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C Shoemaker

Publications and source records attributed to C Shoemaker.

16 recordsLinked to original sources
PubMed2004

In vitro inhibitory effect of gossypol from gossypol-acetic acid, and (+)- and (-)-isomers of gossypol on the growth of Edwardsiella ictaluri.

AIM: This study was conducted to evaluate the toxic effect of gossypol from gossypol-acetic acid, and (+)- and (-)-isomers of gossypol on the growth of Edwardsiella ictaluri. METHODS AND RESULTS: Inhibitory effect of various concentrations of gossypol on the growth of E. ictaluri was determined. Bacterial recovery was performed by preincubation of bacteria in medium containing various concentrations of gossypol and subsequent activation of bacteria by inoculating on gossypol-free plates. Concentrations of racemic gossypol, (+)-gossypol and (-)-gossypol of 1.5 microg ml(-1) or higher significantly reduced the number of bacterial colonies compared with that of the control. The growth of E. ictaluri was completely inhibited on agar plates supplemented with 3 microg ml(-1), regardless of the forms of gossypol. The inhibitory effect of (+)-gossypol was higher than that of (-)-gossypol or gossypol-acetic acid. Recovery of E. ictaluri was <50% for all three forms of gossypol at concentrations of 5 microg ml(-1). Bacterial recovery remained relatively constant (6.5%) at gossypol concentrations from 10 to 100 microg ml(-1). Complete killing of E. ictaluri was not reached at gossypol levels up to 100 microg ml(-1). CONCLUSION: Gossypol-acetic acid, and (+)- and (-)-optical isomers have anti-bacterial effect against E. ictaluri. The results suggest the action is bacteriostatic rather than bactericidal. SIGNIFICANCE AND IMPACT OF THE STUDY: The therapeutic effect of gossypol against E. ictaluri may be useful in controlling enteric septicaemia of catfish.

Anti-Bacterial Agents↗
PubMed1998

Alcohol consumption and mortality. I. Characteristics of drinking groups.

AIMS: This is the first of a set of three papers evaluating drinking status and mortality risk. Analyses of multiple studies describe associations of drinking patterns with characteristics hypothesized to confound the relationships between drinking status and mortality. Characteristics which both significantly differentiate drinking groups and are consistent across studies would suggest that mortality studies not controlling for them may be compromised. DESIGN AND PARTICIPANTS: Associations are evaluated from the raw data of 10 general population studies which contained mortality data. Long-term abstainers are compared to former drinkers, long-term abstainers and former drinkers are compared to light drinkers (by quantity, frequency and volume in separate analyses) and moderate to heavy drinkers are compared to light drinkers. Tetrachoric correlation coefficients assess statistical significance; meta-analysis determines if associations are homogeneous across studies. MEASUREMENTS: Measures of alcohol consumption are quantity, frequency and volume; long-term abstainers are differentiated from former drinkers. Multiple measures of health, social position, social integration and mental health characteristics are evaluated. FINDINGS: Across studies, adult male former drinkers are consistently more likely to be heavier smokers, depressed, unemployed, lower SES and to have used marijuana than long-term abstainers. Adult female former drinkers are consistently more likely to be heavier smokers, in poorer health, not religious, and unmarried than long-term abstainers. Both types of abstainers tend to be of lower SES than light drinkers and report poorer health (not consistent). Female abstainers are more likely to be of normal or overweight than light drinkers. CONCLUSIONS: Characteristics of two groups of abstainers, other than their non-use of alcohol, may confound the associations found between drinking and mortality risk.

Adolescent↗
PubMed1998

Alcohol consumption and mortality. II. Studies of male populations.

