Relationship of blood corticosterone, immunoglobulin and haematological values in young crocodiles (Crocodylus porosus) to water temperature, clutch of origin and body weight

Objective To examine whether sub-optimal temperature induced stress and immunosuppression in farmed saltwater crocodile (Crocodylus porosus) hatchlings. Design A clinico-pathological study. Animals A total of 140 hatchlings were used. Procedure Body weight and length, plasma corticosterone and immunoglobulin concentrations and total and differential white blood cell counts were measured in 140 hatchlings from five clutches divided between five water temperature treatment groups. Initially all groups were housed at 32°C for 10 weeks, then two groups (L, LC) were changed to low temperature (28°C) and two groups (H, HC) to high temperature (36°C), while one group (C) remained at 32°C. The LC and HC groups were maintained at these temperatures for 10 days, after which the water temperature of both groups was returned to 32°C. Blood samples were collected twice (at 6 and 9 weeks of age) before the initial temperature change, and at 10 days and 4 weeks after the initial temperature change (at 11.5 and 14 weeks of age). Results Except for an increase in plasma corticosterone in the HC group and a decrease in the L group when the temperature change was first introduced, changes in plasma corticosterone were not significant. There were no significant changes in immunoglobulin concentrations. There were, however, significant decreases in the total white cell and lymphocyte counts in the LC group after the temperature was decreased to 28°C, and an increase in these counts after water temperature was returned to 32°C. Clutch of origin had significant effects on body weight and length gains, and there were negative relationships between body weight and corticosterone concentrations and between body weight and immunoglobulin concentrations. Conclusions As haematological changes indicative of stress were not associated with significant changes in serum corticosterone, immunosuppression in young crocodiles may be independent of the hypothalamic-pituitary-adrenal cortical axis.     

Transmission of capripoxvirus

The transmission of capripoxvirus to sheep, using an aerosol suspension of a Yemen isolate of the virus, was demonstrated. Capripoxvirus was also transmitted by contact to sheep and goats kept with animals infected with virus isolates from the Yemen, Sudan, India and Nigeria. The incubation period for capripoxvirus infection in sheep and goats was approximately eight to 12 days. Animals that had well developed clinical signs transmitted capripoxvirus more rapidly than animals which died of peracute disease or animals that had only mild clinical signs.     

Cross-protective immunity and the serological classification system for Bacteroides nodosus

The relationship between the serological classification system for serogroup B and for serogroup H of Bacteroides nodosus and cross-protection between subgroups within these serogroups was examined. Protection against ovine footrot following vaccination was achieved against other subgroup strains provided sufficient cross-reactive antibody was induced by shared pilus antigens. Within serogroup B, better cross-protection against one subgroup was obtained with a pili vaccine than a whole cell vaccine which correlated with higher pilus antibody titres induced by the former. For serogroup H, a lack of cross-protection and serological reactivity between subgroups was demonstrated, which indicates that the prototype strain of subgroup H2 should be designated a new serogroup.     

Spectroscopic Observation of the Formyl Cation in a Condensed Phase

The formyl cation, HCO+, has long been believed to be an important intermediate in the chemistry of carbon monoxide (CO) in acidic environments, but its spectroscopic observation in solution has been elusive. This species was generated by the reaction of CO with the liquid superacid hydrofluoric acid-antimony pentafluoride (HF-SbF5) under pressure and was observed by nuclear magnetic resonance and infrared spectroscopy. Equilibria between CO in the gas phase, CO dissolved in HF-SbF5, the SbF5 adduct of formyl fluoride, and HCO+ associated with several equilibrating anions of the type [SbxF5x+1]- are proposed to describe the system.     

Predatory Dinosaurs from the Sahara and Late Cretaceous Faunal Differentiation

Late Cretaceous (Cenomanian) fossils discovered in the Kem Kem region of Morocco include large predatory dinosaurs that inhabited Africa as it drifted into geographic isolation. One, represented by a skull approximately 1.6 meters in length, is an advanced allosauroid referable to the African genus Carcharodontosaurus. Another, represented by a partial skeleton with slender proportions, is a new basal coelurosaur closely resembling the Egyptian genus Bahariasaurus. Comparisons with Cretaceous theropods from other continents reveal a previously unrecognized global radiation of carcharodontosaurid predators. Substantial geographic differentiation of dinosaurian faunas in response to continental drift appears to have arisen abruptly at the beginning of the Late Cretaceous.     

Capripox in the Yemen Arab Republic and the Sultanate of Oman

Summary Capripox was shown to be endemic in all the provinces of the Yemen Arab Republic and the Sultanate of Oman. Investigations into outbreaks of capripox indicated that some strains of capripoxvirus were infecting both sheep and goats and this was confirmed by inoculating experimental sheep and goats with isolates derived from field cases. The husbandry methods prevalent in the Middle East predispose to the rapid spread of capripox and annual vaccination of all sheep and goats must be considered as the only effective method of controlling the disease.

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Resumen Se comprobó que el capripox era endémico en todas las provincias de la República Arabe de Yemen y en el Sultanato de Oman. Las investigaciones de los brotes ocurridos, dieron como resultado el aislamiento de una cepa de virus capripox entre otras, capaz de infectar ovejas y cabras. Lo anterior se comprobó mediante la inoculación experimental. El sistema de manejo en el Este Medio favorece la rápida difusión de la enfermedad, siendo la vacunación anual de todo el efectivo, el único método efectivo para controlar la enfermedad.

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Résumé On a montré que l’infection Capripox est endémique dans toutes les provinces de la République Arabe et du Sultanat d’Oman. Des recherches conduites dans des foyers de capripox ont montré que quelques souches de virus capripox étaient infectieuses pour les moutons et les chèvres; ceci a pu être confirmé expérimentalement en inoculant des moutons et des chèvres avec des souches originaires de cas naturels. Les méthodes d’élevage existant au Moyen-Orient favorisent la dissémination rapide du capripox; la vaccination annuelle doit être considérée comme étant la seule méthode effective de contr?le de la maladie.

     

Transmission of foot-and-mouth disease by vaccinated cattle following natural challenge

Cattle vaccinated with a conventional monovalent type O1 foot-and-mouth disease (FMD) vaccine were challenged between four and 21 days after vaccination by short-term exposure to homologous airborne virus produced by pigs. Transmission was then assessed by housing susceptible cattle with the vaccinated animals and testing and observing all the animals for signs of infection and clinical disease. All 18 cattle vaccinated three weeks before challenge resisted clinical disease and although four contracted subclinical infection, there was no transmission to susceptible cattle in contact. One of the two groups of cattle vaccinated two weeks previously transmitted subclinical infection, but not disease, to susceptible animals housed with them from day 0 after challenge. Subclinical infection was manifested by a transient viraemia which was not followed by a detectable circulating antibody response. Shorter periods (seven or four days) from vaccination to challenge resulted in transmission of disease from clinically normal vaccinated to in-contact animals in one of two experiments. The severe challenge presented by the diseased in-contact animals than overwhelmed the immunity of the vaccinated animals. The results indicate that during emergency vaccination programmes it is advisable to vaccinate all FMD-susceptible animals within the vaccination zone and that at the outer boundary of the zone vaccinated animals should be kept separated from unvaccinated animals for at least three weeks.