Search

A safe, effective, and reversible nonhormonal male contraceptive drug is greatly needed for male contraception as well as for circumventing the side effects of female hormonal contraceptives. Phosducin-like 2 (PDCL2) is a testis-specific phosphoprotein in mice and humans. We recently found that male PDCL2 knockout mice are sterile due to globozoospermia caused by impaired sperm head formation, indicating that PDCL2 is a potential target for male contraception. Herein, our study for the first time developed a biophysical assay for PDCL2 allowing us to screen a series of small molecules, to study structure-activity relationships, and to discover two PDCL2 binders with novel chemical structure.To identify a PDCL2 ligand for therapeutic male contraception, we performed DNA-encoded chemical library (DECL) screening and off-DNA hit validation using a unique affinity selection mass spectrometry (ASMS) biophysical profiling strategy.We employed the screening process of DECL, which contains billions of chemically unique DNA-barcoded compounds generated through individual sequences of reactions and different combinations of functionalized building blocks. The structures of the PDCL2 binders are proposed based on the sequencing analysis of the DNA barcode attached to each individual DECL compound. The proposed structure is synthesized through multistep reactions. To confirm and determine binding affinity between the DECL identified molecules and PDCL2, we developed an ASMS assay that incorporates liquid chromatography with tandem mass spectrometry (LC-MS/MS).After a screening process of PDCL2 with DECLs containing 440 billion compounds, we identified a series of hits. The selected compounds were synthesized as off-DNA small molecules, characterized by spectroscopy data, and subjected to our ASMS/LC-MS/MS binding assay. By this assay, we discovered two novel compounds, which showed good binding affinity for PDCL2 in comparison to other molecules generated in our laboratory and which were further confirmed by a thermal shift assay.With the ASMS/LC-MS/MS assay developed in this paper, we successfully discovered a PDCL2 ligand that warrants further development as a male contraceptive.

Xanthomonas oryzae pv. oryzicola (Xoc) depends on its type III secretion system (T3SS) to translocate type III secreted effectors (T3SEs), including transcription activator-like effectors (TALEs) and non-transcription activator-like effectors (non-TALEs), into host cells. T3SEs can promote the colonization of Xoc and contribute to virulence by manipulating host cell physiology. We annotated 25 genes encoding non-TALEs in Xoc strain GX01, an isolate from Guangxi in the South China's rice growing region. Through systematic mutagenesis of non-TALEs, we found that xopN, the virulence contribution of which was previously unknown for Xoc, significantly contributes to the virulence of Xoc GX01, as does avrBs2.

Significance SARS-CoV-2 has had a crippling impact on human life globally. Vaccine development has been used as a first-line strategy for COVID-19 prevention and mitigation; however, small-molecule drugs are still vitally needed to extend treatment options. Traditional screening methods for identifying biologically active small molecules are sluggish and often sample an insufficient number of compounds to identify suitable hits. Here, we applied a screening method known as DNA-encoded chemistry technology (DEC-Tec) to screen billions of compounds against a critical viral protein, Mpro. In rapid fashion, we identified the compound CDD-1713 as a potent and selective Mpro inhibitor. This study illuminates DEC-Tec as a highly expeditious strategy toward generating small molecules against critical targets of infectious agents., Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed more than 4 million humans globally, but there is no bona fide Food and Drug Administration–approved drug-like molecule to impede the COVID-19 pandemic. The sluggish pace of traditional therapeutic discovery is poorly suited to producing targeted treatments against rapidly evolving viruses. Here, we used an affinity-based screen of 4 billion DNA-encoded molecules en masse to identify a potent class of virus-specific inhibitors of the SARS-CoV-2 main protease (Mpro) without extensive and time-consuming medicinal chemistry. CDD-1714, the initial three-building-block screening hit (molecular weight [MW] = 542.5 g/mol), was a potent inhibitor (inhibition constant [Ki] = 20 nM). CDD-1713, a smaller two-building-block analog (MW = 353.3 g/mol) of CDD-1714, is a reversible covalent inhibitor of Mpro (Ki = 45 nM) that binds in the protease pocket, has specificity over human proteases, and shows in vitro efficacy in a SARS-CoV-2 infectivity model. Subsequently, key regions of CDD-1713 that were necessary for inhibitory activity were identified and a potent (Ki = 37 nM), smaller (MW = 323.4 g/mol), and metabolically more stable analog (CDD-1976) was generated. Thus, screening of DNA-encoded chemical libraries can accelerate the discovery of efficacious drug-like inhibitors of emerging viral disease targets.

