Transcriptomic and physiological comparison of Shatangju (Citrus reticulata) and its late-maturing mutant provides insights into auxin regulation of citrus fruit maturation

Previous studies have shown that abscisic acid (ABA) and ethylene are involved in pulp maturation and peel coloration in the nonclimacteric citrus fruits. There are also signs indicating that other plant hormones may play some roles in citrus fruit ripening. In this study, we compared profiles of genome-wide gene expression and changes in hormones and peel pigments between fruits of Shatangju mandarin (Citrus reticulata Blanco, designated WT) and its natural mutant, Yuenongwanju (designated MT). The MT fruit matures ~2 months later than the WT fruit. Significant differences in fruit diameter, total soluble solids, titratable acid content, chlorophylls and carotenoids were detected between the fruits of the two genotypes at the sampled time points. Genome-wide transcriptome profiling showed that many genes involved in auxin and ABA metabolism and/or signaling pathways were differentially expressed between the MT and the WT fruits. Importantly, the expression of CrYUCCA8 was significantly lower and the expression of CrNCED5 was significantly higher in WT than in MT fruits at 230 and 250 DPA, respectively. In addition, the indole-3-acetic acid (IAA) level in the MT fruit was significantly higher than that in the WT counterpart, whereas a significantly lower level of ABA was detected in the mutant. Treatment of the WT fruit with exogenous IAA significantly delayed fruit maturation. Our results provide experimental evidence supporting the notion that auxin is a negative regulator of fruit maturation in citrus.

[Directed differentiation of human induced pluripotent stem cells into midbrain]

OBJECTIVE

To establish an efficient protocol for directed differentiation of human induced pluripotent stem cells (hiPSCs) into functional midbrain dopaminergic progenitor cells (DAPs) in vitro.

METHODS

hiPSCs were induced to differentiate into DAPs in two developmental stages. In the first stage (the first 13 days), hiPSCs were induced into intermediate cells morphologically similar to primitive neuroepithelial cells (NECs) in neural induction medium containing a combination of small molecule compounds. In the second stage, the intermediate cells were further induced in neural differentiation medium until day 28 to obtain DAPs. After CM-DiI staining, the induced DAPs were stereotactically transplanted into the right medial forebrain bundle (MFB) of rat models of Parkinson's disease (PD). Eight weeks after transplantation, the motor behaviors of PD rats was evaluated. Immunofluorescence assay of brain sections of the rats was performed at 2 weeks after transplantation to observe the survival, migration and differentiation of the transplanted cells in the host brain microenvironment.

RESULTS

hiPSCs passaged stably on Matrigel showed a normal diploid karyotype, expressed the pluripotency markers OCT4, SOX2, and Nanog, and were positive for alkaline phosphatase. The primitive neuroepithelial cells obtained on day 13 formed dense cell colonies in the form of neural rosettes and expressed the neuroepithelial markers (SOX2, Nestin, and PAX6, 91.3%-92.8%). The DAPs on day 28 highly expressed the specific markers (TH, FOXA2, LMX1A and NURR1, 93.3-96.7%). In rat models of PD, the hiPSCs-DAPs survived and differentiated into TH⁺, FOXA2⁺ and Tuj1⁺ neurons at 2 weeks after transplantation. Eight weeks after transplantation, the motor function of PD rats was significantly improved as shown by water maze test (P < 0.0001) and apomorphine-induced rotation test (P < 0.0001) compared with rats receiving vehicle injection.

CONCLUSION

HiPSCs can be effectively induced to differentiate into DAPs capable of differentiating into functional neurons both in vivo and in vitro. In rat models of PD, the transplanted hiPSCs-DAPs can survive for more than 8 weeks in the MFB and differentiate into multiple functional neurocytes to ameliorate neurological deficits of the rats, suggesting the potential value of hiPSCs-DAPs transplantation for treatment of neurological diseases.

Determining the hydronium pK[Formula: see text] at platinum surfaces and the effect on pH-dependent hydrogen evolution reaction kinetics

Electrocatalytic hydrogen evolution reaction (HER) is critical for green hydrogen generation and exhibits distinct pH-dependent kinetics that have been elusive to understand. A molecular-level understanding of the electrochemical interfaces is essential for developing more efficient electrochemical processes. Here we exploit an exclusively surface-specific electrical transport spectroscopy (ETS) approach to probe the Pt-surface water protonation status and experimentally determine the surface hydronium pKa [Formula: see text] 4.3. Quantum mechanics (QM) and reactive dynamics using a reactive force field (ReaxFF) molecular dynamics (RMD) calculations confirm the enrichment of hydroniums (H3O[Formula: see text]) near Pt surface and predict a surface hydronium pKa of 2.5 to 4.4, corroborating the experimental results. Importantly, the observed Pt-surface hydronium pKa correlates well with the pH-dependent HER kinetics, with the protonated surface state at lower pH favoring fast Tafel kinetics with a Tafel slope of 30 mV per decade and the deprotonated surface state at higher pH following Volmer-step limited kinetics with a much higher Tafel slope of 120 mV per decade, offering a robust and precise interpretation of the pH-dependent HER kinetics. These insights may help design improved electrocatalysts for renewable energy conversion.

235 Assessing coding of diagnosis for atypical parkinsonian syndromes

Background

Atypical Parkinsonian syndromes, including Progressive Supranuclear Palsy (PSP), Multiple System Atrophy (MSA) and Corticobasal Syndrome (CBS), are rare neurodegenerative diseases. Reports showed that the use of the health services for patients with these diseases is underestimated. The NHS uses International Classification of Disease revision 10 (ICD-10) to code health use which has led to error in patient data for these diseases, as they are relatively new entries to this system and there were changes in coding practice in 2016.

