Amoebic meningoencephalitis caused by Balamuthia mandrillaris in an orang utan

Objective
To describe a case of meningoencephalitis caused by Balamuthia mandrillaris in an orang utan.
Design
A pathological case report.
Animal
A 20 years old male orang utan (Pongo pygmaeus).
Procedure
The disease process was investigated by clinical pathology, necropsy, histopathology and immunofluorescence labelling.
Results
The orang utan developed sudden onset of depression, lethargy, inappetence and apparent head pain. The condition was considered to be related to a 2 year history of upper and lower respiratory disease, and the animal was placed on antibiotics after extensive testing. By the seventh day the animal had become ataxic and disoriented and a brain abscess was suspected. He died on the ninth day of illness. At necropsy, and subsequent sectioning, the brain showed multiple circular, soft, white to grey brown areas of varying size, the largest being in the left temporal (3.5 cm diameter) and right occipital (2.5 cm diameter) regions of the cerebrum. Histological examination of these regions revealed many amoebic trophozoites and occasional cysts associated with areas of haemorrhage and inflammatory necrosis. The trophozoites were packed in perivascular spaces and their nuclei often contained two or more prominent nucleoli. Immunofluorescent labelling of histological sections suggested that the agent was B mandrillaris.
Clinical implications
This report provides further evidence that B mandrillaris , a free living amoeba, can act as a pathogen in animals as well as people, and cause fatal meningoencephalitis. Along with Naegleria and Acanthamoeba spp, B mandrillaris should be considered amongst the causes of acute onset meningoencephalitis in animals.     

The association between plasma levels of acute phase proteins, haptoglobin, alpha-1 acid glycoprotein (AGP), pig-MAP, transthyretin and serum amyloid A (SAA) in Large White and Meishan pigs

During infection, the acute phase response triggers the release of acute phase proteins (APP), alpha-(1) acid glycoprotein (AGP), serum amyloid A (SAA) and Pig-MAP into the circulation, accompanied by a decrease in plasma levels of transthyretin. We quantified the association between these APP in 26 apparently healthy pigs from two breeds, 13 Large White and 13 Meishan (16 male; 10 female). There was a significant correlation between plasma levels of haptoglobin and Pig-MAP (r=0.57; p<0.05), but no significant associations between any of the other APP tested. We also measured the relationship between PigMAP, transthyretin and SAA, and the proportions of peripheral blood mononuclear sub-sets, CD8(+) cells, CD4(+) cells, CD11R1(+) cells, MHC DQ(+) cells, and monocytes. There were correlations between both plasma levels of Pig-MAP and the proportion of monocytes (r=0.55; p<0.05) and plasma levels of transthyretin and the proportion of MHC DQ(+) cells (r=0.40; p<0.01). Breed and sex influenced plasma levels of Pig-MAP but not plasma levels of transthyretin. Overall, these results suggest closer links between the mechanisms that regulate the release haptoglobin, Pig-MAP and monocytes compared to those that regulate the release of AGP, SAA and transthyretin.     

Output of methylmercury from a Catchment in northern Sweden

The runoff output of methylmercury (MeHg) from the 50 ha Svartberget Catchment in northern Sweden was studied during 1993. These outputs are compared to those from the Gårdsjön Catchment in the southwestern part of Sweden. Although the wet deposition of MeHg is several times higher in southern Sweden the output of MeHg per unit area from the two catchments was comparable (0.12 g /km_* ²yr). Furthermore, the concentration of MeHg (0.4 ng/L) in the Svartberget Catchment was more than twice that from the Gårdsjön Catchment. These results suggest that the contemporary wet deposition of MeHg in itself is not a good indicator of runoff concentration or output per unit area. DOC transport and catchment characteristics such as wetland area, or possibly other forms of contemporary atmospheric deposition may all be more important for explaining MeHg output from the terrestrial ecosystem.     

LC-MS investigation of oxidation products of phenolic antioxidants

Two oxidation systems were examined for the oxidation of three groups of phenolic antioxidants; five cinnamic acids, two benzoic acids, and two phenols characteristic of olive fruits. Periodate oxidation, which is reported to produce products similar to polyphenol oxidase, was contrasted with the reactivity of the Fenton system, an inorganic source of hydroxyl radicals. Reaction products were identified as various quinones, dimers, and aldehydes, but the nature of the products differed between the two oxidation systems. Structure-activity effects were also observed for the different phenols. All cinnamic acids in this study reacted with the Fenton reagent to produce benzaldehydes as the main products, with the exception of 5-caffeoylquinic acid. In contrast, periodate oxidation gave no reaction with some of the cinnamic acids. Quinone formation was observed for the two compounds, caffeic acid and 5-caffeoylquinic acid, possessing o-hydroxy groups. Caffeic acid was unusual in that dimer formation was the main initial product of reaction. Benzoic acids were readily oxidized by both systems, but no identifiable products were isolated. Oleuropein was oxidized by both oxidants used in this study, resulting in quinones in each system, whereas little or no oxidation of tyrosol was observed. This highlights the importance of conjugation between the alkene double bond and the hydroxy group. The results question the validity of many existing methods of testing antioxidant activity.     

Evolution of bunyaviruses by genome reassortment in dually infected mosquitoes (Aedes triseriatus)

Aedes triseriatus mosquitoes became dually infected after ingesting two mutants of LaCrosse (LAC) virus simultaneously or after ingesting, by interrupted feeding, the two viruses sequentially within a 2-day period. After 2 weeks of incubation, approximately 25 percent of the vectors contained new virus genotypes as the result of RNA segment reassortment. New viruses were transmitted when the mosquitoes fed on mice. Viruses ingested more than 2 days after the initial infecting virus did not cause superinfection of the mosquito vectors.     

Amplification of N-myc in untreated human neuroblastomas correlates with advanced disease stage

A domain of DNA designated N-myc is amplified 20- to 140-fold in human neuroblastoma cell lines but not in cell lines from other tumor types. N-myc has now been found to be amplified in neuroblastoma tissue from 24 of 63 untreated patients (38 percent). The extent of amplification appears to be bimodal, with amplification of 100- to 300-fold in 12 cases and 3- to 10-fold in 10 others. Amplification was found in 0 of 15 patients with stage 1 or 2 disease, whereas 24 of 48 cases (50 percent) with stage 3 or 4 had evidence of N-myc amplification. These data indicate that N-myc amplification is a common event in untreated human neuroblastomas. Furthermore, N-myc amplification is highly correlated with advanced stages of disease (P less than 0.001) and with the ability to grow in vitro as an established cell line, both of which are associated with a poor prognosis.     

Molecular basis of bunyavirus transmission by mosquitoes: role of the middle-sized RNA segment

In an examination of the molecular basis of oral transmission of bunyaviruses by mosquitoes., La Crosse (LAC), snowshoe hare (SSH), and LAC-SSH reassortant viruses were compared in their ability to be transmitted to laboratory mice by the natural mosquito vector of LAC virus, Aedes triseriatus. Both LAC virus and the reassortment viruses containing the middle-sized (M) segment from the LAC parent were efficiently transmitted. In contrast, SSH virus and reassortment viruses containing the M RNA from the SSH parent were inefficiently transmitted. Thus, the M RNA segment, which codes for the virion glycoproteins, may be a major determinant of oral transmission of bunyaviruses by mosquitoes.