Polymorphism of the CD4 and CD5 differentiation antigens in cattle.

Monoclonal antibodies (mAbs) specific for bovine CD4 and CD5 antigens have been found to identify polymorphic determinants on these molecules. In the case of CD5, mAb IL-A67 recognises one allotypic form of the antigen while four other CD5-specific mAbs in the workshop (CC17, CC29, BLT-1 and 8C11) recognise a second allotype. The CD4-specific mAbs submitted to the workshop reacted with the cells of all animals tested. However, a further two mAbs (CC26 and IL-A18) specific for CD4 were found to react with cells only from about 85% of animals tested. Sequential immuno-precipitation experiments together with family studies showed that the allotypes of CD4 and CD5 are both inherited in a simple Mendelian manner and are co-dominantly expressed. One of the CD5 allotypes was not detected in Bos taurus animals while the gene frequency of the second allotype was only about 10% in the B. indicus animals tested. The gene frequency of the CD4 allotype detected by CC26 and IL-A18 was similar in the two sub-species.     

Isolation of poxvirus from debilitating cutaneous lesions on four immature grackles (Quiscalus sp.).

Poxvirus was isolated from nodules on four immature grackles (Quiscalus sp.) collected in two residential areas of Victoria, Texas. All of the birds were emaciated and had nodules on the eyelids, bill, legs, toes, and areas of the skin on the wings, neck, and ventral abdomen. These pox nodules were extensive and probably interfered with both sight and flight. The preliminary diagnosis was confirmed by virus isolation, histopathology, and electron microscopy. Poxvirus was isolated on the chorioallantoic membrane of embryonated hen's eggs and in Muscovy duck embryo fibroblast cell culture. Phaenicia calliphoridae (blowfly) larvae were found in one of the pox nodules, raising the possibility of mechanical transmission of the virus by contaminated adult blowflies.     

Efficacy of the immunoblot assay for cysticercosis in pigs and modulated expression of distinct IgM/IgG activities to Taenia solium antigens in experimental infections

A recently invented immunoblot assay for human cysticercosis was evaluated for efficacy in pigs. The test population consists of 45 pigs with parasitologically confirmed cysticercosis, 47 with heterologous infections, 45 SPF or concrete raised control animals. With this group of 137 animals the test performance was 100% sensitive and 100% specific. The antigen-specific responses of immunoglobulin A (IgA), IgG and IgM in four pigs infected with Taenia solium eggs derived from a human were quantified by immunoblot. Antigen-specific activities were observed as early as 1 week postinfection. The first antigen-specific isotypic response was IgM antibodies directed against a glycoprotein at 97 KD (GP97). This activity generally disappeared between the sixth and ninth week postinfection. Between Weeks 5 and 8, IgG activity rose as IgM activity fell. The IgG activity, however, was directed mostly towards GP50 and GP42 antigens. If the same response occurs in people with cysticercosis, identifying specific isotype activity may help to distinguish new infection from old.     

Antigenic analysis of four species of the genus Ehrlichia by use of protein immunoblot

The antigenic profile of Ehrlichia canis, E risticii, E sennetsu, and E equi was investigated by the use of protein (western) immunoblot technique. Results of analysis of serum from acutely and chronically infected animals indicated that the 4 Ehrlichia species share a unique 25-kD polypeptide in addition to other peptides. Immune sera from dogs inoculated with E canis recognized a wide range of E canis polypeptide antigens, as determined by western blot analysis. A larger number of E sennetsu polypeptides were detected when homologous antiserum and antiserum to E equi were used. The latter antiserum did not recognize antigens of E canis or E risticii. Antisera to E canis, E risticii, and E sennetsu detected E equi antigens. Data indicate that a 25-kD protein is a common antigen among the species of the genus Ehrlichia and that the ascending order of abundance of immunodominant determinants in the 4 species of Ehrlichia studied would be: E risticii----E equi----E sennetsu----E canis. Implications of these findings for diagnosis of ehrlichial infections and prophylaxis are evident.     

Effect of intramammary infusion of beta-1,3-glucan or interleukin-2 on leukocyte subpopulations in mammary glands of sheep.

