The findings address the longstanding debate among scientists about whether or not the bacterium Yersinia pestis –responsible for the Black Death—remained within Europe for hundreds of years and was the principal cause of some of the worst re-emergences and subsequent plague epidemics in human history. Until now, some researchers believed repeated outbreaks were the result of the bacterium being re-introduced through major trade with China, a widely-known reservoir of the plague. Instead, it turns out the plague may never have left. "The more plague genomes we have from these disparate time periods, the better we are able to reconstruct the evolutionary history of this pathogen" says evolutionary geneticist Hendrik Poinar, director of McMaster University's Ancient DNA Centre and a principal investigator at the Michael G. DeGroote Institute for Infectious Disease Research. Poinar collaborated with Edward Holmes at the University of Sydney, Olivier Dutour of the École Pratique des Hautes Études in France, and Kirsti Bos and Johannes Krause at the University of Tubingen, and others, to map the complete genomes of Y.pestis which was harvested from five adult male victims of the 1722 Plague of Provence. To do so, they analyzed the dental pulp taken from the five bodies, originally buried in Marseille, France. Researchers were able to extract, purify and enrich specifically for the pathogen's DNA, and then compare the samples with over 150 plague genomes representing a world wide distribution as well as from other points in time, both modern and ancient. By comparing and contrasting the samples, researchers determined the Marseille strain is a direct descendant of the Black Death that devastated Europe nearly 400 years earlier and not a divergent strain that came, like the previous pandemic strains Justinian and Black Death, from separate emergences originating in Asia. More extensive sampling of modern rodent populations, in addition to ancient human and rodent remains from various regions in Asia, the Caucasus and Europe, may yield additional clues about past ecological niches for plague. "There are many unresolved questions that need to be answered: why did the plague erupt in these devastating waves and then lay dormant? Did it linger in the soil or did it re-emerge in rats? And ultimately why did it suddenly disappear and never come back? Sadly, we don't have the answer to this yet," says Poinar. "Understanding the evolution of the plague will be critically important as antibiotic resistance becomes a greater threat, particularly since we treat modern-day plague with standard antibiotics. Without methods of treatment, easily treatable infections can become devastating again," he says. The research was published online today in the bioarchive bioRXIV, and is under review at the journal eLife. Explore further: Researchers reconstruct genome of the Black Death
Lv J.-Y.,Institute for Infectious Disease |
Yang Y.-P.,Institute for Infectious Disease
World Journal of Gastroenterology | Year: 2012
AIM: To investigate the intratumoral expression of metastasis-associated in colon cancer 1 (MACC1) and c-Met and determine their clinical values associated with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). METHODS: A retrospective study admitted three hundred fifty-four patients with HBV-related HCC. The expression and distribution of MACC1 and c-Met were assessed by quantitative real-time polymerase chain reaction and immunohistochemistry staining. Prognostic factors influencing survival, metastasis and recurrence were assessed. RESULTS: Intratumoral MACC1 level was found to be associated with HCC disease progression. Both median tumor-free survival (TFS) and overall survival (OS) were significantly shorter in the postoperative HCC patients with high intratumoral MACC1 expression, as compared to those with low intratumoral MACC1 levels (TFS: 34 mo vs 48.0 mo, P < 0.001; OS: 40 mo vs 48 mo, P < 0.01). Multivariable analysis indicated that high MACC1 expression or co-expression with c-Met were independent predictors for HCC clinic outcome (P < 0.001). CONCLUSION: High intratumoral MACC1 expression can be associated with enhanced tumor progression and poor outcome of HBV-related HCC. MACC1 mayserve as a prognostic biomarker for postoperative HCC. © 2012 Baishideng. All rights reserved.
Lyu Y.,Institute for Infectious Disease |
Tian L.,Institute for Infectious Disease |
Zhang L.,U.S. Center for Disease Control and Prevention |
Dou X.,Institute for Infectious Disease |
And 7 more authors.
PLoS ONE | Year: 2013
To investigate the risk factors of scrub typhus infection in Beijing, China, a case-control study was carried out. Cases (n = 56) were defined as persons who were diagnosed by PCR and serological method within three years. Three neighborhood control subjects were selected by matching for age and occupation. Living at the edge of the village, living in the houses near grassland, vegetable field or ditch, house yard without cement floor, piling weeds in the house or yard, all of these were risk factors for scrub typhus infection. Working in vegetable fields and hilly areas, and harvesting in autumn posed the highest risks, with odds ratios (ORs) and 95% confidence intervals (CIs) of 3.7 (1.1-11.9), 8.2 (1.4-49.5), and 17.2 (5.1-57.9), respectively. These results would be useful for the establishment of a detail control strategy for scrub typhus infection in Beijing, China. © 2013 Lyu et al.