Oxyenamides as Versatile Building Blocks for a Highly Stereoselective One-Pot Synthesis of the 1,3-Diamino-2-ol-Scaffold Containing Three Continuous Stereocenters.

A highly diastereoselective one-pot synthesis of the 1,3-diamino-2-alcohol unit bearing three continuous stereocenters is described. This method utilizes 2-oxyenamides as a novel type of building block for the rapid assembly of the 1,3-diamine scaffold containing an additional stereogenic oxygen functionality at the C2 position. A stereoselective preparation of the required (Z)-oxyenamides is reported as well.

Iron(III)-Mediated Oxysulfonylation of Enamides with Sodium and Lithium Sulfinates.

An iron-mediated vicinal difunctionalization of enamides and enecarbamates with sulfinic acid salts and alcohols is described. This reaction proceeds under mild conditions and furnishes the oxysulfonylated products in moderate to excellent yields. Moreover, the direct incorporation of sulfur dioxide into the sulfonylated products via organolithium chemistry has been achieved. The formed N-O-acetals are competent acylimine precursors. Their utilization as building blocks for the synthesis of biologically relevant ß-amidosulfones is described as well.

Manganese(iii) acetate-mediated direct C(sp2)-H-sulfonylation of enamides with sodium and lithium sulfinates.

A Mn(OAc)3 mediated oxidative C(sp2)-H sulfonylation of enamides and encarbamates with sodium and lithium sulfinates is reported. This operationally simple transformation provides a straightforward and highly stereoselective access to (E)-ß-amidovinyl sulfones in moderate to excellent yields. The reaction proceeds readily under mild conditions at room temperature and tolerates various sensitive functional groups. This process affords exclusively (E)-configurated ß-amidovinyl sulfones independent of the starting material configuration. Moreover, a direct transformation of organolithium reagents and sulfur dioxide into ß-amidovinyl sulfones is described.

An Enamide-Based Domino Reaction for a Highly Stereoselective Synthesis of Tetrahydropyrans.

A novel method for the highly stereoselective synthesis of tetrahydropyrans is reported. This domino reaction is based on a twofold addition of enamides to aldehydes followed by a subsequent cyclization and furnishes fully substituted tetrahydropyrans in high yields. Three new σ-bonds and five continuous stereogenic centers are formed in this one-pot process with a remarkable degree of diastereoselectivity. In most cases, the formation of only one out of 16 possible diastereomers is observed. Two different stereoisomers can be accessed in a controlled fashion starting either from an E- or a Z-configured enamide.

Bi(OTf)3-Catalyzed Diastereoselective One-Pot Synthesis of 1,3-Diamines with Three Continuous Stereogenic Centers.

A highly modular, diastereoselective one-pot-synthesis of 1,3-diamines with three contiguous stereogenic centers is reported. Our method provides a fast and efficient access to 1,2- anti-2,3- anti-1,3-diamines from three readily available building blocks. This Bi(OTf)3-catalyzed reaction is insensitive to air and moisture and can be performed on a multigram scale.

Enhancing the quantification of tissue sodium content by MRI: time-efficient sodium B1 mapping at clinical field strengths.

Tissue sodium content (TSC) is a sensitive measure of pathological changes and can be detected non-invasively by MRI. For the absolute quantification of TSC, B1 inhomogeneities must be corrected, which is not well established beyond research applications. An in-depth analysis of B1 mapping methods which are suitable for application in TSC quantification is presented. On the basis of these results, a method for simultaneous B1 mapping and imaging is proposed in order to enhance accuracy and to reduce measurement time at clinical field strengths. The B1 mapping techniques used were phase-sensitive (PS), Bloch-Siegert shift (BSS), double-angle (DAM) and actual flip-angle imaging (AFI) methods. Experimental and theoretical comparisons demonstrated that the PS technique yields the most accurate field profiles and exhibits the highest signal-to-noise ratio (SNR). Simultaneous B1 mapping and imaging was performed for the PS method, employing both degrees of freedom of the MR signal: the B1 field is encoded into signal phase and the amplitude provides the concentration information. In comparison with the more established DAM, a 13% higher SNR was obtained and field effects could be corrected more accurately without the need for additional measurement time. The protocol developed was applied to measure TSC in the healthy human head at an isotropic resolution of 4 mm. TSC was determined to be 35 ± 1 mM in white matter and 134 ± 3 mM in vitreous humor. By employing the proposed simultaneous characterization of the B1 field and acquisition of the spin density-weighted sodium signal, the accuracy of the non-invasive measurement of TSC is enhanced and the measurement time is reduced. This should allow (23)Na MRI to be better incorporated into clinical studies and routine.