Aims

To retrospectively investigate the scale of miscoding of PSP, MSA and CBS in England since the introduction of ICD-10.

Methods

Freedom of information requests were issued to 150 NHS trusts in England to investigate their method of coding and determine the coding error rate.

Results

The coding error rates prior to, and after 2016 respectively were: 29.5%, 0% (PSP); 3.8%, 2.3% (MSA); 24.2%, 24.2% (CBS). The indexing for CBS is difficult as no specific coding exists for CBS in ICD-10.

Conclusion

The high error rate for PSP is contributed by miscoding of PSP (G23.1) as MND (G12.2), due to the coding techniques employed. These errors have largely been rectified in later versions of ICD-10 with the exception of CBS.

ggz1g17@soton.ac.uk

Having a Same Type IIS Enzyme's Restriction Site on Guide RNA Sequence Does Not Affect Golden Gate (GG) Cloning and Subsequent CRISPR/Cas Mutagenesis

Golden gate/modular cloning facilitates faster and more efficient cloning by utilizing the unique features of the type IIS restriction enzymes. However, it is known that targeted insertion of DNA fragment(s) must not include internal type IIS restriction recognition sites. In the case of cloning CRISPR constructs by using golden gate (GG) cloning, this narrows down the scope of guide RNA (gRNA) picks because the selection of a good gRNA for successful genome editing requires some obligation of fulfillment, and it is unwanted if a good gRNA candidate cannot be picked only because it has an internal type IIS restriction recognition site. In this article, we have shown that the presence of a type IIS restriction recognition site in a gRNA does not affect cloning and subsequent genome editing. After each step of GG reactions, correct insertions of gRNAs were verified by colony color and restriction digestion and were further confirmed by sequencing. Finally, the final vector containing a Cas12a nuclease and four gRNAs was used for Agrobacterium-mediated citrus cell transformation. Sequencing of PCR amplicons flanking gRNA-2 showed a substitution (C to T) mutation in transgenic plants. The knowledge derived from this study could widen the scope of GG cloning, particularly of gRNAs selection for GG-mediated cloning into CRISPR vectors.

Analysis of CcGASA family members in Citrus clementina (Hort. ex Tan.) by a genome-wide approach

The Gibberellic Acid Stimulated Arabidopsis (GASA) proteins were investigated in the study to help understand their possible roles in fruit trees, particularly in Citrus. A total of 18 CcGASA proteins were identified and characterized in Citrus clementina via a genome-wide approach. It was shown that the CcGASA proteins structurally shared a conserved GASA domain but varied considerably in primary sequences and motif compositions. Thus, they could be classified into three major phylogenetic groups, G1~G3, and two groups, G1 and G3 could be further classified into subgroups. The cis- elements on all CcGASA promoters were identified and categorized, and the associated transcription factors were predicted. In addition, the possible interactions between the CcGASA proteins and other proteins were predicted. All the clues suggested that these genes should be involved in defense against biotic and abiotic stresses and in growth and development. The notion was further supported by gene expression analysis that showed these genes were more or less responsive to the treatments of plant hormones (GA₃, SA, ABA and IAA), and infections of citrus canker pathogen Xanthomonas citri. It was noted that both the segmental and the tandem duplications had played a role in the expansion of the CcGASA gene family in Citrus. Our results showed that the members of the CcGASA gene family should have structurally and functionally diverged to different degrees, and hence, the representative group members should be individually investigated to dissect their specific roles.

Temporal association between antibiotic use and resistance in Gram-negative bacteria

The β-lactam/lactamase inhibitors (BLBLIs) combination drugs are considered an effective alternative to carbapenems. However, there is a growing concern that the increased use of BLBLIs may lead to increased resistance. This study determined the temporal association between the consumption of BLBLI and the antimicrobial resistance in Gram-negative bacteria. In this retrospective study, electronic data on the Gram-negative bacterial isolates, including A. baumannii, P. aeruginosa, E. coli, and K. pneumoniae from in-patients and susceptibility testing results were retrieved from the medical records of the clinical laboratory. A linear regression and cross-correlation analysis were performed on the acquired data. Increasing trends (p<0.05) in the consumption of BIBLI and carbapenem with a median use of 27.68 and 34.46 DDD/1000 PD per quarter were observed, respectively. A decreased trend (p=0.023) in the consumption of fluoroquinolones with a median use of 29.13 DDD/1000 PD per quarter was observed. The resistance rate of K. pneumoniae was synchronized with the BIBLI and carbapenem consumptions with a correlation coefficient of 0.893 (p=0.012) and 0.951 (p=0.016), respectively. The cross-correlation analysis against the consumption of BIBLI and meropenem resistant K. pneumoniae was peaked at 0-quarter lag (r=951, p=0.016). There was an increasing trend in the consumption of BLBLI and carbapenems. The increasing trend in the rates of resistance to piperacillin/tazobactam, in line with the increasing consumption of BLBLI, suggests that BLBLI has to be used with caution and cannot be directly considered as a long-term alternative to carbapenems.

