Synthesis of novel hybrids of pyrazole and coumarin as dual inhibitors of COX-2 and 5-LOX

In our previous study, we designed a series of pyrazole derivatives as novel COX-2 inhibitors. In order to obtain novel dual inhibitors of COX-2 and 5-LOX, herein we designed and synthesized 20 compounds by hybridizing pyrazole with substituted coumarin who was reported to exhibit 5-LOX inhibition to select potent compounds using adequate biological trials sequentially including selective inhibition of COX-2 and 5-LOX, anti-proliferation in vitro, cells apoptosis and cell cycle. Among them, the most potent compound 11g (IC₅₀ = 0.23 ± 0.16 μM for COX-2, IC₅₀ = 0.87 ± 0.07 μM for 5-LOX, IC₅₀ = 4.48 ± 0.57 μM against A549) showed preliminary superiority compared with the positive controls Celecoxib (IC₅₀ = 0.41 ± 0.28 μM for COX-2, IC₅₀ = 7.68 ± 0.55 μM against A549) and Zileuton (IC₅₀ = 1.35 ± 0.24 μM for 5-LOX). Further investigation confirmed that 11g could induce human non-small cell lung cancer A549 cells apoptosis and arrest the cell cycle at G2 phase in a dose-dependent manner. Our study might contribute to COX-2, 5-LOX dual inhibitors thus exploit promising novel cancer prevention agents.     

Endogenous osteopontin induces myocardial CCL5 and MMP-2 activation that contributes to inflammation and cardiac remodeling in a mouse model of chronic Chagas heart disease

Cardiac dysfunction with progressive inflammation and fibrosis is a hallmark of Chagas disease caused by persistent Trypanosoma cruzi infection. Osteopontin (OPN) is a pro-inflammatory cytokine that orchestrates mechanisms controlling cell recruitment and cardiac architecture. Our main goal was to study the role of endogenous OPN as a modulator of myocardial CCL5 chemokine and MMP-2 metalloproteinase, and its pathological impact in a murine model of Chagas heart disease. Wild-type (WT) and OPN-deficient (spp1 ?/?) mice were parasite-infected (Brazil strain) for 100 days. Both groups developed chronic myocarditis with similar parasite burden and survival rates. However, spp1 ?/? infection showed lower heart-to-body ratio (P < 0.01) as well as reduced inflammatory pathology (P < 0.05), CCL5 expression (P < 0.05), myocyte size (P < 0.05) and fibrosis (P < 0.01) in cardiac tissues. Intense OPN labeling was observed in inflammatory cells recruited to infected heart (P < 0.05). Plasma concentration of MMP-2 was higher (P < 0.05) in infected WT than in spp1 ?/? mice. Coincidently, specific immunostaining revealed increased gelatinase expression (P < 0.01) and activity (P < 0.05) in the inflamed hearts from T. cruzi WT mice, but not in their spp1 ?/? littermates. CCL5 and MMP-2 induction occurred preferentially (P < 0.01) in WT heart-invading CD8⁺ T cells and was mediated via phospho-JNK MAPK signaling. Heart levels of OPN, CCL5 and MMP-2 correlated (P < 0.01) with collagen accumulation in the infected WT group only. Endogenous OPN emerges as a key player in the pathogenesis of chronic Chagas heart disease, through the upregulation of myocardial CCL5/MMP-2 expression and activities resulting in pro-inflammatory and pro-hypertrophic events, cardiac remodeling and interstitial fibrosis.     

Synthesis and biological evaluation of N9-cis-cyclobutylpurine derivatives for use as cyclin-dependent kinase (CDK) inhibitors

A novel 6-aminopurine scaffold bearing an N9-cis-cyclobutyl moiety was designed using structure-based molecular design based on two known CDK inhibitors, dinaciclib and Cmpd-27. A series of novel 6-aminopurine compounds was prepared for structure–activity relationship (SAR) studies of CDK2 and CDK5 inhibitors. Among the compounds synthesized, compound 8l displayed potent CDK2 and CDK5 inhibitory activities with low nanomolar ranges (IC₅₀ = 2.1 and 4.8 nM, respectively) and showed moderate cytotoxicity in HCT116 colon cancer and MCF7 breast cancer cell lines. Here, we report the synthesis and evaluation of novel 6-aminopurine derivatives and present molecular docking models of compound 81 with CDK2 and CDK5.     

