Citrullinaemia in Friesian calves

Six Friesian calves from a pedigree herd died or were killed within 1 week of birth because of progressive central nervous disease in which the only consistent lesion was cerebral oedema. The cause was citrullinaemia, resulting from an autosomally inherited dysfunction of the urea cycle enzyme arginosuccinate synthetase. Citrullinaemia was diagnosed by demonstrating markedly elevated concentrations of citrulline in the blood of one calf and in the cerebral spinal fluid of another. One of two sires used in the herd was a heterozygous carrier of the disease. Heterozygocity was demonstrated using a polymerase chain reaction/restriction endonuclease test designed to detect the genetic mutation that causes citrullinaemia in cattle.     

Comparative studies of BHV-1 variants by in vivo--in vitro tests.

The new encephalitogenic BHV-1.3 and previously characterized BHV-1 strains were studied with reference to their immunogenic and protective potency and their antigenic relationships using "in vitro" and "in vivo" tests. The "in vitro" results obtained by neutralization kinetics showed that the Los Angeles (LA) strain (BHV-1.1) and a vaginal isolate L-114 strain (BHV-1.2) had antigenic similarities. Conversely, the behavior of the encephalitogenic strain A-663 (BHV-1.3), was significantly distinct. The "in vivo" protection test was carried out in calves using LA and A-663 strains. Post-vaccination antibodies and challenge with A-663 strain showed that the immunogenic behavior and protective capacities of both strains were similar. Neutralization kinetics differences between BHV-1.1 and BHV-1.3 did not alter the "in vivo" protection against BHV-1.3 challenge.     

Comments on the method to test side effects of pesticides on the predatory mitePhytoseiulus persimilis Ath.-Hen

A paper published byKniehase & Zoebelein (1990) describes a new laboratory method to test the side effects of pesticides on the predatory mitePhytoseiulus persimilis and criticizes the laboratory test developed by the International Working Group pesticides and beneficial organisms of the International Organization for Biological Control (IOBC), West Palaearctic Regional Section (WPRS). The present publication discusses the advantages and disadvantages of both methods, responds to the criticism and mention the overall concept of the IOBC/WPRS Working Group including semifield and field test methods.In einer Arbeit vonKniehase undZoebelein (1990) wird ein neues Laborverfahren zur Prüfung der Nebenwirkung von Pflanzenschutzmitteln auf die RaubmilbePhytoseiulus persimilis beschrieben. Die genannten Autoren äußern sich kritisch über das seither von der Arbeitsgruppe Pflanzenschutzmittel und Nutzorganismen der International Organization for Biological Control (IOBC), West Palaearctic Regional Section (WPRS) praktizierte Verfahren. In der vorliegenden Arbeit werden die Vor- und Nachteile der beiden Prüfmethoden diskutiert. Einer Reaktion auf die Kritik folgt eine kurze Beschreibung der gesamten Konzeption der genannten Arbeitsgruppe, die auf einer Kombination aus Labor-, Halbfreiland- und Feldprüfverfahren beruht.     

A study of periodontal disease in sheep over a twelve month period

Sheep affected by broken mouth periodontal disease (P.D.) were examined over a twelve month period for different clinical parameters. It is suggested that P.D. in sheep is an episodic phenomenon similar to human P.D., and that only a few animals with signs of P.D. may undergo clinically significant destruction over a yearly period. No single parameter could reliably predict future deterioration in other parameters.     

Platelet activating factor as a mediator of equine cell locomotion

Equine polymorphonuclear (PMN) and mononuclear (MN) leucocytes were separated on Percoll gradients and used to study the chemoattractant properties of the polar ether-linked phospholipid, platelet activating factor (PAF). Six concentrations of PAF ranging from 1 ng/ml to 100 g/ml were studied in each of two in vitro assay systems, the agarose microdroplet and a microfilter technique. Very significant (p<0.01) increases in the movement of both PMN and MN cells were obtained with most concentrations of PAF. In two instances there was no apparent concentration-response relationship, although the action of PAF was approximately bell-shaped in two others. The possible significance of these findings for equine inflammatory conditions is discussed.