Determination of residues of the molluscicide trifenmorph and its breakdown product triphenylcarbinol: I.—Method

A procedure has been developed for the analysis of crops and soils for residues of trifenmorph (N-trityl-morpholine) molluscicide and its breakdown product triphenylcarbinol (TPC). Samples were extracted with 20% by vol. acetone in petroleum ether and the efficiency of the extraction was established using radiochemical techniques. The extracts were subjected to column chromatography on basic alumina columns to separate trifenmorph from the TPC. The residues were converted to trichloroethyl ether derivatives followed by clean-up by column chromatography on silica gel and analysis of down to 0·02 ng by gas-liquid chromatography. Blank values were generally 0·01–0·02 ppm, recoveries were on average about 80% and were limited to this value by the yield of the etherification reaction. The storage stability of the residues at —10°c was satisfactory.     

Hyperthermia and disturbances of prenatal development

Pregnant guinea pigs at all stages of gestation were exposed for 1 hr daily on 1, 2 , 4 or 8 days to temperatures of 42–43°C. ‘High doses’ of heat stress resulted in maternal death; progressively smaller doses caused foetal death, abortion, foetal malformations or no effect. The commonest foetal abnormalities were micrencephaly, hypoplasia of digits, umbilical hernia, club-foot and arthrogryposis. Proliferating neuroblasts were especially susceptible to heat between days 20 and 23. Résumé. Des cobayes enceintes à tous les stades de la gestation ont été exposées pour une heure par jour pendant 1, 2 , 4 ou 8 jours à des températures de 42–43° C. De ‘hautes doses’ de temps de chaleur ont eu pour résultat la mort de la mère; des doses progressivement plus petites ont causé la mort du f?tus, l'avortement, la malformation du f?tus ou n'ont eu aucun effet. Les anomalies f?tales les plus fréquentes étaient la microcéphalie, l'hypoplasie des doigts, l'hernie ombilicale. le pied bot et l'arthrogrypose. Des neuroblastes proliflres étaient particulièrement sensibles à la chaleur entre les 20ième à 23ième jours. Zusammenfassung. Trächtige Meerschweinchen in allen Stadien der Trächtigkeit wurden 1, 2 , 4 oder 8 Tage eine Stunde täglich Temperaturen von 42–43° C ausgesezt. ‘Hohe Dosen’ der Wärmebelastung führten zum Tode des Muttertiers; zunehmend kleinere Dosen führten zum Tod des Fetus, zur Fehlgeburt, zu fetalen Missbildungen oder sie blieben wirkungslos. Die häufigsten fetalen Anomalien waren Mikrenzephalie, Hypoplasie de Zehen, Nabelbrüche, Klumpfuss und Arthrogryposis. Proliferierende Neuroblasten waren besonders vom 20. bis 23. Tag empfindlich gegen Wärme.     

Isolates of Verticillium dahliae Pathogenic to Crucifers Are of at Least Three Distinct Molecular Types

ABSTRACT Diverse isolates of the soilborne wilt fungi Verticillium dahliae and V. albo-atrum were studied to understand the nature and origins of those infecting cruciferous hosts. All isolates from cruciferous crops produced microsclerotia, and the majority produced long conidia with a high nuclear DNA content; these isolates were divided into two groups by amplified fragment length polymorphism (AFLP) analysis. One group could be subdivided by other criteria such as rRNA sequences and mitochondrial DNA restriction fragment length polymorphism (RFLP) analysis. Two crucifer isolates were short spored and had a low nuclear DNA content. The results are consistent with the crucifer isolates being interspecific hybrids. The long-spored isolates are best regarded as amphihaploids (or allodiploids) with the AFLP groups probably each representing separate interspecific hybridization events. The short-spored crucifer isolates appear to be derived from interspecific hybrids and are here called 'secondary haploids'. Molecular evidence suggests that one parent in the crosses was similar to V. dahliae. The other parent of the amphihaploids seems to have been more similar to V. albo-atrum than to V. dahliae, but was distinct from all isolates of either species so far studied. The implications for the taxonomy of crucifer isolates are discussed and the use of the name V. longisporum, proposed elsewhere for just some of these isolates, is discouraged.     

Development of an indirect ELISA for the detection of serum antibodies to Aspergillus fumigatus in captive penguins

Aspergillosis is a significant cause of mortality in captive penguins (Sphenisciformes). An indirect ELISA for the detection of Aspergillus fumigatus-specific immunoglobulin in penguins was developed and standardised by making use of a family-specific antiserum (anti-Aptenodyptes patagonica patagonicus). The results were calculated quantitatively as ELISA units, derived by polynomial regression analysis, and semi-quantitatively as end titres. Serum samples from 61 captive penguins were tested with the assay, and the results were compared with those obtained by counterimmunoelectrophoresis (CIE). The ELISA results correlated with the CIE results only when end titres were reported (R(s) = -0.676, P < 0.002). Fifty-seven of the penguins (93 per cent) were seropositive, but the detection of immunoglobulin did not correlate with clinical disease. At Whipsnade Wild Animal Park, Humboldt's penguins (Spheniscus humboldti) demonstrated higher seropositivity than king penguins (Aptenodyptes patagonicapatagonicus) (P = 0.022), but Humboldt's penguins at Fota Wildlife Park had a significantly higher seropositivity than Humboldt's penguins at Whipsnade (P = 0.035).     

Three cases of ovarian epidermoid cysts in cattle

Three cases of bovine, ovarian epidermoid cysts were diagnosed as unilateral benign lesions in three out of 1,971 cows at slaughter. A stratified, cornifying, and squamous epithelium without associated skin adnexal structures or tissues from other embryonic tissue layers lined the cysts. The cysts were small, usually multiple, and contained keratin debris. Macroscopically, they resembled abscesses. These are benign, congenital lesions that are a separate entity from dermoids and teratomas, and they appear to have a higher incidence in cattle with Bos indicus breeding.     

Survival and inactivation of classical swine fever virus

Classical swine fever virus, like many enveloped viruses, may be regarded as moderately fragile. It shows a short but variable survival time in the environment, depending on physical conditions, but may remain viable for prolonged periods in favourable circumstances as found, for example, in stored meat. Published information is reviewed on the survival time of the virus under a variety of physical and chemical conditions, including the variable influence of environmental factors. The principles of virus inactivation by heat, pH or chemicals are discussed, with a consideration of the principles of containment for laboratories working with the virus.