Biomedical subjects

W J Foley

Publications and source records attributed to W J Foley.

At least 19 recordsLinked to original sources

PubMed2005

Marker-based quantitative genetics in the wild?: the heritability and genetic correlation of chemical defenses in eucalyptus.

Marker-based methods for estimating heritability and genetic correlation in the wild have attracted interest because traditional methods may be impractical or introduce bias via G x E effects, mating system variation, and sampling effects. However, they have not been widely used, especially in plants. A regression-based approach, which uses a continuous measure of genetic relatedness, promises to be particularly appropriate for use in plants with mixed-mating systems and overlapping generations. Using this method, we found significant narrow-sense heritability of foliar defense chemicals in a natural population of Eucalyptus melliodora. We also demonstrated a genetic basis for the phenotypic correlation underlying an ecological example of conditioned flavor aversion involving different biosynthetic pathways. Our results revealed that heritability estimates depend on the spatial scale of the analysis in a way that offers insight into the distribution of genetic and environmental variance. This study is the first to successfully use a marker-based method to measure quantitative genetic parameters in a tree. We suggest that this method will prove to be a useful tool in other studies and offer some recommendations for future applications of the method.

Australian Capital Territory↗

PubMed2003

Differential susceptibility to Eucalyptus secondary compounds explains feeding by the common ringtail (Pseudocheirus peregrinus) and common brushtail possum (Trichosurus vulpecula).

The effect of two plant secondary metabolites, tannins and formylated phloroglucinol compounds (FPCs), on the intake of Eucalyptus foliage by common ringtail (Pseudocheirus peregrinus) and common brushtail possums (Trichosurus vulpecula) was studied. We manipulated the amount of tannin that was free to bind with protein by coating foliage with polyethylene glycol 4000 (PEG) and relied on natural intraspecific variation in FPC concentrations. In contrast to ringtail possums, brushtail possums showed a greater tolerance to FPCs and ate more foliage when it was coated with PEG, suggesting that tannins limited their food intake. Brushtails detected the effects of tannins through immediate oral sensations rather than through systemic effects. Ringtail possums appeared highly tolerant of foliar tannins yet susceptible to low concentrations of FPCs. We could not detect any interaction between tannins and FPCs that affected the intake of Eucalyptus foliage by either species of possum. Although ringtail and brushtail possums are widely regarded as specialist and generalist folivores, respectively, their differential susceptibility to co-occurring secondary metabolites suggests greater complexity. Each possum species appears to be a specialist in its own right, which leads to a partitioning of available foliage. Brushtails avoid tannins and ringtails avoid FPCs.

Animal Feed↗

PubMed2002

The effect of excesses and deficiencies in amino acids on the feeding behaviour of the common brushtail possum (Trichosurus vulpecula).

In this study of the amino acid nutrition of a marsupial we tested three hypotheses: (a) that brushtail possums eat less when diets contain excesses or deficiencies in essential amino acids, (b) that brushtail possums choose diets that do not contain amino acid excesses, and (c) that amino acid consumption is mediated partly by the 5HT3 receptor. Possums ate less when 0.2-1.0% methionine (wet matter) was added to the diet, but similar concentrations of lysine and threonine had little effect. However, when given a choice, possums always selected the basal ration over one with added lysine, methionine or threonine at concentrations between 0.05% and 0.9%. In contrast to the experiments with excess amino acids, possums did not eat less of a diet almost devoid of an essential amino acid. Instead, the possums ate less when their diets contained synthetic amino acids rather than similar amounts and proportions of amino acids as casein. Contrary to the third hypothesis, the 5HT3 receptor antagonist, ondansetron, did not affect feeding by possums given a diet containing 0.8% methionine, suggesting that post-ingestive feedback, via the 5HT3 receptor, does not regulate amino acid intake when diets contain amino acid excesses.

Adaptation, Physiological↗

PubMed2001

Does excretion of secondary metabolites always involve a measurable metabolic cost? Fate of plant antifeedant salicin in common brushtail possum, Trichosurus vulpecula.

