Microsoft word - abstract_vol_3_01_.doc

HÉMA-VIGIE…always on the lookout!
A Monthly Newsletter Summarizing Important Advances in Transfusion
Volume 3, Number 1

West Nile virus – infected birds: an early
tral role in the peripheral circulation problems commonly warning sign of upcoming human infec-
encountered in sickle-cell disease patients. Reiter, C. D., et al. (2002). Cell-free hemoglobin limits
nitric oxide bioavailability in sickle-cell disease. Nat
To gain further insights on this emerging pathogen, Gup- Med 8 (12): 1383-1389. doi: 10.1038/nm799. till et al. (U.S. Geological Survey, VA, USA) analyzed epidemiological data on the prevalence of infected birds and human infections per US county as a function of time Are there bacteria in the blood of healthy
in 2001 and 2002. Their results indicate that for a given individuals?
area, the identification of infected birds early in the sea- son when the virus is active increases the likelihood of Up until now, the vascular compartment of healthy indi- viduals was thought to be devoid of bacteria. The results of a collaborative effort led by Eddie C. S. Chan (McGill Guptill, S. C., et al. (2003). Early-season avian deaths
University, Montreal) suggest that bacteria are found in from West Nile virus as warnings of human infection.
low numbers in the blood of otherwise healthy individuals. Presumably harmless, the isolated bacteria are particu- larly difficult to grow, which may partly explain why they Transmissible spongiform encephalopathies
(TSE): Antibodies against prions are protec-
McLaughlin, R. W., et al. (2002). Are there naturally
occurring pleomorphic bacteria in the blood of heal-
thy humans? J Clin Microbiol 40 (12): 4771-4775. doi:
White et al., under the supervision of Simon Hawke (Im- perial College, London, United Kingdom) demonstrate that prophylactic infusion of antibodies specific to the Gene therapy for anemia by controlled ex-
prion protein prevent encephalopathy in mice previously inoculated with an infectious prion in the abdominal cav- pression of erythropoietin (EPO)
ity. However, treatment has to be started relatively early after infection, i.e., before infectious prions reach the Two articles describing animal models of gene therapy central nervous system, in order to be efficacious. designed for treatment of anemia have been recently published. Samakoglu, Bohl, and Heard (Pasteur Insti- White, A. R., et al. (2003). Monoclonal antibodies in-
tute, Paris, France) succeeded in controlling EPO ex- hibit prion replication and delay the development of
pression from a gene therapy vector using a pharmacol- prion disease. Nature 422 (6927): 80-83. doi:
ogical agent. Furthermore, Binley et al. (Oxford Bio- Medica (UK) Ltd., Oxford, United Kingdom) designed a gene therapy vector whereby EPO expression is auto-regulated in response to oxygen concentration in the Hemolysis-induced vasoconstriction: In-
tissue in which the vector is delivered. sights on the molecular mechanisms
Samakoglu, S., Bohl, D., and Heard, J. M. (2002). Me-
Sickle-cell disease, an inherited disorder affecting red chanisms leading to sustained reversion of beta-
blood cell hemoglobin, results in frequent peripheral vas- thalassemia in mice by doxycycline-controlled Epo
cular occlusions caused by the abnormal rigidity of sick- delivery from muscles. Mol Ther 6 (6): 793-803. doi:
led red blood cells. These episodes are often associated with hemolysis, that is, free hemoglobin in blood. A group led by Mark T. Gladwin (National Institutes of Health, Binley, K., et al. (2002). Long-term reversal of chronic
Bethesda, MD, USA) presents results suggesting that anemia using a hypoxia-regulated erythropoietin
nitric oxide inactivation by free hemoglobin plays a cen- gene therapy. Blood 100 (7): 2406-2413. doi:
10.1182/blood-2002-02-0605.
NOTICE. This newsletter aims at informing Héma-Québec personnel and partners of the most recent scientific developments which may exert an impact in the field of blood and transfusion. The information contained herein should not be interpreted as exhaustive accounts of the findings being presented. Opinions and analyses presented herein constitute personal interpretations of scientific articles and/or newsclips presented to the reader and are the sole responsibility of the author. Héma-Québec denies any liability whatsoever with regards to the use or misuse by the reader of the information contai-ned herein.

Source: http://www.hema-quebec.qc.ca/userfiles/file/media/anglais/rd/rd_abregevol3_01a.pdf