Chlorine and sodium chemical shift imaging during acute stroke in a rat model at 9.4 Tesla.

OBJECT: A triple-resonant coil setup with an (1)H linear resonator and a double-tuned (23)Na/(35)Cl surface coil was used to study the evolution of T 2 (*) and M 0 for (35)Cl and (23)Na in a rat stroke model during the acute phase at 9.4 Tesla. MATERIALS AND METHODS: In vivo measurements were performed 1.5-7 h after onset of stroke (n = 2), ten days after onset (n = 1) and on a healthy control rat by a chemical shift imaging sequence. Measurement times were 15 min ((23)Na) and 57 min ((35)Cl). RESULTS: The relaxation times ten days after onset [T 2 (*) = 14.3 ± 1.8 ms ((23)Na) and 6.0 ± 1.3 ms ((35)Cl)] are clearly prolonged in comparison to a healthy rat [T 2 (*) = 4.8 ± 0.6 ms ((23)Na) and 2.1 ± 0.3 ms ((35)Cl)] and the acute phase [T 2 (*) = 5.6 ± 0.2 ms ((23)Na) and 1.9 ± 0.1 ms ((35)Cl)]. CONCLUSION: M 0 in the infarcted region clearly rises later and slower for chlorine than for sodium. To the best of our knowledge, these are the first combined proton, sodium, and chlorine measurements in an animal stroke model during the acute phase.

Influence of ANKK1 and DRD2 polymorphisms in response to haloperidol.

The present study explores whether ankyrin repeat and kinase domain containing 1 (ANKK1) and dopamine receptor D2 (DRD2) variants could predict efficacy and tolerability of haloperidol in the treatment of psychotic patients. We also attempted to replicate findings in a group of schizophrenic patients from the Clinical Antipsychotic Trials in Intervention Effectiveness (CATIE) study. Eighty-eight acutely psychotic patients were genotyped for 9 ANKK1 and 27 DRD2 SNPs. Treatment efficacy and tolerability were assessed using the Positive and Negative Symptoms Scale and the Udvalg for Kliniske Undersogelser side effects rating scales, respectively. Multivariate analyses were employed to test possible influences of single-nucleotide polymorphisms on clinical and safety variables. Analysis of haplotypes was also performed. Outcomes in the replication sample were response versus nonresponse and the presence versus absence of motor side effects at 1 month of treatment. rs2242592 within ANKK1 gene and rs1124493 within DRD2 gene were associated with clinical improvement (p = 0.008 and p = 0.001, respectively). Results were confirmed in the allelic analysis. Three haplotype blocks, one among ANKK1 and two among DRD2 gene were associated with better clinical improvement. Our results were not replicated in the CATIE sample, although rs11604671, which is in strong linkage disequilibrium with rs2242592, was associated with response in the replication sample. Our findings support a possible role of ANKK1 and DRD2 variability on haloperidol efficacy. However, due to the discrepancies between the results in the two samples, our results need further validation.

Shell Disease Syndrome Is Associated with Reduced and Shifted Epibacterial Diversity on the Carapace of the Crustacean Cancer pagurus.

