Stereoselective Synthesis of the IDO Inhibitor Navoximod

A highly efficient asymmetric synthesis of the IDO inhibitor navoximod, featuring the stereoselective installation of two relative and two absolute stereocenters from an advanced racemic intermediate, is described. The stereocenters were set via a crystallization-induced dynamic resolution along with two selective ketone reductions: one via a biocatalytic ketoreductase transformation and one via substrate-controlled hydride delivery from LiAlH(Ot-Bu)₃. Following this strategy, navoximod was synthesized in 10 steps from 2-fluorobenzaldehyde and isolated in 23% overall yield with 99.7% ee and high purity.

Purification of a GalNAc-cluster-conjugated oligonucleotide by reversed-phase twin-column continuous chromatography

Multicolumn Countercurrent Solvent Gradient Purification (MCSGP) is a continuous chromatography technique used to maximize purification yields compared to traditional batch purification methods. Here we apply MCSGP for the reversed phase purification of a N-acetylgalactosamine (GalNAc)-cluster-conjugated DNA-LNA gapmer oligonucleotide therapeutic using a twin-column chromatography system. Based on a batch process as a starting point, MCSGP was designed, optimized and compared with the batch process regarding process performance and scale-up requirements. Product yields increased from 52.7% using batch chromatography to 91.5% using MCSGP, with purity, productivity, and buffer consumption otherwise comparable. In a manufacturing scenario, use of MCSGP would allow the downscaling of oligonucleotide synthesis by 42.5%, which would result in a significant cost reduction and increased throughput. Moreover, the equipment, chemicals and methodology used in MCSGP are analogous to a standard reversed phase purification allowing for a "like for like" transition to the upgraded MCSGP process.

Sustainability Challenges and Opportunities in Oligonucleotide Manufacturing

With a renewed and growing interest in therapeutic oligonucleotides across the pharmaceutical industry, pressure is increasing on drug developers to take more seriously the sustainability ramifications of this modality. With 12 oligonucleotide drugs reaching the market to date and hundreds more in clinical trials and preclinical development, the current state of the art in oligonucleotide production poses a waste and cost burden to manufacturers. Legacy technologies make use of large volumes of hazardous reagents and solvents, as well as energy-intensive processes in synthesis, purification, and isolation. In 2016, the American Chemical Society (ACS) Green Chemistry Institute Pharmaceutical Roundtable (GCIPR) identified the development of greener processes for oligonucleotide Active Pharmaceutical Ingredients (APIs) as a critical unmet need. As a result, the Roundtable formed a focus team with the remit of identifying green chemistry and engineering improvements that would make oligonucleotide production more sustainable. In this Perspective, we summarize the present challenges in oligonucleotide synthesis, purification, and isolation; highlight potential solutions; and encourage synergies between academia; contract research, development and manufacturing organizations; and the pharmaceutical industry. A critical part of our assessment includes Process Mass Intensity (PMI) data from multiple companies to provide preliminary baseline metrics for current oligonucleotide manufacturing processes.

Effect of Pretransplant Preconditioning by Whole Body Hyperthermia on Islet Graft Survival

Previous observations in heat-shocked pig islets revealed the ambivalent character of the stress response simultaneously inducing processes of protection and apoptosis. To clarify whether the proapoptotic character of the stress response is reduced in heat-exposed islets still embedded in their native environment, hyperthermia was performed in the present study either as whole body hyperthermia (WBH) prior to pancreas resection or as in vitro heat shock (HS) after isolation. HS (42°C/45 min) was induced in donors 12 h before isolation (WBH, n = 32) or in freshly isolated islets prior to 12 h of culture at 37°C (in vitro HS, n = 25). Islets continuously incubated at 37°C served as controls (n = 34). Proinflammatory treatment was performed with H2O2, DETA-NO, or a combination of IL-1β, TNF-α, and IFN-γ. Quality assessment included islet yield, viability staining, static glucose incubation, and nude mouse transplantation. WBH was significantly less effective than in vitro HS to induce HSP70 overexpression and to increase islet resistance against inflammatory mediators. Although characterized by an unaltered Bax to Bcl-2 ratio, islets subjected to WBH partially failed to restore sustained normoglycemia in diabetic nude mice. The inflammatory response observed in the pancreas of WBH-treated rats was associated with significantly reduced viability that seems to have a higher predictive value for posttransplant outcome compared to islet in vitro function or mitochondrial activity. In contrast, in vitro HS significantly decreased transcript levels of Bcl-2, but did not affect posttransplant function compared to sham-treated islets. These findings suggest that WBH is primarily associated with increased necrosis as a secondary tissue type-specific effect of pancreas damage while in vitro HS mainly induces apoptosis.

