Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

A suspected case of Clostridium perfringens sepsis with intravascular hemolysis after transhepatic arterial chemoembolization: a case report

Abstract Introduction Sepsis due to Clostridium perfringens, one of several clostridial species, is an important cause of massive intravascular hemolysis in patients with underlying malignancies. Chronic liver diseases, immunosuppression, and presence of malignancies were risk factors for Clostridium perfringens sepsis. Therefore, Clostridium perfringens sepsis should always be considered in patients presenting with liver damage after chemo-embolic therapy for hepatocellular carcinoma. This case report focuses on findings characteristic of an intravascular hemolysis due to Clostridium perfringens after transhepatic arterial chemoembolization. Case presentation An 83-year-old Japanese man presented to our hospital because of a third recurrence of hepatocellular carcinoma. He had nonalcoholic steatohepatitis-related cirrhosis, and underwent radiofrequency ablation and transhepatic arterial chemoembolization therapy for hepatocellular carcinoma of S4/S8 and S2. He had a medical history of pancreatic carcinoma and underwent pylorus-preserving pancreaticoduodenectomy approximately 5 years ago. Because follow-up computed tomography showed a recurrence of the hepatocellular carcinoma, he underwent transhepatic arterial chemoembolization with a hepatic arterial infusion of 20 mg epirubicin, followed by 4 mL Lipiodol (ethiodized oil). On the sixth day after the procedure, he complained of fever and hematuria with jaundice. Laboratory findings indicated hemolysis and increased inflammatory response. Although we initiated antibiotic therapy combined with surgical debridement for infection after transhepatic arterial chemoembolization, he died within 6 hours. The autopsy showed a 4-cm local necrotic hepatic tumor. The cut surface revealed a tumor with an internal spongiform appearance, which was a pseudocystic and partially necrotic lesion. In addition, a diffuse spread of Gram-positive rods in multiple organs including the heart was histologically confirmed. The culture obtained by fluid aspiration from the hepatic abscess revealed Clostridium perfringens. Although the role of Clostridium perfringens was never established during the life of this patient, based on the clinical course and the culture from the hepatic abscess at postmortem, intravascular hemolysis secondary to Clostridium perfringens sepsis was suspected. Conclusion Intravascular hemolysis secondary to Clostridium perfringens should always be considered in patients presenting with liver damage after chemo-embolic therapy for hepatocellular carcinoma. Biliary reconstruction is an especially important risk factor for infection

Homeostatically Maintained Resting Naive CD4+ T Cells Resist Latent HIV Reactivation

Homeostatic proliferation (HSP) is a major mechanism by which long-lived naïve and memory CD4+ T cells are maintained in vivo and suggested to contribute to the persistence of the latent HIV-1 reservoir. However, while many in vitro latency models rely on CD4+ T cells that were initially differentiated via T-cell receptor (TCR) stimulation into memory/effector cells, latent infection of naïve resting CD4+ T cells maintained under HSP conditions has not been fully addressed. Here, we describe an in vitro HSP culture system utilizing the cytokines IL-7 and IL-15 that allows studying latency in naïve resting CD4+ T cells. CD4+ T cells isolated from several healthy donors were infected with HIV pseudotypes expressing GFP and cultured under HSP conditions or TCR conditions as control. Cell proliferation, phenotype, and GFP expression were analyzed by flow cytometry. RNA expression was quantified by qRT-PCR. Under HSP culture conditions, latently HIV-1 infected naïve cells are in part maintained in the non-dividing (= resting) state. Although a few HIV-1 provirus+ cells were present in these resting GFP negative cells, the estimated level of GFP transcripts per infected cell seems to indicate a block at the post-transcriptional level. Interestingly, neither TCR nor the prototypic HDAC inhibitor SAHA were able to reactivate HIV-1 provirus from these cells. This lack of reactivation was not due to methylation of the HIV LTR. These results point to a mechanism of HIV control in HSP-cultured resting naïve CD4+ T cells that may be distinct from that in TCR-stimulated memory/effector T cells.This work was supported by Grants from the Ministry of Health, Labor and Welfare in Japan for AIDS Research and from the Japan Agency for Medical Research and Development, AMED (YT-Y). JM and AM were funded by a grant from the Spanish Ministry of Economy and Competitiveness and FEDER (Grant no. SAF2013-46077-R)