[Targeted therapy of pyogenic sterile arthritis, pyoderma gangrenosum, and acne syndrome (PAPA): a case report and literature review]

Objective: To analyze the clinical course and targeted therapy of pyogenic sterile arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome. Methods: The clinical history of a 6-year-old boy with PAPA syndrome, who was admitted to Hong Kong University Shenzhen Hospital in September 2017, was reviewed. His genetic diagnosis was confirmed by whole exome sequencing. The response to targeted therapy was evaluated by comparing the inflammatory markers (erythrocyte sedimentation rate (ESR) and C reactive protein (CRP) and serum cytokines (interleukin (IL)-1, IL-6 and tumor necrosis factor-α (TNF-α)) before and after biological agents treatment. For literature review, "PAPA syndrome" and"PSTPIP1 gene"were used as keywords to retrieve papers published from January 1997 to December 2019 from Pubmed, Wanfang and CNKI database. Results: The patient was a 6-year-old boy, admitted to the hospital due to recurrent joint swelling and pain for more than 4 years. Before treatment, the CRP (256 mg/L), ESR (105 mm/1 h) and cytokines including serum TNF-α (7.43 ng/L), IL-1 (<5 ng/L), IL-6 (301 ng/L) were significantly elevated. Culture of the joint effusion was negative, but the IL-6 level was above 1 000 ng/L. MRI showed osteomyelitis at the lower end of the right femur. Gene detection found a heterozygous variation of PSTPIP1 gene (c.748G>A, p.E250K). Arthralgia once alleviated after the initiation of tocilizumab and infliximab, but recurred after 1 year of treatment. Thereafter, the anti-IL-1 receptor antagonist (Anakinra) was commenced, followed by a significant improvement of the arthralgia, and a complete remission during the follow-up. Besides, the level of CRP, ESR, serum TNF-α, IL-1 and IL-6 were all decreased to normal on the last followed up in December 2019. Literature review found 29 articles and 87 patients in total. The initial symptoms included those of arthritis (n=58), pyoderma gangrenosum (n=33), and acne (n=24). Among all the cases, 13 genotypes were confirmed, and 47 variations involved amino acid p.E250. Steroid and/or biological agents were used in most patients. Conclusions: PAPA syndrome should be suspected in children with recurrent pyogenic sterile arthritis, and an early diagnosis could be achieved by genetic test. Targeted treatment with biological agent may control the symptoms effectively. Biological agents can control symptoms of this disorder effectively.

Gastric cancer nodal tumour-stroma ratios influence prognosis

This study showed that nodal tumour-stroma ratio (NTSR) is an independent prognostic factor for overall and disease-free survival of patients with gastric cancer. Both relative stroma-rich primary tumour-stroma ratio (PTSR) and NTSR were independent negative prognostic factors for overall survival in gastric cancer. This study supports assessment of tumour-stroma ratio in the routine pathological diagnosis of gastric cancer. validated in node-positive disease.

Genome-Wide Identification and Characterization of UTR-Introns of Citrus sinensis

Introns exist not only in coding sequences (CDSs) but also in untranslated regions (UTRs) of a gene. Recent studies in animals and model plants such as Arabidopsis have revealed that the UTR-introns (UIs) are widely presented in most genomes and involved in regulation of gene expression or RNA stability. In the present study, we identified introns at both 5'UTRs (5UIs) and 3'UTRs (3UIs) of sweet orange genes, investigated their size and nucleotide distribution characteristics, and explored the distribution of cis-elements in the UI sequences. Functional category of genes with predicted UIs were further analyzed using GO, KEGG, and PageMan enrichment. In addition, the organ-dependent splicing and abundance of selected UI-containing genes in root, leaf, and stem were experimentally determined. Totally, we identified 825 UI- and 570 3UI-containing transcripts, corresponding to 617 and 469 genes, respectively. Among them, 74 genes contain both 5UI and 3UI. Nucleotide distribution analysis showed that 5UI distribution is biased at both ends of 5'UTR whiles 3UI distribution is biased close to the start site of 3'UTR. Cis- elements analysis revealed that 5UI and 3UI sequences were rich of promoter-enhancing related elements, indicating that they might function in regulating the expression through them. Function enrichment analysis revealed that genes containing 5UI are significantly enriched in the RNA transport pathway. While, genes containing 3UI are significantly enriched in splicesome. Notably, many pentatricopeptide repeat-containing protein genes and the disease resistance genes were identified to be 3UI-containing. RT-PCR result confirmed the existence of UIs in the eight selected gene transcripts whereas alternative splicing events were found in some of them. Meanwhile, qRT-PCR result showed that UIs were differentially expressed among organs, and significant correlation was found between some genes and their UIs, for example: The expression of VPS28 and its 3UI was significantly negative correlated. This is the first report about the UIs in sweet orange from genome-wide level, which could provide evidence for further understanding of the role of UIs in gene expression regulation.

Genetic Diversity, Pedigree Relationships, and A Haplotype-Based DNA Fingerprinting System of Red Bayberry Cultivars

High throughput sequencing was used to reveal the distribution of whole-genome variations in cultivated Morella rubra (Sieb. et Zucc.). A total of 3,151,123 SNPs, 371,757 small indels, and 15,904 SVs were detected in 52 accessions. Verification by Sanger sequencing demonstrated that the positive rate of the SNPs was approximately 97.3%. Search for more genetic variations was expanded to 141 red bayberry accessions, most of which were cultivars, by sequencing 19 selected genomic segments (SEG1-19). The results showed that each segment harbored, on average, 7.8 alleles (haplotypes), a haplotype diversity of 0.42, and a polymorphic information content (PIC) of 0.40. Seventy-two different genotypes were identified from the 141 accessions, and statistical analysis showed that the accessions with duplicated genotypes were either somatic mutants or simply synonyms. Core set selection results showed that a minimum of 34 genotypes could already have covered all the alleles on the segments. A DNA fingerprinting system was developed for red bayberry, which used the diversity information of only 8 DNA segments yet still achieved a very high efficiency without losing robustness. No large clade was robustly supported by hierarchical clustering, and well-supported small clusters mainly included close relatives. These results should lead to an improved understanding of the genetic diversity of red bayberry and be valuable for future molecular breeding and variety protection.