Cancer pagurus is highly susceptible to shell disease syndrome. However, little is known about concomitant changes in the epibacterial community. We compared the bacterial communities of black spot affected and nonaffected areas of the carapace by amplicon sequencing of 16S rRNA genes and 16S rRNA. Within each spot, bacterial communities of affected areas were less diverse compared to communities from nonaffected areas. Communities of different affected spots were, however, more divergent from each other, compared to those of different nonaffected areas. This indicates a reduced and shifted microbial community composition caused by the black spot disease. Different communities found in black spots likely indicate different stages of the disease. In affected areas, Flavobacteriaceae rose to one of the most abundant and active families due to the increase of Aquimarina spp., suggesting a significant role in shell disease syndrome. We isolated 75 bacterial strains from diseased and healthy areas, which are primarily affiliated with Proteobacteria and Bacteroidetes, reflecting the dominant phyla detected by amplicon sequencing. The ability to degrade chitin was mainly found for Gammaproteobacteria and Aquimarina spp. within the Flavobacteriia, while the ability to use N-acetylglucosamine, the monomer of the polysaccharide chitin, was observed for most isolates, including many Alphaproteobacteria. One-third of the isolates, including most Aquimarina spp., showed antagonistic properties, indicating a high potential for interactions between the bacterial populations. The combination of bacterial community analysis and the physiological properties of the isolates provided insights into a functional complex epibacterial community on the carapace of C. pagurus. IMPORTANCE In recent years, shell disease syndrome has been detected for several ecologically and economically important crustacean species. Large proportions of populations are affected, e.g., >60% of the widely distributed species Cancer pagurus in different North Sea areas. Bacteria play a significant role in the development of different forms of shell disease, all characterized by microbial chitinolytic degradation of the outer shell. By comparing the bacterial communities of healthy and diseased areas of the shell of C. pagurus, we demonstrated that the disease causes a reduced bacterial diversity within affected areas, a phenomenon co-occurring also with many other diseases. Furthermore, the community composition dramatically changed with some taxa rising to high relative abundances and showing increased activity, indicating strong participation in shell disease. Characterization of bacterial isolates obtained from affected and nonaffected spots provided deeper insights into their physiological properties and thus the possible role within the microbiome.

M1-like, but not M0- or M2-like, macrophages, reduce RSV infection of primary bronchial epithelial cells in a media-dependent fashion.

Respiratory syncytial virus (RSV) is a common childhood infection that in young infants can progress into severe bronchiolitis and pneumonia. Disease pathogenesis results from both viral mediated and host immune processes of which alveolar macrophages play an important part. Here, we investigated the role of different types of alveolar macrophages on RSV infection using an in vitro co-culture model involving primary tissue-derived human bronchial epithelial cells (HBECs) and human blood monocyte-derived M0-like, M1-like, or M2-like macrophages. It was hypothesized that the in vitro model would recapitulate previous in vivo findings of a protective effect of macrophages against RSV infection. It was found that macrophages maintained their phenotype for the 72-hour co-culture time period and the bronchial epithelial cells were unaffected by the macrophage media. HBEC infection with RSV was decreased by M1-like macrophages but enhanced by M0- or M2-like macrophages. The medium used during the co-culture also impacted the outcome of the infection. This work demonstrates that alveolar macrophage phenotypes may have differential roles during epithelial RSV infection, and demonstrates that an in vitro co-culture model could be used to further investigate the roles of macrophages during bronchial viral infection.

Reconstitution of the ancestral glycoprotein of human endogenous retrovirus k and modulation of its functional activity by truncation of the cytoplasmic domain.