AIMS: This is the second of a set of three papers evaluating drinking status and mortality risk. Analysis of eight general population surveys of men evaluated all-cause mortality rates by drinking pattern. DESIGN AND PARTICIPANTS: Raw data from three studies of youth and five studies of adults were evaluated. Logistic regression models controlled for confounding characteristics. Meta-analysis combined study results. MEASUREMENTS: Drinking pattern was alternatively defined by quantity, frequency and volume of drinking. Final models included drinking pattern (as well as abstinence in the youth models and long-term abstainers and former drinkers in adult models), age and other confounding variables. Models also evaluated interactions of age and, respectively, long-term abstinence and former drinking. FINDINGS: No evidence was found for the hypothesis that abstinence is associated with greater mortality risk than light drinking. In the youth samples, abstainers had a lower risk of dying than those drinking less than 15 times per month. One study of the adult samples showed a significant age by former drinker interaction; this did not alter the lack of association of former drinking with mortality risk or the homogeneity of results across studies for this finding. The most consistent finding was the association of heavy drinking with mortality among youth. Among adults, drinking 43 or more drinks per month and drinking 21 or more times per month were associated with increased mortality risk. Quantity per occasion was not significantly associated with mortality risk among adults. CONCLUSIONS: That frequent drinking was related to mortality risk, whereas heavier quantity was unrelated, is inconsistent with the belief that daily consumption of a few glasses of wine has salutary effects. Empirically, however, this pattern tends to be unusual. Findings were homogeneous across studies lending generalizability to results.

Adolescent↗
PubMed1998

Alcohol consumption and mortality. III. Studies of female populations.

AIMS: This is the third of a set of three papers evaluating drinking status and mortality risk. Analysis of three general population surveys of women evaluated all-cause mortality rates by drinking pattern. DESIGN AND PARTICIPANTS: Raw data from three studies of adult women were evaluated. Logistic regression models controlled for confounding characteristics. Meta-analysis combined study results. MEASUREMENTS: Drinking pattern was alternatively defined by quantity, frequency and volume of drinking. Final models included drinking pattern (including long-term abstainers and former drinkers) as well as age and other confounding variables. Models also evaluated interactions of age and, respectively, long-term abstinence and former drinking. FINDINGS: In models in which age was controlled, odds of death for long-term abstainers and former drinkers (defined by volume or quantity) were greater than those for light drinkers; odds of death for moderate and heavy drinkers (defined by quantity) were greater than those for light drinkers. When other psychosocial attributes were controlled, odds of death were similar for abstainers and light drinkers. When other psychosocial attributes were controlled, odds of death for heavy drinkers (defined by volume and quantity) were greater than those for light drinkers. When interactions of age and the two forms of abstinence were introduced, one study showed a significant effect of age and former drinking. CONCLUSIONS: Results were consistent with the hypothesis that characteristics of abstainers other than their non-use of alcohol may account for their higher mortality risk. With the exception of former drinkers compared to light drinkers, when interactions were introduced into models (for measures of quantity and frequency) findings were homogeneous across studies, lending generalizability to results.

Adult↗
PubMed1995

Gender differences for the risk of alcohol-related problems in multiple national contexts.

The primary research question asked is: After holding alcohol consumption constant, will men and women be at equal risk for a variety of alcohol-related problems? Since women are actually at a higher blood alcohol content at the same consumption levels, a physiological argument would suggest that women are at equal or greater risk for alcohol problems than men. However, variation in societal norms surrounding gender roles and/or societal-level stress may mediate the experience of men and women, regardless of the differences in physiology. Ten cross-sectional general population studies are used. Analyses control for individual-level variables (age, quantity, and frequency of drinking) and societal-level variables (proportion of women in the work force and female suicide rate) that might confound these relationships; cross-study homogeneity is examined.

Alcohol Drinking↗
PubMed1992

cDNA cloning and functional expression of the Schistosoma mansoni protective antigen triose-phosphate isomerase.

M.1 monoclonal antibody has previously been shown to passively transfer partial resistance to schistosome infection within mice and to recognize a 28-kDa antigen that has peptide sequence homology with triose-phosphate isomerase (TPI; D-glyceraldehyde-3-phosphate ketol-isomerase, EC 5.3.1.1). We have now isolated the complete coding DNA for Schistosoma mansoni TPI and confirmed that this cDNA encodes the 28-kDa antigen recognized by M.1. The predicted translation product has strong homology with other TPIs, particularly from higher eukaryotes, and the sequence homology is greatest in regions known to form the active site. The complete coding DNA has been expressed within an Escherichia coli host to produce high levels of soluble, recombinant S. mansoni TPI protein. The product is recognized and purified by the M.1 antibody and is a functional TPI with an intrinsic specific activity comparable to that of rabbit and yeast TPI.

