Viral clearance using disposable systems in monoclonal antibody commercial downstream processing

Once highly selective protein A affinity is chosen for robust mAb downstream processing, the major role of polishing steps is to remove product related impurities, trace amounts of host cell proteins, DNA/RNA, and potential viral contaminants. Disposable systems can act as powerful options either to replace or in addition to polishing column chromatography to ensure product purity and excellent viral clearance power for patients' safety. In this presentation, the implementation of three disposable systems such as depth filtration, membrane chromatography, and nanometer filtration technology in a commercial process are introduced. The data set of viral clearance with these systems is presented. Application advantages and disadvantages including cost analysis are further discussed.     

Genotype-specific genomic markers associated with primary hepatomas, based on complete genomic sequencing of hepatitis B virus

We aimed to identify genomic markers in hepatitis B virus (HBV) that are associated with hepatocellular carcinoma (HCC) development by comparing the complete genomic sequences of HBVs among patients with HCC and those without. One hundred patients with HBV-related HCC and 100 age-matched HBV-infected non-HCC patients (controls) were studied. HBV DNA from serum was directly sequenced to study the whole viral genome. Data mining and rule learning were employed to develop diagnostic algorithms. An independent cohort of 132 cases (43 HCC and 89 non-HCC) was used to validate the accuracy of these algorithms. Among the 100 cases of HCC, 37 had genotype B (all subgenotype Ba) and 63 had genotype C (16 subgenotype Ce and 47 subgenotype Cs) HBV infection. In the control group, 51 had genotype B and 49 had genotype C (10 subgenotype Ce and 39 subgenotype Cs) HBV infection. Genomic algorithms associated with HCC were derived based on genotype/subgenotype-specific mutations. In genotype B HBV, mutations C1165T, A1762T and G1764A, T2712C/A/G, and A/T2525C were associated with HCC. HCC-related mutations T31C, T53C, and A1499G were associated with HBV subgenotype Ce, and mutations G1613A, G1899A, T2170C/G, and T2441C were associated with HBV subgenotype Cs. Amino acid changes caused by these mutations were found in the X, envelope, and precore/core regions in association with HBV genotype B, Ce, and Cs, respectively. In conclusion, infections with different genotypes of HBV (B, Ce, and Cs) carry different genomic markers for HCC at different parts of the HBV genome. Different HBV genotypes may have different virologic mechanisms of hepatocarcinogenesis.     

Network medicine

To more effectively target complex diseases like cancer, diabetes and schizophrenia, we may need to rethink our strategies for drug development and the selection of molecular targets for pharmacological treatments. Here, we discuss the potential use of protein signaling networks as the targets for new therapeutic intervention. We argue that by targeting the architecture of aberrant signaling networks associated with cancer and other diseases new therapeutic strategies can be implemented. Transforming medicine into a network driven endeavour will require quantitative measurements of cell signaling processes; we will describe how this may be performed and combined with new algorithms to predict the trajectories taken by a cellular system either in time or through disease states. We term this approach, network medicine.     

Central lactate metabolism regulates food intake

The central nervous system regulates food intake (FI) and body weight (BW), but the associated mechanisms remain to be elucidated. Here we report that central injections of lactate reduced FI and BW in rodents. Inhibition of central lactate metabolism to pyruvate with the lactate dehydrogenase inhibitor oxamate abolished the central effects of lactate on FI and BW. Conversely, central injections of pyruvate recapitulated the effects of lactate. Finally, inhibition of central lactate metabolism prevented the ability of circulating lactate to lower FI and BW. Together, the data indicate that activation of central lactate metabolism lowers FI and BW.     

Molecular tools to detect the IncJ elements: a family of integrating, antibiotic resistant mobile genetic elements

The IncJ group of enterobacterial mobile genetic elements, which include R391, R392, R705, R997 and pMERPH, have been shown to be site-specific integrating elements encoding variable antibiotic and heavy metal resistance genes. They insert into a specific 17-bp site located in the prfC gene, encoding peptide release factor 3, in Escherichia coli and other hosts. A key feature of known IncJ elements is the presence of a site-specific recombination module consisting of an attachment site on the element and an integrase-encoding gene of the tyrosine recombinase class, which promotes integration between the attachment site on the element and a similar site on the host chromosome. We have cloned and sequenced the integrases from a number of known IncJ elements and designed PCR primers for specific amplification of this gene. Using conserved regions of enterobacterial prfC genes upstream and downstream of the insertion site, and conserved sequences at the ends of the integrated IncJ elements, we have designed specific primers to amplify across the integrated IncJ attL and attR junction fragments. Alignment of over 30 enterobacterial prfC-like genes indicates that the primers designed to amplify attR junction would amplify IncJ element: host junctions from a wide variety of hosts. The IncJ elements have been shown to sensitise recA(+)E. coli K12 strains to UV irradiation. A simple and rapid procedure for demonstrating this effect is described. These tools should enable the rapid detection of such elements in clinical and environmental settings.     

Discovery of potent and cell-active allosteric dual Akt 1 and 2 inhibitors

This paper describes the improvement of cell potency in a class of allosteric Akt 1 and 2 inhibitors. Key discoveries include identifying the solvent exposed region of the molecule and appending basic amines to enhance the physiochemical properties of the molecules. Findings from the structure–activity relationships are discussed.