Preclinical Assessment of the Treatment of Second-Stage African Trypanosomiasis with Cordycepin and Deoxycoformycin

There is an urgent need to substitute the highly toxic arsenic compounds still in use for treatment of the encephalitic stage of African trypanosomiasis, a disease caused by infection with Trypanosoma brucei. We exploited the inability of trypanosomes to engage in de novo purine synthesis as a therapeutic target. Cordycepin was selected from a trypanocidal screen of a 2200-compound library. When administered together with the adenosine deaminase inhibitor deoxycoformycin, cordycepin cured mice inoculated with the human pathogenic subspecies T. brucei rhodesiense or T. brucei gambiense even after parasites had penetrated into the brain. Successful treatment was achieved by intraperitoneal, oral or subcutaneous administration of the compounds. Treatment with the doublet also diminished infection-induced cerebral inflammation. Cordycepin induced programmed cell death of the parasites. Although parasites grown in vitro with low doses of cordycepin gradually developed resistance, the resistant parasites lost virulence and showed no cross-resistance to trypanocidal drugs in clinical use. Our data strongly support testing cordycepin and deoxycoformycin as an alternative for treatment of second-stage and/or melarsoprol-resistant HAT

Sequential Hematological Study of Experimental Infectious Bursal Disease Virus Infection in Chickens, Turkeys and Ducks

Following experimental infectious bursal disease virus infections in four-weekold broiler chicks, turkey poults and ducklings, blood samples were chronologically collected and analyzed for postinfection (pi) changes. Although there was a net increase in packed cell volume values in chicks reaching a peak of 31% from 12 h to 144 h pi, there was, on the contrary, a general decline in the values in turkey poults and ducklings to minima of 26.5% at 12 h pi and 28.2% at 48 h pi, respectively. Leukocyte counts in chicks significantly increased (p < 0.05) to a peak of 66.83 x 103/μl at 120 h, while counts in poults decreased to a minimum of 26.75 x 103/μl at 96 h pi. Lymphocyte counts in chicks were reduced to a minimum of 5.9 x 103/μl at 48 h pi after an initial reduction between three and six hours postinfection. A similar decline occurred in poults with a minimum of 7.81 x 103/μl at 48 h pi. The trend of changes in heterophil counts for the three species was similar to those observed for leukocyte counts. While eosinophil counts in chicks initially increased to a peak of 1.93 x 103/μl at 6 h pi and subsequently declined, eosinophil values in poults declined to a minimum of 0.88 x 103/μl at 6 h pi, followed by an increase to a maximum of 5.7 x 103/μl at 72 h pi. However, all hematological values in ducklings remained relatively unchanged. These results showed that there was biphasic lymphopenia, eosinophilia and heterophilia in chicks, lymphopenia and delayed eosinophilia in poults, and relatively unchanged values in ducklings. This emphasizes the fact that different levels of susceptibility exist in the three poultry species studied

SIMULATION OF THE DYNAMICS OF CASSAVA STEM CUTTINGS ON AN INCLINED WOOD SURFACE

Development of precision machines to handle some of the field activities involved in the cultivation of cassava is a highly welcomed project among young enterprising farmers who are keen in resolving the posterity of their wellbeing as a big time farmer. Mechanization of cassava in the tropics is grossly hampered by lack of extensive knowlegde on the behaviour, physical properties of cassava stems and parameters that have great influence on the handling of the stems during cultivation, hence the limita-tion of advancing the present semi-automatic planter to fully automated one is still a mirage in the tropics. This paper presents the flow properties of cassava cuttings that can lend it to proper handling in a metering machine. A variable inclined wood surface rig with an ejection outlet was used to study the properties of the stem. Measured cassava stem predictive parameters; diamater, lentgh,weight; angle variation on the rig; response parameters; percentage ejected, percentage sliding through, forces acting on stems were obtained. The results from the study could be used to predict acurately the exact dynamics of a given stem isolated from the bulk of stem cuttings stacked in the metering hopper. Models to predict the flow properties of the stems were obtained; further simulation of the dynamics was embarked upon using MATLAB software. A major transition zone of stem characteris-tics per pecentage sliding to ejection occurred within the range of angles of 150 -300. This might be a favourable angular zone for isolating the stems from the bulk mass while the effectively isolated stems can be metered appropriately by another mechanism in the process of developing a metering device for cassava stem cuttings

A multi-country outbreak of Salmonella Newport gastroenteritis in Europe associated with watermelon from Brazil, confirmed by whole genome sequencing: October 2011 to January 2012

In November 2011, the presence of Salmonella Newport in a ready-to-eat watermelon slice was confirmed as part of a local food survey in England. In late December 2011, cases of S. Newport were reported in England, Wales, Northern Ireland, Scotland, Ireland and Germany. During the outbreak, 63 confirmed cases of S. Newport were reported across all six countries with isolates indistinguishable by pulsed-field gel electrophoresis from the watermelon isolate. A subset of outbreak isolates were whole-genome sequenced and were identical to, or one single nucleotide polymorphism different from the watermelon isolate. In total, 46 confirmed cases were interviewed of which 27 reported watermelon consumption. Further investigations confirmed the outbreak was linked to the consumption of watermelon imported from Brazil. Although numerous Salmonella outbreaks associated with melons have been reported in the United States and elsewhere, this is the first of its kind in Europe. Expansion of the melon import market from Brazil represents a potential threat for future outbreaks. Whole genome sequencing is rapidly becoming more accessible and can provide a compelling level of evidence of linkage between human cases and sources of infection, to support public health interventions in global food markets

A multi-country outbreak of salmonella newport gastroenteritis in europe associated with watermelon from brazil, confirmed by whole genome sequencing: october 2011 to january 2012

In November 2011, the presence of Salmonella Newport in a ready-to-eat watermelon slice was confirmed as part of a local food survey in England. In late December 2011, cases of S. Newport were reported in England, Wales, Northern Ireland, Scotland, Ireland and Germany. During the outbreak, 63 confirmed cases of S. Newport were reported across all six countries with isolates indistinguishable by pulsed-field gel electrophoresis from the watermelon isolate. A subset of outbreak isolates were whole-genome sequenced and were identical to, or one single nucleotide polymorphism different from the watermelon isolate. In total, 46 confirmed cases were interviewed of which 27 reported watermelon consumption. Further investigations confirmed the outbreak was linked to the consumption of watermelon imported from Brazil. Although numerous Salmonella outbreaks associated with melons have been reported in the United States and elsewhere, this is the first of its kind in Europe. Expansion of the melon import market from Brazil represents a potential threat for future outbreaks. Whole genome sequencing is rapidly becoming more accessible and can provide a compelling level of evidence of linkage between human cases and sources of infection, to support public health interventions in global food markets