Pulmonary alveolar microlithiasis in an alpaca (Vicugna pacos)

Pulmonary alveolar microlithiasis (PAM) is a rare, familial disease of unknown aetiology characterised by intra‐alveolar formation and accumulation of microliths. Multiple formalin‐fixed tissues were submitted from a 5‐month‐old female alpaca that died suddenly without significant clinical signs. No gross abnormalities were observed on postmortem examination. Histological findings included PAM and severe centrilobular hepatic necrosis. Although the hepatic lesion was the likely cause of death, PAM was an incidental finding that has not been reported previously in alpacas. An overview of PAM, including pathogenesis and histopathological characteristics, are discussed in relation to the concurrent hepatic disease in the present case.     

Non-invasive assessment of adrenocortical activity as a measure of stress in leopards Panthera pardus

Leopards Panthera pardus are classified in the IUCN Red List as Vulnerable, primarily due to habitat loss, natural prey base depletion and exploitation caused by various anthropogenic activities. Although protected areas are important for leopard conservation, the majority of suitable leopard habitat lies beyond protected area boundaries exposing individuals to different environmental, physiological and psychosocial stressors. This study aimed to examine the suitability of five different enzyme immunoassays (EIAs) for monitoring adrenocortical function in the leopard based on faecal glucocorticoid metabolite (fGCM) analysis. After performing an adrenocorticotrophic hormone (ACTH) stimulation test and investigating the stability of fGCM post-defaecation, faeces from free-ranging leopards in a peri-urban and a conservation area were collected to investigate the potential impact of habitat variability on glucocorticoid output. An EIA measuring fGCM with a 5α-3β-11β-diol structure performed best, demonstrating a ～200%–330% increase in fGCM concentrations approximately 40 h post-ACTH administration. Concentrations of fGCM remained quite stable for up to six days post-defaecation and showed a maximum increase of 8% and a maximum decrease of 9%. Although not significantly different, overall median fGCM concentrations were 68% higher in individuals utilising the peri-urban area compared with leopards utilising the conservation area. The ranges of fGCM concentrations between sites, however, were similar. Individual median fGCM concentrations differed distinctly between free-ranging males and females, possibly linked to female reproductive status. The established method can now assist in addressing some of the issues facing local wildlife managers, conservationists and researchers tackling various aspects related to leopard conservation and management under different land-use practices.     

Cyclic Related and Pathological Changes in the Lectin-binding Sites on the Swine Oviduct

This study was carried out to compare the lectin-binding pattern in the normal and pathological oviduct of sows during the ovarian cycle. Lectin-binding patterns showed differences between segments, phases of ovarian cycle and presence of morphologic lesions. In the infundibulum, it was observed that the cysts, in the follicular phase, reduced Ricinus communis-I (RCA-I) and Ulex europaeus-I (UEA-I) binding. Furthermore, in the pathological oviducts of the luteal-phase group, there is a reduction of Concanavalia ensiformis (Con-A) reactivity in this segment of the tube having wall cysts, adenomyosis and diverticulus. The Arachis hypogaea (PNA) binding in the infundibulum, during the luteal phase, decreased in the tube having adenomyosis. In animals with wall cysts, the Con-A, Triticum vulgaris (WGA) and RCA-I reactivity was minor in the glycocalyx of the isthmus epithelium during follicular phase. Con-A and Dolichos biflorus (DBA) binding pattern was minor in the luteal-phase isthmus of the tube having wall cysts, adenomyosis and diverticulus. In the ampulla, the wall cysts impaired the Con-A reaction only in the basal region of the epithelium, in the follicular phase. Binding with Con-A was decreased in the ampulla of animals in the luteal phase in the tube lesions with cysts and diverticulus. In addition, the diverticulus observed in the ampulla, during the luteal phase, reduced the PNA tubaric binding. The results of this study showed that the morphologic alterations modify the sugar pattern in the oviduct of sows. These modifications in glycoconjugates may be one of the reasons for the failure of fertility in sows.     

Effect of substrate on progression and healing of skin erosions and epidermal papillomas of Atlantic halibut, Hippoglossus hippoglossus (L.)

Juvenile Atlantic halibut cultured on a smooth substrate often develop skin lesions on the blind (abocular) side, significantly reducing carcass value and causing economic losses. We discovered that fish not only developed skin erosions, but also extensive epidermal papillomas when held on a smooth substrate for 39 months. This is the first time that epidermal papillomas have been reported in Atlantic halibut. To determine whether substrate type affected the progression or healing of these lesions, fish with papillomas and skin erosions were moved to identical rearing units having either an irregular (sand, gravel or Netlon) substrate, or a smooth (gel-coated fibreglass) substrate. After 62 days, 42-50% of fish held on any of the three irregular substrates had a skin erosion area (SEA) that had either diminished or appeared to be completely healed via gross examination. In contrast, none of the fish held on the smooth substrate showed improvement and 75-100% had a more severe SEA. Changes in the papilloma area (PA) were less dramatic: none of the fish held on an irregular substrate had any clear change in PA, although there was a suggestion that the PA in some fish might becoming less severe. Similarly, none of the fish held on the smooth substrate had a change in PA, although there was a suggestion that the PA in some fish was becoming more severe. After 97 days, there was also a suggestion that specific growth rates were higher in fish held on an irregular substrate when compared with those held on the smooth substrate. Overall, these data further substantiate previous studies suggesting that an irregular substrate, including the commercially used Netlon, is best for rearing Atlantic halibut. While there was a clear relationship between substrate type and whether skin erosions or papillomas progressed or healed, the exact cause(s) of these two responses is uncertain. Future studies should focus on risk factors such as stress, burrowing behaviour and the microenvironment of the substrate.     

