Experimental Study of the Mechanical Transmission of Rabbit Hemorrhagic Disease Virus (RHDV2/b) by Aedes albopictus (Diptera: Culicidae) and Phlebotomus papatasi (Diptera: Psychodidae).

Rabbit hemorrhagic disease (RHD) is caused by a lagovirus mainly affecting European rabbits (Oryctolagus cuniculus), although other European and North American lagomorph species are also susceptible to fatal infection by the new viral variant RHDV2/b. In the present work, direct mechanical transmission of the rabbit hemorrhagic disease virus (RHDV2/b variant) by the hematophagous Diptera Aedes albopictus (Skuse) (Diptera: Culicidae) and the sand fly Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae) was tested. For each species, six and three laboratory rabbits were exposed to bites of dipterous females partially fed on RHDV2/b viral suspension 2 h and 24 h prior to exposure, respectively. The rabbits were then monitored for clinical changes and mortality for 35 d, and seroconversion was assessed by indirect ELISA. No rabbit died or showed clinical signs of disease, and seroconversion was recorded in two rabbits challenged with P. papatasi females fed the viral suspension 2 h prior to exposure. The number of RHDV2/b RNA copies/female was higher in Ae. albopictus than in P. papatasi but the decrease over time of RNA load in Ae. albopictus was greater than that in P. papatasi. The results of this study suggest the inability of Ae. albopictus to serve as a direct mechanical vector of RHDV2/b, but sand flies could play a role in the local transmission of RHD.

[Incidence and prognostic factors of breast cancer diagnosed within and outside of the organised screening program in the department of Loire-Atlantique (1991-2002)]. / Incidence et facteurs pronostiques des cancers du sein découverts au cours et en dehors du programme de dépistage organisé en Loire-Atlantique (1991-2002).

BACKGROUND: This study aimed to evaluate the impact of breast cancer mass screening, which began in 1996 in Loire-Atlantique (France), on the evolution of incidence and characteristics of breast cancer between 1991 and 2002. METHODS: The cancer Registry of Loire-Atlantique recorded characteristics of 9263 incident breast cancers diagnosed between 1991 and 2002. The level of participation to the organised screening program was 48%, thus the screening management structure allowed characterizing 736 cancers discovered by organised screening between 1997 and 2002. RESULTS: The 1991-2002 period was marked by a strong increase of in situ cancer proportion (from 5% at the beginning to 10% at the end of the period) and of standardised incidence rates (from 77 to 103/10(5) and from 4 to 13/10(5) for invasive and in situ cancers, respectively). Incidence was already rising before the beginning of the organised screening program in 1996. During the 1997-2002 period, in spite of steady rates for cancers detected by organised screening, incidence of cancers detected outside organised screening went on increasing. Cancers detected by organised screening were more often of smaller size (33% versus 22% smaller than 10mm) and without lymph node invasion (70% versus 62%). CONCLUSION: A strong increase of breast cancer incidence was observed in Loire-Atlantique, particularly in the organised screening age groups. The persistent increase of in situ cancers for women younger than 50 years old unconcerned by the organised screening program, and also for women of 50-74 years old detected outside the organised screening program suggested a parallel contribution of individual screening. These preliminary results confirm better prognostic factors for cancer detected by organised screening than for others.

Prediction of acute toxicity of organophosphorus pesticides using topological indices.

Topological indices were used in the prediction of the acute toxicity (intraperitoneal and oral LD(50)) of organophosphorus pesticides on rats. Models with six variables for the prediction of LD(50)-i.p. (r = 0.849, Q(2) = 0.613) and eight variables for LD(50)-oral (r = 0.906, Q(2) = 0.701) were selected. External group and cross-validation by use of leave-n-out tests were also performed in order to assess the stability and the prediction performance of the selected topological models.

Specific long-chain fatty acids promote optimal growth of Frankia: accumulation and intracellular distribution of palmitic and propionic acid

Frankia isolates from nodules of the genera Casuarina (BR, S21, Thr), Allocasuarina (Allo2), and Gymnostoma (G80) were found to grow exponentially with high biomass yield and minimal sporangia formation in stirred propionate mineral medium when supplemented either with 2.4 µM palmitic acid (C16:0), pentadecanoic (C15:0), heptadecanoic (C17:0), or linoleic (C18:2, cis 9, 12) fatty acids. Strains also grew with lauric (C12:0) or myristic (C14:0) acids, but gave lower biomass yield. Stearic acid (C18:0) produced a good biomass yield, but cultures slowly accumulated sporangia; oleic acid (C18:1, cis-9) was detrimental to growth. Caprylic (C8:0) or capric (C10:0) acids proved to be prejudicial for long-term storage of Frankia strains. In experiments using labeled 1,2-dipalmitoyl phosphatidylcholine and palmitic acid, radioactivity bound rapidly to the insoluble, but solvent-extractable fraction of Frankia cells. In contrast, label from propionic acid accumulated in the cytosolic fraction. Therefore, the beneficial effect of some specific phospatidylcholines or free fatty acids on Frankia growth appears to result from their utilization as building blocks for the membrane, suggesting that membrane biosynthesis may be the limiting step for Frankia growth in unamended propionate mineral medium.

The decline of myths and myopia? The use and abuse of nursing history.

Since 1980 a 'new' history of nursing has been emerging, one that attempts to address serious problems within nursing historiography such as the subordination of nursing history to medical history. There is a need for nurses to reject the narrow celebratory narratives produced by typical amateur medical historians. While problems of 'outsiders' writing the history of professions have been highlighted, problems inherent in the production of their own history by 'insiders' have been overlooked. A critical approach to the history of nursing will display different qualities and emphases to most previous writing in this field.