Two key factors bear on reaction rates for the conjugate addition of alkenyl boronic acids to heteroaryl-appended enones: the proximity of inductively electron-withdrawing heteroatoms to the site of bond formation and the resonance contribution of available heteroatom lone pairs to stabilize the developing positive charge at the enone β-position. For the former, the closer the heteroatom is to the enone β-carbon, the faster the reaction. For the latter, greater resonance stabilization of the benzylic cationic charge accelerates the reaction. Thus, reaction rates are increased by the closer proximity of inductive electron-withdrawing elements, but if resonance effects are involved, then increased rates are observed with electron-donating ability. Evidence for these trends in isomeric substrates is presented, and the application of these insights has allowed for reaction conditions that provide improved reactivity with previously problematic substrates.

Background Xanthomonas oryzae (Xo) is one of the important pathogenic bacterial groups affecting rice production. Its pathovars Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc) cause bacterial blight and bacterial leaf streak in rice, respectively. Xo infects host plants by relying mainly on its transcription activator-like effectors (TALEs) that bind to host DNA targets, named effector binding elements (EBEs), and induce the expression of downstream major susceptibility genes. Blocking TALE binding to EBE could increase rice resistance to the corresponding Xo. Findings We used CRISPR/Cas9 to edit the EBEs of three major susceptibility genes (OsSWEET11, OsSWEET14 and OsSULTR3;6) in the rice varieties Guihong 1 and Zhonghua 11. Both varieties have a natural one-base mutation in the EBE of another major susceptibility gene (OsSWEET13) which is not induced by the corresponding TALE. Two rice lines GT0105 (from Guihong 1) and ZT0918 (from Zhonghua 11) with target mutations and transgene-free were obtained and showed significantly enhanced resistance to the tested strains of Xoo and Xoc. Furthermore, under simulated field conditions, the morphology and other agronomic traits of GT0105 and ZT0918 were basically the same as those of the wild types. Conclusions In this study, we first reported that the engineering rice lines obtained by editing the promoters of susceptibility genes are resistant to Xoo and Xoc, and their original agronomic traits are not affected.

HSP110 functions to protect cells, tissues, and organs from noxious conditions. Vasectomy induces apoptosis in the testis; however, little is known about the reason leading to this outcome. The aim of the present study was to evaluate the expression and function of HSP110 in mouse testis after vasectomy. Following bilateral vasectomy, we used fluorescent Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) to detect apoptosis, Western blotting and immunohistochemistry to examine HSP110 expression and localization. Serum antisperm antibody (AsAb) and testosterone were measured by Enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay, respectively. Expression of endoplasmic reticulum stress (ERS) sensors and downstream signaling components was measured by Reverse Transcription-Polymerase Chain Reaction (RT-PCR), and the phosphorylation of eIF2α and JNK was detected by Western blotting. Vasectomy induced morphologic changes, increased apoptosis in the testis, increased serum AsAb, and decreased testosterone levels. After vasectomy, ORP150 mRNA level was increased first and then decreased, Bcl-2 was decreased, and the expression of HSPA4l, GRP78, GADD153, PERK, ATF6, IRE-1, XBP-1s, Bax, Bak, and caspases and the phosphorylation of eIF2α and JNK were increased. We present that an ER stress-mediated pathway is activated and involved in apoptosis in the testis after vasectomy. HSPA4l and ORP150 may play important roles in maintaining the normal structure and function of testis.

Enantiodivergent catalyst systems were developed using metals with different ionic radii and a multifunctional brucine diol (BD) ligand. The catalytic use of purported 1:1 Cu-BD complexes in the 1,3-dipolar cycloaddition of azomethine ylides with chalcones resulted in the selective formation of endo-pyrrolidines in 87–96% ees with an absolute stereochemical outcome of (2R,3S,4R,5S). In contrast, an opposite absolute stereochemical outcome was observed by using the catalysts derived from Ag(I) salts and BD. The demonstration of enantiodivergent approaches to a broad class of substrates/reaction types underlines their synthetic value in asymmetric synthesis.