Pathology of shell disease in the blue crab, Callinectes sapidus Rathbun, (Decapoda: Portunidae)

Blue crabs affected with shell disease displayed a wide array of pathologies in response to this very common affliction. Grossly, shell disease lesions most commonly presented as variably sized brown to black foci. Such lesions ranged from very small (1 mm2) to locally extensive (up to 200 mm2 in area). The larger of the melanized lesions sometimes appeared ulcerated. The most severe lesions observed (Pamlico River shell disease-PRSD) resulted in loss of up to 25% of the entire carapace. A diverse bacterial flora consisting of aeromonads, vibrios and five other genera were isolated as the predominant organisms from shell disease lesions. Fungi were rarely observed in larger lesions. Protozoa and algae were also rarely observed on the surface of some lesions. Histologically, lesions ranged from mild erosion of the epicuticle and outermost layers of the calcified endocuticle to more extensive endocuticle erosion with accompanying inflammation. In the most severe cases, there was total loss of the endocuticle and epidermis, with pseudomembrane formation, intense haemocyte infiltration, and involvement of adjacent viscera. There was no apparent relationship between the size of gross lesions and their histological severity (as defined by the extent of tissue damage), suggesting that gross examination of shell disease lesions is not a reliable method for assessing the damage to affected blue crabs.     

Use of azadirachtin as a larvicide or feeding deterrent for control of western flower thrips in orchard systems

Field trials were carried out to assess the efficacy of a 4% azadirachtin (aza)-containing neem seed extract EC, against damage by western flower thrips [Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)] on nectarine crops in the Similkameen Valley, British Columbia, Canada. Several trials were conducted during the years 1993 to 1995 to assess the repellent and larvicidal properties of aza, specifically: whether it was effective against adult or larval thrips; how the effects differed with concentration of aza; and whether female WFT avoided aza-treated flowers. Our results showed that aza has only limited effectiveness as a control agent against WFT on nectarines and the current formulation does not appear to limit larval development sufficiently to be deemed a possible control agent in this field situation.     

The Solar Acoustic Spectrum and Eigenmode Parameters

The Global Oscillation Network Group (GONG) project estimates the frequencies, amplitudes, and linewidths of more than 250,000 acoustic resonances of the sun from data sets lasting 36 days. The frequency resolution of a single data set is 0.321 microhertz. For frequencies averaged over the azimuthal order m, the median formal error is 0.044 microhertz, and the associated median fractional error is 1.6 x 10(-5). For a 3-year data set, the fractional error is expected to be 3 x 10(-6). The GONG m-averaged frequency measurements differ from other helioseismic data sets by 0.03 to 0.08 microhertz. The differences arise from a combination of systematic errors, random errors, and possible changes in solar structure.     

Temporal and spatial changes of chlorophyll fluorescence as a basis for early and precise detection of leaf rust and powdery mildew infections in wheat leaves

Temporal and spatial changes in parameters of fast chlorophyll fluorescence kinetics (ground fluorescence, Fo and maximal fluorescence, Fm) and red/NIR reflectance were assessed with a Pulse-Amplitude-Modulated (PAM)-Imaging system on a daily basis over a period of 2 weeks following inoculation of wheat leaves with powdery mildew and leaf rust. The early detection of these infections by means of fluorescence imaging was possible 2–3 days before visual symptoms or significant changes in normalised-differenced-vegetation index (NDVI) became apparent. The initial infection of both fungi caused an increase in Fo and decrease in photochemical efficiency (Fv/Fm, Fv/Fo). The appearance and development of fungal pustules was accompanied by reduction in Fo and Fm. This resulted mainly from lower absorption of fluorescence exciting light by the leaf mesophyll due to the shielding effect of fungal mycelium, and to lesser extent from the chlorophyll breakdown underneath pustules. Among the evaluated fluorescence parameters, Fv/Fo displayed the most pronounced response to both kinds of infection. Mildew infection influenced chlorophyll fluorescence neither in the direct vicinity of mycelium nor in the apparently healthy leaf regions. Rust infected plants, in contrast, displayed significantly reduced photochemical efficiency Fv/Fm and Fv/Fo in chlorotic tissue around pustules. The same, but less pronounced tendency was found in the apparently healthy regions of rust infected leaves in the last days of the experiment. Dark adaptation of leaves proved to be necessary for accurate detection of both pathogen infections by means of fluorescence imaging. Additional experiments are needed to estimate the potential of this technique for remote sensing under field conditions.     

Propagation in cell culture of the dinoflagellate amyloodinium, an ectoparasite of marine fishes

Amyloodinium ocellatum, a common dinoflagellate ectoparasite of marine fishes, was successfully propagated on a fish gill cell line. In vitro infections were similar in cytopathology and development to those reported on natural hosts, and large numbers of parasites could be produced. Exposure of parasites in cell culture to an antiprotozoal drug produced a dose-dependent inhibition of infectivity that was much more sensitive than a motility assay previously used to assess the toxic effects of a drug on protozoan ectoparasites. This propagation system may be a useful model for studying the biology and control of protozoan skin parasites of fishes and for quantitatively studying hostparasite interaction at cellular interfaces.