Salicin was administered orally to six brushtail possums by incorporation in food for six days at three dose levels (0.05, 0.5, and 1.5% wet weight), giving mean +/- SD daily intakes of 0.31 +/- 0.09, 2.76 +/- 0.75, and 6.04 +/- 1.12 mmol salicin. Metabolites were identified by mass spectrometry and assayed by HPLC. Salicyl alcohol glucuronide accounted for 56-64% of urinary metabolites over the three doses, salicyluric acid 15-26%, salicin 10-18%, and there were smaller amounts of free (2-4%) and conjugated (0-6%) salicylic acid. beta,2-Dihydroxyphenylpropionic acid was a minor metabolite. The hydrolysis of dietary salicin enabled reconjugation of its aglycone, salicyl alcohol, with a more polar sugar, glucuronic acid, thus enhancing its renal excretion and resulting in little net loss of substrates for conjugation and a low measurable metabolic cost of excretion.

Administration, Oral↗

PubMed2000

Nitrogen requirements of the didelphid marsupial Caluromys philander.

The use of fruit-based diets by a small arboreal marsupial, the woolly opossum (Caluromys philander) was studied to elucidate the mechanisms used to compensate for a low dietary protein concentration. The passage of a liquid phase digesta marker (Cr-EDTA) through the gut was significantly faster when animals were fed a diet containing 0.45% N compared to that measured on a diet containing 0.90% N. The size of the gut of the two groups was similar except that the caecum of animals fed 0.45% N was significantly larger than in those animals fed 0.90% N. Animals fed a diet of 0.45% N ate significantly more food than those fed higher levels of nitrogen but there was no significant difference in the dry matter digestibility of the diet. The maintenance nitrogen requirement of the animals was 176 mg dietary N or 146 mg truly digestible nitrogen per kg metabolic body mass, with low losses of non-dietary faecal nitrogen being notable. There was no significant difference between diets in any measured parameter of urea metabolism and all animals recycled between 60% and 80% of the endogenously synthesised urea.

Animal Nutritional Physiological Phenomena↗

PubMed2000

Plant secondary metabolites as mammalian feeding deterrents: separating the effects of the taste of salicin from its post-ingestive consequences in the common brushtail possum (Trichosurus vulpecula).

The effect of the phenolic glycoside, salicin, on food intake of the common brushtail possum (Trichosurus vulpecula) was studied in a series of feeding experiments. Increasing the concentration of salicin in a diet of fruits and cereals led to significant reductions of food intake in the short term (6 days). After prolonged (20 days) exposure to salicin, food intake (19 g kg(-0.75) day(-1)) was still reduced relative to controls (31 g kg(-0.75) day(-1)) but not reduced to the same extent as in the short-term experiments. Nonetheless, over these 20 days, common brushtail possums regulated their intake of salicin so as not to exceed a threshold limit of 1.9 +/- 0.1 g kg(-0.75) day(-1). Manipulative experiments sought to determine whether this threshold intake was in response to pre-ingestive factors (taste) or the post-ingestive consequences of ingesting salicin. Dietary salicin (0.17-5.0% DM) had no significant effect on nitrogen balance or urea metabolism and injection of a specific serotonin receptor antagonist, ondansetron, did not lead to increases in salicin intake as has been found for some other plant secondary metabolites. Similarly, administration of 1.3 g salicin by gavage had no significant effect on the subsequent intake of salicin compared to controls that were gavaged with water. We concluded that pre-ingestive factors were responsible for common brushtail possums limiting their intake of salicin-rich diets rather than any measurable post-ingestive consequence of feeding.

Animal Nutritional Physiological Phenomena↗

PubMed2000

How well can common brushtail possums regulate their intake of Eucalyptus toxins?

