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Biomedical subjects

J A Mayo

Publications and source records attributed to J A Mayo.

At least 37 records · Page 2Linked to original sources
PubMed1985

Social support and long-term lithium outcome.

The failure rate in long-term lithium treatment of bipolar affective disorder is in the range of 20 to 30%, even with rigorous diagnostic criteria an adequate serum lithium levels. This may be due to a variety of biologic and psychosocial factors. Psychosocial factors affecting treatment outcome were studied in 60 RDC diagnosed bipolar patients treated with lithium for one year. Outcome was measured using an affective episode score, a social adjustment scale and a global assessment scale. Social support was the factor most strongly correlated with a good outcome on all three measures.

Adult↗
PubMed1984

Detection of streptococcal mutants presumed to be defective in sugar catabolism.

The tetrazolium method for detection of bacterial mutants defective in sugar catabolism was modified for use with streptococci. The critical factors were (i) the concentration of tetrazolium, which must be titrated to determine the optimum concentration for each species or even strain, and (ii) anaerobic incubation of tetrazolium-containing agar plates. When used with standard mutagenesis protocols, this method yielded lactose-negative mutants of nine streptococcal strains representing six species. A collection of lactose-negative mutants of streptococcus, sanguis Challis was characterized and contained phospho-beta-galactosidase, lactose phosphotransferase, and general phosphotransferase mutants.

Bacteriological Techniques↗
PubMed1984

New species definitions in phages of gram-positive cocci.

About 290 phages of the bacterial genera Leuconostoc, Micrococcus, Staphylococcus, and Streptococcus were surveyed. The phages belong to the Myoviridae, Siphoviridae, and Podoviridae families and comprise seven basic morphotypes. Fourteen new species are proposed, bringing the number of phage species for gram-positive cocci to 27. The distribution of particular phage types may indicate phylogenetic relationships between host bacteria.

Bacteriophages↗
PubMed1980

Synthesis of DNA by Micrococcus luteus is resistant to 6-(p-hydroxyphenylazo)uracil.

The DNA synthesis inhibitor 6-(p-hydroxyphenylazo)uracil (HPUra), at concentrations ranging from 0.2 to 2000 micro M, had essentially no effect on DNA synthesis in Micrococcus luteus strain ML-1. Seven other M. luteus strains were unaffected by 200 micro M HPUra. In vitro DNA synthesis in toluene-treated M. luteus strain ML-1 ws resistant to both HPUra and reduced HPUra.

Adenosine Triphosphate↗
PubMed1979

DNA base composition, nature of intracellular DNA, morphology, and classification of bacteriophages infecting Micrococcus luteus.

Ten bacteriophages infecting Micrococcus luteus have been characterized. All phages contain double-stranded DNA, of 64.3--73.5 mol% guanine plus cytosine (GC). The DNA of phage N7 has the highest GC content reported for any bacterial virus. No unusual bases have been found. The intracellular replicating DNAs of six phages are covalently closed circular molecules. All 10 phages have isometric, probably icosahedral, heads and long, flexible, noncontractile tails and can be sorted into two morphological groups based on size and presence or absence of a collar. Host-range studies indicate six host-range groups.

Bacteriophages↗
PubMed1979

Families of manic-depressive patients: effect of treatment.

The authors studied the families of 12 patients with bipolar manic-depressive illness. They measured family stability using a life events scale for a 2-year period before lithium treatment and for 2 years during lithium treatment. The patients responded well to treatment; they were able to resume normal roles within the family. The life events scores decreased substantially during treatment in comparison with before treatment. The most severe impact of the illness was found in the children: 45% (N = 10) were moderately ill or symptomatic. The authors discuss the effect of manic-depressive illness on the family system as a whole and emphasize the need to combine psychosocial treatment with lithium treatment.

Adolescent↗
PubMed1978

A comparison of methods for detecting bacteriophage contamination of tissue culture sera.

Detection of bacteriophage contamination of tissue culture sera by direct plating has been compared with detection methods based on batch enrichment and on the Poisson distribution (PD plating). Batch enrichment is extremely sensitive for detecting the presence of phage contamination. PD plating combines sensitivity with isolation of each contaminating phage in pure culture. Both batch enrichment and PD plating are more sensitive than direct plating. Neither method requires highly trained personnel or specialized equipment.

Bacteriophages↗
PubMed1977

Changes in macromolecular synthesis in Xanthomonas oryzae infected with bacteriophage XP-12.

Phage XP-12, which has complete substitution of the cytosine residues in its DNA with 5-methylcytosine residues, was shown to inhibit incorporation of uracil into host DNA and RNA during the latent period. This apparent inhibition of host macromolecular synthesis was not accompanied by extensive degradation of the host chromosome. Phage DNA synthesis in infected cells occurred at a faster rate than host DNA synthesis in analogous uninfected cells. However, phage DNA synthesis could not be accurately monitored by incorporation of [methyl-3H]thymidine into DNA because, soon after infection, there was a marked inhibition of utilization of exogenous thymidine for DNA synthesis. Phage infection conferred upon a thymine auxotrophic host the ability to synthesize thymine nucleotides for phage DNA synthesis. It is suggested that a phage-induced thymidylate synthetase activity is partially responsible for the inhibition of thymidine incorporation.

Bacteriophages↗
PubMed1975

Unusual properties of the DNA from Xanthomonas phage XP-12 in which 5-methylcytosine completely replaces cytosine.

Xanthomonas phage XP-12 contains 5-methylcytosine completely replacing cytosine. This substitution confers several unusual properties upon XP-12 DNA. The buoyant density of XP-12 DNA in CsCl gradients is 1.710 g/cm-3, 0.16 g/cm-3 lower than that expected for a normal DNA with the same percentage of adenine plus thymine. The melting temperature for XP-12 DNA in 0.012 M Na+ is the highest reported for any naturally occurring DNA, 83.2 degrees C, 6.1 degrees C higher than that of normal DNAs with the same percentage of adenine plus thymine. Unlike the minor amounts of 5-methylcytosine found in most plant and animal DNAs, the 5-methylcytosine residues of XP-12 derive their methyl group from the 3-carbon of serine instead of from the thiomethyl carbon of methionine. .

Bacteriophages↗