PubMed Health⌕ Search

Biomedical subjects

G Thornton

Publications and source records attributed to G Thornton.

At least 19 recordsLinked to original sources

Stability of polar oxide surfaces.

The structures of the polar surfaces of ZnO are studied using ab initio calculations and surface x-ray diffraction. The experimental and theoretical relaxations are in good agreement. The polar surfaces are shown to be very stable; the cleavage energy for the (0001)-Zn and (0001;)-O surfaces is 4.0 J/m(2) comparable to 2.32 J/m(2) for the most stable nonpolar (1010) surface. The surfaces are stabilized by an electronic mechanism involving the transfer of 0.17 electrons between them. This leads to 2D metallic surface states, which has implications for the use of the material in gas sensing and catalytic applications.

Journal Article↗

In vitro selection criteria for probiotic bacteria of human origin: correlation with in vivo findings.

The enteric flora comprises approximately 95% of the total number of cells in the human body and can elicit immune responses while protecting against microbial pathogens. However, the resident bacterial flora of the gastrointestinal tract may also be implicated in the pathogenesis of diseases such as inflammatory bowel disease (ulcerative colitis and Crohn disease). The objectives of the Probiotic Research Group based at University College Cork were to isolate and identify lactic acid bacteria exhibiting beneficial probiotic traits, such as bile tolerance in the absence of deconjugation activity, acid resistance, adherence to host epithelial tissue, and in vitro antagonism of pathogenic microorganisms or those suspected of promoting inflammation. To isolate potentially effective probiotic bacteria, we screened the microbial population adhering to surgically resected segments of the gastrointestinal tract (the environment in which they may subsequently be reintroduced and required to function). In total, 1500 bacterial strains from resected human terminal ilea were assessed. From among these organisms, Lactobacillus salivarius subsp. salivarius strain UCC118 was selected for further study. In mouse feeding trials, milk-borne L. salivarius strain UCC118 could successfully colonize the murine gastrointestinal tract. A human feeding study conducted in 80 healthy volunteers showed that yogurt can be used as a vehicle for delivery of strain UCC118 to the human gastrointestinal tract with considerable efficacy in influencing gut flora and colonization. In summary, we developed criteria for in vitro selection of probiotic bacteria that may reflect certain in vivo effects on the host such as modulation of gastrointestinal tract microflora.

Animals↗

Treatment of tuberculosis and tuberculosis infection in adults and children. American Thoracic Society and The Centers for Disease Control and Prevention.

Treatment of Tuberculosis. 1. A 6-mo regimen consisting of isoniazid, rifampin, and pyrazinamide given for 2 mo followed by isoniazid and rifampin for 4 mo is the preferred treatment for patients with fully susceptible organisms who adhere to treatment. Ethambutol (or streptomycin in children too young to be monitored for visual acuity) should be included in the initial regimen until the results of drug susceptibility studies are available, unless there is little possibility of drug resistance (i.e., there is less than 4% primary resistance to isoniazid in the community, and the patient has had no previous treatment with antituberculosis medications, is not from a country with a high prevalence of drug resistance, and has no known exposure to a drug-resistant case). This four-drug, 6-mo regimen is effective even when the infecting organism is resistant to INH. This recommendation applies to both HIV-infected and uninfected persons. However, in the presence of HIV infection it is critically important to assess the clinical and bacteriologic response. If there is evidence of a slow or suboptimal response, therapy should be prolonged as judged on a case by case basis. 2. Alternatively, a 9-mo regimen of isoniazid and rifampin is acceptable for persons who cannot or should not take pyrazinamide. Ethambutol (or streptomycin in children too young to be monitored for visual acuity) should also be included until the results of drug susceptibility studies are available, unless there is little possibility of drug resistance (see Section 1 above). If INH resistance is demonstrated, rifampin and ethambutol should be continued for a minimum of 12 mo. 3. Consideration should be given to treating all patients with directly observed therapy (DOT). 4. Multiple-drug-resistant tuberculosis (i.e., resistance to at least isoniazid and rifampin) presents difficult treatment problems. Treatment must be individualized and based on susceptibility studies. In such cases, consultation with an expert in tuberculosis is recommended. 5. Children should be managed in essentially the same ways as adults using appropriately adjusted doses of the drugs. This document addresses specific important differences between the management of adults and children. 6. Extrapulmonary tuberculosis should be managed according to the principles and with the drug regimens outlined for pulmonary tuberculosis, except for children who have miliary tuberculosis, bone/joint tuberculosis, or tuberculous meningitis who should receive a minimum of 12 mo of therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