We studied factors affecting the ability of common brushtail possums (Trichosurus vulpecula) to regulate their intake of a dietary toxin, jensenone, extracted from Eucalyptus leaves. Increasing concentrations of jensenone in the diet led to a dose-dependent decrease in food intake best described as an exponential decay. Animals that had not previously been exposed to jensenone ate significantly more when first offered food containing the compound than on subsequent days. However, when offered the same amount of food in a number of portions throughout the night, naive animals ate significantly less than animals offered the total meal at once. When offered food containing jensenone over a 13-day period, the animals' intake varied cyclically with relatively high food intakes followed by relatively low intakes. Furthermore, animals that were exposed to cold conditions (4 degrees C) ate more than those maintained at 18 degrees C but this difference was abolished when jensenone was included in the diet. We interpret these results as showing that regulation of toxin intake by common brushtail possums depends on learned responses that can override other important influences on feeding.

Animal Nutritional Physiological Phenomena↗

PubMed1999

Restraint reduction reduces serious injuries among nursing home residents.

OBJECTIVES: To describe how removing physical restraints affected injuries in nursing home settings. DESIGN: A 2-year prospective study of an educational intervention for physical restraint reduction. SETTING: Sixteen diverse nursing homes with 2075 beds in California, Michigan, New York, and North Carolina. PARTICIPANTS: Study A: 859 residents who were physically restrained at the onset of the intervention on October 1, 1991. Study B: all residents who occupied the 2075 beds in the 16 facilities 3 months before the intervention and 3 months after its completion. INTERVENTION: Educational program for nursing home staff followed by quarterly site consultations to participating nursing homes. MAIN OUTCOME MEASURES: Rate of physical restraint use and injuries. RESULTS: Study A: Serious injuries declined significantly among the 859 residents restrained initially when restraint orders were discontinued (X2 = 6.2, P = .013). Study B: During the intervention period, physical restraint use among the 2075 residents decreased from 41% to 4%, a 90% reduction. The decrease in the percentage of injuries of moderate to serious severity was significant (i.e., 7.5% vs 4.4%, P2-tail = .0004) as was the rate of moderate and serious injuries combined (Rate Ratio = 1.580, P2-tail = .0033). CONCLUSIONS: A substantial decrease in restraint use occurred without an increase in serious injuries. Although minor injuries and falls increased, restraint-free care is safe when a comprehensive assessment is done and restraint alternatives are used.

Aged↗

PubMed1998

Administration of a 5HT3 receptor antagonist increases the intake of diets containing Eucalyptus secondary metabolites by marsupials.

The effect of a naturally occurring plant phenolic constituent (the acylphloroglucinol derivative, jensenone, derived from Eucalyptus jensenii) on the food intake of two folivorous marsupials, the common ringtail (Pseudocheirus peregrinus) and the common brushtail possum (Trichosurus vulpecula) was studied. When fed diets containing varying concentrations of jensenone, both species regulated their intake of jensenone so as not to exceed a ceiling intake. This ceiling was about twice as high for common ringtails as for common brushtails from northern Australia. Southern populations of common ringtails showed greatly reduced capacities to tolerate jensenone. When common brushtails were injected (0.5 mg.kg-0.75 body mass) with ondansetron (a selective antagonist of serotonin 5HT3 receptors), they ate significantly more jensenone than animals injected with physiological saline. The same pattern was observed when common ringtails were fed diets containing both jensenone and ondansetron (0.0035 mg.g-1 wet mass of diet). Ondansetron injection had no effect on food intake when the food did not contain jensenone while the addition of higher doses of ondansetron to diets of common ringtails very slightly reduced food intakes of a non-jensenone diet. When common brushtails were given 50 mg of jensenone by gastric lavage, their average subsequent intake of dietary jensenone matched the difference between the daily threshold and the dose given, although the response of individuals was highly variable. Lavage with water alone had no effect on subsequent jensenone intake compared with the pre-dose period. We interpret these results as evidence that the antifeedant effects of jensenone and related compounds are partly mediated by serotonin action on 5HT3 receptors most likely via "nausea" to condition a food aversion.