Background Rhein (1,8-dihydroxy-3-carboxyanthraquinone) is a monomer of anthraquinone derivatives mainly found in Polygonaceae plants such as Rhubarb, and Cuspidatum, widely used in the traditional Chinese medicine with many pharmacological activities, such as antitumor, anti-inflammatory and antifibrotic effects, and regulation of glucose and lipid metabolism. Objective To conclude the role of Rhein in cancer control and its mechanisms for its futher deep research and potential clinical application. Method All kinds of reports previously related to Rhein from PubMed datebase were collected, integrated and analyzed. Results Rhein could control many cancer cells by regulating their proliferation and apoptosis, invasion and migration, especially intrinsic and extrinsic apoptosis pathways induced by Rhein plays the core role in cancer control. For good inhibitory role in NF-κB pathway, the Ras/Raf/MEK (MAPK)/ERK and PTEN/PI3K/AKT/mTOR pathways are other two key pathways regulated by Rhein with its role in antiphosphorylation of ERK, PI3K and AKT to control many cancers' development which frequently dysregulated in cancer, involved in the activation, proliferation, invasion, and migration of cancer cells. Conclusion Rhein is a potential cancer treatment agent.

Luminal fluid reabsorption plays a fundamental role in male fertility. We demonstrated that the ubiquitous GPCR signaling proteins Gq and β-arrestin-1 are essential for fluid reabsorption because they mediate coupling between an orphan receptor ADGRG2 (GPR64) and the ion channel CFTR. A reduction in protein level or deficiency of ADGRG2, Gq or β-arrestin-1 in a mouse model led to an imbalance in pH homeostasis in the efferent ductules due to decreased constitutive CFTR currents. Efferent ductule dysfunction was rescued by the specific activation of another GPCR, AGTR2. Further mechanistic analysis revealed that β-arrestin-1 acts as a scaffold for ADGRG2/CFTR complex formation in apical membranes, whereas specific residues of ADGRG2 confer coupling specificity for different G protein subtypes, this specificity is critical for male fertility. Therefore, manipulation of the signaling components of the ADGRG2-Gq/β-arrestin-1/CFTR complex by small molecules may be an effective therapeutic strategy for male infertility.

The Gram-negative bacterium Xanthomonas oryzae pv. oryzicola (Xoc) is the causal agent of rice bacterial leaf streak (BLS), one of the most destructive diseases of rice (Oryza sativa L.) that is the important staple crop. Xoc can invade host leaves via stomata and wounds and its type three secretion system (T3SS) is pivotal to its pathogenic lifestyle. In this study, using a novel dual RNA-seq approach, we examined transcriptomes of rice and Xoc in samples inoculated with wild type Xoc GX01 and its T3SS defective strain (T3SD), to investigate the global transcriptional changes in both organisms. Compared with T3SD strain, rice inoculated with wild type Xoc GX01 resulted in significant expression changes of a series of plant defence related genes, including ones altered in plant signalling pathway, and downregulated in phenylalanine metabolism, flavonoid and momilactone biosynthesis, suggesting repression of plant defence response and reduction in both callose deposition and phytoalexin accumulation. Also, some known transcription activator-like effector (TALE) targets were induced by Xoc GX01, e.g. OsSultr3;6 which contributes to rice susceptibility. Some cell elongation related genes, including several expansin genes, were induced by GX01 too, suggesting that Xoc may exploit this pathway to weaken cell wall strength, beneficial for bacterial infection. On the other hand, compared with wild type, the T3SD strain transcriptome in planta was characterized by downregulation of ATP, protein and polysaccharide synthesis, and upregulation of antioxidation and detoxification related genes, revealing that T3SD strain faced serious starvation and oxidation stresses in planta without a functional T3SS. In addition, comparative global transcript profiles of Xoc in planta and in medium revealed an upregulation of virulence factor synthesis and secretion in planta in favour of bacterial infection. Collectively, this study provides a comprehensive representation of cross talk between the host and bacterial pathogen, revealing insights into the Xoc-rice pathogenic dynamic and reveals novel strategies exploited by this important pathogen to cause disease.

Treatment of the title compounds with NEt3 generates novel vinyl anion synthons which undergo aldol reaction with aldehydes to give aldol-type allene structures.

Enantiodivergent catalyst systems were developed using metals with different ionic radii and a multifunctional brucine diol (BD) ligand. The catalytic use of purported 1:1 Cu-BD complexes in the 1,3-dipolar cycloaddition of azomethine ylides with chalcones resulted in the selective formation of endo-pyrrolidines in 87–96% ees with an absolute stereochemical outcome of (2R,3S,4R,5S). In contrast, an opposite absolute stereochemical outcome was observed by using the catalysts derived from Ag(I) salts and BD. The demonstration of enantiodivergent approaches to a broad class of substrates/reaction types underlines their synthetic value in asymmetric synthesis.