C-Terminal proline-rich sequence broadens the optimal temperature and pH ranges of recombinant xylanase from Geobacillus thermodenitrificans C5

Efficient utilization of hemicellulose entails high catalytic capacity containing xylanases. In this study, proline rich sequence was fused together with a C-terminal of xylanase gene from Geobacillus thermodenitrificans C5 and designated as GthC5ProXyl. Both GthC5Xyl and GthC5ProXyl were expressed in Escherichia coli BL21 host in order to determine effect of this modification. The C-terminal oligopeptide had noteworthy effects and instantaneously extended the optimal temperature and pH ranges and progressed the specific activity of GthC5Xyl. Compared with GthC5Xyl, GthC5ProXyl revealed improved specific activity, a higher temperature (70 °C versus 60 °C) and pH (8 versus 6) optimum, with broad ranges of temperature and pH (60–80 °C and 6.0–9.0 versus 40–60 °C and 5.0–8.0, respectively). The modified enzyme retained more than 80% activity after incubating in xylan for 3 h at 80 °C as compared to wild −type with only 45% residual activity. Our study demonstrated that proper introduction of proline residues on C-terminal surface of xylanase family might be very effective in improvement of enzyme thermostability. Moreover, this study reveals an engineering strategy to improve the catalytic performance of enzymes.     

Traveling behavior of a termite in tunnels with different curvatures and base surface roughness

This study focused on understanding the termite traveling behavior. Artificial tunnels with different curvatures and base surface roughness were constructed. Each tunnel was 50 mm in length, with widths of W (W = 2, 3, or 4 mm). The distance between the two ends of the tunnel was D (D = 20, 30, 40, or 50 mm). A higher value of D means a lower curvature. The roughness, R (R = 60, 120, 240 and ∞), was generated by uniformly sanding the substrate with a sanding machine. A higher R value means a finer base surface. The symbol ∞ represents a smooth surface. Time (τ) taken by a termite to pass through the tunnel was measured. τ was longer in tunnels with a smooth surface compared with the tunnels with a rough surface. When W = 2, there was no effect of the roughness on speed. This is because the narrow tunnel width diluted the effects of the smoothness of the surface. When W = 3, τ was statistically shorter for R = 240, than for R = 60 and 120. This suggests that an appropriate surface roughness could positively contribute to the traveling speed.     

MRI Texture Analysis Reflects Histopathology Parameters in Thyroid Cancer – A First Preliminary Study

OBJECT: Thyroid cancer represents the most frequent malignancy of the endocrine system with an increasing incidence worldwide. Novel imaging techniques are able to further characterize tumors and even predict histopathology features. Texture analysis is an emergent imaging technique to extract extensive data from an radiology images. The present study was therefore conducted to identify possible associations between texture analysis and histopathology parameters in thyroid cancer. METHODS: The radiological database was retrospectively reviewed for thyroid carcinoma. Overall, 13 patients (3 females, 23.1%) with a mean age of 61.6 years were identified. The MaZda program was used for texture analysis. The T1-precontrast and T2-weighted images were analyzed and overall 279 texture feature for each sequence was investigated. For every patient cell count, Ki67-index and p53 count were investigated. RESULTS: Several significant correlations between texture features and histopathology were identified. Regarding T1-weighted images, S(0;1)Sum Averg correlated the most with cell count (r = 0.82). An inverse correlations with S(5;0)AngScMom, S(5;0)DifVarnc S(5;0), DiffEntrp and GrNonZeros (r = ?0.69, ?0.66, ?0.69 and ?0.63, respectively) was also identified. For T2-weighted images, Variance with r = 0.63 was the highest coefficient, WavEnLL_S3 correlated inversely with cell count (r = ?0.57). WavEnLL_S2 derived from T1-weighted images was the highest coefficient r = ?0.80, S(0;5)SumVarnc was positively with r = 0.74. Regarding T2-weighted images WavEnHL_s-1 was inverse correlated with Ki67 index (r = ?0.77). S(1;0)Correlat was with r = 0.75 the best correlation with Ki67 index. For T1-weighed images S(5;0)SumofSqs was the best with r = 0.65 with p53 count. For T2-weighted images S(1;?1)SumEntrp was the inverse correlation with r = ?0.72, whereas S(0;4)AngScMom correlated positively with r = 0.63. CONCLUSIONS: MRI texture analysis derived from conventional sequences reflects histopathology features in thyroid cancer. This technique might be a novel noninvasive modality to further characterize thyroid cancer in clinical oncology.     

