli (thyA), Lactobacillus casei, (thyA) and phage T4 (td). Extensive conservation exists in all four sequences implying a shared tertiary structure.
Amino Acid Sequence↗
Transcription of the Bacillus subtilis bacteriophage phi 3T in vitro.
The in vitro transcription pattern of Bg/II-digested phi 3T DNA is described. Eight Bg/II fragments that hybridized to in vitro transcription products were unequivocally identified. A further hybridizing region corresponding to a Bg/II triplet was also revealed, giving a total of nine to 11 Bg/II fragments. These represent 47 to 53% of the phi 3T genome. Transcription was shown to initiate within Bg/II fragments B, G, C, H, I, F and J, implying that all of these contain at least one promoter. The relevance of these data to the construction of a cloning vector based on phi 3T is discussed.
Bacillus subtilis↗
Mechanism of biodegradation of paraquat by Lipomyces starkeyi.
The biodegradation of ring-14C- and methyl-14C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO2. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.
Ascomycota↗
Gene K of bacteriophage phi X174 codes for a protein which affects the burst size of phage production.
Site-directed mutagenesis has been used to produce a T----A change at nucleotide 70 of phi X174 genome. This generates an am codon, TAG, in the gene K reading frame without affecting the amino acid, leucine, encoded by the overlapping gene A. The gene K mutant produces small plaques on su- hosts. It has an identical latent period, but a more reduced burst size than that of the wild-type phi X174. The reduced burst size in the gene K mutant suggests that the gene K protein, although not essential, has a role in increasing infectivity by increasing the burst size three- to sixfold.
Bacteriophage phi X 174↗
Plasma concentrations of progesterone in female red deer (Cervus elaphus) during the breeding season, pregnancy and anoestrus.
Concentrations of progesterone in peripheral plasma of red deer hinds were basal (less than 1 ng/ml) during lactation/seasonal anoestrus, but increased abruptly at the onset of the breeding season. Lactating hinds (N = 19) started ovarian cycles 10 days later (P less than 0.01) and conceived 16 days later (P less than 0.001) than did 13 weaned hinds. There was no evidence, from plasma progesterone values, of silent oestrus at the start of the season. Progestagen/PMSG treatment induced early ovulations in 8 anoestrous hinds but fertility was low, only 2 conceiving and giving birth. Pregnant hinds (N = 42) had high plasma concentrations of progesterone (mean 3-5 ng/ml) which declined just before parturition.
Anestrus↗
Development of an enzyme-based assay for acetaminophen.
A new and novel method for determination of serum acetaminophen is described. The assay, which can be completed in less than 5 min, is based on the enzymatic hydrolysis of acetaminophen, with subsequent colorimetric detection of the aminophenol so produced. Various possible means of aminophenol estimation are described; the final reaction conditions have been optimized for maximum sensitivity and assay speed. This assay compares favorably with other available procedures; it requires only small sample volumes; it is rapid, simple, and highly specific for the parent drug; and it requires neither great technical ability nor expensive instrumentation.
Acetaminophen↗
Identification of functional regions in the transforming protein of Fujinami sarcoma virus by in-phase insertion mutagenesis.
A novel mutagenesis procedure based on the insertion of a hexameric nucleotide sequence into Rsa I restriction sites of cloned DNA has been applied to a copy of the Fujinami sarcoma virus (FSV) genome with the aim of identifying functional regions in the transforming protein. Mutations specifying peptide insertions in both the NH2- and the COOH-terminal fps-specific portions of the transforming protein reduce or abolish the capacity of the genome to induce transformed foci in rat-2 cells. Insertion of multiple copies of the hexamer into one central position in the oncogene results in dislocation of the NH2- and COOH-terminal regions in the primary structure, but has no inhibitory effect on focus induction. Taken together, the results imply that both the NH2- and COOH-terminal fps-specific portions of the FSV oncogene product possess determinants which function in fibroblast transformation, and that cooperation of these two regions is not sensitive to their separation in the primary structure.
Animals↗
The complete nucleotide sequence of the Pseudomonas gene coding for carboxypeptidase G2.
The complete nucleotide sequence of the Pseudomonas chromosomal gene coding for the enzyme carboxypeptidase G2 (CPG2) has been determined. The nucleotide sequence obtained has been confirmed by comparing the predicted amino acid sequence with that of randomly derived peptide fragments and by N-terminal sequencing of the purified protein. The gene has been shown to code for a 22 amino acid signal peptide at its N-terminus which closely resembles the signal peptides of other secreted proteins. An alternative 36 amino acid signal peptide which may function in Pseudomonas has also been identified. The codon utilisation of the gene is influenced by the high G + C (67.2%) content of the DNA and exhibits a 92.8% preference for codons ending in G or C. This unusual codon preference may contribute to the generally observed weak expression of Pseudomonas genes in Escherichia coli. A region of DNA upstream of the structural gene has also been sequenced and a ribosome binding site and two putative promoter sequences identified.
Amino Acid Sequence↗
Cloning enzyme genes for overproduction.
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Base Sequence↗
Effect of feeding melatonin to red deer (Cervus elaphus) on the onset of the breeding season.
Four non-lactating red deer hinds kept in natural light were each given orally 5 mg melatonin daily in the afternoon from 1 June to 5 October. The time difference between melatonin administration and sunset was 5.5-6 until the end of August, thereafter gradually decreasing to 3.5 h. Onset of oestrous cyclicity occurred in late August and early September, 2-8 weeks in advance of control hinds. A stag given 10 mg melatonin daily shed the antler velvet on 18 July, 4 weeks earlier than untreated stags, and started rutting behaviour in July-August, 2 months before the usual time.
Animals↗
The influence of changes in tension on protein synthesis and prostaglandin release in isolated rabbit muscles.
Intermittent stretching of isolated rabbit muscles increased the rate of protein synthesis by 70% and prostaglandin-F2 alpha release by 105%. Both effects of intermittent stretching were blocked by indomethacin and meclofenamate; the absence of Ca2+ together with added EGTA also inhibited both processes. The residual influence of intermittent stretching on protein synthesis was closely correlated with prostaglandin-F2 alpha release, which may be the link between mechanical activity and protein synthesis in skeletal muscle.
Animals↗
Preparative high-performance liquid affinity chromatography.
The reactive triazine dye, Procion Blue MX-R, has been covalently attached to preparative-grade silica and used for the large-scale purification of rabbit muscle lactate dehydrogenase by high-performance liquid affinity chromatography (HPLAC). Purified dye was coupled directly to glycol-silylated silica via the reactive triazine ring to yield an adsorbent containing 12 mumol dye/g silica. Essentially homogeneous lactate dehydrogenase in 80% overall yield was obtained from crude extracts. Thus this report demonstrates the potential for adapting the speed of operation and resolution shown for triazine dye-HPLAC in analytical applications to preparative protein purification.
Animals↗
The application of triazine dye affinity chromatography to the large-scale purification of glycerokinase from Bacillus stearothermophilus.
Gram quantities of homogeneous glycerokinase have been prepared from the thermophilic bacterium, Bacillus stearothermophilus, using three major steps: precipitation of debris at pH 5.1, ion-exchange chromatography on DEAE-Sephadex, and affinity chromatography on Procion Blue MX-3G-Sepharose. This method is a considerable improvement over conventional techniques; the purified enzyme was obtained with a 40% recovery and a specific activity of 120 units (mumol/min)/mg protein. A modified culture medium enabled yields of 3.4 X 10(6) units of enzyme to be obtained from 400-liter production cultures.
Chromatography, Affinity↗
The potential of microbial enzymes as diagnostic reagents.
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Anti-Bacterial Agents↗