Carcinogen in rock fern (Chielanthes sieberi) from New Zealand and Australia.
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Animals↗
Biomedical subjects
A D Ross
Publications and source records attributed to A D Ross.
Induction of heat stress in beef cattle by feeding the ergots of Claviceps purpurea.
Two groups of 4 Hereford steers were housed in a controlled environment room and exposed to simulated high summer temperatures. Both groups were fed a barley grain and hay diet ad libitum. The barley in one diet contained 0.5% w/w ergots of Claviceps purpurea. Within one week of feeding the ergot diet mean rectal temperature was significantly elevated (P less than 0.05) each afternoon (up to 41 degrees C) but returned to normal overnight. Elevated rectal temperature was accompanied by other signs of heat stress, reduced feed intake, body weight loss and depression or serum prolactin concentration. Symptoms disappeared within 1 week of ceasing to feed the ergot diet.
Animal Feed↗
Streptococcus suis type 1 infection of sucking pigs.
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Animals↗
An ultrastructural study of adenocarcinoma of the small intestine in sheep.
The ultrastructural appearance at primary and metastatic sites of ten ovine small intestinal adenocarcinomas was that of scirrhous tubular adenocarcinoma. Polygonal undifferentiated tumor cells had desmosomes, folded nuclei, and moderate numbers of mitochondria but few other organelles. More differentiated cells were columnar with apical microvilli and basal nuclei. They contained granular endoplasmic reticulum, Golgi and secretory granules. Microvillus-lined intracytoplasmic lumina (5-10 micron diameter), fibrous filaments (10 nm diameter, up to 1.4 micron length) and tubular paracrystalline arrays (hexagonal symmetry, 37-nm periodicity) in lumina and secretory granules were seen in some tumor cells in all ten sheep.
Adenocarcinoma↗
Phenoxy and picolinic acid herbicides and small-intestinal adenocarcinoma in sheep.
A study of age and sex matched groups of adult female sheep from 88 flat, hill, and high-country farms was conducted in the South Island of New Zealand to investigate the influence of breed and certain environmental factors on the prevalence rate of small-intestinal adenocarcinoma (SIA). 20 678 female sheep aged 5.5-7.5 years were examined at slaughter, 125 cases of SIA were found (6 per thousand) in animals from 61 farms (69%) and the prevalence rate for individual farm groups varied from 0 to 38 per thousand. Differences in tumour rate between breed groups were significant but differences between farm type were not. Exposure to phenoxy (Ph), picolinic acid (Pi) herbicides, or both (PhPi) was associated with significant increases in tumour rate. The increase in rate was significant for exposure to each of the 3 herbicide groups. Exposure to recently sprayed feed stuffs was associated with a significantly larger increase in tumour rate than exposure to less recently sprayed food. There was no difference between tumour rates of sheep exposed to Ph herbicides with or without 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Rates rose significantly with the total number of Ph, Pi, PhPi sprays used on the farm. The variation in rates associated with herbicides is sufficient to explain the breed differences recorded.
Adenocarcinoma↗
The prevalence of warts on the hands of workers in a New Zealand slaughterhouse.
Ninety-nine adult male meat workers and 55 similar textile workers were questioned about their current and past experience of hand warts, their contact with affected family members and non-workplace exposure to animals. Period prevalence rates for workers who slaughtered cattle (72%) and pigs (60%)--were significantly higher than those for other meat industry workers (27%) and textile workers (22%). Beef and pig slaughtermen employed for more than five years had a significantly higher period prevalence rate than other meat workers and textile workers. There were no differences between prevalence rates of warts in children and other family members of affected and unaffected meat workers. There was an inverse relationship between the prevalence of hand warts and non-workplace exposure to cats and dogs. Very few meat workers had time off work due to hand warts. The data support the hypothesis that the work environment of beef and pig slaughtermen enhances the prevalence of hand warts.
Abattoirs↗
Small-intestinal adenocarcinoma in cattle.
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Letter↗
Colloids vs. crystalloids--a continuing controversy.
