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Biomedical subjects

E J Harper

Publications and source records attributed to E J Harper.

10 recordsLinked to original sources
PubMed2000

Influence of feeding regimen on body condition in the cat.

The influence of feeding regimen on body condition in the cat was studied in a sample of the UK domestic cat population (n = 136). Data were collected by interviewing cat owners and assessing body condition of cats in the owners' homes. Four main factors were identified which were related to body condition. These were, in descending order of significance: neuter status, age, frequency of treat feeding, and ad libitum feeding. Feeding regimen as a risk factor in feline obesity is discussed.

Animal Feed↗
PubMed1998

Changing perspectives on aging and energy requirements: aging and energy intakes in humans, dogs and cats.

A series of cross-sectional and longitudinal studies conducted in humans has shown that aging is associated with a gradual decline in the maintenance energy requirement. Generally, this is equivalent to a total decrement of 20% of young adult maintenance energy requirements and is a result of a decrease in both physical activity and basal metabolic rate. Relatively few such studies have been conducted in dogs, but the results have been consistent. It appears that maintenance energy requirements decline by approximately 20%, and it is assumed that the causal factors are the same as those for humans. The situation appears to be somewhat different in cats, with evidence to date indicating that maintenance energy requirements remain constant throughout adult life. Why cats should be different from other species is not clear, but it is hypothesized that relative inactivity is typical of most cats' behavior, such that there is no obvious age-related change. In terms of feeding regimens for senior cats and dogs, it is appropriate to decrease energy provision for senior dogs by approximately 20%, whereas the energy provision for senior cats should not be decreased.

Adult↗
PubMed1998

Changing perspectives on aging and energy requirements: aging, body weight and body composition in humans, dogs and cats.

The drivers of the age-related decline in maintenance energy requirement in humans are primarily reduced physical activity and a decrease in basal metabolic rate, which is largely driven by changes in body composition. Most studies indicate that there is a significant loss of lean body mass and a concomitant increase in fat mass with advancing age. The causal factors appear to be changes in physical activity and a reduction in the activity of growth hormone. Sustained physical activity and/or administration of growth hormone have been shown to offset age-related changes in lean:fat ratios in humans and in rats. Very little information is available on dogs, but current data suggest that aging is accompanied by a decrease in lean:fat ratios. The rate and extent of change is similar to that observed in aging humans and it is assumed that the same causal factors are responsible. On this basis, it is likely that basal metabolic rate declines in older dogs. New evidence suggests that the situation is very different in cats, with no apparent change in lean:fat ratios with advancing age. This is probably related to constant activity levels throughout life and suggests that basal metabolic rate probably does not decrease as cats age. On the basis of this evidence, there is no reason to reduce energy provision to the majority of older cats.

Adult↗
PubMed1998

Changing perspectives on aging and energy requirements: aging and digestive function in humans, dogs and cats.

When considering the question of energy balance, it is important to take into account energy provision and the ability of aging animals to digest macronutrients and thus obtain their maintenance energy requirement. A large number of studies have been conducted in humans in an effort to establish whether aging of the gastrointestinal tract has a significant effect on availability of dietary energy. The results of these studies have been conflicting, with indications that some aspects of gut functionality do decline with age, but little evidence overall to suggest that aging humans are at risk of energy deficit due to compromised digestive efficiency. A number of digestibility studies carried out with dogs confirm that there is no evidence of an age-related decline in digestive efficiency. This knowledge makes the determination of energy provision to senior dogs relatively straightforward to calculate. Many senior cats appear to exhibit quite a marked reduction in their ability to digest macronutrients, particularly fat, efficiently. Because this reduces the overall capacity to obtain energy from the diet, it is recommended that old cats should not routinely be offered reduced energy diets. For senior cats, the feeding regimen in later life should be to offer highly digestible diets that provide as much energy as adult maintenance rations.

Aged↗
PubMed1998

Bioactive bone cements.

Poly(methylmethacrylate) (PMMA) bone cement, used to fix implants into the bone, produces good surgical results if used correctly. However, prostheses do eventually become loose and the breakdown of the cement mantle is a factor in this failure. Limitations of PMMA cement, which lead to problems with the fixation of the implant, include its mechanical characteristics and its influence upon surrounding bone, associated with the polymerization reaction. A bioactive bone cement is particularly designed to produce a better interface between the cement and bone. However, an improvement in mechanical properties, especially fatigue, creep and fracture toughness, are an added necessary requirement to increase the lifetime of a cemented implant. The development of a bioactive cement has been conducted mainly in two ways; firstly, to improve existing PMMA cement by the addition of various bioactive agents and secondly, to design an alternative matrix for the bioactive material to be combined with. The most promising investigations which have been conducted, along with their relative benefits and drawbacks, are discussed.

Biocompatible Materials↗
PubMed1998

Use of the breath hydrogen test to assess the effect of age on orocecal transit time and carbohydrate assimilation in cats.

OBJECTIVE: To evaluate the effect of age on orocecal transit time (OCTT) in cats, using the breath hydrogen test, and to assess potential differences in nutrient absorption. ANIMALS: 27 healthy cats. PROCEDURE: Cats were allocated to the following 3 groups on the basis of age: group A (9 kittens, 5 to 7 months old), group B (9 young adults, 3 to 5 years old), and group C (9 older cats, 12 to 15 years old). Cats were fed a standard canned diet for 2 weeks prior to measurement of OCTT. Exhaled hydrogen concentration (parts per minute [ppm x min]) was monitored for 8 hours after feeding 60 g of the canned diet. RESULTS: Mean OCTT in group-A cats was 203 minutes (range, 90 to 345 minutes), which was significantly different from that in group-B (317 minutes; range, 180 to 435 minutes) and group-C (309 minutes; range, 225 to 375 minutes) cats. Median area under the breath hydrogen excretion time curve (ppm x min) for the 8-hour monitoring period, first 45 minutes, and 105 minutes after OCTT for the 3 groups was not significantly different among groups. CONCLUSIONS: Kittens had significantly faster OCTT than did adult cats.

Aging↗
PubMed1996

In situ analysis of the degree of polymerization of bone cement by using FT-Raman spectroscopy.

A method has been developed which enables an in situ analysis of the degree of polymerization of bone cement. The concentration of monomeric double bond is monitored continuously during the entire curing process and hence the method can be used for quantitative studies of polymerization kinetics. In this study, Fourier Transform Raman (FTR) spectroscopy was utilized to investigate the degree of polymerization of a novel bone cement in situ, and the results are compared with the thermal profile obtained for polymerization.

Biocompatible Materials↗