The optimization of aminooxadiazoles as orally active inhibitors of Cdc7

A series of aminooxadiazoles was optimized for inhibition of Cdc7. Early lead isoquinoline 1 suffered from modest cell potency (cellular IC₅₀ = 0.71 μM measuring pMCM2), low selectivity against structurally related kinases, and high IV clearance in rats (CL = 18 L/h/kg). Extensive optimization resulted in azaindole 26 (Cdc7 IC₅₀ = 1.1 nM, pMCM2 IC₅₀ = 32 nM) that demonstrated robust lowering of pMCM2 in a mouse pharmacodynamic (PD) model when dosed orally. Modifications to improve the pharmacokinetic profile of this series were guided by trapping experiments with glutathione in rat hepatocytes.     

Immunotherapy of prostate cancer: identification of new treatments and targets for therapy, and role of WAP domain-containing proteins

Prostate adenocarcinoma is present in over 80% of men over the age of 80 and is by far the most common cancer of men. Although radical prostatectomy is curative in early disease, the risks of incontinence and impotence can affect the quality of life of patients. Early intervention with localized immunotherapy represents a potential solution as lymphocyte infiltration does occur in prostate cancer lesions, and immunotherapy with dendritic cell vaccines can significantly increase survival in late stage disease. However, lymphocytic infiltrates in the cancerous prostates have an anergic character arising from the suppressive effects of the microenvironment resulting from a conversion of effector cells into regulatory T-cells. Although TGFβ (transforming growth factor β) and IL-10 (interleukin-10) are known to be strong suppressor molecules associated with prostate cancer, they are among many possible suppressive factors. We discuss the possible role of alternative suppressor molecules, including the WAP (whey acidic protein) homologue ps20 that is expressed on prostate stroma and other WAP domain-containing proteins in the immunosuppressive prostate cancer milieu and discuss novel immunotherapeutic strategies to combat this disease.     

Discovery and SAR exploration of a novel series of imidazo[4,5-b]pyrazin-2-ones as potent and selective mTOR kinase inhibitors

We report here the discovery of a novel series of selective mTOR kinase inhibitors. A series of imidazo[4,5-b]pyrazin-2-ones, represented by screening hit 1, was developed into lead compounds with excellent mTOR potency and exquisite kinase selectivity. Potent compounds from this series show >1000-fold selectivity over the related PI3Kα lipid kinase. Further, compounds such as 2 achieve mTOR pathway inhibition, blocking both mTORC1 and mTORC2 signaling, in PC3 cancer cells as measured by inhibition of pS6 and pAkt (S473).     

Biodegradation of Polyester Polyurethane by Endophytic Fungi

Bioremediation is an important approach to waste reduction that relies on biological processes to break down a variety of pollutants. This is made possible by the vast metabolic diversity of the microbial world. To explore this diversity for the breakdown of plastic, we screened several dozen endophytic fungi for their ability to degrade the synthetic polymer polyester polyurethane (PUR). Several organisms demonstrated the ability to efficiently degrade PUR in both solid and liquid suspensions. Particularly robust activity was observed among several isolates in the genus Pestalotiopsis, although it was not a universal feature of this genus. Two Pestalotiopsis microspora isolates were uniquely able to grow on PUR as the sole carbon source under both aerobic and anaerobic conditions. Molecular characterization of this activity suggests that a serine hydrolase is responsible for degradation of PUR. The broad distribution of activity observed and the unprecedented case of anaerobic growth using PUR as the sole carbon source suggest that endophytes are a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation.     

Pre-clinical evaluation of an sLe x-glycosylated complement inhibitory protein in a non-human primate model of reperfused stroke

BACKGROUND: Soluble complement receptor-1 (sCR1), a potent complement inhibitor, confers neuroprotection in a murine stroke model. Additional neuroprotective benefit is achieved by sLe x-glycosylation of sCR1. In an effort to translate sCR1-sLe x to clinical trials, we evaluated this agent in a primate stroke model. METHODS: Adult male baboons randomly received either sCR1-sLe x or vehicle. Stroke volume was assessed on day 3, and neurological examinations were conducted daily. Complement activity (CH50) was measured at 30 minute, 2, 6, 12 hour, 3, and 10 days post-ischemia. RESULTS: The experiment was terminated prematurely following an interim analysis. In a preliminary cohort (n = 3 per arm), infarct volume was greater in the treated animals. No difference in neurological score was found between groups. CH50 levels were significantly reduced in the sCR1sLe x-treated groups. A hypotensive response was also observed in animals treated with sCR1-sLe x. Conclusions Further work is necessary to explain the hypotensive response observed in primates prior to further clinical development of sCR1-sLe x.     