Large debris dumps in the northern South China Sea

Knowledge of the abundance, source, and fate of marine debris in the deep sea is largely constrained thus far. Here, we report the existence of large deep-sea debris dumps that have not been reported before on the seafloor worldwide. Marine debris remarkably accumulated at ~1700-1800 m in the tributary submarine canyons of the Xisha Trough, northern South China Sea (SCS). Although marine debris in Xisha Trough is patchy, the debris abundance was as high as 36,818 and 51,929 items/km² at locations SY78 and SY82, respectively, which is one order of magnitude higher than that in other submarine canyons. We propose that most of the debris came from fishery and navigation activities, as indicated by the categories of debris collected from the seafloor dumps. Seasonal surface ocean currents of the SCS and geomorphology of submarine canyons possibly influence the movement of the debris from coasts to the deep seafloor.

The applied anatomy and clinical significance of the proximal, V1 segment of vertebral artery

BACKGROUND

The aim of the study was to probe the morphological features of the proximal segment (V1) of vertebral artery (VA) in a sample of Chinese cadavers.

MATERIALS AND METHODS

The origin, course and outer diameter at origin of the pre-vertebral part of the VAs were evaluated in 119 adult cadavers.

RESULTS

It was found that 94.12% of the VAs originated from the subclavian arteries, bilaterally. The variant origins were present in 5.88% of the cadavers and all originated directly from the arch of the aorta. All the variations were observed on the left side of male cadavers. The average outer diameters at origin of the normal and variation groups were 4.35 ± 1.00 mm and 4.82 ± ± 1.42 mm, respectively, p = 0.035. In the normal group, but not in the variation group, the average diameter in the males was significantly larger than that in the females (4.50 ± 0.99 mm, 3.92 ± 0.92 mm, respectively, p = 0.000). In addition, only 5 cadavers in the normal group had hypoplastic VAs (4.20%, 4 males, 3 right-sided). Vertebral artery dominance (VAD) was present in 91 (69 males) out of 112 cadavers and more common on the left (n = 48). In addition, 3 cadavers satisfied conditions for coexistence of VAD and vertebral artery hypoplasia. All 7 cadavers in the variation group exhibited VAD, which was more common on the right side (n = 5).

CONCLUSIONS

The morphologic variations and frequencies described above have implications for the early prevention, abnormal anatomy detection, accurate diagnosis, safe surgery and endovascular treatment of cardiovascular and neurological disease.

Genome of Wild Mandarin and Domestication History of Mandarin

Mandarin (Citrus reticulata) is one of the most important citrus crops worldwide. Its domestication is believed to have occurred in South China, which has been one of the centers of mandarin cultivation for four millennia. We collected natural wild populations of mandarin around the Nanling region and cultivated landraces in the vicinity. We found that the citric acid level was dramatically reduced in cultivated mandarins. To understand genetic basis of mandarin domestication, we de novo assembled a draft genome of wild mandarin and analyzed a set of 104 citrus genomes. We found that the Mangshan mandarin is a primitive type and that two independent domestication events have occurred, resulting in two groups of cultivated mandarins (MD1 and MD2) in the North and South Nanling Mountains, respectively. Two bottlenecks and two expansions of effective population size were identified for the MD1 group of cultivated mandarins. However, in the MD2 group there was a long and continuous decrease in the population size. MD1 and MD2 mandarins showed different patterns of interspecific introgression from cultivated pummelo species. We identified a region of high divergence in an aconitate hydratase (ACO) gene involved in the regulation of citrate content, which was possibly under selection during the domestication of mandarin. This study provides concrete genetic evidence for the geographical origin of extant wild mandarin populations and sheds light on the domestication and evolutionary history of mandarin.

A long-acting pegylated recombinant human growth hormone (Jintrolong® ) in healthy adult subjects: Two single-dose trials evaluating safety, tolerability and pharmacokinetics

WHAT IS KNOWN AND OBJECTIVE

Jintrolong^® is a pegylated recombinant human growth hormone (rhGH) (PEG-rhGH) developed for weekly subcutaneous (sc) injection. The current human tolerability trial and pharmacokinetics (PK) trial evaluated the safety, tolerability and PK of single-dose Jintrolong^® injection in healthy adult subjects.

METHODS

Both trials were single-centre, randomized, open-label and single-dose studies. In the human tolerability trial, 34 healthy subjects were randomized to receive single-dose Jintrolong^® sc injection (0.01, 0.06, 0.2, 0.5 or 0.8 mg/kg) or placebo. In the PK study, 30 healthy male subjects were evenly randomized into 3 groups to receive single-dose Jintrolong^® sc injection (0.1, 0.2 or 0.4 mg/kg), and the subjects receiving 0.4 mg/kg Jintrolong^® were given a single sc injection of conventional rhGH (0.067 mg/kg) after a 14-day washout period. Safety and PK profiles of Jintrolong^® were evaluated.