The crystalloid vs. colloid controversy is based on a disagreement as to the most effective, safest, and most economical method of maintaining an effective plasma volume in shock patients. This review discusses Starling's law of fluid movement, with a definition of each term in the normal physiological state, and presents examples of how each component of Starling's law differs in the two major types of pulmonary edema: (1) cardiogenic and (2) noncardiogenic. The colloid-crystalloid literature is reviewed briefly with an emphasis on the major studies that support each side, and the deficiencies in each study. The arguments supporting each side of the crystalloid-colloid debate are then listed, with a summary that demonstrates the areas of agreement between the two schools of thought on fluid resuscitation. Each major colloid (albumin, dextran, hetastarch) and a representative crystalloid (lactated Ringer's) are discussed in terms of their chemistry; pharmacology and indications; and precautions, adverse reactions, and side effects. A table is included that summarizes the available products' data regarding composition, volume expansion, duration of expansion, half-life, metabolism, elimination, precautions, adverse reactions, and dose.
Blood Proteins↗
Neoplasms of sheep in Great Britain.
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Animals↗
Formalin and footrot in sheep.
Changes in formalin concentration were measured over time in uncontaminated solutions and solutions heavily contaminated by mud, faeces, wool or straw. Shallow plastic trays containing 1.11 of a 9% aqueous solution of formalin were exposed for 6 days (trial 1) or 8 days (trial 2) to windy autumn weather. Evaporation of solution volumes was high (47-73%). Concentration generally increased over time: by 13-31% in trial 1 and by 61-162% in trial 2. These figures represent actual increases in percentage formalin of up to 3.0% in trial 1 and up to 7.6% in trial 2. Exposure to mud, sheep faeces or wool did not affect the increase in concentration but there was no increase in the presence of straw. As exposure to excessively concentrated formalin solutions produces hyperaemia, cracking of interdigital skin and lameness in sheep it is recommended that footbath solutions should be diluted to 2-S%, prepared on the day of use and discarded daily whether contaminated or not. Addition of formalin or water to existing solutions of unknown strength should be avoided.
Journal Article↗
Small intestinal carcinoma in sheep.
This communication reports a high prevalence of small intestinal carcinoma. Seventeen cases were detected during a survey of 6,248 sheep (0.272%) from 3 export abattoirs in southern New South Wales. The neoplasm appeared on the serosal surface of the jejenum and ileum as a ring of dense white fibrous tissue which caused stenosis and cranial dilation of the intestine. The mucosa and muscularis were thickened and folded but otherwise grossly normal except for 3 cases where small polyps were present. Metastatic lesions occurred regularly in mesenteric lymph nodes and sclerotic deposits were often present on the surface of abdominal visera. In one case metastatic nodules were found throughout the liver and lungs. Histologically, the glandular architecture of the mucosa and submucosa was disturbed and thickened with fibrous tissue. The muscularis was intact; however an intense desmoplastic reaction under the serosa contained scattered islands of PAS-positive epithelial cells; distinct acini were uncommon and mitotic figures rare.
Animals↗
The effect of scrotal insulation on spermatozoal morphology and the rates of spermatogenesis and epididymal passage of spermatozoa in the bull.
In five beef bulls spermatogenic cells labelled with (3)H-thymidine were used to estimate the duration of one cycle of the seminiferous epithelium (S.E.) and epididymal passage (E.P.) of spermatozoa after 10 or 20 hr of scrotal insulation designed to increase testicular temperature. From six autoradiographic estimates in three bulls, the mean value for 1 S.E. cycle was 13.4 days (range 12.9 to 13.6 days). Two estimates of E.P. were both 13.5 days. Scrotal insulation altered both semen quality (lowered percentage live and motile spermatozoa, raised percentage abnormal spermatozoa and lowered concentration per ml spermatozoa) and the histological appearance of the seminiferous epithelium. However, the rate of spermatogenesis and epididymal transport was unchanged.
Journal Article↗
Renal coccidiosis of the horse associated with Klossiella equi.
Klossiella equi in the kidney of a horse is described. Gametocytic and sporogonic stages were observed in the epithelium of the collecting tubules in association with schizonts in the glomeruli and proximal convoluted tubules. The condition was asymptomatic and caused only minor renal damage and inflammation.
Animals↗
The amino acid composition of angiotensin alters its ability to reduce alcohol consumption in rats.