Stereodivergent catalytic asymmetric conjugate reactions of glycine (ket)imines with nitroalkenes have been achieved using various chiral catalyst systems derived from a multidentate amino alcohol (1). The stepwise nature of the [3 + 2] cycloaddition reactions of N-metalated azomethine ylides has also been demonstrated by highly enantio- and diastereoselective syntheses of exo-5 and endo-8 from the respective syn-4 and anti-7 conjugate addition products in a one-pot tandem fashion.

Morphology and micro-structure of the pyrite whiskers synthesized by hydrothermal process were systematically observed by using transmission electron microscope. The results indicated that whiskers revealed various morphologies, including smooth, rough and branched. Combined with the hydrothermal reaction conditions, the causes of whiskers morphology diversity is: straight smooth whiskers grow in the condition of stable concentration, temperature, and interface state; whiskers with rough surface and complex morphology grow in the condition of unstable concentration, temperature, and interface state; the same level branching structure rotation was the result of hydrothermal disturbance; nano-crystalline grains formed after the main growth of the whiskers.

The testis is major male gonad responsible for spermatogenesis and steroidogenesis. Much knowledge is still remained to be learned about the control of these events. In this study, we performed a comprehensive bioinformatics analysis on 1,196 mouse testis proteins screened from public protein database. Integrated function and pathway analysis were performed through Database for Annotation, Visualization and Integrated Discovery (DAVID) and ingenuity Pathway Analysis (IPA), and significant features were clustered. Protein membrane organization and gene density on chromosomes were analyzed and discussed. The enriched bioinformatics analysis could provide clues and basis to the development of diagnostic markers and therapeutic targets for infertility and male contraception.

The Morita-Baylis-Hillman (MBH) reaction of aryl vinyl ketones has been achieved for the first time through cooperative catalysis of proline and brucine N-oxide. A unique mode of activation of the aldehydes through proline iminium intermediates has been identified as a key reaction parameter for the successful MBH reaction of aryl vinyl ketones. The reaction pathways leading to 1:2 MBH products under typical nucleophilic catalysis conditions were investigated. A systematic study revealed two different reaction pathways leading to 1:2 MBH products: (1) the second reaction of normal MBH products with aryl vinyl ketones as a dominating reaction pathway at the initial stage of the reaction, and (2) the aldol reaction pathway of Rauhut-Currier products with aldehydes (auto-catalysis by alcohol products) as a major reaction pathway during the later stage of reaction.

Spectral clustering algorithms have attracted considerable attention in recent years. However, a problem still exists. These approaches are too slow to scale to large problem sizes. This paper aims at addressing a coarsening algorithm for efficiently grouping large-dataset objects within multi-band images. The coarsening algorithm is based on random graph theory, and it proceeds by combining local homogeneous resolution cells into a set of irregular blocks so the spectral clustering algorithms run efficiently at some coarse level. For multi-band images, we formulate the similarity between pairwise objects as a novel normalized expression and reformulate it in the form of a matrix so that we can implement our algorithm in a few lines using IDL. Finally, we illustrate two examples in agriculture which confirm the effectiveness and efficiency of the proposed algorithm.

Background Bilateral chronic rhinosinusitis (CRS), with unilateral nasal polyps (NPs), is a good model for study, being characterized by a similar inflammatory reaction and environment in both nasal cavities of a subject, although NPs exist in only one nasal cavity. It may be feasible to identify specific pathological factors responsible for the disparities by comparing the differences between the nasal cavities. Methods In patients with bilateral CRS, polyp tissue and the middle turbinate tissue on the side of the polyp were examined and compared with contralateral nonpolyp middle turbinate tissue. Tissue and serum-specific immunoglobulin E (sIgE) levels were measured, and eosinophilic infiltration, interleukin (IL)-5 and IL-1-beta were assessed also in the polyp tissue. Results The presence of allergic symptoms correlated well with a positive serum CAP test but poorly with a positive tissue CAP test. There were no obvious differences between tissue sIgE levels on the NP side compared with the nonpolyp side. Tissue eosinophilia was a general characteristic of NPs, whether there was allergy or not. IL-5 and IL-1-beta levels were elevated in NPs, regardless of allergy. There were no differences in the specimens on the nonpolyp side between allergy and nonallergy groups. Conclusion With this model, we have more precise, however, not new results. Localized allergic reaction is not a major factor for the development of a unilateral polyp. Inflammation associated with eosinophilic infiltration and the presence of proinflammatory cytokines, including IL-5 and IL-1-beta, are more important in the pathogenesis of NPs than the allergic reaction.

