Comparative lipid and lipoprotein metabolism

This review summarizes a number of recent reports in several areas of lipid and lipoprotein metabolism. Absorption of dietary lipids, cholesterol synthesis, and biliary cholesterol metabolism are mentioned only briefly to be complete. Comparative aspects of lipoprotein metabolism, however, are detailed in an effort to integrate the myriad metabolic events which characterize these important lipid transport particles. Where comparative information is known, those aspects of lipoprotein metabolism that may be protective against atherogenesis in certain mammalian species are also described. Efforts to understand atherogenic resistance comparatively in animals lends a better understanding of the metabolic events leading to coronary artery disease in humans. They also provide an important basis for understanding lipid metabolism in numerous veterinary species.     

Characterisation ofFusarium oxysporum isolated from carnation in Australia based on pathogenicity,vegetative compatibility and random amplified polymorphic DNA (RAPD) assay

Isolates ofF. oxysporum collected from symptomless carnation cuttings from Australian carnation growers properties, together with isolates from national collections, were screened for pathogenicity and grouped according to vegetative compatibility and random amplified polymorphic DNA (RAPD) patterns. The collection of 82 Australian isolates sorted into 23 different vegetative compatibility groups (VCGs). Of 69 isolates tested for pathogenicity, 24 were pathogenic to carnations, while the remaining 45 were non-pathogenic. All pathogenic isolates were within two VCGs, one of which was also compatible with an isolate obtained from an international culture collection, and which is known to represent VCG 0021 and race 2. Race status of the two pathogenic VCGs remains unknown. The RAPD assay revealed distinct DNA banding patterns which could distinguish pathogenic from non-pathogenic isolates as well as differentiate between isolates from the two pathogenic VCGs.     

Comparison of methods to assess dog owners' therapeutic compliance

Objective To compare different methods for assessing the compliance of veterinary clients administering medication to their dogs.
Procedure Thirty-one owners whose dogs were prescribed amoxycillin-clavulanate, twice and thrice daily, for a duration of five to seven days were recruited from three Sydney veterinary hospitals. Compliance was assessed by electronic monitoring devices, return medication counts, client self-reports and veterinarians' estimation of likely compliance.
Results Electronic monitoring showed owners administered on average 84% (range 7 to 104%) of prescribed medication to their dogs. Both return medication counts and client self-reports tended to overestimate therapeutic compliance when compared with electronic monitoring. When questioned, the majority of owners (71%) claimed perfect compliance with the prescribed regimen. No correlation was found between veterinarians' estimates of owner compliance and that assessed electronically.
Conclusion Electronic monitoring provided valuable information on dose timing and variation, but proved costly and difficult to employ in veterinary practice. Simplicity and low cost of return medication counts makes this method attractive for use in veterinary compliance studies. Client self-reports reliably detected some noncompliers and permitted identification of individual problems or errors. For practical purposes a combination of return medication counts and client self-reports may have merit in future veterinary compliance studies.     

Can giant clam (Tridacna squamosa) populations be restored on Singapore's heavily impacted coral reefs?

• 1. Giant clams have been a sustainable resource for millennia, but unregulated harvesting has led to local extinctions within the Indo‐Pacific region. Giant clam mariculture can produce large numbers of juveniles for restocking wild populations where natural recruitment is low or absent.
• 2. Singapore is surrounded by more than 60 small islands, many with fringing reefs. These reefs, however, experience increased turbidity and sedimentation resulting from massive coastal development projects and regular dredging of shipping lanes.
• 3. Seven reefs off Singapore's southern islands were surveyed (9670 m²) for giant clams. Also, an experiment was conducted to determine the growth of Tridacna squamosa reared in aquaria under three light treatments: ～50% ambient photosynthetically active radiation (PAR); ～25% ambient PAR; and ～12% ambient PAR. Finally, 144 clams (T. squamosa) were transplanted to four reefs around Singapore to study survival and growth in a heavily impacted environment.
• 4. A total of 23 adult clams from three species were found during the survey, representing a mean density of 0.24 per 100 m². Most clams were found at Raffles Lighthouse, Singapore's ‘best’ reef. No juvenile clams were encountered. In the aquarium experiment, clam growth was significantly different among the three light treatments, with growth greatest in the ～50% ambient PAR treatment. Of the 144 transplanted clams, 116 (80.6%) were recovered after 7 months. All specimens had increased in size, with growth rates among reefs ranging from 3.3 mm month^?1 (SD=1.3 mm) to 4.8 mm month^?1 (SD=1.6 mm).
• 5. Results suggest that, despite high levels of sedimentation and turbidity on Singapore's reefs, giant clams can survive and grow well. Restocking efforts using maricultured clams may be effective in enhancing the dwindling local populations. It is not clear, however, whether a self‐sustaining community can be established as high sedimentation may hinder larval settlement and survival.

