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Biomedical subjects

G L Brown

Publications and source records attributed to G L Brown.

At least 73 records · Page 4Linked to original sources

Staphylococcal lysate fails to elicit nonspecific immune enhancement in a simulated surgical infection.

Staphylococcus aureus produces a delayed-type hypersensitivity reaction, which results in some degree of nonspecific immune enhancement. The authors chose to observe the effects of staphylococcal vaccine (staphage lysate) as a possible potentiator of nonspecific immunity. The experiments were performed in a well-known model simulating surgical infection. The experimental results do not support the previously proposed hypothesis that staphylococcal vaccine improves the immune response to a bacterial challenge.

Animals↗

Nutritional screening in surgical patients.

Routine nutritional screening of patients admitted to the surgical services confirms a substantial prevalence of malnutrition. Identification of the malnourished patient and the patient who is likely to become malnourished should be done as early as possible in the hospital stay and usually requires only simple, readily available parameters. Nutritional screening is only the first step in the optimal nutritional management of surgical patients. This information should be used to determine the need for further nutritional assessment, the appropriate consultation, and nutritional therapy.

Adult↗

Aggression, suicide, and serotonin: relationships to CSF amine metabolites.

In an earlier, separate study, the authors found that human aggression and suicide (a specific aggression-related behavior) were associated with lower levels of CSF 5-hydroxyindoleacetic acid (5-HIAA), a serotonin metabolite. That study focused on subjects with personality disorders without affective illness. In the present study they examine the life history of aggression and history of suicidal behavior in 12 subjects with borderline personality disorders without major affective disorder. Histories of aggressive behaviors and of suicide attempts were significantly associated with each other, and each was significantly associated with lower 5-HIAA levels. Altered serotonin metabolism may be a highly significant contributing factor to these behaviors in whatever diagnostic group they occur.

Adolescent↗

The hyperactive child syndrome: peripheral sympathetic nervous system function and the effect of d-amphetamine.

We evaluated sympathetic nervous system function in medication-free hyperactive children by measuring plasma levels of norepinephrine (NE) and dopamine-beta-hydroxylase and then comparing the effects of two therapeutics doses of d-amphetamine to placebo in these patients. The medication-free hyperactive patients and controls had similar plasma NE levels and blood pressures while recumbent, and a similar increase in NE on standing, but the patients had a larger pressor response on standing. In the hyperactive patients d-amphetamine significantly increased blood pressure, pulse rate, and NE levels. The change in NE levels correlated with the change in amphetamine levels. The medication-free patients, when more anxious, had higher plasma NE levels.

Attention Deficit Disorder with Hyperactivity↗

Dopamine receptor supersensitivity and schizophrenia: a review.

Advances in knowledge of brain neurochemistry have lent impetus to the biological study of schizophrenia. A prominent example is the dopamine hypothesis. Increasing additions to and refinements of neurochemical knowledge, particularly the study of receptors, have continued to support biological hypotheses of schizophrenia. A recently proposed hypothesis is that schizophrenic patients suffer from dopamine receptor supersensitivity at certain phases of their illness. The present article selectively reviews data that are relevant to this refinement of the dopamine hypothesis.

Adenylyl Cyclases↗

Isolation of mycobacteria from undecontaminated specimens with selective 7H10 medium.

Media containing antimicrobial agents have been formulated for use as an adjunct to the standard media in an effort to reduce contamination and improve isolation of mycobacteria from clinical specimens. Selective 7H10 (S7H10) was developed for use in the isolation of mycobacteria from undecontaminated material. During a 33-month period, 10,782 clinical specimens were cultured in parallel on S7H10 without decontamination and on 7H11 after treatment with 2% sodium hydroxide-N-acetyl-L-cysteine. Results of this study show the overall contamination rate to be threefold lower on S7H10 than on 7H11 (304 versus 1,000). The number of specimens negative on NaOH-treated, 7H11-cultured specimens and contaminated on S7H10 was 282, whereas that negative on S7H10 but contaminated on NaOH-7H11 was 923. There were 6 positive cultures missed due to contamination on S7H10, compared with 61 on 7H11. Positive cultures on S7H10 outnumbered those on 7H11 by 106. This evaluation of S7H10 shows that it can be used with undecontaminated specimens in conjunction with standard methods and media for isolation of mycobacteria from clinical specimens.

Bacteriological Techniques↗

The similarity of histones from turtle erythrocytes and liver.

Using the fresh-water "red-eared turtle" Pseudomys scriptans elegans, we have confirmed the existence of a minor component H1s among the lysine-rich histones of turtle erythrocytes by three forms of gel electrophoresis and two forms of chromatography. It was separated from the major components by both cation-exchange chromatography and molecular-exclusion chromatography and shown to differ slightly but significantly in content of several amino acids as well as being shorter than the other lysine-rich histones. Although its composition is close to that of the "tissue-specific" F1b of sea turtle erythrocytes, it is present in even greater relative amount in red-eared turtle livers. In most respects it resembles the satellite histone H10 of mammalian tissues. No unusual histones were observed among the perchloric acid insoluble histones of turtle erythrocytes.

Amino Acids↗

Enzymatic addition of modified cytosine nucleotides to DNA. Methacrylate polymerization by an azo pyrimidine.

An azo pyrimidine that induces the polymerization of 1-glyceryl methacrylate has been prepared. 1-Glyceryl methacrylate contains substituent glycol groups for binding heavy atoms for subsequent electron microscopic studies. Oxodation of 1-methyl N4-ureidocytosine (compound 1A) with N-bromosuccinimide produced 4-aminocarbonylazo-2-pyrimidinone (compound 2A). This orange compound shows a broad peak (lambda max = 349 nm) in its ultraviolet absorption spectrum. Mixing compound 2A with mildly acidic aqueous solutions of 1-glyceryl methacrylate (pH 3.6) resulted in polymerization of the methacrylate. Under these conditions, the ester 1-glyceryl methacrylate does not hydrolyze appreciably as judged by oxidation of the glycol groups with NaIO4 and spectrophotometric analysis of the HCHO liberated using Schiff's reagent. Attachment of azo nucleotides to the 3'-terminus of DNA was achieved in two steps. First, N4-ureidocytosine deoxynucleotides were enzymatically added to single strand DNA primers using calf thymus terminal deoxynucleotidyl transferase, Co2+, and N4-ureido-2'-deoxycytidine 5'-triphosphate (prepared by the HSO3--catalyzed transamination reaction of dCTP with semicarbazide). Second, these modified nucleotides were oxidized with N-bromosuccinimide to produce DNA that contained azo pyrimidine nucleotides at its 3'-end (azoDNA). Upon adding acid to the azoDNA, the azo nucleotides decomposed. If these nucleotides induce methacrylate polymerization upon decomposition as did compound 2A, it may be possible to mark the location of DNA termini in situ for electron microscopy by attaching heavy atoms to the poly(1-glyceryl methacrylate) formed. Such studies may elucidate the nature and location of the ends of the eukaryotic chromosomal DNA molecule in both chromosomes and interphase nuclei.

Acrylic Resins↗