Enantio- and diastereodivergent approaches to pyrrolidines are described by using catalyst- and substrate-controlled reaction pathways. A concerted endo-selective [3 + 2]-cycloaddition pathway is developed for the reaction of methyl imino ester, whereas endo-pyrrolidines with an opposite absolute stereochemical outcome are prepared by using the stepwise reaction pathway of tert-butyl imino ester. The development of catalyst- and substrate-controlled stereodivergent approaches highlights the inherent substrate–catalyst interactions in the [3 + 2]-cycloaddition reactions of metalated azomethine ylides.

Traffic congestion can be classified into recurrent congestion and anomalous congestion. Anomalous congestion is probably caused by emergencies, which refer to events that go against historical normal states. Therefore, anomalous congestion can be detected by analyzing the differences between massive historical traffic data and real-time data. It is of great significance to actively detect and quickly deal with anomalous congestion. However, processing massive historical data in standalone mode cannot complete the whole process within the tolerable time. In view of existing problems in the detection of anomalous congestion, a distributed mining algorithm was proposed. The real-time data perceived by microwave radar and massive historical data sets were adopted to define the quantitative expression of traffic abnormal degree, meanwhile consideration was given to technical links such as data cleaning, cumulative effect of time and update of historical data. Results of the experiment show that the proposed algorithm has satisfactory identification effects.

AIM To identify a panel of biomarkers that can distinguish between non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH), and explore molecular mechanism involved in the process of developing NASH from NAFLD. METHODS Biomarkers may differ during stages of NAFLD. Urine and blood were obtained from non-diabetic subjects with NAFLD and steatosis, with normal liver function (n = 33), from patients with NASH, with abnormal liver function (n = 45), and from healthy age and sex-matched controls (n = 30). Samples were subjected to metabolomic analysis to identify potential non-invasive biomarkers. Differences in urinary metabolic profiles were analyzed using liquid chromatography tandem mass spectrometry with principal component analysis and partial least squares-discriminate analysis. RESULTS Compared with NAFLD patients, patients with NASH had abnormal liver function and high serum lipid concentrations. Urinary metabonomics found differences in 31 metabolites between these two groups, including differences in nucleic acids and amino acids. Pathway analysis based on overlapping metabolites showed that pathways of energy and amino acid metabolism, as well as the pentose phosphate pathway, were closely associated with pathological processes in NAFLD and NASH. CONCLUSION These findings suggested that a panel of biomarkers could distinguish between NAFLD and NASH, and could help to determine the molecular mechanism involved in the process of developing NASH from NAFLD. Urinary biomarkers may be diagnostic in these patients and could be used to assess responses to therapeutic interventions.

Yīn-Chén-Hāo decoction (YCHD) is a traditional Chinese medicine formula composed of capillaris (Artemisia capillaris), gardenia (Gardenia jasminoides), and rhubarb (Rheum rhabarbarum) that is used for the treatment of damp-heat jaundice. In modern clinics, YCHD is mostly used for hepatic diseases. This review summarizes the biological activities of YCHD and its medical applications. The main active compounds of YCHD are chlorogenic acid, rhein, geniposide, emodin, and scoparone. The pharmacological actions of YCHD include inhibition of hepatic steatosis, apoptosis, necrosis, anti-inflammation, and immune regulation. YCHD could be developed as a new therapeutic strategy for the treatment of hepatic diseases.

Glycyrrhizic acid (GA) is a triterpene glycoside found in the roots of licorice plants (Glycyrrhiza glabra). GA is the most important active ingredient in the licorice root, and possesses a wide range of pharmacological and biological activities. GA coupled with glycyrrhetinic acid and 18-beta-glycyrrhetic acid was developed in China or Japan as an anti-inflammatory, antiviral, and antiallergic drug for liver disease. This review summarizes the current biological activities of GA and its medical applications in liver diseases. The pharmacological actions of GA include inhibition of hepatic apoptosis and necrosis; anti-inflammatory and immune regulatory actions; antiviral effects; and antitumor effects. This paper will be a useful reference for physicians and biologists researching GA and will open the door to novel agents in drug discovery and development from Chinese herbs. With additional research, GA may be more widely used in the treatment of liver diseases or other conditions.