Animals↗

PubMed1997

Taking charge. The role of nursing administrators in removing restraints.

The leadership and commitment of nursing administrators play a pivotal role in minimizing the use of restraints and maintaining a restraint-free environment. This article describes the role of nursing administrators in reducing the use of physical restraints as part of a 2-year, national nursing home restraint-reduction project. It reviews important information about restraint-free care the benefits of restraint-free care, and strategies to reduce the use of restraints in nursing homes, much of which is applicable to settings other than nursing homes.

Aged↗

PubMed1996

Quantitative urinary excretion of unmetabolised N tau-[Me-14C] methylhistidine by the common ringtail possum (Pseudocheirus peregrinus) marsupialia.

Six common ringtail possums (Pseudocheirus peregrinus) were intravenously injected with a standard dose of radioactive 3-Methylhistidine (N tau-[Me-14C]MeH). The dose was rapidly and quantitatively excreted by the possums. More than 90% of radioactivity was recovered within 3 days. Thin layer chromatography and mass spectroscopy showed that 97% of recovered radioactivity was associated with unmetabolised N tau-[Me-14C]MeH. These data satisfy two key requirements for the validity of urinary 3-Methylhistidine (N tau-3MeH) excretion as an index of muscle protein catabolism, in P. peregrinus.

Animals↗

PubMed1994

Refining a case-mix measure for nursing homes: Resource Utilization Groups (RUG-III).

A case-mix classification system for nursing home residents is developed, based on a sample of 7,658 residents in seven states. Data included a broad assessment of resident characteristics, corresponding to items of the Minimum Data Set, and detailed measurement of nursing staff care time over a 24-hour period and therapy staff time over a 1-week period. The Resource Utilization Groups, Version III (RUG-III) system, with 44 distinct groups, achieves 55.5% variance explanation of total (nursing and therapy) per diem cost and meets goals of clinical validity and payment incentives. The mean resource use (case-mix index) of groups spans a nine-fold range. The RUG-III system improves on an earlier version not only by increasing the variance explanation (from 43%), but, more importantly, by identifying residents with "high tech" procedures (e.g., ventilators, respirators, and parenteral feeding) and those with cognitive impairments; by using better multiple activities of daily living; and by providing explicit qualifications for the Medicare nursing home benefit. RUG-III is being implemented for nursing home payment in 11 states (six as part of a federal multistate demonstration) and can be used in management, staffing level determination, and quality assurance.

Costs and Cost Analysis↗

PubMed1994

Activities of daily living and costs in nursing homes.

Functionality, as measured by activities of daily living (ADL), is the most important predictor of the cost of nursing home care. Data from a field-test version of the federally mandated Minimum Data Set (MDS) were examined using analysis of variance (ANOVA) and recursive partitioning methods to determine the relationships between ADL limitations and nursing cost (wage-weighted nursing time) among nursing home residents (n = 6,663). From this analysis, an index based on limitations in four ADLs was created. The developed ADL index is a readily determined measure of functional status useful in allocating nursing staff within nursing homes and in comparing the functional status of groups of residents, explaining 30 percent of variance in nursing costs among nursing home residents.

Activities of Daily Living↗

PubMed1993

Mental dysfunction and resource use in nursing homes.

The role of dementia and other mental disorders in nursing home case-mix classification systems has been an area of controversy. The role of mental dysfunctions was considered in developing a new case-mix measurement system for facility payment in a national demonstration to understand staff time use in nursing homes. Nursing staff (nurses and aides) time and resident assessment data were collected for 6,663 nursing home residents in 6 states. Measures of signs and symptoms of cognitive impairment (dementia), depression, and delirium were created based on items from the new National Minimum Data Set. These measures then were used to determine whether mental dysfunctions were predictive of resource use (nursing staff times and costs) when controlling for other case-mix variables. Cognitive impairment was associated with slightly higher staff time only in less physically-impaired residents without serious medical conditions and not receiving heavy rehabilitation. Similarly, depression and delirium were associated with higher resource use only in selected types of residents. Based on these findings, the new Resource Utilization Groups Version III (RUG-III) contain a major category of residents who are cognitively impaired but not severely dependent in Activities of Daily Living. Depression is used to differentiate subgroups of residents with major medical conditions such as hemiplegia and aphasia. Delirium, when used together with other resident characteristics, was not found useful in explaining resource use. Case-mix groups defined by mental dysfunctions can foster improved care, but careful consideration must be given to appropriate incentives and documentation requirements for providers.

