Flaxseed oil supplementation alters the expression of inflammatory-related genes in dogs.

Long chain n-3 fatty acids are beneficial to mammals because of their anti-inflammatory role. However, whether flaxseed oil, which is rich in short chain n-3 fatty acids, has such a role, it has not been extensively examined. This study investigated the supplementation of flaxseed oil on the regulation of genes involved in inflammatory responses such as heat shock proteins (HSP90 and HSP70) and interleukin (IL1ß) in the white blood cells of dogs. Five beagles and 5 greyhounds were supplemented with Melrose(®) flaxseed oil at the rate of 100 mL/kg food for 21 days. The blood was collected at day 0, 15, and 22 following supplementation. The expression of 3 genes was quantified using real-time polymerase chain reaction. Plasma concentrations of fatty acids such as alpha linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, linoleic acid, and arachidonic acid were measured, and their correlations with changes in gene expression were determined. Flaxseed oil supplementation downregulated the expression of HSP90 and IL1ßin greyhounds but showed no significant effect on these genes in beagles. HSP70 remained unchanged in both breeds following the supplementation. Correlations of HSP90 and IL1ßexpression levels with the plasma fatty acid concentrations on day 22 showed a significant negative correlation in greyhounds. Dietary flaxseed oil altered the expression of genes involved in inflammation in white blood cells. Because the expression of the genes may vary in different breeds, it will be useful to consider breed responses to dietary manipulation in canine nutrition management.

Global gene expression profiling reveals genes expressed differentially in cattle with high and low residual feed intake.

Feed efficiency is an economically important trait in beef production. It can be measured as residual feed intake. This is the difference between actual feed intake recorded over a test period and the expected feed intake of an animal based on its size and growth rate. DNA-based marker-assisted selection would help beef breeders to accelerate genetic improvement for feed efficiency by reducing the generation interval and would obviate the high cost of measuring residual feed intake. Although numbers of quantitative trait loci and candidate genes have been identified with the advance of molecular genetics, our understanding of the physiological mechanisms and the nature of genes underlying residual feed intake is limited. The aim of the study was to use global gene expression profiling by microarray to identify genes that are differentially expressed in cattle, using lines genetically selected for low and high residual feed intake, and to uncover candidate genes for residual feed intake. A long-oligo microarray with 24 000 probes was used to profile the liver transcriptome of 44 cattle selected for high or low residual feed intake. One hundred and sixty-one unique genes were identified as being differentially expressed between animals with high and low residual feed intake. These genes were involved in seven gene networks affecting cellular growth and proliferation, cellular assembly and organization, cell signalling, drug metabolism, protein synthesis, lipid metabolism, and carbohydrate metabolism. Analysis of functional data using a transcriptional approach allows a better understanding of the underlying biological processes involved in residual feed intake and also allows the identification of candidate genes for marker-assisted selection.

Effects of the absence of protozoa from birth or from weaning on the growth and methane production of lambs.

Merino ewes (n 108) joined to a single sire were allocated into three flocks, with ewes in one flock being chemically defaunated in the second month of gestation. Single lambs born to defaunated ewes (BF lambs) were heavier at birth and at weaning than lambs born to faunated ewes (F lambs). After weaning, all BF and F lambs were individually housed then half of the F lambs were chemically defaunated (DF lambs). In trial 1, BF, DF and F lambs were offered a concentrate-based diet containing either 14 or 19 % protein for a 10-week period. Wool growth rate of BF lambs was 10 % higher than that of DF or F lambs and was increased 9 % by the high-protein diet. While there was no main effect of protozoa treatment on enteric methane production, there was an interaction between protozoa treatment and diet for methane production. BF and DF lambs produced more methane than F lambs when fed the low-protein diet but when fed the high-protein diet, emissions were less than (BF lambs) or not different from (DF lambs) emissions from F lambs. In trial 2, lambs were offered 800 g roughage per d and, again, methane production was not affected by the presence of protozoa in the rumen. The data indicate that while lambs without rumen protozoa have greater protein availability than do faunated ruminants, there is no main effect of rumen protozoa on enteric methane production by lambs fed either a concentrate or roughage diet.

Salmonella Typhimurium persistence in a Hunter Valley dairy herd.