C-type lysozyme genes (Lyzls) belong to the class of lysozymes and are highly expressed in the testis and epididymis. The members Lyzl4 and Spaca3 have been reported to play a role in sperm-egg binding and fertilisation in mice. However, the function of the remaining two mouse c-type lysozyme genes, Lyzl1 and Lyzl6, is still not clear. In the present study, we analysed the tissue expression and androgen-dependent expression of mouse c-type lysozyme genes and the possible contribution of human recombinant LYZL6 (rLYZL6) to immunity. The expression of Lyzls was detected by RT-PCR, Western blots, immunohistochemistry and immunofluorescence. The bacteriolytic activity of rLYZL6 was analysed by a colony-forming assay. In mice, the expression of Lyzl genes was mainly in the testis and epididymis in a developmentally regulated manner and androgen- or testicular factor-regulated manner. Immunodetection revealed the presence of LYZL6 protein in primary spermatocytes and round spermatids of the testis and on the post-acrosomal area and midpiece of mature epididymal spermatozoa. The rLYZL6 protein exhibited antibacterial activity. From the results, Lyzls may play a role in mitochondrial function of spermatozoa and LYZL6 may contribute to the innate immunity of the male genital tract.

The elimination pathway of stereochemically defined β-halovinyl ketones has been investigated using a mild base, NEt3, leading to the formation of allenyl ketones and propargyl ketones. A preferential α-vinyl enolization of (E)-β-chlorovinyl ketones has been observed where a nonplanar s-cis conformation is proposed as a dominant conformation as opposed to a planar s-cis conformation of (Z)-β-chlorovinyl ketones. Other eliminative pathways, such as concerted syn- and anti-E2 as well as γ-deprotonation, are excluded on the basis of the deuterium isotope studies. The synthetic utility of the elimination reaction of β-chlorovinyl ketones was further demonstrated for a one-pot synthesis of 2,5-disubstituted furans in the presence of 1 mol % CuCl.

The elimination pathway of stereochemically defined β-halovinyl ketones has been investigated using a mild base, NEt(3), leading to the formation of allenyl ketones and propargyl ketones. A preferential α-vinyl enolization of (E)-β-chlorovinyl ketones has been observed where a nonplanar s-cis conformation is proposed as a dominant conformation as opposed to a planar s-cis conformation of (Z)-β-chlorovinyl ketones. Other eliminative pathways, such as concerted syn- and anti-E2 as well as γ-deprotonation, are excluded on the basis of the deuterium isotope studies. The synthetic utility of the elimination reaction of β-chlorovinyl ketones was further demonstrated for a one-pot synthesis of 2,5-disubstituted furans in the presence of 1 mol % CuCl.

Glycine imine (I) undergoes syn-selective conjugate addition with nitroalkenes (II) in the presence of chiral catalyst systems consisting of a copper(I) salt and a ligand derived from a multidentate amino alcohol.

The novel protocol for the successful reaction includes a combined catalyst of L-proline and brucine N-oxide.

Amine N-oxide-catalyzed Morita—Baylis—Hillman reaction of vinyl ketones with various aldehydes (Ia-h) results in the formation of racemic products (III).

In most cases, the reversion model for monitoring the severity degree of stripe rust based on the hyperspectral information can not be directly applied by the satellite images with relatively broad bandwidth, while the airborne hyperspectral images can not be applied for large-scale monitoring either, due to the scale limitation of its data and high cost. For resolving this dilemma, we developed a monitoring method based on PHI images, which relies on the construction of spectral knowledge base of winter wheat stripe rust. Three PHI images corresponding to the winter wheat experimental field that included different severity degree of stripe rust were used as a medium to establish the spectral knowledge base of relationships between disease index (DI) and the simulated reflectance of TM bands by using the empirical reversion model of DI(%) and the relative spectral response (RSR) function of TM-5 sensor. Based on this, we can monitor and identify the winter wheat stripe rust by matching the spectral information of an untested pixel to the spectral knowledge base via Mahalanobis distance or spectral angle mapping (SAM). The precision of monitoring was validated by simulated TM pixels, while the effectiveness of identification was tested by pixels from TM images. The results showed that the method can provide high precision for monitoring and reasonable accuracy for identification in some certain growth stages of winter wheat. Based on the simulated TM pixels, the model performed best in the pustulation period, yielded a coefficient of determination R2 = 0.93, while the precision of estimates dropped in the milk stage, and performed worst in the jointing stage, which is basically inappropriate for monitoring. Moreover, by using the pixels from TM images, the infected pixels could be identified accurately in pustulation and milk stages, while failed to be identified in jointing stage. For matching algorithms, the Mahalanobis distance method produced a slightly better result than SAM method.

