Bartonella quintana in Body Lice and Head Lice from Homeless Persons, San Francisco, California, USA

Bartonella quintana is a bacterium that causes trench fever in humans. Past reports have shown Bartonella spp. infections in homeless populations in San Francisco, California, USA. The California Department of Public Health in collaboration with San Francisco Project Homeless Connect initiated a program in 2007 to collect lice from the homeless to test for B. quintana and to educate the homeless and their caregivers on prevention and control of louse-borne disease. During 2007–2008, 33.3% of body lice–infested persons and 25% of head lice–infested persons had lice pools infected with B. quintana strain Fuller. Further work is needed to examine how homeless persons acquire lice and determine the risk for illness to persons infested with B. quintana–infected lice.     

Prevalence of antibody to hepatitis E virus among rodents in the United States

The recent identification of antibody to hepatitis E virus (HEV) in pigs, sheep, and cattle and characterization of an HEV isolated from domestic pigs suggest animal reservoirs for this virus. To investigate whether rodents might be a natural reservoir of HEV, the prevalence of anti-HEV was determined among a variety of species throughout the United States. Serum samples were obtained from 806 rodents of 26 species in 15 genera. Anti-HEV prevalence was assessed by 2 EIAs (mosaic protein- and 55-kDa protein-based), which gave concordant results. The highest prevalence of antibody was found in the genus Rattus (59.7%; 166/278). Overall, rodents from urban habitats had a significantly higher prevalence of anti-HEV than did animals captured from rural areas. A high prevalence of anti-HEV was found in animals captured on mainland versus barrier islands. The results from this study provide convincing evidence of widespread HEV or HEV-like infection in rodents of the United States.     

Maternal embryonic leucine zipper kinase transcript abundance correlates with malignancy grade in human astrocytomas

We have performed cDNA microarray analyses to identify gene expression differences between highly invasive glioblastoma multiforme (GBM) and typically benign pilocytic astrocytomas (PA). Despite the significant clinical and pathological differences between the 2 tumor types, only 63 genes were found to exhibit 2-fold or greater overexpression in GBM as compared to PA. Forty percent of these genes are related to the regulation of the cell cycle and mitosis. QT-PCR validation of 6 overexpressed genes: MELK, AUKB, ASPM, PRC1, IL13RA2 and KIAA0101 confirmed at least a 5-fold increase in the average expression levels in GBM. Maternal embryonic leucine zipper kinase (MELK) exhibited the most statistically significant difference. A more detailed investigation of MELK expression was undertaken to study its oncogenic relevance. In the examination of more than 100 tumors of the central nervous system, we found progressively higher expression of MELK with astrocytoma grade and a noteworthy uniformity of high level expression in GBM. Similar level of overexpression was also observed in medulloblastoma. We found neither gene promoter hypomethylation nor amplification to be a factor in MELK expression, but were able to demonstrate that MELK knockdown in malignant astrocytoma cell lines caused a reduction in proliferation and anchorage-independent growth in in vitro assays. Our results indicate that GBM and PA differ by the expression of surprisingly few genes. Among them, MELK correlated with malignancy grade in astrocytomas and represents a therapeutic target for the management of the most frequent brain tumors in adult and children.     

Molecular Phylogeny of Hantaviruses Harbored by Insectivorous Bats in C?te d’Ivoire and Vietnam

The recent discovery of genetically distinct hantaviruses in multiple species of shrews and moles prompted a further exploration of their host diversification by analyzing frozen, ethanol-fixed and RNAlater^®-preserved archival tissues and fecal samples from 533 bats (representing seven families, 28 genera and 53 species in the order Chiroptera), captured in Asia, Africa and the Americas in 1981–2012, using RT-PCR. Hantavirus RNA was detected in Pomona roundleaf bats (Hipposideros pomona) (family Hipposideridae), captured in Vietnam in 1997 and 1999, and in banana pipistrelles (Neoromicia nanus) (family Vespertilionidae), captured in Côte d’Ivoire in 2011. Phylogenetic analysis, based on the full-length S- and partial M- and L-segment sequences using maximum likelihood and Bayesian methods, demonstrated that the newfound hantaviruses formed highly divergent lineages, comprising other recently recognized bat-borne hantaviruses in Sierra Leone and China. The detection of bat-associated hantaviruses opens a new era in hantavirology and provides insights into their evolutionary origins.     

Trends of infant mortality in Hong Kong (1956–90) and evaluation of preventable infant deaths

Objective: This study describes the time trends for infant mortality in Hong Kong and aims to develop statistical models that can be used to predict changes of infant mortality in places already having low levels of infant mortality.
Methodology: Data on births and deaths of infants in Hong Kong during the years 1956–90 were analysed annually as well as by aggregating the data into seven consecutive quinquennia. To assess the contribution of preventable infant deaths, causes for infant deaths were classified into two broad categories: (i) congenital anomalies; and (ii) preventable diseases. A simple linear regression model was used to analyse the time trend of the mortality rate of the preventable diseases (PIMR) over the seven quinquennia.
Results: During the period 1956–90, the infant mortality rate fell from 60.9 in 1956–5.9 per 1000 in 1990 and the neonatal mortality rate fell from 24.2-3.8 per 1000. There was no clear time trend observed for infant mortality of congenital anomalies. However, the time trend for PIMR (log scale) was very close to a straight line and simple linear regression modelling showed a R² of 0.9970.
Conclusion: As the infant mortality rate (IMR) falls to below 30 per 1000, the further rate of decrease becomes less predictable from the regression model of the IMR. By removing the portion of deaths attributable to congenital anomalies, the further decrease in infant mortality became more predictable down to very low levels of IMR.     

血小板衍生生长因子在肺癌中的意义

目的 探讨血小板衍生生长因子(PDGF)在非小细胞肺癌(NSCLC)和小细胞肺癌(SCLC)中的表达及意义。方法 采用免疫组织化学法观察了PDGF—A链、PDGF—B链在NSCLC和SCLC中的表达。结果 PDGF—B链的过表达在NSCLC显著增高，PDGF—A链的过表达在两组间无显著性差异。结论 PDGF—A链和PDGF—B链的生物学特征可能有所不同，相比而言，肿瘤微血管的增生与PDGF—B链的关系可能更密切。