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Biomedical subjects

D L Anderson

Publications and source records attributed to D L Anderson.

At least 163 records · Page 9Linked to original sources
PubMed1966

Structure of Bacillus subtilis bacteriophage phi 29 and the length of phi 29 deoxyribonucleic acid.

Anderson, D. L. (University of Minnesota, Minneapolis), D. D. Hickman, and B. E. Reilly. Structure of Bacillus subtilis bacteriophage phi29 and the length of phi29 deoxyribonucleic acid. J. Bacteriol. 91:2081-2089. 1966-Bacillus subtilis bacteriophage phi29 were negatively stained with phosphotungstic acid. The head of phi29 has a hexagonal outline with a flattened base, and is about 315 A wide and 415 A in length. The virus has an intricate tail about 325 A in length. Twelve spindle-shaped appendages are attached to the lower of two collars which comprise the proximal portion of the tail. The distal 130 A of the tail axis has a diameter of about 60 A and is larger in diameter than the axis of the upper portion of the tail. Comparison of electron microscopic counts of phi29 with plaque-forming units indicated that about 50% of the microscopic entities were infective. Phenol-extracted phi29 deoxyribonucleic acid (DNA) molecules were prepared for electron microscopy by the cytochrome c film technique of Kleinschmidt et al. Measurement of contour lengths of DNA molecules from three preparations gave skewed distributions of lengths with observed modal class values ranging from 5.7 to 5.9 mu. Assuming that phi29 DNA is a double helix in the B form, the corresponding molecular weights would be 10.9 x 10(6) to 11.3 x 10(6) daltons. The largest DNA molecules would have a volume of 1.9 x 10(7) A(3) which is about 25% greater than the estimated 1.4 x 10(7) A(3) internal volume of the phage head.

Bacillus subtilis↗
PubMed1966

Binding of homologous polymerized deoxyribonucleic acid by Streptomyces griseus.

Germaine, G. R. (University of Minnesota, Minneapolis), and D. L. Anderson. Binding of homologous polymerized deoxyribonucleic acid by Streptomyces griseus. J. Bacteriol. 92:662-667. 1966-An irreversible P(32) deoxyribonucleic acid (DNA) binding system is described for Streptomyces griseus S104. The 69% guanine plus cytosine (GC) S. griseus DNA was bound by late exponential -early stationary phase cultures. Simultaneous addition of deoxyribonuclease with the P(32)-DNA to maximally receptive cultures reduced the uptake by 98%. Saturation of the binding ability occurred after 20-min incubation of cells with P(32)-DNA. Preparative cesium chloride density gradient centrifugation of the P(32)-DNA revealed that 98% of the label banded in the position expected for S. griseus DNA. Sedimentation of the P(32)-DNA at both 23 and 37 mug/ml indicated a molecular weight of 10.8 million. Attempts to transform S. griseus S104 auxotrophs to prototrophy by use of immediate and delayed selective procedures were unsuccessful.

Centrifugation↗
PubMed1965

Morphology of Mycoplasma laidlawii type A. I. Comparison of electron microscopic counts with colony-forming units.

Anderson, D. L. (University of Minnesota, Minneapolis), M. E. Pollock, and L. F. Brower. Morphology of Mycoplasma laidlawii type A. I. Comparison of electron microscopic counts with colony-forming units. J. Bacteriol. 90:1764-1767. 1965.-Cells of Mycoplasma laidlawii A grown in dialyzing flask cultures were counted with the electron microscope by use of a spray technique which deposited mixtures of polystyrene latex of known concentration and M. laidlawii in discrete droplet patterns on specimen films. Glutaraldehyde and formaldehyde were effective in preserving gross morphology of cells in spray preparations. The standard deviation of the mean ratio of latex-M. laidlawii was 5.5% when 2,000 total particles were counted in 18 droplet patterns. Microscopic counts resembled counts of colony-forming units (CFU) at various culture ages when cells larger than 0.25 mu were enumerated. If small bodies ranging from 0.1 to 0.25 mu in diameter were included in microscopic counts of cultures older than 70 hr, these counts exceeded the numbers of CFU by 4 to 10 times.

Bacteriological Techniques↗
PubMed1965

Morphology of Mycoplasma laidlawii type A. II. Effect of glucose on growth and cellular morphology.

