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Biomedical subjects

W Lotz

Publications and source records attributed to W Lotz.

54 records · Page 3Linked to original sources
PubMed1973

Electron microscopy study of length and partial denaturation of Rhizobium bacteriophage DNA.

By electron microscopy and melting of the DNA of some bacteriophages from the soil bacterium Rhizobium lupini, it was found that molecular weights range between 27 and 50 Mdaltons and GC contents between 53 and 62%. All DNAs studied are linear; one has exposed single-stranded terminals. Partial heat denaturation of two phage DNA permitted mapping of AT-rich sites within unique nucleotide sequences. The maps are asymmetric with respect to the midpoints of the DNA.

Bacteriophages↗
PubMed1972

Isolation and characterization of a bacteriophage tail-like bacteriocin from a strain of Rhizobium.

Bacterial strain 16-3 spontaneously produces a bacteriocin which inhibits the growth of closely related strain 16-2. Both strains were newly isolated from root nodules of lupines and probably belong to the species Rhizobium lupini. Production of infectious progeny of newly isolated virulent phage 16-2-4 in strain 16-2 is inhibited completely if complexes are bacteriocin-treated during the first half of the latent period. Treatment begun during the second half leads to premature lysis of complexes and inactivates only those progeny phages which were not yet fully matured at the moment of the particle-induced lysis. Examination by electron microscope of the bacteriocin enrichment revealed the presence of particles 123 nm in length which resemble the tails of T-even bacteriophages. Since the particles sediment together with the bactericidal activity in the sucrose gradient and adsorb specifically to bacteriocin-sensitive cells, it is concluded that they are identical with the bactericidal agent. The particles are not found attached to phage heads and cannot self-propagate; they are regarded as incomplete and are named INCO particles. INCO particles consist of a core enveloped by a contractile sheath. One end of the sheath is connected to a baseplate to which six fibers, each 32 nm in length, are attached. These connect the baseplate of an adsorbing particle to the cell surface. Since INCo cores are probably empty, it is concluded that specific adsorption of the particles to the bacterial surface is sufficient to inactive sensitive cells irreversibly.

Acetates↗
PubMedDate not supplied

Laryngeal aerodynamics associated with selected voice disorders.

Measures of estimated subglottal air pressure and laryngeal air flow during speech production are compared for adults with normal laryngeal function and those with laryngeal abnormalities. The most traditional measure, air flow during sustained vowel production, is not a strong predictor of laryngeal function during speech production. Subglottal air pressure and laryngeal air flow offer insight into voice disorders and provide directions for therapy as well as a method for the quantitative assessment of treatment outcomes.

Air Pressure↗
PubMedDate not supplied

Perceptual-physiologic approach to evaluation and treatment of dysphonia.

The value of a perceptual-physiologic approach to both the evaluation and treatment of voice disorders is described and illustrated with an example of a patient with ventricular fold phonation. Objective measures are obtained to facilitate the understanding of the underlying pathophysiology and to document change over time. Evaluation data are recorded and interpreted collectively by a speech-otolaryngology team and may be valuable for medicolegal cases. Finally, the evaluation methods, particularly videolaryngoscopy, may be used for biofeedback purposes to facilitate voice therapy.

Adult↗