OBJECTIVE: An epidemiological study was undertaken at a Hunter Valley dairy with persistent Salmonella Typhimurium infection. The aim of the study was to identify cattle currently or previously infected with Salmonella, possible sources of the organism, patterns of spread, and husbandry practices that could be improved. METHODOLOGY: Faecal samples, feed, water and environmental samples were cultured for Salmonella and blood samples were tested for antibodies against Salmonella (Dublin and Typhimurium). A questionnaire was designed to identify possible risk factors associated with Salmonella excretion. RESULTS: S Typhimurium was apparently introduced from an old to a new dairy through manure spread as fertiliser. Salmonella apparently persisted in the effluent pond, and the following year clinical cases occurred after pasture, irrigated with water from the pond, was grazed by dry cows, and adult cattle became clinically ill with salmonellosis. The disease spread to other cows and calves. Poor design of calf pens assisted spread of Salmonella from sick to healthy calves. In addition, there was suspected transmission to the dairy farmer's 9-month-old daughter. Salmonellosis on a farm is a potential zoonotic risk to farm workers and their families. There is also the risk that cull cows may carry Salmonella to the abattoir and subsequently into the human food chain. Methods of waste management, and the design of calf pens, were identified as major risk factors that could be improved to minimise the spread of salmonellosis on this property.

Salmonella and on-farm risk factors in healthy slaughter-age cattle and sheep in eastern Australia.

OBJECTIVE: To examine healthy slaughter-age cattle and sheep on-farm for the excretion of Salmonella serovars in faeces and to identify possible risk factors using a questionnaire. PROCEDURE: The study involved 215 herds and flocks in the four eastern states of Australia, 56 with prior history of salmonellosis. Production systems examined included pasture beef cattle, feedlot beef cattle, dairy cattle, prime lambs and mutton sheep and animals were all at slaughter age. From each herd or flock, 25 animals were sampled and the samples pooled for Salmonella culture. All Salmonella isolated were serotyped and any Salmonella Typhimurium isolates were phage typed. Questionnaires on each production system, prepared in Epi Info 6.04, were designed to identify risk factors associated with Salmonella spp excretion, with separate questionnaires designed for each production system. RESULTS: Salmonellae were identified in all production systems and were more commonly isolated from dairies and beef feedlots than other systems. Statistical analysis revealed that dairy cattle were significantly more likely to shed Salmonella in faeces than pasture beef cattle, mutton sheep and prime lambs (P<0.05). A wide diversity of Salmonella serovars, all of which have been isolated from humans in Australia, was identified in both cattle and sheep. Analysis of the questionnaires showed access to new arrivals was a significant risk factor for Salmonella excretion on dairy properties. For beef feedlots, the presence of large numbers of flies in the feedlot pens or around stored manure were significant risk factors for Salmonella excretion. CONCLUSION: Dairy cattle pose the highest risk of all the slaughter-age animals tested. Some of the identified risk factors can be overcome by improved management practices, especially in relation to hygiene.

Alterations of intratumoral pharmacokinetics of 5-fluorouracil in head and neck carcinoma during simultaneous radiochemotherapy.

The kinetics of local drug uptake and metabolism of the anticancer drug 5-fluorouracil (5-FU) has been monitored by means of 19F nuclear magnetic resonance spectroscopy in 17 patients with neck tumors during concurrent radiochemotherapy. All of the patients underwent an accelerated hyperfractionated, concomitant-boost radiochemotherapy with 5-FU [600 or 1000 mg/m2 of body surface (b.s.)] and carboplatin (70 mg/m2 of b.s.). Serial 19F nuclear magnetic resonance spectra were obtained during and after the administration of 5-FU in a 15-T scanner with the use of a 5-cm diameter surface coil positioned on a cervical lymph node metastasis. Examinations were performed at day 1 of therapy and, in 13 patients, also after 43.5 Gy of irradiation at day 1 of the second chemotherapy cycle. Resonances of 5-FU and the catabolites 5,6-dihydro-5-fluorouracil (DHFU) and alpha-fluoro-beta-alanine (FBAL) were resolved in the tumor spectra. The median of the 5-FU and FBAL levels was significantly higher (more than 2-fold) at the second compared with the first examination, whereas the level of DHFU did not change. This effect could indicate an increased delivery of 5-FU into the interstitial space of the tumor in the course of the combined treatment, which would result in an enhanced exposure of the tumor cells to the drug. A potential mechanism for synergy between radio- and chemotherapy is discussed, but alternative mechanisms are also being considered. The findings indicate that a method is available to rationally address the design of dosing schedules in concurrent therapy regimens.

In vivo characterisation of two Australian isolates of Marek's disease virus including pathology, viral load and neuropathotyping based on clinical signs.