Endogenous retroviruses present in the human genome provide a rich record of ancient infections. All presently recognized elements, including the youngest and most intact proviruses of the human endogenous retrovirus K(HML-2) [HERV-K(HML-2)] family, have suffered postinsertional mutations during their time of chromosomal residence, and genes encoding the envelope glycoprotein (Env) have not been spared these mutations. In this study, we have, for the first time, reconstituted an authentic Env of a HERV-K(HML-2) provirus by back mutation of putative postinsertional amino acid changes of the protein encoded by HERV-K113. Aided by codon-optimized expression, we demonstrate that the reconstituted Env regained its ability to be incorporated into retroviral particles and to mediate entry. The original ancient HERV-K113 Env was synthesized as a moderately glycosylated gp95 precursor protein cleaved into surface and transmembrane (TM) subunits. Of the nine N-linked oligosaccharides, four are part of the TM subunit, contributing 15 kDa to its apparent molecular mass of 41 kDa. The carbohydrates, as well as the cytoplasmic tail, are critical for efficient intracellular trafficking, processing, stability, and particle incorporation. Whereas deletions of the carboxy-terminal 6 residues completely abrogated cleavage and virion association, more extensive truncations slightly enhanced incorporation but dramatically increased the ability to mediate entry of pseudotyped lentiviruses. Although the first HERV-K(HML-2) elements infected human ancestors about 30 million years ago, our findings indicate that their glycoproteins are in most respects remarkably similar to those of classical contemporary retroviruses and can still mediate efficient entry into mammalian cells.

Flow-enhanced off-resonance saturation for remote detection of iron-based contrast agents.

A switchable contrast mechanism, flow enhanced off-resonance saturation, is presented. This technique combines the effects of flow and off-resonance saturation for remote detection of iron oxide contrast agents incorporated into a vessel wall. Initial results from phantom experiments are presented and show the feasibility of this method. A specific saturation contrast could be observed. This contrast mechanism is highly dependent on field homogeneity and spectral selectivity of the off-resonance saturation pulses. The contrast scales directly with the pulse offset of the used saturation pulses, the flow velocity in the vessel, and the duration of the off-resonance saturation module prior to the imaging sequence. This technique has the potential to detect iron-loaded atherosclerotic plaques in future in vivo applications.

Hepatic Progenitor Specification from Pluripotent Stem Cells using a Defined Differentiation System.

Liver disease is an escalating global health issue. While liver transplantation is an effective mode of therapy, patient mortality has increased due to shortages in donor organ availability. Organ scarcity also affects the routine supply of human hepatocytes for basic research and the clinic. Therefore, the development of renewable sources of human liver progenitor cells is desirable and is the goal of this study. To be able to effectively generate and deploy human liver progenitors on a large scale, a reproducible hepatic progenitor differentiation system was developed. This protocol aids experimental reproducibility between users in a range of cell cultureware formats and permits differentiations using both, human embryonic and induced pluripotent stem cell lines. These are important advantages over current differentiation systems that will enhance the basic research and may pave the way towards clinical product development.

Gender Disparities in Authorships of Alzheimer's Disease and Dementia Research Articles.

BACKGROUND: Alzheimer's disease and dementia are an increasing burden affecting more than 50 million patients worldwide. Hence, research has increased significantly in recent decades. It is recognized that female authors are systematically underrepresented in research in general. OBJECTIVE: In this article, we examine gender disparities in academic research on dementia and Alzheimer's disease in the last decade. METHODS: 104,858 male and female authorships from 37,961 original research articles were analyzed. The global and country-specific distribution of women across first, co, and last authorships was determined with the inclusion of a citation and productivity analysis. RESULTS: 42.1% of all authorships and 50.2% of the first, 42.2% of the co, and 32.8% of the last authorships were held by women. Women were less commonly cited, published fewer articles and were also less likely to secure prestigious authorships in articles with multiple authors compared with men. Distinct differences were observed among the countries. CONCLUSION: Substantial growth in the number of prestigious female authorships has been observed to date and is predicted to continue in the future, with an emphasis on the progressive representation of women and a diminishing gender gap.

Sex Disparities in Ophthalmic Research: A Descriptive Bibliometric Study on Scientific Authorships.