Synthesis and biological activities of isogranulatimide analogues

The synthesis of new isogranulatimide analogues, their inhibitory activities toward the Checkpoint 1 kinase (Chk1), and their in vitro cytotoxicities toward four tumor cell lines (one murine L1210 leukemia, and three human cell lines: DU145 prostate carcinoma, A549 non-small cell lung carcinoma, and HT29 colon carcinoma) are described. The affinity for DNA of some representative compounds and their ability to induce DNA cleavage mediated by topoisomerase I have been examined. In some of the newly synthesized compounds, the imidazole heterocycle of isogranulatimide is replaced by a pyrrole and/or the indole unit is replaced by a 7-azaindole. Compounds in which a sugar part is attached to the 7-azaindole moiety have also been prepared. Some of the newly synthesized compounds are more potent Chk1 inhibitors than granulatimide. The selectivity of two potent Chk1 inhibitors 24 and 26 has been evaluated using various kinases. The strongest inhibitory properties are found toward Chk1.     

Bias Assessment of General Chemistry Analytes using Commutable Samples

Harmonisation of reference intervals for routine general chemistry analytes has been a goal for many years. Analytical bias may prevent this harmonisation. To determine if analytical bias is present when comparing methods, the use of commutable samples, or samples that have the same properties as the clinical samples routinely analysed, should be used as reference samples to eliminate the possibility of matrix effect. The use of commutable samples has improved the identification of unacceptable analytical performance in the Netherlands and Spain. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has undertaken a pilot study using commutable samples in an attempt to determine not only country specific reference intervals but to make them comparable between countries. Australia and New Zealand, through the Australasian Association of Clinical Biochemists (AACB), have also undertaken an assessment of analytical bias using commutable samples and determined that of the 27 general chemistry analytes studied, 19 showed sufficiently small between method biases as to not prevent harmonisation of reference intervals. Application of evidence based approaches including the determination of analytical bias using commutable material is necessary when seeking to harmonise reference intervals.     

Engineering Amyloid-Like Assemblies from Unstructured Peptides via Site-Specific Lipid Conjugation

Aggregation of amyloid beta (Aβ) into oligomers and fibrils is believed to play an important role in the development of Alzheimer’s disease (AD). To gain further insight into the principles of aggregation, we have investigated the induction of β-sheet secondary conformation from disordered native peptide sequences through lipidation, in 1–2% hexafluoroisopropanol (HFIP) in phosphate buffered saline (PBS). Several parameters, such as type and number of lipid chains, peptide sequence, peptide length and net charge, were explored keeping the ratio peptide/HFIP constant. The resulting lipoconjugates were characterized by several physico-chemical techniques: Circular Dichroism (CD), Attenuated Total Reflection InfraRed (ATR-IR), Thioflavin T (ThT) fluorescence, Dynamic Light Scattering (DLS), solid-state Nuclear Magnetic Resonance (ssNMR) spectroscopy and Electron Microscopy (EM). Our data demonstrate the generation of β-sheet aggregates from numerous unstructured peptides under physiological pH, independent of the amino acid sequence. The amphiphilicity pattern and hydrophobicity of the scaffold were found to be key factors for their assembly into amyloid-like structures.     

Tumefactive multiple sclerosis requiring emergent biopsy and histological investigation to confirm the diagnosis: a case report

Introduction

Tumefactive multiple sclerosis is a demyelinating disease that demonstrates tumor-like features on magnetic resonance imaging. Although diagnostic challenges without biopsy have been tried by employing radiological studies and cerebrospinal fluid examinations, histological investigation is still necessary for certain diagnosis in some complicated cases.

Case presentation

A 37-year-old Asian man complaining of mild left leg motor weakness visited our clinic. Magnetic resonance imaging demonstrated high-signal lesions in bilateral occipital forceps majors, the left caudate head, and the left semicentral ovale on fluid-attenuated inversion recovery and T2-weighted imaging, and these lesions were enhanced by gadolinium-dimeglumin. Tumefactive multiple sclerosis was suspected because the enhancement indistinctly extended along the corpus callosum on magnetic resonance imaging and scintigraphy showed a low malignancy of the lesions. But oligoclonal bands were not detected in cerebrospinal fluid. In a few days, his symptoms fulminantly deteriorated with mental confusion and left hemiparesis, and steroid pulse therapy was performed. In spite of the treatment, follow-up magnetic resonance imaging showed enlargement of the lesions. Therefore, emergent biopsy was performed and finally led to the diagnosis of demyelinating disease. The enhanced lesion on magnetic resonance imaging disappeared after one month of prednisolone treatment, but mild disorientation and left hemiparesis remained as sequelae.

Conclusions

Fulminant aggravation of the disease can cause irreversible neurological deficits. Thus, an early decision to perform a biopsy is necessary for exact diagnosis and appropriate treatment if radiological studies and cerebrospinal fluid examinations cannot rule out the possibility of brain tumors.     

A mob of reps

Emerging structural results confirm that the large Rolling Circle Replication initiator superfamily is composed of two classes of proteins that are circularly permutated with respect to each other, as initially suggested by sequence analysis. The two classes are united by the same endonucleolytic mechanism and a conserved Mg(2+) binding site containing multiple histidine ligands unique to this superfamily.