Calcareous septa formed in snail shells by larvae of snail-killing flies

Larvae of 13 species of Pherbellia and Colobaea that feed in exposed aquatic snails uitilize a product of the Malpighian tubules before they pupate to form a plate-like structure within the shell or to reinforce the anterior end of the puparium. The substance is partly calcium carbonate, and carbonic anhydrase may be involved in its production.     

Defective phagocytosis of isolated rod outer segments by RCS rat retinal pigment epithelium in culture

Retinal pigment epithelium cultured from normal rats phagocytizes large amounts of rod outer segment fragments isolated from normal rats and from RCS rats with inherited retinal degeneration. Cultured RCS rat pigment epithelium rarely ingests outer segment material, although the cells extend cellular processes around fragments of either type. Both normal and RCS pigment epithelium phagocytize polystyrene spheres. This demonstrates that RCS rat pigment epithelial cells contain a defect in the mechanism for phagocytizing outer segments.     

Persistence of colonies of Anaplasma marginale in overwintering Dermacentor variabilis

Dermacentor variabilis were infected as nymphs with Anaplasma marginale by allowing the ticks to feed on a single infected donor calf. Two weeks after molting to the adult stage, the ticks were allotted into 1 of 3 groups and were allowed to overwinter at room temperature (25 C) in the laboratory (group 1), cold storage (4.5 C) in the laboratory (group 2), or outdoors in leaf litter (group 3). Persistence of A marginale was assessed by determining density of colonies (number of colonies/0.1 mm2 of gut tissue examined) in tick gut specimens at 3, 5, 7, 9, and 12 months after molting to the adult stage. Colonies of A marginale were found in all groups at every density evaluation period. Highest colony densities were observed uniformly in specimens collected at month 7 (May); densities decreased at month 9 and were lowest at month 12. Statistical analysis indicated that ticks subjected to cold storage and to outdoor conditions had similar colony densities of A marginale; the density curve in these 2 groups indicated significant quadratic effects over time, with peak densities in May. Mean colony density in ticks kept at room temperature fit a different quadratic equation. The morphologic data indicated that A marginale overwinters in Dermacentor variabilis, and that increasing numbers of organisms are found from January to May.     

EARLY BITE ON WELSH FARMS

The practice of'early bite' was surveyed on sixty dairy farms in Wales during the period 1958–60. Assessment in a financial sense was made of the pros and cons of this practice. It was obvious that'early bite' was wasted or misused on many farms.     

Influence of width and bends on the ease of movement of pigs along races.

Pigs could be moved along a race 120 cm wide more quickly than along a race 45 cm wide. The presence of a bend with an angle of 45 degrees slowed their progress by about 10 per cent, a bend of 90 degrees or 120 degrees slowed them by 19 per cent and a 180 degrees bend slowed them by 44 per cent. There was little evidence of any interaction between the effects of width and angle of bend; the effect of a sharp bend could not be compensated for by increased width. The pigs became accustomed to the races and moved more quickly in later runs.     

Associations between viral infection and respiratory disease in young beef bulls

Blood samples were taken from bull calves at two Meat and Livestock Commission performance testing centres, just after weaning at six months of age and at six weekly intervals until the end of the performance test seven months later. Sera were assayed by specific ELISAS for antibodies to bovine herpes virus 1 (BHV1), respiratory syncytial virus, parainfluenza 3 (Pi3) and adenoviruses A and B. Seroconversions between each sampling were related to the occurrence of clinical respiratory disease using chi-squared (chi 2) and relative risk (RR) analyses. In 294 bulls there were 123 cases of respiratory disease. Seroconversion to bovine respiratory syncytial virus (RR = 4.7, chi 2 = 96.3, P less than 0.001) and adenovirus A (RR = 1.8, chi 2 = 8.9, P less than 0.001) and adenovirus B (RR = 1.9, chi 2 = 5.6, P less than 0.05) were significantly associated with clinical respiratory disease. There was evidence that prior exposure to respiratory syncytial virus (RR = 0.4, chi 2 = 9.8, P less than 0.01) Pi3 (RR = 0.4, chi 2 = 12.8, P less than 0.01) and adenovirus A (RR = 0.7, chi 2 = 7.5, P less than 0.01) conferred some protection against respiratory disease after arrival at the centre. It is concluded that vaccination before weaning, at least against bovine respiratory syncytial virus, would be beneficial.     