The epididymis is an important organ in the male genital system, which is responsible for the maturation, transportation and storage of spermatozoa. The proper function of the epididymis is closely related with its robust physiological metabolism, and free radicals are inevitably produced as a consequence. An excess of free radicals would lead to the oxidative stress of the epididymis, damage the sperm membrane and DNA, seriously affect sperm maturation and result in male infertility. This article reviews the mechanism of epididymal oxidative stress in energy metabolism and inflammatory reaction as well as the roles of superoxide dismutase, catalase, glutathione peroxidase, indoleamine 2, 3 dioxygenase, glutathione and thioredoxin in the antioxidant process, offering a new insight into the prevention, diagnosis and treatment of male infertility.

To explore the functions of human ribonuclease 9 (RNase 9), we constructed a mammalian fusion expression vector pcDNA-hRNase9, prepared recombinant human RNase 9-His fusion protein from HEK293T cells and determined its N-terminal amino acid sequences. According to the determined mature protein, recombinant human RNase 9 was prepared in E. coli. Ribonucleolytic activity and antibacterial activity of recombinant human RNase 9 were detected, and the distribution of human RNase 9 on tissues and ejaculated spermatozoa and in vitro capacitated spermatozoa were analyzed via indirect immunofluorescence assay. The results showed that recombinant human RNase 9 did not exhibit detectable ribonucleolytic activity against yeast tRNA, but exhibited antibacterial activity, in a concentration/time dependent manner, against E. coli. Immunofluorescent analyses showed that the predicted human RNase 9 was present throughout the epididymis, but not present in other tissues examined, and human RNase 9 was also present on the entire head and neck regions of human ejaculated spermatozoa and in vitro capacitated spermatozoa. These results suggest that human RNase 9 may play roles in host defense of male reproductive tract.

To explore the effect of basic fibroblast growth factor 1 (bFGF1) during embryonic development on hematopoiesis, to study the expression of FGF1, vascular endothelial growth factor receptor (KDR), CD133, CD34 and transcription factors Ihh, SCL, GATA-1, GATA-2 and PU. 1 in the yolk sac, and to learn about the role and relationships of FGF1, hematopoietic cells and transcription factors during embryonic hematopoiesis.10 microm sections and total RNA were prepared from 107 human embryos aged 3-12 weeks. Immunohischemical SP staining and RT-PCR were performed.The yolk sac blood islands of human 3 approximately 12 weeks embryos consisted of peripheral vascular endothelial cells and central hematopoietic cells. The expression of FGF1 was firstly found in visceral mesoderm around periphery of yolk sac blood island at day 16, while was little inside it. KDR was not or lowly expressed and CD34 and CD133 were not expressed then. The expression increased, gray value decreased and staining enhanced at day 21. Strong staining of CD34+, CD133+ and KDR+ cells were found in blood island and mesoderm at day 30, their gray values changed from 156 +/- 16, 173 +/- 18 and 160 +/- 14 to 53 +/- 7, 52 +/- 6 and 69 +/- 8 respectively. FGF1 expression was strong positive, the gray value declined dramatically from 161 +/- 13 to 40 +/- 5. Some positive cells formed vessel-like structure along the periphery of blood island. Moderate expression of CD34+, CD133+, KDR+ cells increased at day 45, the cells aggregated into mass in blood island and FGF1+ cells did the same in blood island, while little in mesoderm. Its gray valve was increased. After 7 weeks, CD133+, KDR+, CD34+ cells significantly decreased their gray values increased, the staining became week. FGF1 was weakly expressed in yolk sac and its gray value increased to 179 +/- 22. RT-PCR showed Ihh, SCL, GATA-1 and GATA-2 were expressed at different time in yolk sac. PU. 1 were not expressed at day 16, and then expressed.The hematopoietic properties of yolk sac may be dependent on signaling through FGF receptors and FGF1 plays an important role in hematopoietic stem cell homeostasis. The FGF pathway regulates primitive hematopoiesis by modulating transcription factors such as Gata1 expression level and activity.