OBJECTIVE: To evaluate the pathogenicity of Australian Marek's disease virus (MDV) isolate MPF23 (1985) against the reference strain MPF57 based on pathology, viral load and neuropathotyping on the basis of clinical signs. PROCEDURE: Two MDV challenge isolates (MPF57 or MPF23) were administered to unvaccinated specific-pathogen free (SPF) layer chicks on day 5 after hatch at three challenge doses (500, 2000 or 8000 plaque-forming units (pfu)/chick). Mortality, body weight, immune organ weights, MDV load in peripheral blood lymphocytes (PBL) and clinical signs were measured to 56 days post challenge (dpc). RESULTS: MPF23 was the more pathogenic of the two viruses, inducing higher mortality (81% vs 62%) and incidence of MD lesions (100% vs 76%). MPF23 induced earlier, more sustained and more severe neurological signs in the period 26-56 dpc. However, there were few differences during the 0-23 dpc used in the neuropathotyping classification under test. The observed pattern during this earlier period classified both viruses as neuropathotype B, consistent with a very virulent pathotype. MDV load in PBL at 7 and 44 dpc did not differ between virus isolates, but the load at 7 dpc was significantly and negatively associated with time to euthanasia or death. CONCLUSION: MPF23 appears to be as, or more, virulent than the MDV strains isolated over the subsequent two decades. The neuropathotyping system developed in the USA did not clearly differentiate between the two isolates under test; however, extension of the period of assessment of clinical signs beyond 26 dpc did reveal clear differences.

Repeatability and prognostic impact of the pretreatment pO(2) histography in patients with advanced head and neck cancer.

PURPOSE: The purpose of this study was to evaluate the repeatability and the predictive relevance of the pretreatment pO(2) histography on the survival of patients with advanced head and neck cancer. PATIENTS AND METHODS: From July 1995 to August 1998, polarographic pO(2) measurements of lymph node metastases before therapy were performed in altogether 60 patients with histologically proven squamous cell carcinoma of the head and neck using the Eppendorf histograph. Forty-one of 60 patients were treated with an accelerated-hyperfractionated radiotherapy regimen with or without simultaneous chemotherapy as part of a multicenter phase III study. In 23 of 60 patients, two repeated independent measurements of the same tumor were performed with a time interval of approximately 24 h between the two measurements. RESULTS: The multivariate analysis revealed the fraction of pO(2) values

Field trials of ephemeral fever vaccines.

Various bovine ephemeral fever (BEF) vaccines were tested between 1982 and 1984 in 24 Queensland herds; neutralising antibody responses were monitored and six of the herds were closely observed following natural challenge with ephemeral fever. A vaccine regime of two consecutive vaccinations with attenuated virus combined with the adjuvant Quil A provided excellent protection against BEF for at least 12 months, whereas one vaccination with the Quil A vaccine or two vaccinations with vaccine containing the adjuvant aluminium hydroxide gel did not provide significant protection. Antibody responses were highest for the vaccine incorporating Quil A when it was given as two consecutive injections. There was an apparent relationship between neutralising antibody response and the level of protection.

Detection of papillomavirus DNA in precancerous lesions of the ears of sheep.

Sixty-seven benign precancerous cutaneous lesions from the ears of 51 sheep were examined for papillomavirus DNA by hybridisation to radioactively labelled or biotinylated probes of bovine papillomavirus type 1 (BPV 1) DNA under varying conditions of stringency. An additional 16 precancerous lesions from other cutaneous sites on 15 sheep and 15 samples of lesion-free skin from nine sheep were similarly examined. Both total genomic and subgenomic probes were used. DNA from 10 aural lesions and one vulval lesion reacted with the probe in a manner indicative of the presence of episomal papillomavirus DNA. Papillomavirus DNA was detected at low stringency in eight of the 10 aural lesions and the vulval lesions, and at high stringency in two aural lesions. Three out of the 8 aural lesions that were positive at low stringency reacted when re-tested at high stringency. Hybridisation with one of the samples of lesion-free ovine skin produced occasional equivocal signals. One particular positive lesion, an ovine aural cutaneous horn, was studied in more detail. When treated with restriction endonucleases, its restriction enzyme pattern was the same as that for BPV 2 DNA with eight of twelve enzymes and the same as that for BPV 1 DNA with two of the twelve enzymes. It was concluded that this ovine papillomavirus was more closely related to BPV 2 than to BPV 1. The possibility that it could be a subtype of BPV 2 is discussed.

Prognostic assessment of sonography and tumor volumetry in advanced cancer of the head and neck by use of doppler ultrasonography.