Induction, collection, and partial characterization of induced respiratory macrophages of the turkey

Respiratory macrophages (RM) of the turkey were elicited with a 1:4 (v/v) suspension of incomplete Freund's adjuvant in sterile phosphate-buffered saline injected directly into the abdominal air sacs. RM were purified by passage through a Ficoll-Hypaque gradient resulting in 95.7 +/- 5.9% purity and 94.8 +/- 12.3% viability. On days 7 and 9 postinjection, adequate numbers (7.15 +/- 5.47 X 10(6) macrophages per turkey) of RM for in vitro experiments were obtained. RM of the turkey demonstrated the ability to adhere to glass, phagocytize Zymosan A, and kill Escherichia coli in vitro.     

Echocardiography, electrocardiography, and radiography of cats with dilatation cardiomyopathy, hypertrophic cardiomyopathy, and hyperthyroidism

The echocardiographic, ECG, and radiographic findings of sequentially examined cats with dilatation cardiomyopathy (DCM, n = 7), hypertrophic cardiomyopathy (HCM, n = 8), and hyperthyroidism (HT, n = 20) were compared with those of healthy control cats (n = 11). Cats with DCM were easily differentiated from healthy cats by echocardiography and from cats with HCM and HT by a dilated left ventricle at end-diastole with a mean +/- SD of 2.20 +/- 0.36 cm, reduced fractional shortening (2.9% +/- 3.7%), reduced aortic amplitude (0.07 +/- 0.05 cm), reduced left ventricular wall amplitude (0.09 +/- 0.09 cm), and increased E-point septal separation (0.83 +/- 0.29 cm). The cats with HCM were most consistently recognized echocardiographically by increased left ventricular wall thickness at end-diastole (0.75 +/- 0.12 cm). Some cats with HT had abnormal echocardiograms with left ventricular wall hypertrophy. These cats could usually be differentiated from the cats with HCM because of normal or increased ventricular wall amplitude, aortic amplitude, or percentage of thickening of the left ventricular wall and interventricular septum. Left atrial enlargement (left atrial diameter greater than 1.57 cm or left atrium/aorta greater than 1.75) was commonly detected by the echocardiogram in cats with DCM, HCM, or HT. The echocardiogram was helpful in differentiating the type of cardiomyopathy (DCM, HCM, or HT) when plain thoracic radiographs indicated that cardiomegaly existed. The ECG may have indicated incorrectly that there was left ventricular enlargement in some cats with HT, and it did not indicate consistently that left ventricular enlargement existed when present in cats with DCM or HCM. The ECG was a poor indicator of left atrial enlargement in all cats.     

An evaluation of five serological tests for the detection of antibody to bovine herpesvirus 1 in vaccinated and experimentally infected cattle

More than 300 bovine sera from a previously reported vaccination and challenge trial were tested for antibodies to bovine herpesvirus 1 (BHV1) by five serological assays: enzyme-linked immunosorbent assay (ELISA) for IgM and IgG, passive haemagglutination (PHA), and two methods of virus neutralisation (VN). In a statistical comparison of ELISA (IgG), PHA and VN results, the assays showed highly significant correlations (P less than 0.01). The sensitivities of ELISA and 24-hour neutralisation tests were similar, in contrast to passive haemagglutination and one hour neutralisation which failed to detect BHV1 antibodies in some low titre sera.     

Serological comparisons of antigenically related herpesviruses in cattle,red deer and goats

Serological comparisons were made using related herpesviruses from cattle (bovid herpesvirus 1), red deer (herpesvirus of cervidae 1) and goats (bovid herpesvirus 6) by virus neutralization and enzyme-linked immunosorbent assays. The test samples comprised field sera from British cattle, red deer and goats and sera from experimentally infected or immunized animals. Both the cervine and caprine viruses appeared to be more closely related to bovid herpesvirus 1 than they were to each other. Cattle sera reacted most strongly with the bovine virus and deer sera with the cervine virus. Antibodies to the caprine virus were not detected in the samples from British goats.