The voluntary consumption of alcohol has been shown to be reduced by a variety of manipulations which enhance activity in the renin-angiotensin system, including the administration of the bovine form of angiotensin II-[Val5]-ANG II. The present study investigated the relationship between the amino acid composition of angiotensin II and its ability to reduce alcohol intake by administering a number of different forms or fragments of the parent peptide. [Ile5]-Angiotensin II ([Ile5]-ANG II), two endogenous fragments of angiotensin II [( Des-Asp1]-ANG II and [Des-Phe8]-ANG II) were administered subcutaneously in rats across a range of doses. [Ile5]-ANG II reduced alcohol intake at all doses tested between 20 and 400 micrograms/kg while [Des-Asp1]-ANG II reduced alcohol intake only at the 400 micrograms/kg dose. [Des-Phe8]-ANG II had no effect on alcohol intake at any dose tested. Administration of the antagonist [Sar1-Thr8]-ANG II by itself did not enhance alcohol intake. While the pressor and dipsogenic properties of these fragments sometimes correlated with the reduction in alcohol intake they were not a causal factor in decreasing the intake. These results indicate that variations in the peptide composition of angiotensin can significantly alter its ability to reduce the consumption of alcohol.
Alcohol Drinking↗
Injection site lesions of footrot vaccines in sheep.
Three trials were conducted to assess the size and frequency of lesions induced by an oil-based and an alum-precipitated aqueous B. nodosus commercial footrot vaccine at two injection sites (neck and brisket) with or without prior skin swabbing with methanol. Animals used were previously unvaccinated and clean and dry at time of vaccination. Trial 1 contained 57 2-tooth Booroola Merino x Coopworth ewes, trial 2 contained 60 mixed-age Corriedale ewes, and trial 3 contained 39 rams of mixed age and sex. Firm nodules or plaques with indurated edges and with a maximum dimension of 1cm or more appeared soon after vaccination and were still very common (50-100% of sheep vaccinated) 5-6 weeks after injection. A variable proportion exhibited a liquefied central area of necrosis and later discharged necrotic material. The oil-based vaccine produced significantly larger lesions than the alum-precipitated aqueous vaccine. Lesion size at the brisket site was significantly larger than the neck site in ewes but not in rams. Skin preparation with methanol had no effect on lesion frequency or size.
Journal Article↗
Paradigm to test a drug-induced aversion to ethanol.
The screening of new agents for aversive therapy of alcoholism requires a simple animal model. Animals trained to ingest ethanol solutions and subsequently administered a drug known to produce an aversion to ethanol in humans, do not readily make the association between the malaise induced by the aversive drug-ethanol reaction and the consumption of the same ethanol-containing solution that has been consumed previously without ill effects. An experimental paradigm is reported in which the malaise of the drug-ethanol reaction is quickly recognized by rats as derived from ethanol. Disulfiram was used as the model drug. Lewis rats were deprived of water for 18 h after which 6% (v/v) ethanol was offered as the only fluid. During the first hour of ethanol access, both controls (vehicle) and disulfiram (100 mg/kg)-treated animals consumed intoxicating amounts of ethanol (0.7-0.9 g ethanol/kg). Plasma acetaldehyde levels developed were 3-5 microM and 40-50 microM in the two groups respectively. After this time, disulfiram-treated animals virtually ceased consuming alcohol (90% inhibition), indicating that the disulfiram-ethanol reaction is associated with alcohol ingestion. Control animals continued consuming the alcohol solution for the additional 4-5 h tested. This model should be of value in the testing of new agents that reduce aldehyde dehydrogenase levels for prolonged periods for their potential as an aversive treatment in alcoholism.
Acetaldehyde↗
An apparently new virus (family Paramyxoviridae) infectious for pigs, humans, and fruit bats.
We isolated an apparently new virus in the family Paramyxoviridae from stillborn piglets with deformities at a piggery in New South Wales, Australia. In 1997, the pregnancy rate and litter size at the piggery decreased markedly, while the proportion of mummified fetuses increased. We found serologic evidence of infection in pigs at the affected piggery and two associated piggeries, in humans exposed to infected pigs, and in fruit bats. Menangle virus is proposed as a common name for this agent, should further studies confirm that it is a newly recognized virus.
Agricultural Workers' Diseases↗