Search PubMed⌕ Search

Biomedical subjects

G S Hall

Publications and source records attributed to G S Hall.

At least 73 records · Page 4Linked to original sources
PubMed1987

Rapid identification of Staphylococcus epidermidis.

A panel of Minitek sugar disks, consisting of trehalose, mannitol, xylose, and sucrose, was evaluated for its ability to identify blood culture isolates of Staphylococcus epidermidis (SE). Using a heavy suspension of organism in Mueller-Hinton broth, 50 microL was pipetted onto each disk in wells of a flat-bottomed microtiter tray. The tray was covered, incubated in a moist chamber in non-CO2 at 35 degrees C, and examined after 5 and 24 hours. A color change of yellow or orange was positive; no color change (red) was negative. Expected reactions for SE were as follows: negative trehalose, mannitol, and xylose; positive, sucrose. On evaluation of 227 coagulase-negative staphylococci (CNS) at 5 and 24 hours, the panel had a sensitivity of 94 and 96%, specificity of 92 and 89%, predictive value of positive tests of 97 and 96%, and predictive value of negative tests of 84 and 87%. This panel offered an inexpensive and convenient method for differentiating SE from the other CNS in five hours.

Alkaline Phosphatase↗
PubMed1987

Comparison of conventional and revised isolator blood culture tubes.

A paired clinical study compared bacterial and fungal recovery from 4,553 blood cultures processed by the conventional Isolator (Du Pont Co.) and a revised Isolator consisting of a single-stoppered, round-bottom tube containing the same ingredients as the conventional tube except for an inert fluorochemical. Excluding contaminants, there were 425 positive blood cultures with 450 isolates representing 208 patients. There were no statistically significant differences between systems in the number of positive cultures or patients with positive cultures for each organism group studied, nor were there any statistically significant differences between systems in the time required for detection of positive cultures.

Centrifugation↗
PubMed1987

Collagen binding in clinical isolates of Staphylococcus aureus.

Collagen binding was examined in 90 strains of Staphylococcus aureus derived from patient samples. Slightly under one-half (39 of 90) of the S. aureus strains bound collagen. Collagen binding in S. aureus did not correlate with either immunoglobulin G or fibronectin binding by these organisms. Chi-square analysis of isolates obtained from patients with complicated bacteremia (bacteremia associated with deep tissue infection) compared with isolates from patients with uncomplicated bacteremia (bacteremia without other infection) showed that the former strains were significantly more likely to have collagen-binding ability. Subcloning of primary isolates from patients with bacteremia showed that all clones from individual patients were either all positive for collagen binding or all negative, suggesting a common clonal origin for this characteristic. The ability to bind collagen could not be induced in strains lacking collagen affinity by repeated subculture in media supplemented with collagen.

Collagen↗
PubMed1986

The dispersal of bacteria and skin scales from the body after showering and after application of a skin lotion.

Application of a skin lotion to the body after showering greatly reduced the number of bacteria and skin scales dispersed from 10 men and 10 women. This effect lasted for at least 4 h when surgical clothing was worn. The use of a skin lotion to reduce bacterial dispersal could provide a simple and inexpensive alternative to an ultraclean air system or uncomfortable operating clothing during surgery requiring these procedures.

Humans↗
PubMed1986

Collagen binding to Staphylococcus aureus.

Staphylococcus aureus can bind soluble collagen in a specific, saturable manner. We have previously shown that some variability exists in the degree of collagen binding between different strains of heat-killed, formaldehyde-fixed S. aureus which are commercially available as immunologic reagents. The present study demonstrates that live S. aureus of the Cowan 1 strain binds amounts of collagen per organism equivalent to those demonstrated previously in heat-killed, formaldehyde-fixed bacteria but has an affinity over 100 times greater, with Kd values of 9.7 X 10(-11) M and 4.3 X 10(-8) M for live and heat-killed organisms, respectively. Studies were also carried out with S. aureus killed by ionizing radiation, since this method of killing the organism seemed less likely to alter the binding moieties on the surface than did heat killing. Bacteria killed by exposure to gamma radiation bound collagen in a manner essentially indistinguishable from that of live organisms. Binding of collagen to irradiated cells of the Cowan 1 strain was rapid, with equilibrium reached by 30 min at 22 degrees C, and was fully reversible. The binding was not inhibited by fibronectin, fibrinogen, C1q, or immunoglobulin G, suggesting a binding site for collagen distinct from those for these proteins. Collagen binding was virtually eliminated in trypsin-treated organisms, indicating that the binding site has a protein component. Of four strains examined, Cowan 1 and S. aureus ATCC 25923 showed saturable, specific binding, while strains Woods and S4 showed a complete lack of binding. These results suggest that some strains of S. aureus contain high-affinity binding sites for collagen. While the number of binding sites per bacterium varied sixfold in the two collagen-binding strains, the apparent affinity was similar. The ability of S. aureus to bind collagen with high affinity may provide a mechanism for bacterial adhesion to host tissue and thereby play a role in the invasive characteristics of this organism.