3D-QSAR (CoMFA,CoMSIA), molecular docking and molecular dynamics simulations study of 6-aryl-5-cyano-pyrimidine derivatives to explore the structure requirements of LSD1 inhibitors

Recently, Histone Lysine Specific Demethylase 1 (LSD1) was regarded as a promising anticancer target for the novel drug discovery. And several small molecules as LSD1 inhibitors in different structures have been reported. In this work, we carried out a molecular modeling study on the 6-aryl-5-cyano-pyrimidine fragment LSD1 inhibitors using three-dimensional quantitative structure–activity relationship (3D-QSAR), molecular docking and molecular dynamics simulations. Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were used to generate 3D-QSAR models. The results show that the best CoMFA model has q² = 0.802, r²_ncv = 0.979, and the best CoMSIA model has q² = 0.799, r²_ncv = 0.982. The electrostatic, hydrophobic and H-bond donor fields play important roles in the models. Molecular docking studies predict the binding mode and the interactions between the ligand and the receptor protein. Molecular dynamics simulations results reveal that the complex of the ligand and the receptor protein are stable at 300 K. All the results can provide us more useful information for our further drug design.     

Design and synthesis of new triazoles linked to xanthotoxin for potent and highly selective anti-gastric cancer agents

Two series of xanthotoxin-triazole derivatives were designed, synthesized, and studied for their antiproliferative properties. The in vitro cytotoxicity of the compounds in the AGS cancer cell line and the L02 normal cell line was evaluated via MTT assay. Among the synthesized compounds, 9-((1-(4-(trifluoromethyl)phenyl)-1H-1,2,3-triazol-4-yl)methoxy)-7H-furo[3,2-g]chromen-7-one (6p) was found to have the greatest antiproliferative activity against AGS cells (IC₅₀ = 7.5 μM) and showed better activity than the lead compound (xanthotoxin, IC₅₀ > 100 μM) and the reference drug (5-fluorouracil, IC₅₀ = 29.6 μM) did. The IC₅₀ value of 6p in L02 cells was 13.3 times higher than that in the AGS cells. Therefore, the compound exhibited better therapeutic activity and specificity compared with the positive control 5-fluorouracil. Cell cycle analysis revealed that compound 6p inhibited cell growth via the induction of S/G2 phase arrest in AGS cells. Compound 6p was identified as a promising lead compound for the further development and identification of 1,2,3-triazole-based anticancer agents.     

Genetic diversity and population structure of a protected species: Polygala tenuifolia Willd

Polygala tenuifolia Willd. is an important protected species used in traditional Chinese medicine. In the present study, amplified fragment length polymorphism (AFLP) markers were employed to characterize the genetic diversity in wild and cultivated P. tenuifolia populations. Twelve primer combinations of AFLP produced 310 unambiguous and repetitious bands. Among these bands, 261 (84.2%) were polymorphic. The genetic diversity was high at the species level: percentage of polymorphic loci (PPL) = 84.2%, Nei's gene diversity (h) = 0.3296 and Shannon's information index (I) = 0.4822. Between the two populations, the genetic differentiation of 0.1250 was low and the gene flow was relatively high, at 3.4989. The wild population (PPL = 81.9%, h = 0.3154, I = 0.4635) showed a higher genetic diversity level than the cultivated population (PPL = 63.9%, h = 0.2507, I = 0.3688). The results suggest that the major factors threatening the persistence of P. tenuifolia resources are ecological and human factors rather than genetic. These results will assist with the design of conservation and management programs, such as in natural habitat conservation, setting the excavation time interval for resource regeneration and the substitution of cultivated for wild plants.     