Aged↗

PubMed1989

Case-mix classification of Medicare residents in skilled nursing facilities: resource utilization groups (RUG-T18).

Medicare residents in Skilled Nursing Facilities (SNFs) represent a small but unique population about which little is known. Data collected in a national sample of 2,564 Medicare residents in 38 SNFs were used to derive a resident classification system appropriate for use in a payment system. The classification system, Resource Utilization Groups-Medicare (RUG-T18) explains 55.5% of the per-diem resource cost differences of Medicare SNF residents. No classification system could be derived to provide significant explanation of per-episode costs. Although Medicare residents are admitted to SNFs immediately following an acute stay that is paid according to their diagnosis-related groups, the DRGs were ineffective in explaining SNF resource costs.

California↗

PubMed1988

Case mix for nursing home payment: resource utilization groups, version II.

A study of 3,427 nursing home residents in New York State, measuring both resources used and resident characteristics, was used to develop a resident classification system for payment purposes. The system balances clinical, statistical, and administrative criteria, making it useful both for the New York State Medicaid payment system and for quality of care and facility management.

Activities of Daily Living↗

PubMed1987

Digestion and metabolism of high-tannin Eucalyptus foliage by the brushtail possum (Trichosurus vulpecula) (Marsupialia: Phalangeridae).

The digestion and metabolism of Eucalyptus melliodora foliage was studied in captive brushtail possums (Trichosurus vulpecula). The foliage was low in nitrogen and silica but high in lignified fibre and phenolics compared with diets consumed by most other herbivores. The high lignin content was suggested as the main cause of the low digestibility of E. melliodora cell walls (24%); microscopic observations of plant fragments in the caecum and faeces revealed few bacteria attached to lignified tissues. The conversion of digestible energy (0.34 MJ X kg-0.75 X d-1) to metabolizable energy (0.26 MJ X kg-0.75 X d-1) was low compared to most other herbivores, probably because of excretion of metabolites of leaf essential oils and phenolics in the urine. When the inhibitory effect of leaf tannins on fibre digestion was blocked by supplementing the animals with polyethylene glycol (PEG), intake of dry matter, metabolizable energy and digestible fibre increased. These effects were attributed to the reversal by PEG of tannin-microbial enzyme complexes. It was concluded that the gut-filling effect of a bulk of indigestible fibre is a major reason why the brushtail possum does not feed exclusively on Eucalyptus foliage in the wild.

Animals↗

PubMed1984

Central venous thrombosis and embolism associated with peritoneovenous shunts.

During a five-year period from Aug 1, 1977 through Aug 1, 1982, 36 patients required 47 peritoneovenous shunt procedures (36 initial and 11 revisions) for the management of their intractable ascites. The results at six months showed 23 (63.9%) of 36 patients were dead, but in those living, 12 (92.3%) of 13, the ascites was satisfactorily controlled. Patency was measurably prolonged by appropriate revision of the shunt. The early and late complication rates were surprisingly high, 38.3% and 40.4%, respectively. The most serious complication was central venous thrombosis, 11 (23.4%) of 47 procedures, including one nonfatal and two fatal pulmonary emboli. Treatment included the use of fibrinolytic agents, anticoagulation, and shunt revisions. Careful attention to the details of shunt fabrication, insertion, and patient selection may help to reduce the occurrence of central venous thrombosis associated with peritoneovenous shunts.

Adolescent↗