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Biomedical subjects

F J Young

Publications and source records attributed to F J Young.

7 recordsLinked to original sources
PubMed2006

Acute phase proteins in bovine milk in an experimental model of Staphylococcus aureus subclinical mastitis.

The objectives were to establish the origin of 2 acute phase proteins in milk during subclinical bovine mastitis and to characterize the relationship between those proteins in milk and blood. Haptoglobin (Hp) and mammary-associated serum amyloid A (M-SAA3) appear in milk during mastitis, whereas Hp and serum amyloid A increase in serum during mastitis. The concentrations of these proteins were determined in an experimental model using a field strain of Staphylococcus aureus to induce subclinical mastitis in dairy cows. The expression of mRNA coding for these proteins was assessed and the presence of M-SAA3 in mammary tissues was determined using immunocytochemistry. Increases of M-SAA3 and Hp in milk occurred within 12 h of Staphylococcus aureus infusion, with peak concentrations occurring 3 d after infusion of the bacteria. The increase of acute phase proteins in milk (15 h) preceded the increase in serum concentrations of both proteins (24 h). Expression of mRNA for M-SAA3 and Hp increased in both mammary and hepatic tissues 48 h after infusion of the mammary glands. In mammary tissue, the increase of M-SAA3 mRNA was greater than the increase in Hp mRNA expression, whereas in hepatic tissue, the increase in M-SAA3 mRNA was less than that for Hp mRNA. Immunocytochemistry demonstrated that M-SAA3 protein was present within secretory epithelial cells at significantly higher levels in infected mammary glands than in control tissues. These proteins, which have host defense and antibacterial activities, may play a significant role in the early response to invasion of mammary tissues by pathogenic bacteria.

Acute-Phase Proteins↗
PubMed2005

Treatment of persistent intramammary infections with Streptococcus uberis in dairy cows.

A survey was conducted of the prevalence of environmental pathogens, especially Streptococcus uberis, as causes of clinical mastitis in dairy cows. The response of intramammary infections with S uberis to conventional treatment was monitored by taking milk samples for bacteriology and somatic cell counting seven, 14 and 21 days after the treatment. The results showed that 51 per cent of the infections failed to respond, and the odds of cases failing to respond was significantly increased when the individual quarter somatic cell count seven days after the treatment was greater than 201,000 cells/ml. Ninety-six per cent of the suspected S uberis isolates identified by culture were confirmed as S uberis by using the api 20 Strep system. Restriction endonuclease fingerprinting was used to type the strains of S uberis isolated from 75 milk samples from 32 cows. Analysis showed that 96 per cent of the cases of S uberis that failed to respond to conventional treatment were persistent infections with one strain rather than reinfections with different strains. The persistent cases of S uberis were treated further with an extended course of intramammary preparations containing either procaine penicillin with dihydrostreptomycin or cefquinome. There was no significant difference between the cure rates achieved by the two preparations, and 55 per cent of the cases that had failed to respond to conventional treatment responded to the additional treatment.

Animals↗
PubMed2005

In vitro peripheral blood mononuclear cell proliferation in a crossbred cattle population.

Immune function measured by Staphylococcus aureus- and phytohemagglutinin- (PHA-) induced cell proliferation was assessed in a population of 445 genetically defined, F2 and backcross Charolais-Holstein crossbred cattle when the animals were approximately 5 mo of age. Variation in Staph. aureus-induced, PHA-induced, and control proliferation [peripheral blood mononuclear cell (PBMC) and media only] was observed at d 2, 3, 4, 5, 9, and 10 of in vitro culture. The levels of Staph. aureus-induced, PHA-induced, and control proliferation were strongly positively correlated between days of culture within-assay (e.g., between d 2 and d 3 or between d 4 and d 5). Responses were also positively correlated when the same individuals were resampled and the assay repeated within 3 mo. Analyses fitting linear mixed models using REML showed that Staph. aureus-induced and PHA-induced proliferation was significantly associated with control proliferation and the year of birth. The age of the animal at sampling influenced only Staph. aureus-induced proliferation, with Staph. aureus-induced proliferation increasing with the age of the animal. Control proliferation was influenced by a sex x cross interaction, although in this study, sex was confounded by management, as female cattle were housed and reared differently from male cattle. All 3 measures of immune function were influenced by sire, demonstrating that these traits are partially under genetic control, and indicating that it may ultimately be possible to identify quantitative trait loci for these measures of immunity.

Animals↗
PubMed2001

Acute phase proteins in serum and milk from dairy cows with clinical mastitis.

The serum concentrations of haptoglobin, serum amyloid A and alpha1 acid glycoprotein were determined in serum collected from healthy dairy cows and cows with clinical mastitis, graded as mild (clots in milk) or moderate (clots in milk and visible signs of inflammation in the mammary gland/s) to assess their relative diagnostic value in detecting the disease. The concentrations of haptoglobin and serum amyloid A were also measured in milk collected from infected and uninfected quarters. The concentrations of haptoglobin and serum amyloid A were higher in the serum and milk from the cows with mild or moderate mastitis. The diagnostic value of haptoglobin in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 82 per cent and 94 per cent respectively with serum and 86 per cent and 100 per cent with milk. The diagnostic value of serum amyloid A in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 83 per cent and 90 per cent with serum and 93 per cent and 100 per cent with milk. The diagnostic value of serum alpha1 acid glycoprotein in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 62 per cent and 91 per cent.

Acute Disease↗
PubMed1992

Improvement of sexual behavior in aged rats by p-chlorophenylalanine and methysergide.

The effects of methysergide, a serotonin antagonist, and p-chlorophenylalanine (PCPA), a serotonin synthesis blocker on the sexual behavior of intact old male rats at 19-23 months of age and female rats at 17-18 months of age were studied. Female rats with prolonged vaginal cornification and a lordosis quotient (LQ) of less than 50%, and male rats displaying no ejaculation were selected as experimental animals. The receptivity of aged female rats, but not the approach behavior to males nor proceptivity was improved by PCPA or methysergide. The LQ of intact aged female rats in non-exit tests was improved by the i.p. administration of 50 mg/kg B.W. of PCPA 2 to 4 hours prior to the sexual behavior test or 3 mg/kg B.W. of methysergide 4 hours prior to the test. Total mount frequency and mount latency of intact aged male rats were improved by the administration of methysergide (3 mg/kg B.W.), while total mount frequency and intromission latency were improved by the administration of PCPA (20 mg/kg B.W. for 4 days). The present results together with the finding from our previous study suggest that the increase of serotonin (5-HT) activity per se plays an important role in the decline of receptivity of aged female rats and the copulatory activity of aged male rats.

Aging↗
PubMedDate not supplied

HIV/AIDS, advocacy and anti-discrimination legislation--the Australian response.

This paper will address the role of mass communication strategies in the reduction of HIV/AIDS discrimination in Australia. It will focus on the interdependence of mass communication and legislation in health promotion campaigns with particular reference to the Disability Discrimination Act 1992. This will be discussed in the context of other HIV/AIDS strategies in Australia. The public health impact of discrimination is explored in relation to HIV/AIDS and the role of anti-discrimination legislation is discussed. Public health legislation can serve as a symbolic reflection of public opinion or actively change it. Laws can transform the practices of both public and private institutions and thus decrease discrimination. They can also provide specific remedies for people adversely affected by discriminatory attitudes and practices. Mass communication can maximize the impact of legislation by promoting awareness of new laws and, more importantly, lead changes in the attitudes of the polity and the wider public.

Acquired Immunodeficiency Syndrome↗