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G S Hall

Publications and source records attributed to G S Hall.

79 records · Page 5Linked to original sources
PubMed1968

The pattern and control of isoprenoid quinone and tocopherol metabolism in the germinating grain of wheat (Triticum vulgare).

1. The syntheses of ubiquinone-9 and plastoquinone-9 were used as parameters respectively of mitochondrial and proplastid development in the germinating wheat grain. 2. The changes in the amounts of the tocopherols were also studied and the possible biological significance of these changes is discussed. During germination, the dimethyl tocopherols of the resting grain are probably not utilized for the synthesis of alpha-tocopherol. 3. It was demonstrated that ubiquinone synthesis, and hence probably mitochondrial development, in the aleurone cells during germination, is independent of control by gibberellic acid from the embryo. 4. The influence of light on the syntheses of the isoprenoid quinones in the etiolated wheat shoot was investigated. In particular, illumination did not stimulate the synthesis of either alpha-tocopherol or alpha-tocopherolquinone.

Anti-Bacterial Agents↗
PubMedDate not supplied

Isolation of agent associated with cat scratch disease bacillus from pretibial biopsy.

We describe the isolation and cultural characteristics of a Gram-negative bacillus that is very similar to the presumed etiologic agent of cat scratch disease. The organism was isolated from a tibial lesion of a male patient who had been hospitalized for severe necrotizing pancreatitis. The significance of the isolate in this patient remains uncertain.

Acute Disease↗
PubMedDate not supplied

Examination of some morphologically unusual cultures of Phytophthora species using a mitochondrial DNA miniprep technique and a standardised sporangium caducity assessment.

Using the mitochondrial DNA miniprep technique, the identity of sixteen morphologically unusual cultures allocated to Phytophthora nicotianae, Phytophthora mexicana or Phytophthora porri was determined by comparison with a library of mtDNA band patterns obtained from reference cultures. Seven cultures were identified as Phytophthora nicotianae (including those assigned to Phytophthora mexicana and Phytophthora porri), six as strains of Phytophthora palmivora with small, ovoid, weakly caducous sporangia, and one as Phytophthora citrophthora. Some cultures of P. nicotianae had a low percentage of caducous sporangia. Percentage sporangium caducity, but not sporangium L:B ratio, is considered a useful taxonomic criterion for separating species morphologically similar to Phytophthora nicotianae. One culture from tobacco in New Zealand had a highly unusual morphology and a unique DNA band pattern, but was not identifiable. One culture from Acacia mearnsii in South Africa had a unique DNA band pattern which was identical to that of an isolate from Annona squamosa from Australia previously identified as Phytophthora palmivora, the precise identity of which is still unclear. The identity of most isolates from diseased durian was found to be Phytophthora palmivora, confirming its role as the main pathogen, but P. nicotianae was also identified from this host.

Journal Article↗
PubMedDate not supplied

Multilaboratory evaluation of an agar diffusion disk susceptibility test for rapidly growing anaerobic bacteria.

A multilaboratory collaborative study was undertaken to determine whether the anaerobic disk diffusion test of Horn et al. could be performed reproducibly and accurately. Tests with nine different antimicrobial disks were evaluated. Reproducibility of the agar diffusion disk method was similar to that of the reference agar dilution test procedure. The anaerobic disk diffusion procedure was found to be a potentially useful method for testing some antimicrobial agents against rapidly growing anaerobes belonging to the Bacteroides fragilis group. These promising results warrant further investigations and validations.

Bacteria, Anaerobic↗
PubMedDate not supplied

Pulmonary malacoplakia associated with Rhodococcus equi infection in an AIDS patient. Report of a case with diagnosis by fine needle aspiration.

BACKGROUND: Malacoplakia is an uncommon, peculiar inflammatory disease with few cytologic descriptions. It is seen mostly in the lower urinary tract, with rare occurrences in the lungs. Escherichia coli is the most common underlying etiologic agent, with only a few cases reported with Rhodococcus equi infection. CASE: A 36-year-old female with AIDS presented with dysphagia, dry cough and fever. Physical examination revealed diffuse bronchi and wheezing. Chest roentgenography showed multiple cavitary lesions bilaterally in the lungs. Fine needle aspiration (FNA) of one of these lesions revealed clusters of granular histiocytes with numerous intracytoplasmic and extracytoplasmic Michaelis-Gutman bodies. Also noted were numerous coccobacillary bacteria, which, on culture, were identified as R equi. Ultrastructural findings are also presented. CONCLUSION: The case illustrates the cytologic findings of malacoplakia in a rare pulmonary lesion associated with R equi infection in an AIDS patient. It reiterates the diagnostic role of FNA in dealing with a nonneoplastic entity for timely and definitive treatment and follow-up.

AIDS-Related Opportunistic Infections↗