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M Leaver

Publications and source records attributed to M Leaver.

18 recordsLinked to original sources
PubMed2002

Comparison of the antioxidant properties of HYAFF-11p75, AQUACEL and hyaluronan towards reactive oxygen species in vitro.

In chronic wounds, a number of host factors are released which perpetuate the inflammatory process, including polymorphonuclear leukocyte (PMN)-derived reactive oxygen species (ROS), such as superoxide radical (O2*-) and hydroxyl radical (*OH) species. The glycosaminoglycan. hyaluronan, has been shown to act as an antioxidant towards ROS, although the potential for biomaterials, such as HYAFF -11p75 (the 75% benzyl ester of hyaluronan) and AQUACEL (carboxymethylcellulose), to act in this manner has yet to be elucidated. This study compared the antioxidant properties of high and low molecular weight hyaluronan (HMWT HA and LMWT HA), HYAFF -11p75, AQUACEL and an AQUACEL /hyaluronan composite (AQUACEL /HA) against O2*- and *OH. The antioxidant capacities of each material were assessed by their ability to inhibit cytochrome C reduction by O2*- fluxes, generated via the oxidation of hypoxanthine by xanthine oxidase, and their inhibition of 2-deoxy-D-ribose degradation by *OH fluxes, generated by the reaction of hydrogen peroxide (H2O2) and iron (Fe2+). All materials studied possessed dose dependent antioxidant properties towards O2*-, with HYAFF 11p75 having the greatest antioxidant potential towards these species, followed by AQUACEL, HMWT HA, AQUACEL /HA and LMWT HA. Only HMWT HA exhibited dose dependent antioxidant properties towards *OH at the fluxes examined. Gas chromatography/mass spectrometry analysis implied that ester bonds between the hyaluronan backbone and benzyl groups of HYAFF -11p75 are highly susceptible to O2*- hydrolysis, with the de-esterified benzyl alcohol being rapidly degraded in the presence of *OH. This data supports the hypothesis that HYAFF -11p75 has greater antioxidant capacity towards O2*-, due to the esterified benzyl groups providing alternative sites for O2*- attack other than the hyaluronan backbone of HYAFF -11p75 itself and explains the inability of HYAFF -11p75 to scavenge *OH, due to benzyl alcohol degradation by *OH. The antioxidant activities of these biomaterials, particularly HYAFF -11p75 and AQUACEL, towards O2*- could be beneficial, as the scavenging of PMN-derived O2*- may remove initial sources of O2*- and further prevent the secondary formation of *OH. These ROS are thought to be a primary causal factor for the extensive degradation and metabolic alterations observed in chronic wounds.

Antioxidants↗
PubMed2000

Residential aged care--accreditation and infection control.

As we approach the new millennium, many changes are becoming evident in all areas of health care. In particular, the accreditation of residential aged care facilities (RAC), already begun, is becoming a major agent of change both for the way in which RAC facilities operate as well as being a requirement for continuing Commonwealth funding.

Accreditation↗
PubMed1999

TB on the rise.

In Australia, infection rates have remained stable over the last decade although drug resistance has increased from 0.7 percent in 1995 to two percent in 1996. Early detection and treatment together with the monitoring of compliance with and sensitivity to drug regimens is essential, as is careful management of those admitted to hospital. Because of the global distribution of tuberculosis and the presence within the population of groups with high rates of disease, tuberculosis control and management activities must be maintain and developed within Australia (Oliver & Harvey 1997).

Australia↗
PubMed1999

Influenza.

In Australia in April this year, there were 25 cases of influenza A and 8 cases of influenza B reported. Most of these, 11 of type A and all 8 type B occurred in Western Australia. In May, 33 type A and two type B were reported. Of these, 25 type A were in South Australia and the two type B were in Victoria. In addition, two type H3N2, an epidemic strain, were reported in Victoria. Most recently, in June 1999 36 type A (14 in Victoria and 12 in Western Australia) plus one case of H1N1 9 (also an epidemic strain) was reported in Victoria and 10 type B (seven in Western Australia and three in Victoria) were reported. This brings the numbers for the year to 263 type A and 48 type B. Although it was anticipated that this year could see the arrival of an influenza epidemic in Australia, this has not yet occurred.

Australia↗
PubMed1998

Legionellae.

Legionellae cannot be eradicated from the water supply, since they are naturally occurring and ubiquitous. Routine bacteriologic culturing of man made aquatic environments is not recommended (Soule et al 1995). Therefore any water use that results in production of aerosols should be regularly evaluated to ensure the source has not been contaminated with the bacteria. Any aerosolised water entering a sterile area such as the lungs should be sterile. Tap water should not be used to rinse any respiratory therapy equipment. Routine maintenance of water supplies to eliminate sediment and scale from tanks and trays is essential (Benenson 1995, Lowry & Tompkins 1993). Australian & New Zealand Standard AS/NZ 3666-1995 Parts 1 and 2 outline these requirements.

Australia↗
PubMed1998

Helicobacter pylori.

H pylori is now recognised as a treatable primary cause of both gastric ulcers and gastric adenocarcinoma. Most infections remain asymptomatic. Persons with signs and symptoms which correlate with potential infection with H pylori should be tested and, if positive, treated with a recognised triple antibiotic regimen. Evaluation of the response to the treatment regimen should be undertaken.

Endoscopes↗
PubMed1997

Salmonella: a villain in 'food poisoning'.

The majority of these reports occurred during and shortly after the hottest summer recorded in Melbourne. It has been suggested that meat coming from the abattoirs may have carried a higher than usual load of organisms. Variability of the severity of the symptoms is related to host factors and food handling as well as to the virulence of the particular serovar. Investigations by the staff of the Department of Human Services revealed some major errors in food handling in some situations and minor breaches in others. Mishandling by consumers is also likely (Lester et al 1997). Such outbreaks serve to remind us not only of the importance, particularly in hot weather, of careful handling of meat, especially smallgoods, but also of the need for rapid notification to the appropriate authority of diarrhoeal illness where food is suspected to be the cause.

Abattoirs↗