Anderson, D. L. (University of Minnesota, Minneapolis), M. E. Pollock, and L. F. Brower. Morphology of Mycoplasma laidlawii type A. II. Effect of glucose on growth and cellular morphology. J. Bacteriol. 90:1768-1777. 1965.-Cells of Mycoplasma laidlawii A grown in soy peptone-yeast extract (SP-YE) broth reached higher maximal titers than cells grown in SP-YE supplemented with 0.2% glucose, and remained viable longer than glucose-grown cells. Moreover, addition of glucose to SP-YE markedly affected the morphological developmental sequence of the organism. The diameter of glucose-grown cells at 28 to 40 hr was often two to four times that of cells grown without glucose; these large glucose-grown cells deteriorated progressively, and presumably liberated 0.1- to 0.25-mu small bodies. In contrast, pleomorphic 22- to 28-hr cells grown in SP-YE without glucose gave rise to uniform bodies 0.5 to 1.0 mu in diameter; limited numbers of 0.1- to 0.25-mu small bodies were also liberated in nonglucose cultures after 45 to 64 hr. Electron-microscopic counts of 16- to 64-hr cultures agreed well with counts of colony-forming units (CFU) when organisms larger than 0.25 mu were included in the microscopic counts. Small bodies, 0.1 to 0.25 mu in diameter, apparently did not contribute substantially to numbers of CFU. Droplet patterns of cells grown in Arginine Assay Medium and L15 Tissue Culture Medium were cleaner than patterns of cells grown in SP-YE.

Culture Media↗
PubMedDate not supplied

Neutron capture prompt-gamma activation analysis of foods.

The suitability of neutron capture prompt-gamma activation analysis (PGAA) for multielement analysis of foods was investigated. A total of 22 elements was observed in 40 food and mineral supplements. Hydrogen, B, C, N, Na, S, Cl, and K concentrations were determined in NIST RM 8431a Mixed Diet and in a wet diet composite made from FDA Total Diet Study collections. Because the neutron flux is so low for PGAA, the method is nondestructive and reanalysis of analytical portions is possible. Both diet materials were analyzed before and after freeze-drying to check for element losses during this process. No losses were found for RM 8431a, but significant losses of B and Na were observed for the wet composite. The measured loss of hydrogen for the wet composite was not consistent with the assumption that the lost mass was water only.

Diet↗
PubMedDate not supplied

Diltiazem overdose: case report and review.

We present a case of diltiazem overdose in which the patient ingested 4.2 grams in an apparent suicide attempt. He arrived in the emergency department two hours postingestion with a blood pressure of 60/40 torr and a heart rate of 62 beats/min in a junctional rhythm. Intervention included activated charcoal, gastric lavage, intravenous fluids, calcium (both chloride and gluconate), dopamine, and atropine with improvement in vital signs. Diltiazem levels were obtained and half-life calculated. This ingestion is one of the largest reported in the literature and is remarkable in that the patient recovered without pacing or other extraordinary measures. All eight previously published cases of diltiazem overdose, including all unpublished reports to the manufacturer, are reviewed and their management strategies examined. Successful treatment in which recovery has occurred in less than 48 hours, includes pressors, calcium, glucagon, pacing, and charcoal hemoperfusion. A strategy for emergency physicians to use when approaching this problem is suggested from the review.

Adult↗
PubMedDate not supplied

Shared neuroendocrine patterns of post-traumatic stress disorder and alexithymia.

High norepinephrine/cortisol ratios have been shown to be useful indicators of post-traumatic stress disorder (PTSD). Alexithymia can result from overwhelming stress; thus, we hypothesized that sympathetic-adrenal medullary/hypothalamic-pituitary adrenal ratios would be positively associated with alexithymia severity. In the present study, we correlated 3-methoxy-4-hydroxyphenylethylene glycol (MHPG)/adrenocorticotropic hormone (ACTH) and MHPG/cortisol ratios with self-report Toronto Alexithymia Scale (TAS) scores in a group (n = 17) of nondepressed, formerly alcohol-dependent men. The correlations between the respective ratios and TAS scores were 0.515 (p = 0.034) and 0.561 (p = 0.019). We suggest that increasing degrees of alexithymia are accompanied by an increasing separation of these two endocrine systems and then speculate that this dissociation has an anatomical basis in the lateralization of emotions.

Adrenocorticotropic Hormone↗