RESULTS AND DISCUSSION

Jintrolong^® was well tolerated with no serious adverse events or local injection responses. The PK trial showed that the plasma growth hormone concentration elevated quickly and stayed at peak level between 12 and 48 hours post-Jintrolong^® injection, then decreased gradually back to baseline within 168 hours. Compared to single-dose conventional rhGH, Jintrolong^® at all doses demonstrated significantly longer half time and time to maximum plasma concentration, lower clearance and higher systemic drug exposure, indicating prolonged presence of GH in the subjects' circulation. Additionally, systemic exposure to Jintrolong^® increased in a dose-dependent manner.

WHAT IS NEW AND CONCLUSION

Single-dose Jintrolong^® injection was well tolerated in healthy adult subjects, and the maximum tolerable dose was no lower than 0.8 mg/kg. Jintrolong^® was long-acting with the potential for weekly administration.

On-Chip in Situ Monitoring of Competitive Interfacial Anionic Chemisorption as a Descriptor for Oxygen Reduction Kinetics

The development of future sustainable energy technologies relies critically on our understanding of electrocatalytic reactions occurring at the electrode-electrolyte interfaces, and the identification of key reaction promoters and inhibitors. Here we present a systematic in situ nanoelectronic measurement of anionic surface adsorptions (sulfates, halides, and cyanides) on ultrathin platinum nanowires during active electrochemical processes, probing their competitive adsorption behavior with oxygenated species and correlating them to the electrokinetics of the oxygen reduction reaction (ORR). The competitive anionic adsorption features obtained from our studies provide fundamental insight into the surface poisoning of Pt-catalyzed ORR kinetics by various anionic species. Particularly, the unique nanoelectronic approach enables highly sensitive characterization of anionic adsorption and opens an efficient pathway to address the practical poisoning issue (at trace level contaminations) from a fundamental perspective. Through the identified nanoelectronic indicators, we further demonstrate that rationally designed competitive anionic adsorption may provide improved poisoning resistance, leading to performance (activity and lifetime) enhancement of energy conversion devices.

Digital Gene Expression Analysis of Ponkan Mandarin (Citrus reticulata Blanco) in Response to Asia Citrus Psyllid-Vectored Huanglongbing Infection

Citrus Huanglongbing (HLB), the most destructive citrus disease, can be transmitted by psyllids and diseased budwoods. Although the final symptoms of the two main HLB transmission ways were similar and hard to distinguish, the host responses might be different. In this study, the global gene changes in leaves of ponkan (Citrus reticulata) mandarin trees following psyllid-transmission of HLB were analyzed at the early symptomatic stage (13 weeks post inoculation, wpi) and late symptomatic stage (26 wpi) using digital gene expression (DGE) profiling. At 13 wpi, 2452 genes were downregulated while only 604 genes were upregulated in HLB infected ponkan leaves but no pathway enrichment was identified. Gene function analysis showed impairment in defense at the early stage of infection. At late stage of 26 wpi, however, differentially expressed genes (DEGs) involved in carbohydrate metabolism, plant defense, hormone signaling, secondary metabolism, transcription regulation were overwhelmingly upregulated, indicating that the defense reactions were eventually activated. The results indicated that HLB bacterial infection significantly influenced ponkan gene expression, and a delayed response of the host to the fast growing bacteria might be responsible for its failure in fighting against the bacteria.

Enzymatic [4+2] Cycloadditions in the Biosynthesis of Spirotetramates and Spirotetronates

The Diels-Alder reaction is a quintessential type of [4+2] cycloaddition that remains one of the most intriguing transformations in synthetic chemistry. This reaction has long been envisaged to participate in the biosynthesis of a number of cyclohexene-containing natural products, although the question of whether a bona fide Diels-Alderase exists remains unsolved. In nature, there are remarkably few enzymes known to have the activity of [4+2] cycloaddition. These enzymes are phylogenetically distinct and are often classified according to the specific chemical structures. The variation of protein ancestors and in many cases the instability/complexity of the substrates and products pose a significant challenge in identification of the [4+2] cycloaddition catalysts using general homology-based mining approaches. We here provide the detailed description of the multiple comparison-based strategy and methods for the characterization of two distinct types of dedicated [4+2] cyclases (eg, PyrE3 and PyrI4) in the biosynthesis of spirotetramates and spirotetronates, where they act in tandem for coordinated cross-bridging of a linear polyene intermediate into a enantiomerically pure pentacyclic core. The search of new protein scaffolds with the [4+2] cycloaddition activity could enrich the pool of the candidates for mechanistic examination of a true enzymatic Diels-Alder reaction. The protocols presented in this study would also be applicable to the study of other functionally similar but phylogenetically different proteins, eg, the spiroketal cyclases.

Single- and Multiple-dose Pharmacokinetic, Safety and Tolerability Study of Mildronate Injection in Healthy Chinese Subjects Pharmacokinetic of Mildronate Injection

Mildronate is an agent for cardioprotection and neuroprotection. This study aimed to evaluate the pharmacokinetic (PK) profiles, safety and tolerability of mildronate injection after single escalating doses and multiple doses in healthy Chinese subjects. We performed a randomized, open-label, single- and multiple-dose phase I trial including 3 doses of mildronate: 250, 500 and 750 mg. Plasma and urine samples were collected and concentrations of mildronate were analyzed by liquid chromatography-mass spectrometry (LC-MS/MS). PK parameters were calculated using noncompartmental analysis. Safety and tolerability was assessed throughout noting subjects' vital signs and monitoring adverse events (AEs) and conduct a comprehensive physical examination and laboratory analyses before and after the study. There was no significant difference in C 0, AUC0-t, AUC0-∞ among 3 single-dose groups, whereas T 1/2 had significant statistical difference which may be caused by the inhibition of metabolic enzymes. Single- and multiple-dose intravenous injection of mildronate exhibited linear PK profiles in the range of 250-750 mg. An unconspicuous accumulation phenomenon was found after multiple-dose mildronate administration. No significant gender difference was found and mildronate is primarily excreted by the kidney. No serious AEs were observed. The formulation was safe and well tolerated from 250 to 750 mg.