OBJECTIVE: The objective of this trial was to examine the degree of tumor vascularity in lymph node metastases as depicted by computer-assisted color Doppler sonography and the tumor volumes associated with prognosis in carcinomas of the oropharynx and hypopharynx after primary radiochemotherapy. PATIENTS AND METHODS: In a prospective trial, 25 patients with advanced squamous cell carcinomas of the oropharynx and hypopharynx (stage IV UICC 1997) were treated with radiochemotherapy. The color Doppler findings were quantified with a computer-assisted protocol that quantitatively describes color Doppler images by the relative color pixel density (CPD). As important prognostic cofactor, total tumor volume (TTV) was calculated from CT sections and related to the degree of vascularity. RESULTS: Low CPD in neck metastases showed a correlation with better overall survival. A high-CPD group and a high-TTV group (median survival 10.1 months) were determined and were compared with all other CPD/TTV combinations (median survival 28.4 months); the difference in survival was significant (P = 0.002). CONCLUSION: The results indicate that high tumor vascularity in combination with high TTV indicates a particularly bad prognosis in patients treated with primary radiochemotherapy for head and neck cancer.

Oxygenation of advanced head and neck cancer: prognostic marker for the response to primary radiochemotherapy.

Recent clinical studies suggest that the degree of tumor oxygenation may be predictive of the response of radiation therapy for cancer. In an exploratory investigation of cervical lymph node metastases in 27 patients with advanced squamous cell carcinoma of the oropharynx and hypopharynx, this relationship was investigated by means of oxygen measurements with an Eppendorf PO (2) histograph. The measurements were made before the start of radiation therapy and after the first week of therapy. Clinical response was evaluated 6 weeks after the completion of therapy. Before therapy, marked hypoxia was observed in the lymph node metastases, with a mean PO (2) value of 16.1 +/- 8.2 mm Hg and a hypoxic fraction (PO (2) < 10 mm Hg) of 56.4% +/- 20.0%. After the first week of radiation (9 Gy) there was a general reoxygenation (DeltaPO (2) = 5.0 +/- 10.1 mm Hg, P < 0.05; Deltahypoxic fraction = -11.3% +/- 31.3%, P = 0.11). A relationship between the degree of reoxygenation and tumor response was not observed. Patients without at least partial lymph node response (n = 8) showed poorer pretherapeutic oxygenation (PO (2) mean = 11.1 +/- 2.9 mm Hg) than those who responded to the therapy (n = 19, PO (2) mean = 18.2 +/- 8.8 mm Hg). In this investigation of a defined set of patients with advanced carcinoma of the oropharynx and hypopharynx, we found that pretherapeutic oxygenation data are predictive for the therapeutic response to radiation therapy or radiochemotherapy.

Rise of oxygenation in cervical lymph node metastasis during the initial course of radiochemotherapy.

It has been hypothesized that during radiation treatment a reoxygenation of hypoxic tumor tissue takes place. To test this hypothesis, we have investigated whether reoxygenation in lymph node metastases could be determined by invasive PO (2) measurements. Through a hypodermic needle inserted transcutaneously into tumor-positive lymph nodes, polarographic oxygen determinations were made in 18 patients with advanced squamous cell carcinomas of the oropharynx and hypopharynx. These measurements were performed before therapy and a week after the onset of radiotherapy or radiochemotherapy, respectively. Low PO (2) values before treatment (mean value of the patient's median was 12.6 mm Hg PO (2)) and a mean hypoxic fraction (PO (2) < 5 mm Hg) of 39.6% indicated manifest tumor hypoxia. After 1 week of treatment, a significant increase in the median PO (2) (mean value of shift: 7.3 mm Hg) and a reduction in the hypoxic fraction (mean value of shift: 13.4% PO (2) < 5 mm Hg, P < 0.03) were observed after both radiotherapy and radiochemotherapy. Thus invasive PO (2) histography fulfills the requirements for a method to confirm tumor hypoxia in head and neck tumors. The results obtained indicate that reoxygenation occurs during the initial phases of radiotherapy and radiochemotherapy, and they will form the basis for future comparative investigations on the possible influence of hypoxic parameters on tumor responsiveness toward radiation and radiochemotherapy.

BCG emulsion immunotherapy of equine sarcoid.

Of 61 horses with sarcoids treated with intralesional injection of a double emulsion incorporating inactivated bacillus Calmette Guérin organisms, 36 (59 per cent) showed complete regression and 11 (18 per cent) showed partial regression. The majority of cases required only one treatment. Not all sarcoids were responsive to this therapy; those not responding were usually large or on horses with multiple sarcoids.