Polytwistane

Twistane, C10H16, is a classic D2-symmetric chiral hydrocarbon that has been studied for decades due to its fascinating stereochemical and thermodynamic properties. Here we propose and analyze in detail the contiguous linear extension of twistane with ethano (ethane-1,2-diyl) bridges to create a new chiral, C2-symmetric hydrocarbon nanotube called polytwistane. Polytwistane, (CH)n, has the same molecular formula as polyacetylene but is composed purely of C(sp(3))-H units, all of which are chemically equivalent. The polytwistane nanotube has the smallest inner diameter (2.6 Å) of hydrocarbons considered to date. A rigorous topological analysis of idealized polytwistane and a C236H242 prototype optimized by B3LYP density functional theory reveals that the polymer has a nonrepeating, alternating σ-helix, with an irrational periodicity parameter and an instantaneous rise (or lead) angle near 15 °. A theoretical analysis utilizing homodesmotic equations and explicit computations as high as CCSD(T)/cc-pVQZ yields the enthalpies of formation Delta(f)H(0)°(twistane) = -1.7 kcal mol(-1) and Delta(f)H(0)°(polytwistane) = +1.28 kcal (mol CH)(-1), demonstrating that the hypothetical formation of polytwistane from acetylene is highly exothermic. Hence, polytwistane is synthetically viable both on thermodynamic grounds and also because no obvious pathways exist for its rearrangement to lower-lying isomers. The present analysis should facilitate the preparation and characterization of this new chiral hydrocarbon nanotube.

Clinical Trial Educator program - a novel approach to accelerate enrollment in a phase III International Acute Coronary Syndrome Trial

BACKGROUND

The conduct of current cardiovascular outcome trials requires investigation of thousands of patients at hundreds of investigator sites. Such large trials are clinically and logistically highly demanding and often tend to finish with significant delays, consequently delaying patient access to new medicines.

PURPOSE

To address this issue, we designed and implemented a novel approach - a Clinical Trial Educator (CTE) program - to accelerate enrollment in the Thrombin-Receptor Antagonist for Clinical Event Reduction (TRA•CER) trial. This article analyzes the effect of this approach on the study milestones: patient recruitment, site start-up time, and recruitment rate.

METHODS

Scientifically qualified and specifically trained CTEs regularly visited TRA•CER investigator sites in 18 European countries where they trained and educated investigators and site personnel to support them address recruitment challenges. Patient recruitment was assessed in absolute numbers and as recruitment rates, both in relation to CTE site visits.

RESULTS

CTEs performed 2184 visits at 373 European TRA•CER sites (out of 921 global sites). Of sites visited by a CTE, significantly less remained without enrolling any patient than of sites not visited by a CTE (5.9% vs. 15.3%; p < 0.001). Sites visited within 30 days after initiation showed a significantly shortened median time to recruitment of the first patient (28 vs. 59 days with visits ≤30 or >30 days after initiation; p < 0.001). Mean patient recruitment rates were significantly higher at visited than at not-visited sites (1.13 vs. 0.89 patients per site per month, p < 0.001) and significantly increased after the first CTE site visit (from 0.70 to 1.17 patients per site per month; p < 0.001). Finally, there were fewer low-recruiting sites and more high-recruiting sites among the CTE-visited sites compared to the not-visited sites, and the mean recruitment rate at high-recruiting sites visited by CTEs was significantly higher than at high-recruiting sites without CTE visits (2.07 vs. 1.64 patients per site per month; p < 0.01).

LIMITATIONS

The possibility for selection bias is inherent to this post hoc analysis of a nonrandomized data set. The European focus of the CTE program described here might add some geographical bias. Also, other activities such as investigator meetings conducted in parallel with CTE activities might have partly masked the results of our analysis. Finally, the analysis is limited to recruitment-related parameters, and the aspect of cost-effectiveness has not been quantitatively assessed.

CONCLUSION

We found a significant positive association between CTE site visits and the assessed recruitment-related study milestones in the TRA•CER trial, and enrollment finished ahead of plan. We propose that a CTE program could efficiently accelerate enrollment in other clinical trials and therapeutic areas and could contribute to shortening patient access time to novel and potential lifesaving treatments in cardiovascular medicine and beyond.

Transcriptome analysis of ozone-responsive genes in leaves of European beech (Fagus sylvatica L.)