The push-pull strategy for citrus psyllid control

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the only natural vector of Candidatus Liberibacter asiaticus that causes citrus huanglongbing (HLB), a most destructive disease of citrus. Currently, no remedial therapy exists for the disease, and so effective control of ACP is very important in curbing the transmission of the disease. The push-pull strategy should be thoroughly explored as an approach to ACP management. This mini-review summarises the current progress towards more effective repellent and attractant chemicals through investigating known repellent and attractive plants. Interactions between ACP and its host plants are also addressed, with emphasis on the possible involvement of the host biochemicals in attracting the insect. Potential ways to increase the effectiveness of the pull-push strategy are briefly discussed. It is expected that the pull-push strategy will be gradually developed following more extensive research.

Profiling gene expression in citrus fruit calyx abscission zone (AZ-C) treated with ethylene

On-tree storage and harvesting of mature fruit account for a large proportion of cost in the production of citrus, and a reduction of the cost would not be achieved without a thorough understanding of the mechani sm of the mature fruit abscission. Genome-wide gene expression changes in ethylene-treated fruit calyx abscission zone (AZ-C) of Citrus sinensis cv. Olinda were therefore investigated using a citrus genome array representing up to 33,879 citrus transcripts. In total, 1313 and 1044 differentially regulated genes were identified in AZ-C treated with ethylene for 4 and 24 h, respectively. The results showed that mature citrus fruit abscission commenced with the activation of ethylene signal transduction pathway that led to the activation of ethylene responsive transcription factors and the subsequent transcriptional regulation of a large set of ethylene responsive genes. Significantly down-regulated genes included those of starch/sugar biosynthesis, transportation of water and growth promoting hormone synthesis and signaling, whereas significantly up-regulated genes were those involved in defense, cell wall degradation, and secondary metabolism. Our data unraveled the underlying mechanisms of some known important biochemical events occurring at AZ-C and should provide informative suggestions for future manipulation of the events to achieve a controllable abscission for mature citrus fruit.

Carbon nanotube growth for through silicon via application

Through silicon via (TSV) technology is key for next generation three-dimensional integrated circuits, and carbon nanotubes (CNT) provide a promising alternative to metal for filling the TSV. Three catalyst preparation methods for achieving CNT growth from the bottom of the TSV are investigated. Compared with sputtering and evaporation, catalyst deposition using dip-coating in a FeCl2 solution is found to be a more efficient method for realizing a bottom-up filling of the TSV (aspect ratio 5 or 10) with CNT. The CNT bundles grown in 5 min exceed the 50 μm length of the TSV and are multi-wall CNT with three to eight walls. The CNT bundles inside the TSV were electrically characterized by creating a direct contact using a four-point nanoprober setup. A low resistance of the CNT bundle of 69.7 Ω (297 Ω) was measured when the CNT bundle was contacted midway along (over the full length of) the 25 μm deep TSV. The electrical characterization in combination with the good filling of the TSV demonstrates the potential use of CNT in fully integrated TSV applications.

Bioequivalence evaluation of 2 tablet formulations of entecavir in healthy chinese volunteers: a single-dose, randomized-sequence, open-label crossover study

A randomized, 2-way crossover study was conducted in healthy Chinese male volunteers to evaluate the bioequivalence of a new generic formulation of entecavir (CAS 142217-69-4) tablets (test) and the available branded formulation (reference) to meet the requirements for marketing the test product in China. Test and reference tablets were administered as a single dose on 2 treatment days separated by a 2-week washout period. Blood samples were collected for a period of 24 h following drug administration. Plasma concentration of entecavir was determined by a liquid chromatography-tandem mass spectrometry (LC/MS/MS) method. Pharmacokinetic parameters were calculated using a noncompartmental model. Bioequivalence was determined by calculating 90% CIs for the ratios of Cmax, AUC0-t and AUC0-∞ values for the test and reference products. Tolerability was assessed by monitoring vital signs, laboratory tests and interviews with the volunteers before administration and every 2 h during the study. The 90% CIs of entecavir for Cmax, AUC0-t and AUC0-∞ were 95.2-106.9%, 98.4-104.6% and 97.3-104.4%, respectively, which fell within the interval of 80-125%. No clinically important adverse effects were reported. These results suggested that the test formulation of entecavir tablets met the regulatory criterion for bioequivalence to the reference formulation.

Abnormal motor reflexes and dormant facial motor neurons in rats with facial-facial anastomosis

After facial nerve injury, some post-paralysis sequelae, such as synkinesis, hemispasm and 'crocodile tears' syndrome appear. The psychosocial impact of these sequelae is unavoidable. Despite recent advances and the growing popularity of this field, the pathophysiological mechanisms of facial nerve injury and regeneration are still not well understood. In this report, an abnormal motor reflex coincident with synkinetic facial movement was examined in a rat model using the blink reflex technique. Some dormant facial motor neurons were found which could not innervate through the suture site but remained alive. These results suggest that such dormant neurons might exert roles distinct from those of re-innervated neurons during facial nerve injury and regeneration. Further study is required to elucidate the biomolecular structure and electrophysiological features of such neurons.