IMPORTANCE: Previous studies examined sex distributions in different medical faculties, especially because increasingly more women entered the medical field in recent decades. Little is known at present about the female representation in ophthalmic research. OBJECTIVE: To clarify sex equalities in ophthalmic research by evaluating the representation of female authorships. DESIGN AND SETTING: This bibliometric analysis included original English-language articles published in ophthalmologic journals indexed in the Web of Science from January 2008 to August 2018. Authorships were assigned by sex according to first name. MAIN OUTCOMES AND MEASURES: Outcomes included the proportion of female authorships, odds ratios of women holding prestigious first and last authorships compared with men (measured by the prestige index), citation rates, a productivity analysis, and cross-journal and transnational female representation within ophthalmic research. The hypothesis was formulated during data collection. RESULTS: Bibliometric data were abstracted from 87 640 original articles published in 248 ophthalmologic journals. Of 344 433 total authorships, female scholars held 34.9% (120 305 of 344 433) of all authorships, 37.1% (24 924 of 67 226) of first authorships, 36.7% (77 295 of 210 372) of coauthorships, and 27.1% (18 086 of 66 835) of last authorships. The female-to-male odds ratio was 1.12 (95% CI, 1.10-1.14) for first authorships, 1.20 (95% CI, 1.18-1.22) for coauthorships, and 0.63 (95% CI, 0.62-0.64) for last authorships, with annual growth rates of 1.6% overall, 1.6% for first authorships, 1.3% for coauthorships, and 2.5% for last authorships. Women were underrepresented in prestigious authorships (prestige index = -0.22). The underrepresentation remains almost stable for articles with many authors (prestige index = -0.17 for articles with >9 authors per article). Articles with female key authors were cited slightly less frequently (95% CI for female vs male authors, 10.8-11.0 vs 11.5-11.7 citations/articles). Women published fewer papers than men (42.5% [n = 41 383]; women held 34.9% [n = 120 207] of the authorships), show cross-journal uniformity and differences among single countries (change in prestige index = 0.66 vs 1.96). Overall, 44.1% of female authorships and a sex-neutral distribution of prestigious authorships are prognosticated for 2028. CONCLUSIONS AND RELEVANCE: This algorithm analysis suggests the integration of women into ophthalmic research is average compared with other disciplines. A sex-specific gap exists for last authorship, suggesting career inequalities. With a growing number of female researchers in ophthalmology, the number of women in senior ranks may increase in the future.

Loss of ZnT8 function protects against diabetes by enhanced insulin secretion.

A rare loss-of-function allele p.Arg138* in SLC30A8 encoding the zinc transporter 8 (ZnT8), which is enriched in Western Finland, protects against type 2 diabetes (T2D). We recruited relatives of the identified carriers and showed that protection was associated with better insulin secretion due to enhanced glucose responsiveness and proinsulin conversion, particularly when compared with individuals matched for the genotype of a common T2D-risk allele in SLC30A8, p.Arg325. In genome-edited human induced pluripotent stem cell (iPSC)-derived ß-like cells, we establish that the p.Arg138* allele results in reduced SLC30A8 expression due to haploinsufficiency. In human ß cells, loss of SLC30A8 leads to increased glucose responsiveness and reduced KATP channel function similar to isolated islets from carriers of the T2D-protective allele p.Trp325. These data position ZnT8 as an appealing target for treatment aimed at maintaining insulin secretion capacity in T2D.

Stereoselective One-Pot Synthesis of Dihydropyrimido[2,1-a]isoindole-6(2H)-ones.

A diastereoselective one-pot synthesis of highly substituted dihydropyrimido[2,1-a]isoindole-6(2H)-ones containing three continuous stereocenters is reported. The reaction sequence is based on a hetero-Diels-Alder reaction between an enimide and a N-acylimine followed by an unprecedented Brønsted acid mediated rearrangement of an intermediate 5,6-dihydro-4H-1,3-oxazine to a pyrimido[2,1-a]isoindole.

Synthesis and crystal structures of two structurally related kryptoracemates.