Antileishmanial potential of fused 5-(pyrazin-2-yl)-4H-1,2,4-triazole-3-thiols: Synthesis,biological evaluations and computational studies

A series of newer 1,2,4-triazole-3-thiol derivatives 5(a–m) and 6(a–i) containing a triazole fused with pyrazine moiety of pharmacological significance have been synthesized. All the synthesized compounds were screened for their in vitro antileishmanial and antioxidant activities. Compounds 5f (IC₅₀ = 79.0 µM) and 6f (IC₅₀ = 79.0 µM) were shown significant antileishmanial activity when compared with standard sodium stibogluconate (IC₅₀ = 490.0 µM). Compounds 5b (IC₅₀ = 13.96 µM) and 6b (IC₅₀ = 13.96 µM) showed significant antioxidant activity. After performing molecular docking study and analyzing overall binding modes it was found that the synthesized compounds had potential to inhibit L. donovani pteridine reductase 1 enzyme. In silico ADME and metabolic site prediction studies were also held out to set an effective lead candidate for the future antileishmanial and antibacterial drug discovery initiatives.     

Preliminary SAR and biological evaluation of antitubercular triazolothiadiazine derivatives against drug-susceptible and drug-resistant Mtb strains

Following up the SAR study of triazolothiadiazoles for their antitubercular activities targeting Mt SD in our previous study, on the principle of scaffold hopping, the C3 and C6 positions of triazolothiadiazine were examined systematically to define a preliminary structure–activity relationship (SAR) with respect to biological activity. This study herein highlights the potential of two highly potent advanced leads 6c-3, 6g-3 and several other compounds with comparable potencies as promising new candidates for the treatment of TB (6c-3, MIC-H37Rv = 0.25 μg/mL; MIC-MDRTB = 2.0 μg/mL; MIC-RDRTB = 0.25 μg/mL; Mt SD-IC₅₀ = 86.39 μg/mL; and 6g-3, MIC-H37Rv = 1.0 μg/mL; MIC-MDRTB = 4.0 μg/mL; MIC-RDRTB = 2.0 μg/mL; Mt SD-IC₅₀ = 73.57 μg/mL). Compounds 6c-3 and 6g-3 possessed a para-nitro phenyl at the 6 position showed low Vero and HepG2 cells toxicity, turning out to be two excellent lead candidates for preclinical trials. In addition, in vitro Mt SD inhibitory assay indicates that Mt SD is at least one of the targets for their antitubercular activity. Thus, they may turn out to be promising multidrug-resistance-reversing agents.     

Study of antileishmanial activity of 2-aminobenzoyl amino acid hydrazides and their quinazoline derivatives

A new small library of 2-aminobenzoyl amino acid hydrazide derivatives and quinazolinones derivatives was synthesized and fully characterized by IR, NMR, and elemental analysis. The activity of the prepared compounds on the growth of Leishmania aethiopica promastigotes was evaluated. 2-Benzoyl amino acid hydrazide showed higher inhibitory effect than the quinazoline counterpart. The in vitro antipromastigote activity demonstrated that compounds 2a, 2b, 2f and 4a had IC₅₀ better than standard drug miltefosine and comparable activity to amphotericin B deoxycholate, which indicates their high antileishmanial activity against Leishmania. aethiopica. Among the prepared compounds; 2-amino-N-(6-hydrazinyl-6-oxohexyl)benzamide 2f (IC₅₀ = 0.051 μM) has the best activity, 154 folds more active than reference standard drug miltefosine (IC₅₀ = 7.832 μM), and half fold the activity of amphotericin B (IC₅₀ = 0.035 μM). In addition, this compound was safe and well tolerated by experimental animals orally up to 250 mg/kg and parenterally up to 100 mg/kg.     

Design,synthesis, X-ray studies,and biological evaluation of novel macrocyclic HIV-1 protease inhibitors involving the P1′-P2′ ligands

Design, synthesis, and evaluation of a new class of HIV-1 protease inhibitors containing diverse flexible macrocyclic P1′-P2′ tethers are reported. Inhibitor 5a with a pyrrolidinone-derived macrocycle exhibited favorable enzyme inhibitory and antiviral activity (K_i = 13.2 nM, IC₅₀ = 22 nM). Further incorporation of heteroatoms in the macrocyclic skeleton provided macrocyclic inhibitors 5m and 5o. These compounds showed excellent HIV-1 protease inhibitory (K_i = 62 pM and 14 pM, respectively) and antiviral activity (IC₅₀ = 5.3 nM and 2.0 nM, respectively). Inhibitor 5o also remained highly potent against a DRV-resistant HIV-1 variant.     