Controlling the catalyst during carbon nanotube growth

We have recently been able to grow single-walled carbon nanotubes by purely thermal chemical vapour deposition (CVD) at temperatures as low as 400 degrees C. This has been achieved by separating the catalyst pre-treatment step from the growth step. In the pre-treatment step, a thin film catalyst is re-arranged into a series of nano-droplets, which are then the active catalysts. Both steps have been studied by in-situ environmental transmission electron microscopy and X-ray photoemission spectroscopy. We have also studied the catalyst yield, the weight of nanotubes grown per weight of transition metal catalyst. Using very thin layers of Fe on Al2O3 support in a remote plasma-assisted CVD, we have achieved yields of order 100,000. This may be due to control of catalyst poisoning by ensuring an etching path.

Enhanced Maturation and Functional Capacity of Dendritic Cells Induced by Mannosylated L2 Domain of ErbB2 Receptor

The nature of antigens and functional state of dendritic cells (DC) are important in antigen presentation. The ability of DC for the induction of T-cell responses is promoted by maturation. It has been confirmed that mannose receptors mediate highly efficient endocytosis and presentation of mannosylated proteins. In the present study, L2 domain of ErbB2 ectodomain was expressed in Escherichia coli, purified and mannosylated. The maturation and functional capacity of DC induced by mannosylated L2 (mL2) protein were investigated. The results showed that L2 protein could induce DC maturation, which was accompanied by elevated expression of MHC and co-stimulatory molecules. The effect of mL2 protein on DC maturation was more remarkable than that of non-mL2 proteins. Uptake of mL2 antigens by DC was more efficient. Furthermore, the T cells can be stimulated to proliferate in vitro and secrete Th1 and Th2 cytokines. Higher levels of both IFN-gamma and IL-10 were detected from the T cells stimulated by mL2-pulsed DC, suggesting a concurrent activation of CD4+ and CD8+ T cells. The results demonstrated that L2 domain of ErbB2 receptor is an immunodominant molecule. The mL2 domain of ErbB2 can induce an enhanced maturation and functional capacity of DC. It may become an effective strategy to induce anti-ErbB2 response.

Expression of estrogen receptors ERalpha and ERbeta in endometrial hyperplasia and adenocarcinoma

We assessed the expression of estrogen receptors (ER)alpha and ERbeta in 114 human endometrial hyperplasia and adenocarcinomas. The aim of this study was to determine the expression of both ER isoforms in human endometrial tissue by immunohistochemistry. From normal proliferation to simple and complex hyperplasia, the expression of ERalpha was increased (P < 0.05), while ERbeta did not change much (P > 0.05). In atypia hyperplasia and adenocarcinoma, both ERalpha and ERbeta were decreased significantly (P < 0.05). Most endometrial adenocarcinomas expressed ERalpha, either alone or in combination with ERbeta, and the ERbeta/ERalpha ratio was decreased when compared to normal proliferation (P < 0.05). Also, we found that the expression of ERalpha and ERbeta has no relationship with the status of lymph node of adenocarcinoma (P > 0.05). Both ERalpha and ERbeta play an important role in endometrial hyperplasia and carcinomas, the levels of ERalpha and ERbeta appear be used as prognostic indicators.

Expression of estrogen receptors ERα and ERβ in endometrial hyperplasia and adenocarcinoma

We assessed the expression of estrogen receptors (ER)α and ERβ in 114 human endometrial hyperplasia and adenocarcinomas. The aim of this study was to determine the expression of both ER isoforms in human endometrial tissue by immunohistochemistry. From normal proliferation to simple and complex hyperplasia, the expression of ERα was increased (P < 0.05), while ERβ did not change much (P > 0.05). In atypia hyperplasia and adenocarcinoma, both ERα and ERβ were decreased significantly (P < 0.05). Most endometrial adenocarcinomas expressed ERα, either alone or in combination with ERβ, and the ERβ/ERα ratio was decreased when compared to normal proliferation (P < 0.05). Also, we found that the expression of ERα and ERβ has no relationship with the status of lymph node of adenocarcinoma (P > 0.05). Both ERα and ERβ play an important role in endometrial hyperplasia and carcinomas, the levels of ERα and ERβ appear be used as prognostic indicators.

Matrix metalloproteinase 2 and tissue inhibitor of metalloproteinase 2 expression is not regulated by norgestimate or norelgestromin

Steroid hormones regulate endometrial expression of matrix metalloproteinases (MMPs) and their inhibitors. Synthetic progestins are widely used in oral contraceptives and for hormone replacement therapy. To assess whether the synthetic progestins norgestimate and its derivative norelgestromin (17-deacetylnorgestimate) modulate the expression of MMPs, Ishikawa endometrial cancer cells were separately treated with 17 beta-estradiol, 17 alpha-hydroxyprogesterone, norgestimate and norelgestromin. Culture supernatants were assayed for MMPs 2, 3 and 9, and for tissue inhibitors of MMPs (TIMP-1 and TIMP-2) by enzyme-linked immunosorbent assays (ELISAs). No marked modulation of MMP-2 and TIMP-2 expression was observed upon incubation of the cells with the synthetic progestins. By ELISA, neither MMP-3 or MMP-9 nor TIMP-1 immunoreactivity was detected. Interestingly, TIMP-2 expression was down-regulated by 17 beta-estradiol and 17 alpha-hydroxyprogesterone.