Copyright © 2007 John Wiley & Sons, Ltd.     

Vascular-Streak Dieback: A New Encounter Disease of Cacao in Papua New Guinea and Southeast Asia Caused by the Obligate Basidiomycete Oncobasidium theobromae

ABSTRACT The basidiomycete Oncobasidium theobromae was identified as the cause of a devastating disease of cacao named vascular-streak dieback (VSD) in Papua New Guinea in the 1960s. VSD now causes losses among cacao seedlings and kills branches in mature cacao trees throughout Southeast Asia and parts of Melanesia. The characteristic symptoms include a green-spotted chlorosis and fall of leaves beginning on the second or third flush behind the stem apex, raised lenticels, and darkening of vascular traces at the leaf scars and infected xylem. Eventually complete defoliation occurs and, if the fungus spreads to the trunk, the tree will die. O. theobromae is a highly specialized, near-obligate parasite of cocoa. It is a windborne, leaf-penetrating, vascular pathogen, and may have evolved as an endophyte on an as yet unidentified indigenous host. The rate of disease spread on cocoa is limited because basidiocarps develop only on fresh leaf scars during wet weather, and basidiospores remain viable for a few hours on the night they are shed. Consequently, very few new infections occur beyond 80-m from diseased trees. Transmission of the disease through seed or infected cuttings has not been demonstrated. Strict quarantine measures applied to the movement of intact plants are crucial in reducing spread of the disease. Integrated management, including the planting of less susceptible genotypes, nursery construction and management, canopy pruning and shade management, provides effective control.     

Kisspeptin,c‐Fos and CRFR Type 2 Co‐expression in the Hypothalamus after Insulin‐Induced Hypoglycaemia

Normal reproductive function is dependent upon availability of glucose and insulin‐induced hypoglycaemia is a metabolic stressor known to disrupt the ovine oestrous cycle. We have recently shown that IIH has the ability to delay the LH surge of intact ewes. In the present study, we examined brain tissue to determine: (i) which hypothalamic regions are activated with respect to IIH and (ii) the effect of IIH on kisspeptin cell activation and CRFR type 2 immunoreactivity, all of which may be involved in disruptive mechanisms. Follicular phases were synchronized with progesterone vaginal pessaries and at 28 h after progesterone withdrawal (PW), animals received saline (n = 6) or insulin (4 IU/kg; n = 5) and were subsequently killed at 31 h after PW (i.e., 3 h after insulin administration). Peripheral hormone concentrations were evaluated, and hypothalamic sections were immunostained for either kisspeptin and c‐Fos (a marker of neuronal activation) or CRFR type 2. Within 3 h of treatment, cortisol concentrations had increased whereas plasma oestradiol concentrations decreased in peripheral plasma (p < 0.05 for both). In the arcuate nucleus (ARC), insulin‐treated ewes had an increased expression of c‐Fos. Furthermore, the percentage of kisspeptin cells co‐expressing c‐Fos increased in the ARC (from 11 to 51%; p < 0.05), but there was no change in the medial pre‐optic area (mPOA; 14 vs 19%). CRFR type 2 expression in the lower part of the ARC and the median eminence was not altered by insulin treatment. Thus, disruption of the LH surge after IIH in the follicular phase is not associated with decreased kisspeptin cell activation or an increase in CRFR type 2 in the ARC but may involve other cell types located in the ARC nucleus which are activated in response to IIH.     

Owner compliance with short term antimicrobial medication in dogs

Summary: The degree to which dog owners complied with instructions to administer a 5 to 10 day course of antimicrobial medication to their pets was assessed using microprocessor based monitoring devices. Twenty two clients gave an average of 84% of prescribed doses of amoxycillin-clavulanate. No difference was found between twice and thrice daily dosing regimens in the overall percentage of prescribed doses given. However, timing of doses was far from ideal in many cases and only 34% of doses were given within the designated optimum time period. Adherence to desired dosing intervals tended to be better with twice daily than with thrice daily dosing, although the difference was statistically insignificant.