An Endogenous Murine Leukemia Viral Genome Contaminant in a Commercial RT-PCR Kit is Amplified Using Standard Primers for XMRV

During pilot studies to investigate the presence of viral RNA of xenotropic murine leukemia virus (MLV)-related virus (XMRV) infection in sera from chronic fatigue syndrome (CFS) patients in Japan, a positive band was frequently detected at the expected product size in negative control samples when detecting a partial gag region of XMRV using a one-step RT-PCR kit. We suspected that the kit itself might have been contaminated with small traces of endogenous MLV genome or XMRV and attempted to evaluate the quality of the kit in two independent laboratories. We purchased four one-step RT-PCR kits from Invitrogen, TaKaRa, Promega and QIAGEN in Japan. To amplify the partial gag gene of XMRV or other MLV-related viruses, primer sets (419F and 1154R, and GAG-I-F and GAG-I-R) which have been widely used in XMRV studies were employed. The nucleotide sequences of the amplicons were determined and compared with deposited sequences of a polytropic endogenous MLV (PmERV), XMRV and endogenous MLV-related viruses derived from CFS patients. We found that the enzyme mixtures of the one-step RT-PCR kit from Invitrogen were contaminated with RNA derived from PmERV. The nucleotide sequence of a partial gag region of the contaminant amplified by RT-PCR was nearly identical (99.4% identity) to a PmERV on chromosome 7 and highly similar (96.9 to 97.6%) to recently identified MLV-like viruses derived from CFS patients. We also determined the nucleotide sequence of a partial env region of the contaminant and found that it was almost identical (99.6%) to the PmERV. In the investigation of XMRV infection in patients of CFS and prostate cancer, researchers should prudently evaluate the test kits for the presence of endogenous MLV as well as XMRV genomes prior to PCR and RT-PCR tests

Targeting protein homodimerization: A novel drug discovery system

AbstractTo identify a novel class of antibiotics, we have developed a high-throughput genetic system for targeting the homodimerization (HD system) of histidine kinase (HK), which is essential for a bacterial signal transduction system (two-component system, TCS). By using the HD system, we screened a chemical library and identified a compound, I-8-15 (1-dodecyl-2-isopropylimidazole), that specifically inhibited the dimerization of HK encoded by the YycG gene of Staphylococcus aureus and induced concomitant bacterial cell death. I-8-15 also showed antibacterial activity against MRSA (methicillin-resistant S. aureus) and VRE (vancomycin-resistant Enterococcus faecalis) with MICs at 25 and 50μg/ml, respectively

A Case of Granulocyte-Colony Stimulating Factor-Producing Hepatocellular Carcinoma Confirmed by Immunohistochemistry

Granulocyte-colony stimulating factor (G-CSF) is a naturally occurring glycoprotein that stimulates the proliferation and maturation of precursor cells in the bone marrow into fully differentiated neutrophils. Several reports of G-CSF-producing malignant tumors have been published, but scarcely any in the hepatobiliary system, such as in hepatocellular carcinoma (HCC). Here, we encountered a 69-yr-old man with a hepatic tumor who had received right hepatic resection. He showed leukocytosis of 25,450/µL along with elevated serum G-CSF. Histological examination of surgical samples demonstrated immunohistochemical staining for G-CSF, but not for G-CSF receptor. The patient survived without recurrence for four years, but ultimately passed away with multiple bone metastases. In light of the above, clinicians may consider G-CSF-producing HCC when encountering patients with leukocytosis and a hepatic tumor. More cases are needed to clarify the clinical picture of G-CSF-producing HCC

No association of xenotropic murine leukemia virus-related virus with prostate cancer or chronic fatigue syndrome in Japan

<p>Abstract</p> <p>Background</p> <p>The involvement of xenotropic murine leukemia virus-related virus (XMRV) in prostate cancer (PC) and chronic fatigue syndrome (CFS) is disputed as its reported prevalence ranges from 0% to 25% in PC cases and from 0% to more than 80% in CFS cases. To evaluate the risk of XMRV infection during blood transfusion in Japan, we screened three populations--healthy donors (<it>n </it>= 500), patients with PC (<it>n </it>= 67), and patients with CFS (<it>n </it>= 100)--for antibodies against XMRV proteins in freshly collected blood samples. We also examined blood samples of viral antibody-positive patients with PC and all (both antibody-positive and antibody-negative) patients with CFS for XMRV DNA.</p> <p>Results</p> <p>Antibody screening by immunoblot analysis showed that a fraction of the cases (1.6-3.0%) possessed anti-Gag antibodies regardless of their gender or disease condition. Most of these antibodies were highly specific to XMRV Gag capsid protein, but none of the individuals in the three tested populations retained strong antibody responses to multiple XMRV proteins. In the viral antibody-positive PC patients, we occasionally detected XMRV genes in plasma and peripheral blood mononuclear cells but failed to isolate an infectious or full-length XMRV. Further, all CFS patients tested negative for XMRV DNA in peripheral blood mononuclear cells.</p> <p>Conclusion</p> <p>Our data show no solid evidence of XMRV infection in any of the three populations tested, implying that there is no association between the onset of PC or CFS and XMRV infection in Japan. However, the lack of adequate human specimens as a positive control in Ab screening and the limited sample size do not allow us to draw a firm conclusion.</p

Vaginal delivery in the presence of huge vulvar varicosities: a case report with MRI evaluation.

Vulvar varicosities are generally not an indication for a caesarean section but in a rare case of severe vulvar varicosities, it would be a controversial issue whether to perform a caesarean section for fear they might rupture during a vaginal delivery. We present a case of huge vulvar varicosities during pregnancy. MRI revealed obstruction of the internal iliac system by the gravid uterus and subsequent incompetence of a collateral pathway via the round ligament vein that emptied into the ovarian vein. The patient went into labour at 38 weeks, and successfully vaginally delivered a baby. The vulvar varicose veins became compressed by the foetal head from the inside, and markedly diminished in size during crowning and after delivery. Women with vulvar varicosities can be allowed to attempt a vaginal birth regardless of their severity. The use of MRI aids in the overall anatomical understanding of vulvar varicosities in pregnancy