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Biomedical subjects

M Gracey

Publications and source records attributed to M Gracey.

At least 91 records · Page 5Linked to original sources
PubMed1987

Biotyping as a method of screening for enterotoxigenic Escherichia coli.

A scheme of biotyping described originally for E. coli isolated from urine was used to investigate enterotoxigenic (ETEC) and non-enterotoxigenic (non-ETEC) fecal E. coli. Primary biotype was determined by fermentation of raffinose, sorbose and dulcitol and decarboxylation of ornithine. Failure to ferment sorbose correlated best with enterotoxicity; 95.5% of ETEC and less than 40% of non-ETEC did not ferment sorbose. The sensitivity compares favourably with reported results of the use of polyvalent antisera for recognition of serotypes associated with ETEC, although specificity was lower using biotyping. Strains included in our study were mainly from Australia, New Zealand or Indonesia and we do not know if our observations apply to E. coli isolated elsewhere. If failure to ferment sorbose proved to be a characteristic of most ETEC, this reaction offers the possibility of developing selective media to increase the yield of ETEC from primary plates for laboratories in which gene probe techniques for recognition of ETEC are not available.

Bacteriological Techniques↗
PubMed1986

The Busselton children's survey, 1983. Body size from five to 16 years of age.

In 1983, 1623 primary and secondary schoolchildren took part in a health survey which was organized by the Busselton Population Studies Group. Age, sex, weight, height and country of birth were recorded for each child. Where possible, the country of birth of parents and the occupation of the father were extracted from previous Busselton surveys of adults. Compared with Perth schoolchildren, the difference in the attained weight and height of Busselton children at any age was small. This was so even though the two communities differ in location (rural compared with metropolitan), in ethnic origin (mainly British compared with diverse origins) and, probably, in social-rank distribution. Data from the two communities showed that a similar small secular increase in height had occurred since 1970/1971. This increase averaged at 1.2 cm for children at each year of age in Busselton and 1.5 cm to 1.6 cm for children in Perth.

Adolescent↗
PubMed1986

Protection of rats against cholera toxin and cholera-like enterotoxins by immunization with enteric-coated cholera toxin.

Pure cholera toxin (CT) given as a booster in enteric-coated tablets to rats produced a humoral and intestinal immune response similar to the result of instilling the boosting dose of CT directly into the duodenum. This method protects the antigen against gastric acid and allows delivery of the immunogen to intestinal mucosa, an essential step in producing intestinal secretory IgA. Immunization gave protection against pure CT during intestinal perfusion but also significantly protected against the secretory effects of E. coli LT and CT-like toxin of A. sobria. The use of enteric-coated vaccines offers advantages for mass immunization programmes and our results suggest that immunization with preparations containing CT holotoxin may protect against heterologous toxins which cross-react with CT.

Aeromonas↗
PubMed1986

Bacterial diarrhoea.

Bacterial infections are important causes of diarrhoea in infants and children, particularly in developing countries and in other settings where standards of personal and community hygiene are low. Knowledge of bacterial diarrhoeas has been significantly expanded in recent years by the finding that many episodes of acute diarrhoea are due to infections with bacteria which produce enterotoxins that interfere with intestinal fluid and electrolyte transport (the 'enterotoxigenic' diarrhoeas). Several 'newer' bacterial agents have also been identified which would not have been detected in earlier studies of the epidemiology of infective diarrhoeas; these include Aeromonas, Campylobacter, Clostridium difficile and Yersinia. Another important advance has been new knowledge about mechanisms by which bacteria cause diarrhoea; this has led to the widespread successful application of oral rehydration therapy in treatment of acute watery diarrhoeas.

Aeromonas↗
PubMed1985

The use of the coagglutination test to determine whether Australian and New Zealand isolates of Escherichia coli produce the heat-labile enterotoxin.

A rapid method for identifying strains of enterotoxigenic Escherichia coli (ETEC) which produce the heat-labile enterotoxin (LT) was evaluated. It was shown generally to be more sensitive in identifying LT producing ETEC than the traditional methods. It is considered particularly useful for the small laboratory, because no complex equipment is required.

Agglutination Tests↗
PubMed1985

Use of non-carbonated soft drinks to provide safe drinking water.

