Isolation of antigenic proteins from erythrocytes parasitised with Babesia divergens and a comparison of their immunising potential

Soluble proteins present in the supernatant prepared from a sonicated lysate of concentrated erythrocytes infected with Babesia divergens were separated by isoelectric focussing into acidic and non acidic fractions. The acidic fraction was further separated by passage through Concanavalin A Sepharose (Con A) into two fractions, the first (Fraction 2) consisting of proteins plus one glycoprotein which did not bind to Con A, the second of glycoproteins (Fraction 1) which were eluted after binding to Con A. One group of six cows was treated with three injections of Fraction 2 with incomplete Freunds adjuvant (IFA); two other groups received the same number of injections of Fraction 1, one with IFA, the other with glucan as adjuvant. These cows plus an untreated control group were infected with 10(5) erythrocytes infected with a heterologous isolate of B. divergens. Only the group treated with Fraction 2 (Group 1) resisted lethal multiplication of the parasite. There were significant differences in magnitude of parasitaemia, reduction of packed cell volume and antibody titres between Group 1 and the other groups.     

Cellular morphology of Clostridium spiroforme

The helically-coiled bacterium, Clostridium spiroforme, has been shown to consist of an ordered aggregation of numerous individual semi-circular cells joined end to end.     

Nitrogenous constituents in plasma of foals weaned at three, four or six months of age

A study was conducted to measure the nitrogenous constituents in the blood of foals weaned at 3, 4 or 6 months of age (four foals per weaning age).Jugular blood was sampled from one week prior to weaning until one month post-weaning, and was analyzed for total protein, albumin, creatinine, urea Nitrogen and free amino acid content. Results indicated that the concentrations of most of the constituents in the blood of foals were not altered by the age of weaning, however, free amino acids decreased as age at weaning increased and creatinine was significantly higher in foals weaned at 6 months of age. Plasma creatinine, lysine and methionine levels generally decreased between pre-weaning and one month post-weaning. These data establish baseline values for blood nitrogenous constituents in foals at weaning.     

Nephrotic syndrome: a platelet hyperaggregability state

Nephrotic syndrome characterized by hypoalbuminemia and hyperlipidemia is associated with an increased incidence of thromboembolism and increased platelet hyperaggregability. Although plasma coagulation proteins are also abnormal, changes are too inconsistent to attribute thromboembolic complications to the coagulation cascade alone. Antithrombin III (ATIII) has been shown to be deficient in nephrotic syndrome. There is, however, an increase in alpha 2 macroglobulin. It is clear that platelet to platelet interactions require exposure of platelet fibrinogen receptors, the binding of fibrinogen to these receptors, platelet crossbridging, and subsequent platelet aggregation. Fibrinogen is consistently elevated in nephrotic syndrome. Hyperlipidemia and hypoalbuminemia in nephrotic syndrome increases the availability of thromboxane A2 (TxA2) by increasing the availability of TxA2 precursors and the removal of TxA2 inhibitors. Thromboxane A2 is a known inducer of platelet aggregation probably through the exposure of platelet fibrinogen receptors. Recently, fibronectins a group of adhesive proteins, were implicated in platelet to platelet interactions. Since thrombin increases the expression of platelet surface fibronectin, fibronectin may be involved in thrombus formation in nephrotic syndrome. Thromboembolic formation in nephrotic syndrome is a composite mechanism involving the coagulation cascade, platelet-platelet interactions, and platelet-surface interactions.     

Cell surface markers of the canine natural killer (NK) cell

Studies were performed to determine which of several cell surface markers are expressed on canine peripheral blood leukocyte (PBL) natural killer (NK) cells. Chromium-51 release assays showed a decrease in NK activity after depletion of PBL by carbonyl iron ingestion and adherence to IgG-antibody-coated ovine erythrocytes (EA gamma) and to IgM-antibody-complement-coated ovine erythrocytes (EA mu C). Effector cell adherence to and subsequent lysis of canine thyroid adenocarcinoma (CTAC) target cell monolayers provided direct visual identification of the putative canine NK cell. These surface immunoglobulin-negative cells, individually identified by their physical adherence to dead CTAC target cells, failed to form nonimmune rosettes with guinea pig erythrocytes or rosettes with EA mu or EA mu C. However, 39.0 +/- 4.2% of these adherent cells formed rosettes with EA gamma and 73.3 +/- 0.8% expressed the canine T-lymphocyte marker, Thy-1.