Suppression subtractive hybridization (SSH) was performed to isolate cDNAs representing genes that are differentially expressed in leaves of Fagus sylvatica upon ozone exposure. 1248 expressed sequence tags (ESTs) were obtained from 2 subtractive libraries containing early and late ozone-responsive genes. Sequences of 1139 clones (91 %) matched the EBI/NCBI database entries. For 578 clones, no putative function could be assigned. Most abundant transcripts were O-methyltransferases, representing 7 % of all sequenced clones. ESTs were organized into 12 functional categories according to the MIPS database. Among them, 12 % (early)/15 % (late) were associated with disease and defence, 19/11 % with cell structure, 4/10 % with signal transduction, and 9/6 % with transcription. The expression pattern of selected ESTs (ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit [rbcS], WRKY-type transcription factor, ultraviolet-B-repressible protein, aquaporine, glutathione S-transferase, catalase, caffeic acid O-methyltransferase, and pathogenesis-related protein 1 [PR1]) was analysed by quantitative real-time RT-PCR (qRT-PCR) which confirmed changed transcript levels upon ozone treatment of European beech saplings. The ESTs characterized will contribute to a better understanding of forest tree genomics and also to a comparison of ozone-responsive genes in woody and herbaceous plants.

Timing of hyperthermic preconditioning affects islet resistance against inflammation

BACKGROUND

Heat exposure of isolated islets enhances resistance against inflammation but decreases islet graft function. In contrast, donor preconditioning by whole-body hyperthermia increases islet ischemic tolerance and improves viability of pancreatic isografts. This study aimed to compare yield, viability, and inflammatory resistance of rat islets subjected to heat shock prior to (pre-HS) or after isolation (post-HS).

METHODS

Islets were isolated as previously described. HS (42 degrees C/45 min) was induced 12 hours before islet isolation (pre-HS, n = 31) or in freshly isolated islets prior to 12 hours of recovery at 37 degrees C (post-HS, n = 12). Islets continuously incubated at 37 degrees C served as controls (n = 33). Proinflammatory treatment included incubation with 0.05 mmol/L H(2)O(2), 1.0 mmol/L DETA-NO or cytokines (interleukin-1beta + tumor necrosis factoralpha + interferongamma).

RESULTS

Purified islet yield was 1200 +/- 80 IEQ in unconditioned donors (n = 45) and 980 +/- 80 IEQ after pre-HS (ns). Islet viability was not affected by post-HS, but the glucose stimulation index (P < 0.001, P < 0.01) and formazan production (P < 0.05) were significantly lower compared to pre-HS or sham treatment. The expression of heat shock protein HSP70 in pre-HS islets was slightly higher compared to controls (ns) but lower compared to post-HS islets (P < 0.05), correlating with the resistance against H(2)O(2) and DETA-NO compared to post-HS islets (P < 0.05) or controls (ns). Cytokines did not affect mitochondrial formazan production.

CONCLUSIONS

The findings indicate that hyperthermic islet treatment is less harmful if performed in the native pancreatic environment. This beneficial effect is associated with a decreased HSP70 expression resulting in a reduced resistance against inflammatory mechanisms.

The STAR/GSG family protein rSLM-2 regulates the selection of alternative splice sites

We identified the rat Sam68-like mammalian protein (rSLM-2), a member of the STAR (signal transduction and activation of RNA) protein family as a novel splicing regulatory protein. Using the yeast two-hybrid system, coimmunoprecipitations, and pull-down assays, we demonstrate that rSLM-2 interacts with various proteins involved in the regulation of alternative splicing, among them the serine/arginine-rich protein SRp30c, the splicing-associated factor YT521-B and the scaffold attachment factor B. rSLM-2 can influence the splicing pattern of the CD44v5, human transformer-2beta and tau minigenes in cotransfection experiments. This effect can be reversed by rSLM-2-interacting proteins. Employing rSLM-2 deletion variants, gel mobility shift assays, and linker scan mutations of the CD44 minigene, we show that the rSLM-2-dependent inclusion of exon v5 of the CD44 pre-mRNA is dependent on a short purine-rich sequence. Because the related protein of rSLM-2, Sam68, is believed to play a role as an adapter protein during signal transduction, we postulate that rSLM-2 is a link between signal transduction pathways and pre-mRNA processing.