Non-carbonated, low-calorie soft drink concentrates (cordials), when diluted according to manufacturers' instructions, had significant antibacterial effects in vitro. Bacteria affected include Vibrio cholerae, Aeromonas hydrophila, Shigella sonnei, Salmonella typhimurium and Escherichia coli. With vibrios, bacterial counts were reduced from 10(6)/ml to undetectable numbers in less than 10 min. Escherichia coli in an initial concentration of 10(6)/ml became undetectable after incubation for 1 h with one brand of cordial. Naturally contaminated water can be rendered potable by incubation with cordials at room temperature for 1 h. This may be a way to reduce the risk of water-borne diarrhoea, particularly where the cleanliness of drinking waters cannot be otherwise assured, for example when making up oral rehydration fluids and for travellers in high-risk areas.

Bacteria↗
PubMed1985

Breast milk lactoferrin levels in relation to maternal nutritional status.

Lactoferrin was measured in breast milk from Aboriginal and non-Aboriginal Australian women using an enzyme immunoassay. There was no diurnal variation in lactoferrin concentration or change in concentration between the beginning and end of a feed. Lactoferrin levels were significantly higher in the first 15 days postpartum than in the period after the 15th day. Regression analysis showed that in milk from Aboriginal women less than 15 days postpartum, higher concentrations of lactoferrin were associated with weight for height (WFH) greater than 90% and with increased parity. Comparable data were not available for Caucasian women. For Aboriginal and Caucasian women more than 15 days postpartum, lactoferrin concentrations were higher in women greater than 90% WFH. Other variables, such as parity, were not significant in the regression.

Adult↗
PubMed1985

The growth of breast fed and artificially fed infants from birth to twelve months.

Growth data collected from 394 healthy infants were analysed in relation to feeding practices. Infants were grouped on the basis of sex, if breast fed or artificially fed, and duration of breast feeding. From birth to 3 months, weight gains were similar for boys (2.5 kg) and also for girls (2.3 kg) irrespective of feeding method. From 3 to 6 months weight gains were greater in infants who were artificially fed from birth (2.0 kg both sexes) or breast fed for only a short time (1.9 kg) than for those exclusively breast fed for 6 months (1.6 kg) or longer (1.7 kg). Weight gains continued to be greater in artificially fed infants after 6 months. Over 12 months, artificially fed boys gained 410 g and girls 750 g more than those who were breast fed from birth. These differences occurred even though the artificial feedings that prevailed to 6 months and longer were low-solute ('humanized') formulas.

Body Weight↗
PubMed1985

Invasiveness of Aeromonas spp. in relation to biotype, virulence factors, and clinical features.

Of 69 fecal isolates of Aeromonas spp., 18 had the ability to invade HEp-2 cells. Invasiveness correlated with biotype; of the 18 invasive strains, 16 were A. sobria and 2 were A. hydrophila. No invasive strains were found among the A. caviae. Of the 18 invasive strains, 13 were enterotoxigenic. Of the enterotoxigenic and invasive strains, 12 were A. sobria, but enterotoxicity was also more common among noninvasive strains of A. sobria. Fucose-resistant hemagglutination was also more common in A. sobria, but invasive strains were equally divided between fucose-resistant hemagglutination and other patterns. Detailed clinical information was available for 27 of the 69 strains. All 15 strains of A. sobria or A. hydrophila associated with diarrhea were enterotoxigenic; 6 of the 10 strains of A. sobria were also invasive. Blood was present in the stool samples of five of the six patients with invasive A. sobria and in none of the patients with noninvasive strains. Although limited, these observations suggest that dysenteric symptoms may be produced by invasive Aeromonas spp.

Adult↗
PubMed1984

Maternal and childhood nutrition among Aborigines of the Kimberley region.

A cross-sectional anthropometric survey of 128 Aboriginal children under five years of age and of 388 Aboriginal girls and women of child-bearing age was undertaken in seven communities in the Kimberley Region of Western Australia. More than 20% of the children were undernourished, three individuals severely so. All but one of those who were undernourished were over 12 months of age. Less than 60% of the female subjects of child-bearing age had a satisfactory nutritional status; one-sixth were undernourished and one-quarter, mostly older women, were overweight. The findings indicate that poor nutrition is widespread among Aboriginal female subjects of child-bearing age. Maternal malnutrition may contribute significantly to unsatisfactory nutrition and health in Aboriginal infants and young children.

Adolescent↗