Amino Acid Sequence↗
PubMed1985

Identification of functional murine adenosine deaminase cDNA clones by complementation in Escherichia coli.

Total poly(A+) RNA derived from a mouse cell line with amplified adenosine deaminase genes was used as template to synthesize double-stranded cDNA. The cDNAs were inserted into the PstI site of the beta-lactamase gene in plasmid pBR322 following G-C tailing. After transformation into adenosine deaminase-deficient Escherichia coli hosts, recombinant plasmids containing functional murine adenosine deaminase cDNAs were identified by selecting for functional complementation. Analysis of plasmids containing functional adenosine deaminase cDNA sequences strongly suggested that adenosine deaminase expression resulted mainly from beta-lactamase/adenosine deaminase fusion proteins even when the adenosine deaminase codons were out-of-frame with respect to the beta-lactamase gene codons upstream. The nucleotide sequence of a 1.65-kilobase pair cDNA insert in one of the functional recombinant clones was determined and found to contain a 1056-nucleotide open reading frame. When this 1056-nucleotide open reading frame was inserted into a mammalian expression vector and introduced into monkey kidney cells, a high level of authentic mouse adenosine deaminase was produced. Nucleic acid blot analysis using a full-length adenosine deaminase cDNA clone as probe revealed that the mouse adenosine deaminase structural gene was at least 21 kilobase pairs in size and encoded three polyadenylated mRNAs. Analysis of the cDNA library from which the functional clones were isolated suggested that this approach of cloning functional mammalian adenosine deaminase cDNA clones by genetic complementation of enzyme-deficient bacteria could be accomplished even if the abundance of the adenosine deaminase mRNA sequences were as low as approximately 0.001%.

Adenosine Deaminase↗
PubMed1984

Human T-cell growth factor: partial amino acid sequence, cDNA cloning, and organization and expression in normal and leukemic cells.

The partial amino acid sequences of human T-cell growth factors (TCGFs) isolated from normal peripheral blood lymphocytes and from a leukemia T-cell line (Jurkat) show that the amino-terminal sequences of the two proteins (15 residues) are identical. Oligonucleotides based on the published Jurkat TCGF DNA sequence were used to isolate six cDNA clones of TCGF mRNA from normal lymphocytes. The predicted amino acid sequence of normal lymphocyte TCGF was identical to the sequence of the Jurkat protein, showing that the differences in biochemical properties of the two proteins result from post-translational events. Amino acid and nucleotide sequence data suggest that TCGF is derived from a precursor polypeptide that is cleaved at the amino terminus but not at the carboxyl terminus. Hybridization of the cloned lymphocyte TCGF cDNA to cellular DNA and RNA strongly suggested that the TCGF gene is expressed as a single mRNA species from a single-copy gene. No differences in the organization of the TCGF gene in normal, leukemic, and human T-cell leukemia/lymphoma virus-infected cells was detected regardless of whether they produce TCGF or not.

Amino Acid Sequence↗
PubMed1984

Strong and regulated expression of Escherichia coli beta-galactosidase in insect cells with a baculovirus vector.

The N-terminal region of the gene encoding polyhedrin, the major occlusion protein of the insect baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV), has been fused to DNA encoding Escherichia coli beta-galactosidase. The fused gene was inserted into the AcNPV DNA genome by cotransfection of insect cells with recombinant plasmid DNA and wild-type AcNPV genomic DNA. Recombinant viruses were selected as blue plaques in the presence of a beta-galactosidase indicator, 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside. Studies of one such virus, L1GP-gal3, indicated that the synthesis of beta-galactosidase is temporally controlled beginning late (20 h) in infection after the release of infectious virus particles from the cell. By 48 h postinfection, a remarkably high level of expression is achieved. On the basis of these results, AcNPV should be a useful vector for the stable propagation and expression of passenger genes in a lepidopteran cell background. A generalized transplacement vector that facilitates the construction and selection of recombinant viruses carrying passenger genes under their own promoter control has also been developed.

Amino Acid Sequence↗
PubMed1981

Intramolecular integration within Moloney murine leukemia virus DNA.