OBJECTIVE: To investigate effects of intramammary infusion of beta-1,3-glucan or recombinant ovine interleukin-2 (rOvIL-2) on blood and mammary leukocyte subpopulations and their expression of various surface antigens in sheep. ANIMALS: 12 healthy multiparous, nonpregnant, nonlactating fine-wool Merino ewes. PROCEDURE: Beta-1,3-glucan in pyrogen-free saline solution (PFSS; n = 6), rOvIL-2 in PFSS (3), or PFSS (3) was infused on days 0 and 7 in 1 udder half of each ewe. Jugular vein blood and mammary secretion samples were taken before infusion and on days 2, 7, and 21 after infusion. Total and differential leukocyte counts were obtained, and blood and mammary cells were labeled for flow cytometry. RESULTS: Slight swelling of the mammary glands was observed on day 2 after rOvIL-2 but not after beta-1,3-glucan infusion. Both substances induced significant increase in mammary secretion leukocyte numbers, compared with controls. Beta-1,3-Glucan induced an influx of monocyte/macrophages, whereas neutrophils were the predominating cell population after rOvIL-2 infusion. Beta-1,3-glucan induced selection for CD4+, B-cell+, WC1+, and L-selectin+ lymphocytes on day 14 after infusion. By comparison, rOvIL-2 induced selection for B-cell+ and L-selectin+ lymphocytes on days 14 and 21 and depletion of CD8 and, to some degree, of IL-2R+ lymphocytes. Beta-1,3-Glucan induced an increase in the proportion of CD14+ leukocytes, indicating selective migration of monocyte/ macrophages to the nonlactating udder. CONCLUSION: Beta-1,3-Glucan and rOvIL-2 can modulate nonspecific immunity in the udder of sheep but may exert their effects by differing mechanisms. Clinical Relevance-Stimulation of the nonspecific defense against udder infections may improve control of mastitis.     

Development of a polymerase chain reaction to detect Vietnamese isolates of duck virus enteritis.

A polymerase chain reaction (PCR) method for the detection of duck virus enteritis (DVE) virus in tissues of infected and affected ducks, and in cell culture was developed. This required us to obtain specific nucleotide sequence information as we could not find any specific data about the genome of the virus. We found the assay to be highly effective in detecting the virus under experimental conditions and to be easily transferred to laboratories in Vietnam where it is being used in studies on the epidemiology of the disease. We have applied this simple and rapid diagnostic method to the detection of DVE isolates grown in cell culture and tissues from infected birds. The assay was also able to differentiate DVE from other avian herpesviruses, such as Marek's disease, infectious laryngotracheitis virus and goose herpesvirus.     

The effects of cyclophosphamide and its uroprotective agents, mesna and hyperbaric oxygen, on urinary bladder motility in guinea pigs

The aim of this research was to observe the effects of cyclophosphamide and its uroprotective agents, mesna and hyperbaric oxygen (HBO), on the motility of urinary bladder muscle in guinea pigs. In the experimental groups, mesna and cyclophosphamide were intraperitoneally injected at a dose of 21.5 mg/kg and 68.1 mg/kg, respectively. For the combination of mesna and cyclophosphamide, one dose of mesna was injected 20 min before cyclophosphamide administration and three additional injections of mesna were repeated every three hours. A total of 8 HBO exposures were performed at 2.8 ATA for 90 min twice daily for another experimental group. In the HBO and cyclophosphamide combined group 5 HBO exposures were given prophylactically before cyclophosphamide. The combination of mesna, HBO and cyclophosphamide was administered by the same procedure. The contractions obtained in response to acetylcholine (ACh, 10(-4) M) in the control group were reduced using cyclophosphamide and HBO individually, but not by mesna. However, the contractions belonging to the various combinations of these three agents were not different from those seen in the control group. On the other hand, the combinations of cyclophosphamide, mesna and HBO showed higher responses to ACh than the groups in which cyclophosphamide and HBO were used individually, while the responses elicited by the cyclophosphamide and HBO combination were greater than those seen in the group treated with HBO only.     

Infection of the subcutis and skin of cats with rapidly growing mycobacteria: a review of microbiological and clinical findings.

Mycobacteria were isolated and characterised from 49 cats with extensive infections of the subcutis and skin. Cats were generally between 3 and 10 years of age, and female cats were markedly over-represented. All isolates were rapid-growers and identified as either Mycobacteria smegmatis (40 strains) or M fortuitum (nine strains). On the basis of Etest for minimum inhibitory concentration and/or disc diffusion susceptibility testing, all strains of M smegmatis were susceptible to trimethoprim while all strains of M fortuitum were resistant. M smegmatis strains were typically susceptible to doxycycline, gentamicin and fluoroquinolones but not clarithromycin. All M fortuitum strains were susceptible to fluoroquinolones, and often also susceptible to gentamicin, doxycycline and clarithromycin. Generally, M smegmatis strains were more susceptible to antimicrobial agents than M fortuitum strains. Treatment of mycobacterial panniculitis involves long courses of antimicrobial agents, typically of 3-6 months, chosen on the basis of in vitro susceptibility testing and often combined with extensive surgical debridement and wound reconstruction. These therapies will result in effective cure of the disease. One or a combination of doxycycline, ciprofloxacin/enrofloxacin or clarithromycin are the drugs of choice for long-term oral therapy.     

Suspected venous air embolism in three horses

Venous air embolism was suspected in 3 hospitalised horses on the basis of an inadvertently open jugular venous line. Subsequently the 3 horses developed clinical signs including cardiovascular collapse, cardiac dysrhythmia, pulmonary oedema, behavioural abnormalities and neurological signs consistent with central nervous system injury. Treatment included intranasal oxygen therapy, i.v. fluid administration and anti‐inflammatory therapy. Specific therapy aimed at treating air embolism in man is reviewed, with pertinent therapy potentially applicable to horses emphasised.