Clinical features of consecutive intramammary infections with Streptococcus agalactiae in vaccinated and non-vaccinated heifers

The clinical, haematological and functional changes which followed three consecutive intramammary infections of Streptococcus agalactiae in the first lactation of eight heifers, four of which were systemically hyperimmune to the organism, are described. Irrespective of whether it was a vaccinated or non-vaccinated heifer or first, second or third infection the clinical features during the first 24 hours were characterised by elevated temperatures with hard, swollen and painful infected quarters. First infections were almost all of short duration because of self cure, while second or third infections were prolonged, with intermittent excretion of bacteria and low cell counts. Milk yields of infected quarters were depressed, ranging from 8 per cent in short infections to 31 per cent in chronic infections. All blood parameters remained within normal limits with the exception of total and differential white cell counts, which showed a change from a quantitative to a qualitative response by the third infection. The most significant finding was the absence of any real difference between the systemically hyperimmune and the non-vaccinated heifers, suggesting that circulating antibody has little effect against intramammary infection.     

Molecular and Biochemical Characterisation of HMW Glutenin Subunits fromT. tauschiiand the D Genome of Hexaploid Wheat

Electrophoretic (urea SDS–PAGE) and chromatographic (RP–HPLC) analysis was performed on 8 allelic variants of HMW glutenin subunits derived fromTriticum tauschiiand from the D genome of a hexaploid wheat species (Triticum macha) and hexaploid landraces. These subunits had been previously identified using SDS–PAGE. The characterisation revealed that subunits Dy10^tand Dy12^tfromT. tauschiicould be differentiated from their bread wheat counterparts using both urea SDS–PAGE and RP–HPLC. In the latter case, theT. tauschiiy-type subunits were clearly more hydrophobic than the Dy type subunits of bread wheat. The characterisation also suggested that subunit Dx5^t, derived from two separateT. tauschiiaccessions, did not contain the extra cysteine residue characteristic of Dx5 from bread wheat. RFLP analysis of the genes encoding the HMW glutenin subunits of interest suggested that the absence of Dx-type HMW glutenins in two hexaploid landraces was due to lack of expression of their encoding genes. The relationship betweenHindIII DNA fragment size and protein subunit size, as measured by electrophoretic mobility, is examined and discussed. Finally, the solubility properties of a HMW protein designated T1 (derived fromT. tauschiiaccession AUS 18913) suggested that it was not a HMW glutenin subunit as was previously thought. Further studies are needed to clarify the identity of this subunit.     

Avian infectious bronchitis: cross-protection studies using different Australian subtypes

The cross-immunity of vaccinated chickens after challenge with some Australian infectious bronchitis viruses was assessed by humoral antibody responses and by ciliary activity in tracheal rings of vaccinated chickens following challenge. Four viruses were used for vaccination: Vac 3, Vac 4, both current infectious bronchitis vaccine viruses, and Q1/76 and N2/62. IBV N1/62 (synonym T0 and infectious bronchitis virus N9/74 (synonym Appin) were used to challenge the vaccinated chickens. Results showed a lack of correlation between humoral antibody levels and protection. Cross-immunity was found after vaccination with each subtype, but was lower for Vac 3 and Vac 4 than for Q1/76 and N2/62.     

CASE REPORT AND CLINICAL REVIEW: Unilateral facial myokymia in a dog with an intracranial meningioma

A 23-month-old castrated male Cavalier King Charles spaniel was evaluated because of a 6-month history of unusual rippling/undulating movements of the right facial muscles that were continuous and persisted during sleep. Neurological examination revealed narrowing of the right palpebral fissure and unilateral right-sided facial myokymia that was characterised by myokymic, and to a lesser degree, neuromyotonic discharges on concentric needle electromyographic examination. After persisting unchanged for almost 2.5 years from its onset, the facial myokymia gradually disappeared over a 6-month period concomitant with the emergence of a persistent ipsilateral facial paralysis and head tilt. At 5 years and 9 months after the first examination, signs of ipsilateral lacrimal, pharyngeal and laryngeal dysfunction became evident and the dog was euthanased. Postmortem examination identified a malignant (WHO grade III) meningioma in the right cerebellopontomedullary angle that compressed the ventrolateral cranial medulla, effaced the jugular foramen and internal acoustic meatus and extended into the facial canal of the petrous temporal bone. Novel findings were the unique observation of isolated unilateral facial myokymia preceding diagnosis of a meningioma affecting facial nerve function within the caudal cranial fossa and the remarkably long duration of neurological signs (75 months) attributable to the neoplasm.