Kryptoracemates are racemic compounds (pairs of enantiomers) that crystallize in Sohnke space groups (space groups that contain neither inversion centres nor mirror or glide planes nor rotoinversion axes). Thus, the two symmetry-independent molecules cannot be transformed into one another by any symmetry element present in the crystal structure. Usually, the conformation of the two enantiomers is rather similar if not identical. Sometimes, the two enantiomers are related by a pseudosymmetry element, which is often a pseudocentre of inversion, because inversion symmetry is thought to be favourable for crystal packing. We obtained crystals of two kryptoracemates of two very similar compounds differing in just one residue, namely rac-N-[(1S,2R,3S)-2-methyl-3-(5-methylfuran-2-yl)-1-phenyl-3-(pivalamido)propyl]benzamide, C27H32N2O3, (I), and rac-N-[(1S,2S,3R)-2-methyl-3-(5-methylfuran-2-yl)-1-phenyl-3-(propionamido)propyl]benzamide dichloromethane hemisolvate, C25H28N2O3·0.5CH2Cl2, (II). The crystals of both compounds contain both enantiomers of these chiral molecules. However, since the space groups [P212121 for (I) and P1 for (II)] contain neither inversion centres nor mirror or glide planes nor rotoinversion axes, there are both enantiomers in the asymmetric unit, which is a rather uncommon phenomenon. In addition, it is remarkable that (II) contains two pairs of enantiomers in the asymmetric unit. In the crystal, molecules are connected by intermolecular N-H...O hydrogen bonds to form chains or layered structures.

Prospective isolation of NKX2-1-expressing human lung progenitors derived from pluripotent stem cells.

It has been postulated that during human fetal development, all cells of the lung epithelium derive from embryonic, endodermal, NK2 homeobox 1-expressing (NKX2-1+) precursor cells. However, this hypothesis has not been formally tested owing to an inability to purify or track these progenitors for detailed characterization. Here we have engineered and developmentally differentiated NKX2-1GFP reporter pluripotent stem cells (PSCs) in vitro to generate and isolate human primordial lung progenitors that express NKX2-1 but are initially devoid of differentiated lung lineage markers. After sorting to purity, these primordial lung progenitors exhibited lung epithelial maturation. In the absence of mesenchymal coculture support, this NKX2-1+ population was able to generate epithelial-only spheroids in defined 3D cultures. Alternatively, when recombined with fetal mouse lung mesenchyme, the cells recapitulated epithelial-mesenchymal developing lung interactions. We imaged these progenitors in real time and performed time-series global transcriptomic profiling and single-cell RNA sequencing as they moved through the earliest moments of lung lineage specification. The profiles indicated that evolutionarily conserved, stage-dependent gene signatures of early lung development are expressed in primordial human lung progenitors and revealed a CD47hiCD26lo cell surface phenotype that allows their prospective isolation from untargeted, patient-specific PSCs for further in vitro differentiation and future applications in regenerative medicine.

The human endogenous retrovirus K(HML-2) has a broad envelope-mediated cellular tropism and is prone to inhibition at a post-entry, pre-integration step.

The HERV-K(HML-2) family is the most recent addition to the collection of human endogenous retroviruses. It comprises proviruses that encode functional proteins that can assemble into replication defective particles carrying the envelope protein. Using a reconstituted HERV-K113 envelope sequence, we have analyzed its ability to mediate entry into a set of 33 cell lines from 10 species. Of these, 30 were permissive, demonstrating an amphotropism consistent with a broad expression of receptor protein(s). In an initial effort to identify a receptor for HERV-K(HML-2) we investigated whether transferrin receptor 1 and hyaluronidase 2, known cellular receptors of the closely related betaretroviruses mouse mammary tumor virus (MMTV) and Jaagsiekte sheep retrovirus (JSRV), could facilitate HERV-K(HML-2) entry. However, neither of these proteins could serve as a receptor for HERV-K(HML-2). Moreover, during attempts to further characterize the tropism of HERV-K(HML-2), we identified a cellular activity that inhibits infection at a post-entry, pre-integration step.