Binding, Competitive↗
PubMed1986

Mycobacterium fortuitum peritonitis associated with continuous ambulatory peritoneal dialysis.

Mycobacterium fortuitum has been isolated from skin and soft tissue lesions with increasing frequency. Rarely, however, has it been a documented cause of peritonitis in patients receiving continuous ambulatory peritoneal dialysis. We report here the second such case and discuss both the possibility of M. fortuitum or similar organisms as one cause of "sterile" peritonitis in this patient population and the in vitro antimicrobial susceptibility testing of such isolates.

Adult↗
PubMed1986

Detection of methicillin-resistant Staphylococcus epidermidis.

To determine whether methods suggested for detecting methicillin-resistant Staphylococcus aureus apply equally to methicillin-resistant Staphylococcus epidermidis, 135 S. epidermidis isolates were tested by the Vitek AMS gram-positive susceptibility card (Vitek Systems, Inc., Hazelwood, Mo.) and by modifications of agar screen, disk diffusion, and microdilution methods. Modifications included 24- versus 48-h incubation, unsupplemented versus 2% NaCl-supplemented broth, and standard versus direct inoculum. At 24 h, the highest number of resistant strains, 59, was detected by oxacillin (1 microgram) disk diffusion. At 48 h, three additional strains were judged resistant. With one exception, results for oxacillin disk diffusion and agar screen were equivalent at 24 and 48 h. Vitek detected 50 resistant strains. Significantly fewer resistant strains were detected at 24 h by methicillin disk diffusion (5 micrograms) and methicillin microdilution with 2% NaCl. For oxacillin microdilution, neither 2% NaCl supplementation nor the method of inoculum preparation significantly affected the results. Oxacillin microdilution with cation- rather than non-cation-supplemented broth detected significantly fewer (n = 33) resistant strains at 24 h; 51 were resistant at 48 h. To detect methicillin-resistant S. epidermidis, a direct inoculum with either 24-h oxacillin disk diffusion and reincubation of intermediate strains for an additional 24 h or 24-h oxacillin agar screen and reincubation of strains with no growth for a total of 48 h is recommended.

Humans↗
PubMed1982

Timber treatment.

Explore the source record for details and available documents.

Construction Materials↗
PubMed1977

Mycotic tuberculous aneurysm of the thoracic aorta.

Tuberculous mycotic aneurysm has been reported with surprising frequency, especially in the aorta. Because the diagnosis can often be made on clinical and roentgenologic grounds, and because of the very poor prognosis if untreated and surgical curability if recognized, experience with three cases is reported. The aneurysm is generally of the false variety, representing a walled-off perforation of the aorta. Contiguous tuberculosis in the form of lymphadenitis or Pott abscess is generally responsible for the aortic involvement that results in the aneurysm. Miliary tuberculosis, which is often present, is probably a result rather than the cause.

Aged↗
PubMed1969

Neurological disease after partial gastrectomy.

Clinical and laboratory signs of neurological disease were found in 14 patients many years after partial gastrectomy. Vitamin B(12) deficiency occurred in most patients, but only those three who had signs of subacute combined degeneration of the cord and no osteomalacia responded well to treatment.

Adult↗
PubMed1968

The determination of tocopherols and isoprenoid quinones in the grain and seedlings of wheat (Triticum vulgare).

1. A comparison is made of several procedures for the extraction of tocopherols and isoprenoid quinones from plant tissues. 2. Gradient-elution column chromatography on acid-washed alumina efficiently separates the isoprenoid quinones and tocopherols into groups that can then be assayed spectrophotometrically or, with the tocopherols, separated into their individual components and determined by gas-liquid chromatography. 3. This improved analytical procedure was used to study the distribution of the tocopherols and of ubiquinone in the ungerminated wheat grain.

1-Propanol↗