Arterial Phase with CAIPIRINHA-Dixon-TWIST (CDT)–Volume-Interpolated Breath-Hold Examination (VIBE) in Detecting Hepatic Metastases

PURPOSE: To evaluate lesion enhancement performance of Multi-Arterial CAIPIRINHA-Dixon-TWIST–Volume-Interpolated Breath-Hold Examination (MA-CDT-VIBE) for the detection of hepatic metastases. MATERIALS AND METHODS: Thirty-one patients with suspicious hepatic metastases were enrolled in this retrospective study. Two independent radiologists scored visualization of each lesion on a scale of 1 (poor visualization) to 11 (excellent visualization) on 11 sets of images. These included 6 hepatic arterial sub-phases acquired in one breath-hold, 1 series of the mean of 6 hepatic arterial sub-phases, 3 subtracted arterial sub-phases, and 1 portal venous phase. The phases with good (score 8–10) and excellent (score 11) lesion visualization were identified, and the number of lesions seen on each of these phases was compared to the number of lesions that was seen best on the equivalent-to-conventional single arterial phase as well as to those that were see best on the mean of 6 hepatic arterial sub-phases. Inter-reader agreement was also calculated. RESULTS: The MA-CDT-VIBE was successfully acquired in 25 patients with hypervascular metastases (96 lesions) and 6 patients with hypovascular metastases (13 lesions). In case of hypervascular metastases, the 6th/6 arterial sub-phase had excellent lesion visualization (sore of 11) in 56 and 44 lesions for the 2 readers, respectively. Good lesion visualization (score of 8-10) was recorded in 5th/6 arterial subphases, in 81 and 67 lesions for the 2 readers, respectively. In case of hypovascular metastases, the portal venous phase had excellent lesion visualization (sore of 11) in all 13 lesions for the 2 readers. Good lesion visualization (score of 8–10) was recorded in 12 and 13 lesions on the 5th/6 and 6th/6 arterial subphases, respectively. More hypervascular lesions scored good (score of 8–10) and excellent (score of 11) on the 5th/6 and 6th/6 phases of MA-CDT-VIBE compared with the equivalent-to-conventional single arterial phase (3rd/6) and the set with mean of 6 hepatic arterial sub-phases. The results were statistically significant (t test, P < .0001). Inter-reader agreement was good for hypervascular lesions (kappa = 0.627, P < .0001) and excellent for hypovascular lesions (kappa = 1.0, P < .0001), respectively. CONCLUSIONS: The MA-CDT-VIBE improves lesion conspicuity by providing a wide observation window for hypervascular lesions. For hypovascular lesions, the advantage of multiple arterial sub-phases over the portal venous phase is not apparent.     

Evaluation of effect of high frequency electromagnetic field on growth and antibiotic sensitivity of bacteria

This study was aimed to evaluate the impact of high frequency electromagnetic fields (HF-EMF at 900 and 1800 MHz) on DNA, growth rate and antibiotic susceptibility of S. aureus, S. epidermidis, and P. aeruginosa. In this study, bacteria were exposed to 900 and 1800 MHz for 2 h and then inoculated to new medium when their growth rate and antibiotic susceptibility were evaluated. Results for the study of bacterial DNA unsuccessful to appearance any difference exposed and non-exposed S. aureus and S. epidermidis. Exposure of S. epidermidis and S. aureus to electromagnetic fields mostly produced no statistically significant decrease in bacterial growth, except for S. aureus when exposure to 900 MHz at 12 h. Exposure of P. aeruginosa to electromagnetic fields at 900 MHz however, lead to a significant reduction in growth rate, while 1800 MHz had insignificant effect. With the exception of S. aureus, treated with amoxicillin (30 µg) and exposed to electromagnetic fields, radiation treatment had no significant effect on bacterial sensitivity to antibiotics.     

