The rediscovery of smallpox.

Smallpox is an infectious disease that is unique to humans, caused by a poxvirus. It is one of the most lethal of diseases; the virus variant Variola major has a mortality rate of 30%. People surviving this disease have life-long consequences, but also assured immunity. Historically, smallpox was recognized early in human populations. This led to prevention attempts--variolation, quarantine, and the isolation of infected subjects--until Jenner's discovery of the first steps of vaccination in the 18th century. After vaccination campaigns throughout the 19th and 20th centuries, the WHO declared the eradication of smallpox in 1980. With the development of microscopy techniques, the structural characterization of the virus began in the early 20th century. In 1990, the genomes of different smallpox viruses were determined; viruses could be classified in order to investigate their origin, diffusion, and evolution. To study the evolution and possible re-emergence of this viral pathogen, however, researchers can only use viral genomes collected during the 20th century. Cases of smallpox in ancient periods are sometimes well documented, so palaeomicrobiology and, more precisely, the study of ancient smallpox viral strains could be an exceptional opportunity. The analysis of poxvirus fragmented genomes could give new insights into the genetic evolution of the poxvirus. Recently, small fragments of the poxvirus genome were detected. With the genetic information obtained, a new phylogeny of smallpox virus was described. The interest in conducting studies on ancient strains is discussed, in order to explore the natural history of this disease.

mtDNA variation in the Buryat population of the Barguzin Valley: New insights into the micro-evolutionary history of the Baikal area.

BACKGROUND: Southern Siberian populations, including the Buryat, have been of great interest in investigating the exchanges between Eastern and Western Eurasia and understanding the peopling of Siberia and the New World. AIM: Previous studies mainly employed a phylogenetic approach, and thus used pooled samples to detect a maximum of variability. As different sampling strategies may result in different pictures of a population's evolutionary history, we proposed in this study to focus on a local Buryat population selected on the basis of geographical, archaeological and ethno-historical data. SUBJECTS AND METHODS: This study investigated a local population from the Barguzin Valley, on the north-western shores of Lake Baikal identified as the most likely place of Buryat origin. We analysed mitochondrial DNA (mtDNA) RFLPs markers, HVS-I and HVS-II sequences to discuss the genetic variability of this population, and to compare our local sample with pooled Buryat samples and neighbouring Siberian populations. RESULTS: The Barguzin Buryat sample shows depressed neutrality scores compared to the pooled Buryat sample, and different genetic affinities with the Mongol and Turco-Evenk populations. CONCLUSION: These results underline the need to use local samples, in addition to pooled samples, to investigate the history of human populations at the micro-evolutionary level.

[The percutaneous bone biopsy: in vitro study for comparison of bone biopsy needles]. / Die perkutane Knochenbiopsie: Experimentelle Studie zum Vergleich von Knochenbiopsiesystemen.

PURPOSE: The aim of this study was to assess the differences in ease of use and quality of samples of several bone biopsy needles in an animal test. MATERIALS AND METHODS: An evaluation of eight bone biopsy needles of different gauges was undertaken. With each needle, 5 biopsies of an animal bone (lumbal vertebral body of calf, pig and lamb) were performed and compared to each other. The subjective assessment of force to obtain a sample, ease of needle use and ease of sample removal were graded on a 5-point scale. Each biopsy specimen was measured before and after fixation and the gross state was evaluated. For evaluation of histopathological quality, width and degree of fragmentation were also evaluated on a scale. RESULTS: The Somatex, Bone Marrow and Safe Cut 8 G and the Cardinal Health, Jamshidi 8 G needles were rated as being the easiest ones to use, while the Bloodline, Easy Trap 8 G and the RADI, Bonopty 15 G biopsy needles were rated as being the most difficult ones. Histological specimen quality was highest for the Somatex 8 G needles, the Cardinal Health, Jamshidi 8 G and the Bloodline, Easy Trap 8 G needles. The Inter.V, SnareLok 8 G and the RADI, Bonopty 15 G needles had the lowest yield. Furthermore, differences in length before and after fixation were recorded. The average decrease of core length after fixation was 18 %. CONCLUSION: The bone biopsy needles tested here vary significantly in performance and quality of the histopathological specimen. Detailed knowledge of the strengths and weaknesses of different needles could facilitate the decision for the selection of an appropriate instrument.