Sequences of papillomavirus DNA in equine sarcoids.

DNA was extracted from 14 equine sarcoids, electrophoresed and hybridised with a radioactively labelled probe of bovine papillomavirus type I (BPV 1) DNA under conditions of low stringency. Twelve sarcoids contained sequences of DNA that hybridised with the probe and that comigrated with BPV 2 DNA. The viral DNAs in four of these sarcoids differed from BPV 1 and BPV 2 DNA on restriction endonuclease analysis. One of four cell lines derived from sarcoids also contained BPV 1 related DNA. The results confirm the frequent presence in equine sarcoids of unintegrated papillomaviral DNA and suggest a role for papillomavirus infection in this disease.

An epizootic of bovine malignant catarrh in Malaysia.

A severe epizootic of bovine malignant catarrh occurred from November 1976 until June 1977 in cattle at an agricultural institute in peninsular Malaysia. In a group of 82 Kedah-Kelantan cattle the morbidity rate was 47.6 per cent with a fatality rate of 89.7 per cent. In a group of 43 local Indian dairy cattle the morbidity rate was 23.3 per cent with a fatality rate of 100 per cent. Although evidence suggested that sheep acted as a common source of infection, the disease occurred in one animal which had no contact with sheep but had contact with infected cattle and carcases.

A bovine ephemeral fever vaccine incorporating adjuvant Quil A: a comparative study using adjuvants Quil A, aluminium hydroxide gel and dextran sulphate.

Various vaccines containing the 919 strain of ephemeral fever virus were evaluated in experimental calves and in commercial cattle. The vaccine virus was mixed with one of the adjuvants, Quil A (a saponin derivative), aluminium hydroxide gel, dextran sulphate or combinations of these. The response of experimental calves was evaluated by measuring the production of neutralising antibodies and by resistance to challenge with virulent virus; the response of commercial cattle was judged only by the production of neutralising antibody. Twelve calves given two doses of vaccine containing Quil A produced neutralising antibodies to bovine ephemeral fever virus and all were resistant to challenge with virulent virus given 28 to 76 days after the second vaccination. The vaccine given in three of these calves also contained aluminium hydroxide gel. Six of eight unvaccinated control calves succumbed to experimental challenge. In commercial cattle (17 to 26 animals per group) the serological response after two doses of vaccine containing Quil A or Quil A and dextran sulphate was significantly better than that after vaccines containing only dextran sulphate or after vaccines containing combinations of aluminium hydroxide gel and Quil A. The adjuvant Quil A alone was tested in cattle and shown to produce a transient soft swelling at the injection site as well as a rise in rectal temperature of greater than 1 degree C one day after inoculation. At least 99.99 per cent of viral infectivity was destroyed when the vaccine was mixed with Quil A, suggesting that live virus may not be essential in the immunogenicity of the vaccine. This vaccine overcame two of the problems associated with previous attenuated vaccines tested in Australia; the necessity for adjuvant and virus to be mixed immediately before use and the large volume of the vaccine.

Economy class syndrome: rheology, fluid balance, and lower leg edema during a simulated 12-hour long distance flight.

In order to study pathological changes that might lead to deep vein thrombosis and pulmonary embolism in long-distance air travel passengers, 12 healthy volunteers were investigated during 4 simulated 12-h flights (day and night). The influence of repeated leg exercise was compared with constant sitting. Plasma viscosity, hematocrit, albumin, fluid balance, and lower leg swelling were measured. Rheological studies showed only circadian rhythm alterations. An average of 1150 ml fluid was retained, which correlated with an increase in body weight. The lower leg volume increase was significant, but not pathological. Periodic leg exercising showed no measurable preventive effects. These changes in healthy human volunteers are within physiological variations and are not sufficient to provide a definitive cause of venous thrombosis in healthy passengers. They do, however, suggest alterations produced by long-distance air travel that could intensify the risk of developing deep venous thrombosis in passengers with predisposing risk factors.

A phonocardiographic study of equine heart sounds.

The occurrence and timing of heart sounds were examined from phonocardiograms taken from the mitral, aortic and tricupsid recording areas in each of 18 horses. 10 sound events could be identified with each cardiac cycle. Atrial contraction produced up to 3 sound events. The first heart sound consisted of 4 components whereas the second sound was single. Two sound events were associated with the 3rd heart sound in early diastole. The occurrence of third and fourth heart sound components varied between horses and between recording areas. The mitral recording area was considered most satisfactory for routine phonocardiographic studies in horses.