Effect of stand age on soil microbial community structure in wolfberry (Lycium barbarum L.) fields

Soil physicochemical properties and microbes are essential in terrestrial ecosystems through their role in cycling mineral compounds and decomposing organic matter. This study examined the effect of stand age on soil physicochemical properties and microbial community structure in wolfberry (Lycium barbarum L.) fields, in order to reveal the mechanism of soil degradation due to long-term stand of L. barbarum. The objective of the study was achieved by phospholipid fatty acid (PLFA) biomarker analysis of soil samples from L. barbarum fields in Zhongning County, Ningxia Province—the origin of L. barbarum. Five stand ages of L. barbarum were selected, < 1, 3, 6, 9, and 12 years (three plots each). The results showed that soil bulk density increased slightly with increasing stand age, while no clear trend was observed in soil pH or total salinity. As the stand age increased, soil organic matter and nutrients first increased before decreasing, with the highest levels being found in year 9. There was an amazing variety of PLFA biomarkers in soil samples at different stand ages. The average concentrations of total, bacterial, fungal, and actinomycete PLFAs in the surface soil initially decreased and then increased, before decreasing with the stand age in summer. The PLFA concentrations of major microbial groups were highest in year 9, with the total PLFA concentrations being 32.97% and 10.67% higher than those in years < 1 and 12, respectively. Higher microbial PLFA concentrations were detected in summer relative to autumn and in the surface relative to the subsurface soil. The highest ratios of Gram-positive to Gram-negative bacterial (G^?/G⁺) and fungal to bacterial (F/B) PLFAs were obtained in year 6, on average 76.09% higher than those at the other four stand ages. The soil environment was most stable in year 6, with no differences between other stand ages. Therefore, soil microbial community structure was strongly influenced by the stand age in year 6 only. The effect of stand age on soil G^?/G⁺ and microbial community structure varied with season and depth; there was little effect for F/B in the 20–40 cm soil layer. Principal component analysis revealed no correlations between microbial PLFA concentrations and total salinity in the soil; negative correlations were noted between soil pH and F/B in summer (P < 0.01), as well as between soil pH and fungal PLFA in autumn (P < 0.05). Moreover, microbial PLFA concentrations were correlated with soil organic matter (mean R = 0.7725), total nitrogen (mean R = 0.8296), total phosphorus (mean R = 0.8175), available nitrogen (mean R = 0.7458), and available phosphorus (mean R = 0.7795) (P < 0.01). On the whole, the soil ecosystem was most stable in year 6, while soil organic matter, nutrients, and microbial PLFA concentrations were maximal in year 9; thereafter, soil fertility indices and microbial concentrations decreased and soil quality declined gradually as the stand age increased. Therefore, farmers should reduce the application rate of fertilizers, especially compound or mixed fertilizers, in L. barbarum fields; organic or bacterial manure can be applied increasingly to improve the soil environment and prolong the economic life of L. barbarum.     

Effect of oregano essential oil and carvacrol on Cryptosporidium parvum infectivity in HCT-8 cells

Cryptosporidium parvum is the second leading cause of persistent diarrhea among children in low-resource settings. This study examined the effect of oregano essential oil (OEO) and carvacrol (CV) on inhibition of C. parvum infectivity in vitro. HCT-8 cells were seeded (1 × 10⁶) in 96-well microtiter plates until confluency. Cell viability and infectivity were assessed by seeding HCT-8 cell monolayers with C. parvum oocysts (1 × 10⁴) in two modalities: 1) 4 h co-culture with bioactive (0–250 μg/mL) followed by washing and incubation (48 h, 37 °C, 5% CO₂) in bioactive-free media; and 2) 4 h co-culture of C. parvum oocysts followed by washing and treatment with bioactive (0–250 μg/mL) during 48-h incubation. Cell viability was tested using Live/Dead? assay whereas infectivity was measured using C. parvum-specific antibody staining via immunofluorescence detection. Loss of cell viability was observed starting at 125 μg/mL and 60 μg/mL for OEO and CV, respectively. Neither OEO nor CV modulated the invasion of C. parvum sporozoites in HCT-8 cells. Treatment with bioactive after invasion reduced relative C. parvum infectivity in a dose-dependent manner to 55.6 ± 10.4% and 45.8 ± 4.1% at 60 and 30 μg/mL of OEO and CV, respectively. OEO and CV are potential bioactives to counteract C. parvum infection in children.     