By screening a library of unintegrated, circular Moloney murine leukemia virus (M-MuLV) DNA cloned in lambda phage, we found that approximately 20% of the M-MuLV DNA inserts contained internal sequence deletions or inversions. Restriction enzyme mapping demonstrated tht the deleted segments frequently abutted a long terminal repeat (LTR) sequence, whereas the inverted segments were usually flanked by LTR sequences, suggesting that many of the variants arose as a consequence of M-MuLV DNA molecules integrating within their own DNA. Nucleotide sequencing also suggested that most of the variant inserts were generated by autointegration. One of the recombinant M-MuLV DNA inserts contained a large inverted repeat of a unique M-MuLV sequence abutting an LTR. This molecule was shown by nucleotide sequencing to have arisen by an M-MuLV DNA Molecule integrating within a second M-MuLV DNA molecule before cloning. The autointegrated M-MuLV DNA had generally lost two base pairs from the LTR sequence at each junction with target site DNA, whereas a four-base-pair direct repeat of target site DNA flanked the integrated viral DNA. Nucleotide sequencing of preintegration target site DNA showed that this four-base-pair direct repeat was present only once before integration and was thus reiterated by the integration event. The results obtained from the autointegrated clones were supported by nucleotide sequencing of the host-virus junction of two cloned M-MuLV integrated proviruses obtained from infected rat cells. Detailed analysis of the different unique target site sequences revealed no obvious common features.

Bacteriophage lambda↗
PubMed1980

Structure of a cloned circular Moloney murine leukemia virus DNA molecule containing an inverted segment: implications for retrovirus integration.

Closed circular Moloney murine leukemia virus (M-MuLV) DNA was prepared from recently infected cells and cloned in a lambda vector. Four classes of cloned M-MuLV inserts were found: Class I, full length 8.8-kilobase (kb) inserts with two tandem long terminal repeats (LTRs) of 600 base pairs; class 2, 8.2-kb inserts with a single copy of a LTR; class 3, M-MuLV DNA inserts with various portions deleted; and class 4, an 8.8-kb insert with an internal sequence inversion. Determination of nucleotide sequence at the junction between the two LTRs from a class 1 insert suggested that circularization occurred by blunt-end ligation of an 8.8-kb linear DNA. The class 4 molecule had an inversion that was flanked by inverted LTRs, each of which had lost two terminal base pairs at the inversion end points. Also, four base pairs that were present only once in standard M-MuLV DNA were duplicated at either end of the inversion. This molecule was interpreted as resulting from an integrative inversion in which M-MuLV DNA has integrated into itself. Its analysis thus provided explicit information concerning the mechanism by which retrovirus DNA integrates into host cell DNA. Models of retrovirus integration based on bacterial DNA transposition mechanisms are proposed.

Bacteriophage lambda↗
PubMedDate not supplied

Molecular cloning of a cDNA encoding human antihaemophilic factor.

A complete copy of the mRNA sequences encoding human coagulation factor VIII:C has been cloned and expressed. The DNA sequence predicts a single chain precursor of 2,351 amino acids with a relative molecular mass (Mr) 267,039. The protein has an obvious domain structure, contains sequence repeats and is structurally related to factor V and ceruloplasmin.

Animals↗
PubMedDate not supplied

Isolation and characterization of genomic and cDNA clones of human erythropoietin.

The glycoprotein hormone erythropoietin regulates the level of oxygen in the blood by modulating the number of circulating erythrocytes, and is produced in the kidney or liver of adult and the liver of fetal or neonatal mammals. Neither the precise cell types that produce erythropoietin nor the mechanisms by which the same or different cells measure the circulating oxygen concentration and consequently regulate erythropoietin production are known. Cells responsive to erythropoietin have been identified in the adult bone marrow, fetal liver or adult spleen. In cultures of erythropoietic progenitors, erythropoietin stimulates proliferation and differentiation to more mature red blood cells. Detailed molecular studies have been hampered, however, by the impurity and heterogeneity of target cell populations and the difficulty of obtaining significant quantities of the purified hormone. Highly purified erythropoietin may be useful in the treatment of various forms of anaemia, particularly in chronic renal failure. Here we describe the cloning of the human erythropoietin gene and the expression of an erythropoietin cDNA clone in a transient mammalian expression system to yield a secreted product with biological activity.

Amino Acid Sequence↗