To study the expression and distribution of KDR, VEGF and CD34 in yolk sac and liver of human embryo at different development stage.Yolk sacs and livers of 15 human embryos were analyzed by the immunohistochemical SP kits for the expression of KDR, VEGF and CD34.KDR, VEGF and CD34 were all expressed in yolk sacs and livers of the embryos. In the intermediate liver group, the grey value of KDR and VEGF were 103.8 +/- 6.1 and 96.4 +/- 6.3, respectively, stronger than that in the late liver group which were 90.4 +/- 6.0 and 87.4 +/- 6.3, respectively (P0.05). A positive correlation between the levels of KDR and VEGF was observed (P0.05).The expression of KDR and CD34 in yolk sac and liver of embryo suggests the presence of hemangioblast in these organs. Interaction of KDR and VEGF might relate to survival, proliferation, migration and differentiation of hemangioblasts.

To provide materials for the study of the function of ESC42 protein specifically expressed in the human epididymis.The ESC42 gene was amplified from the human epididymis cDNA library by PCR and then cloned into prokaryotic expression vector pGEX-4T-1, expressed and purified by recombinant DNA techniques. The specificity of ESC42 protein was identified by Western blot and MALDI-TOF-MS. The database was searched by Ms-Fit.The recombinant plasmid expressed a Mr 38 x 10(3) fusion protein in E. coli at a level of 30% of the total protein, and the purity was as high as 99%. The ESC42 protein was identified by ESC42 monoclonal antibody and its molecular weight was 11 978.12, tested by MALDI-TOF-MS. The peptide mass fingerprint analysis showed that the coverage rate of the sequence reached 48% with 100% matching. The motif scan in Prosite database reveal that ESC42 belonged to the beta-defensin family and had antibacterial activity.Obtaining high purity of rhESC42 protein may lay a foundation for the study of its functions.

To investigate whether the -344T/C polymorphism of CYP11B2 gene is associated with essential hypertension in the Hans in Shandong province.Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured with radioimmunoassays; the hypertensives were classified as low-renin and normal- or high-renin group by PAC/PRA ratio. -344T/C polymorphism was determined by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) in controls and hypertensives.No significant differences were found in genotype distribution or allele frequency between groups of control and primary hypertension or between groups of control and normal- or high-renin hypertension. The C allele frequency in low-renin hypertension group was significantly higher than that in normotensives and normal- or high-renin hypertension group (P0.05).These results suggest that -344T/C polymorphism of CYP11B2 gene may be associated with low-renin essential hypertension in the Han nationality in Shandong province.

Background Human pancreatic islet transplantation is a prospective curative treatment for diabetes. However, the lack of donor pancreases greatly limits this approach. One approach to overcome the limited supply of donor pancreases is to generate functional islets from human embryonic stem cells (hESCs), a cell line with unlimited proliferative capacity, through rapid directed differentiation. This study investigated whether pancreatic insulin-producing cells (IPCs) differentiated from hESCs could correct hyperglycemia in severe combined immunodeficient (SCID)/non-obese diabetic (NOD) mice, an animal model of diabetes. Methods We generated pancreatic IPCs from two hESC lines, YT1 and YT2, using an optimized four-stage differentiation protocol in a chemically defined culture system. Then, about 5–7×106 differentiated cells were transplanted into the epididymal fat pad of SCID/NOD mice (n = 20). The control group were transplanted with undifferentiated hESCs (n = 6). Graft survival and function were assessed using immunohistochemistry, and measuring serum human C-peptide and blood glucose levels. Results The pancreatic IPCs were generated by the four-stage differentiation protocol using hESCs. About 17.1% of differentiated cells expressed insulin, as determined by flow cytometry. These cells secreted insulin/C-peptide following glucose stimulation, similarly to adult human islets. Most of these IPCs co-expressed mature β cell-specific markers, including human C-peptide, GLUT2, PDX1, insulin, and glucagon. After implantation into the epididymal fat pad of SCID/NOD mice, the hESC-derived pancreatic IPCs corrected hyperglycemia for ≥8 weeks. None of the animals transplanted with pancreatic IPCs developed tumors during the time. The mean survival of recipients was increased by implanted IPCs as compared to implanted undifferentiated hESCs (P