‘Candidatus Dichloromethanomonas elyunquensis’ gen. nov., sp. nov., a dichloromethane-degrading anaerobe of the Peptococcaceae family

Taxonomic assignments of anaerobic dichloromethane (DCM)-degrading bacteria remain poorly constrained but are important for understanding the microbial diversity of organisms contributing to DCM turnover in environmental systems. We describe the taxonomic classification of a novel DCM degrader in consortium RM obtained from pristine Rio Mameyes sediment. Phylogenetic analysis of full-length 16S rRNA gene sequences demonstrated that the DCM degrader was most closely related to members of the genera Dehalobacter and Syntrophobotulus, but sequence similarities did not exceed 94% and 93%, respectively. Genome-aggregate average amino acid identities against Peptococcaceae members did not exceed 66%, suggesting that the DCM degrader does not affiliate with any described genus. Phylogenetic analysis of conserved single-copy functional genes supported that the DCM degrader represents a novel clade. Growth strictly depended on the presence of DCM, which was consumed at a rate of 160 ± 3 μmol L^?1 d^?1. The DCM degrader attained 5.25 × 10⁷ ± 1.0 × 10⁷ cells per μmol DCM consumed. Fluorescence in situ hybridization revealed rod-shaped cells 4 ± 0.8 μm long and 0.4 ± 0.1 μm wide. Based on the unique phylogenetic, genomic, and physiological characteristics, we propose that the DCM degrader represents a new genus and species, ‘Candidatus Dichloromethanomonas elyunquensis’.     

Design,synthesis, and X-ray structural studies of BACE-1 inhibitors containing substituted 2-oxopiperazines as P1′-P2′ ligands

We report the design and synthesis of a series of BACE1 inhibitors incorporating mono- and bicyclic 6-substituted 2-oxopiperazines as novel P1′ and P2′ ligands and isophthalamide derivative as P2-P3 ligands. Among mono-substituted 2-oxopiperazines, inhibitor 5a with N-benzyl-2-oxopiperazine and isophthalamide showed potent BACE1 inhibitory activity (K_i = 2 nM). Inhibitor 5g, with N-benzyl-2-oxopiperazine and substituted indole-derived P2-ligand showed a reduction in potency. The X-ray crystal structure of 5g-bound BACE1 was determined and used to design a set of disubstituted 2-oxopiperazines and bicyclic derivatives that were subsequently investigated. Inhibitor 6j with an oxazolidinone derivative showed a BACE1 inhibitory activity of 23 nM and cellular EC₅₀ of 80 nM.     

Contrast Enhancement on Cone-Beam Breast-CT for Discrimination of Breast Cancer Immunohistochemical Subtypes

PURPOSE: To evaluate whether contrast enhancement on cone-beam breast-CT (CBBCT) could aid in discrimination of breast cancer subtypes and receptor status. METHODS: This study included female patients age >40 years with malignant breast lesions identified on contrast-enhanced CBBCT. Contrast enhancement of malignant breast lesions was standardized to breast fat tissue contrast enhancement. All breast lesions were approved via image-guided biopsy or surgery. Immunohistochemical staining was conducted for expression of estrogen (ER), progesterone (PR), human epidermal growth factor receptor-2 (HER2) and Ki-67 index. Contrast enhancement of breast lesions was correlated with immunohistochemical breast cancer subtypes (Luminal A, Luminal B, HER2 positive, triple negative), receptor status and Ki-67 expression. RESULTS: Highest contrast enhancement was seen for Luminal A lesions (93.6 HU) compared to Luminal B lesions (47.6 HU, P = .002), HER2 positive lesions (83.5 HU, P = .359) and triple negative lesions (45.3 HU, P = .005). Contrast enhancement of HER2 positive lesions was higher than Luminal B lesions (P = .044) and triple negative lesions (P = .039). No significant difference was evident between Luminal B and triple negative lesions (P = .439). Lesions with high Ki-67 index showed lower contrast enhancement than those with low Ki-67 index (P = .0043). ER, PR and HER2 positive lesions demonstrated higher contrast enhancement than their receptor negative counterparts, although differences did not reach statistical significance (P = .1714; P = .3603; P = .2166). CONCLUSIONS: Contrast enhancement of malignant breast lesions on CBBCT correlates with immunohistochemical subtype and proliferative potential. Thereby, CBBCT might aid in selecting individualized treatment strategies for breast cancer patients based on pre-operative imaging.