Obesity and hypertestosteronaemia are independently and synergistically associated with elevated insulin concentrations and dyslipidaemia in pre-menopausal women

The association of obesity and hypertestosteronaemia with elevated insulin concentration and dyslipidaemia was studied in 15 non-obese and 15 obese, hypertestosteronaemia patients; 14 non-obese and 10 obese, normotestosteronaemic subjects served as controls. Data were subjected to multivariate analysis. Enhanced body mass index (BMI kg/m2) resulted in a significant elevation of basal insulin (b-Ins), glucose-stimulated (delta) insulin (del-Ins), triglycerides (TG), very low density lipoprotein (VLDL), low density lipoprotein (LDL), and LDL/high density lipoprotein (HDL) ratio, and in a significant reduction of HDL. Furthermore, it was shown that BMI was positively correlated with TG, VLDL, LDL and LDH/HLD ratio, and negatively correlated with HDL in the normotestosteronaemic groups. Hypertestosteronaemia was associated with a significant increase of del-Ins, VLDL and LDL/HDL ratio, and with a significant decrease of HDL concentration. Testosterone was directly associated with del-Ins and LDL/HDL ratio, and inversely related to HDL in the non-obese groups. Summation effects of obesity and hypertestosteronaemia were found for del-Ins and VLDL. The data suggest that obesity and hypertestosteronaemia are independently and jointly associated with insulin resistance and dyslipidaemia, indicating an increased risk for coronary heart disease. The highest risk rate was found in obese hypertestosteronaemic patients. Serum testosterone may be a useful marker in detecting metabolic disorders connected with cardiovascular risk.

Immunological mechanisms giving rise to latency of herpes simplex virus in the spinal ganglia of the mouse

In the model of genital herpes simplex virus (HSV)-infection of mice, early latency could be induced by passive immunization with HSV-specific antibodies and, to a lesser degree, by adoptive transfer of immune lymphocytes prepared from spleen and draining lymph nodes of genitally infected syngeneic mice. Conversely, spontaneously occurring latency was inhibited by treatment of the animals with cyclophosphamide (Cph) and, to a lesser degree, with cyclosporin A (CyA). Whereas the effect of CyA could be compensated by passively administered HSV-specific antibodies, that of Cph could not. Apparently specific antibodies cooperate with a non-specific proliferating cell type, probably macrophages and/or NK-cells, as could be demonstrated by significantly reduced antibody effect in silica-treated mice. Moreover, F(ab)2 fragments, in contrast to complete antibody molecules, were inactive. HSV-specific antibodies and also immune lymphocytes had little effect on virus production in the mucous membranes, immune lymphocytes being at least as active as antibodies. It is therefore not probable that latency is induced by attenuation of the peripheral disease. It can rather be concluded that the neuron itself is the target for the action of specific antibodies, cooperating in turn with macrophages and/or NK cells.

Pathogenesis of genital herpes simplex virus infection in mice. III. Comparison of the virulence of wild and mutant strains

This study was undertaken to establish the role of virulence of various herpes simplex virus (HSV) strains in the course of infection when applying the virus to the non-injured mucous membranes of mice. Wild-type HSV-type 1 (HSV-1) strains with marked differences in their neurovirulence following intracerebral inoculation showed minor differences in virulence after vaginal inoculation, but essentially their neurovirulence in cerebral infection corresponded to their virulence on the mucous membranes. In comparison with the wild-types, however, there were pronounced differences among syn- and TK--mutants of HSV-1 and HSV-2 in the degree of virulence at different sites in the course of virus infection. Whereas syn-mutants proved avirulent on the mucous membranes but not in neural tissues, TK--mutants were avirulent both on mucous membranes and in neural tissues. Ts-mutants of HSV-2 were not found to establish themselves when administered to the non-injured mucous membranes, nor did they induce neutralizing antibodies, but a later challenge with the wild-type virus at the same site lead only to an attenuated course of infection.

Effects of genetic resistance against Herpes simplex virus in vaginally infected mice

In order to take the conditions of natural Herpes simplex virus (HSV) infection into consideration, the genetic resistance of C57-Bl mice, which was established by intraperitoneal HSV-1 infection [Lopez, 1975], was investigated in vaginally infected mice. The course of infection in the mucous membranes did not differ in sensitive (NMRI) and resistant (C57-Bl) mice: both number of takes and virus elimination from the vagina were equal, and no difference in viral titer produced in the vagina was detected. Viral titer in the productively infected lumbosacral ganglia, however, was less in the resistant mice. An experiment with foot-pad-infected mice confirmed that the number of productively infected ganglia was reduced in resistant mice, and contralateral ganglia were infected only in the sensitive mouse strain. In spite of this, the number of latently infected animals did not vary significantly in the mouse strains. Higher activity of defense mechanisms in resistant mice, apparently localized in the ganglia, resulted in reduced lethality. As to the mechanisms of the resistance, neither antibody nor interferon response were enhanced in C57-Bl mice, but resistance was abolished by depletion of several cellular functions, i.e., lymphocytes by cyclophosphamide or X-rays, macrophages by silica or macrophage-antiserum, and M-cells by 89Sr.