LacSwitch II regulation of connexin43 cDNA expression enables gap-junction single-channel analysis

Metabolic and electrical coupling through gap junction channels is implicated in cell differentiation, tissue homeostasis, and electrotonic propagation of signals in excitable tissues. The characterization of gating properties of these channels requires electrophysiological recordings at both single- and multiple-channel levels. Hence, a system that is able to control connexin expression by external means would provide a useful tool. To regulate the expression of connexins in cells, plasmids encoding a transactivator and/or a lac-operon IPTG response-dependent Cx43 target gene were transfected into communication-deficient N2a neuroblastoma cells. Immunoblotting, dye coupling, and electrophysiological methods revealed that expression of Cx43 in selected clones could be tightly regulated. After 15-20 h of acute induction with IPTG, cell-to-cell communication reached its peak with junctional conductances of 15-30 nS. Chronic induction at specific doses of IPTG produced constant, controlled levels of Cx43 expression, which were reflected by predictable junctional coupling levels. These conditions allowed prolonged recordings from either lowly or highly coupled cells, making lac operon an ideal regulatory system for channel gating studies at a single-channel level.

[A textual research on drinking disease and antidrinking remedies]

This subject is investigated through three aspects, viz., definition of drinking disease, its manifestations and treatment, and recipes and drug for antidrinking. The term "drinking disease" (Jiu Bing) was first recorded in Wang Shuhe's Canon of Pulsology, while abnormal drinking (Jiu Bo) was mentioned in Miraculous Pivot (Ling Shu). On Pathogenesis Manifestation of all diseases (Zhu Bing Yuan Hou Lun) gives the pathology and etiology. Great influence was exerted from Jin-yuan dynasties concerning its treatment. Zhang Jiebin expounded the comatous syndrome due to drinking (Jiu Jue). The earliest antidrinking drug was recorded in Shen Nong's Classic of Herbology. Through investigation, the commonly applied drug for relieving drunk include Flos Puerariae, Fructus Hovenariae, while the famous recipe for relieving drunk is Anti-tipsy Decoction of Flos Puerariae.

Chlamydia pneumoniae major outer membrane protein is a surface-exposed antigen that elicits antibodies primarily directed against conformation-dependent determinants

The major outer membrane protein (MOMP) of Chlamydia trachomatis serovariants is known to be an immunodominant surface antigen. Moreover, it is known that the C. trachomatis MOMP elicits antibodies that recognize both linear and conformational antigenic determinants. In contrast, it has been reported that the MOMP of Chlamydia pneumoniae is not surface exposed and is immunorecessive. We hypothesized that the discrepancies between C. trachomatis and C. pneumoniae MOMP exposure on intact chlamydiae and immunogenic properties might be because the focus of the host's immune response is directed to conformational epitopes of the C. pneumoniae MOMP. We therefore conducted studies aimed at defining the surface exposure of MOMP and the conformational dominance of MOMP antibodies. We present here a description of C. pneumoniae species-specific monoclonal antibody (MAb), GZD1E8, which recognizes a conformational epitope on the surface of C. pneumoniae. This MAb is potent in the neutralization of C. pneumoniae infectivity in vitro. Another previously described C. pneumoniae species-specific monoclonal antibody, RR-402, displayed very similar characteristics. However, the antigenic determinant recognized by RR-402 has yet to be identified. We show by immunoprecipitation of C. pneumoniae with GZD1E8 and RR-402 MAbs and by mass spectrometry analysis of immunoprecipitated proteins that both antibodies GZD1E8 and RR-402 recognize the MOMP of C. pneumoniae and that this protein is localized on the surface of the organism. We also show that human sera from C. pneumoniae-positive donors consistently recognize the MOMP by immunoprecipitation, indicating that the MOMP of C. pneumoniae is an immunogenic protein. These findings have potential implications for both C. pneumoniae vaccine and diagnostic assay development.

Identification of a chlamydial protease-like activity factor responsible for the degradation of host transcription factors

Microbial pathogens have been selected for the capacity to evade or manipulate host responses in order to survive after infection. Chlamydia, an obligate intracellular pathogen and the causative agent for many human diseases, can escape T lymphocyte immune recognition by degrading host transcription factors required for major histocompatibility complex (MHC) antigen expression. We have now identified a chlamydial protease- or proteasome-like activity factor (CPAF) that is secreted into the host cell cytosol and that is both necessary and sufficient for the degradation of host transcription factors RFX5 and upstream stimulation factor 1 (USF-1). The CPAF gene is highly conserved among chlamydial strains, but has no significant overall homology with other known genes. Thus, CPAF represents a unique secreted protein produced by an obligate intracellular bacterial pathogen to interfere with effective host adaptive immunity.

Chlamydia pneumoniae infection significantly exacerbates aortic atherosclerosis in an LDLR-/- mouse model within six months

We have previously shown that infection with the C. pneumoniae AR39 strain once monthly for 9 consecutive months significantly exacerbated atherosclerosis in mice with LDL receptor deficiency (LDLR-/-) in the presence of a high cholesterol diet. To further optimize the LDLR-/- mouse model for studying the mechanisms of C. pneumoniae atherogenesis, we have tested a different infection protocol with intranasal inoculation twice monthly for 6 consecutive months in the present study. We found that C. pneumoniae infection for 6 months was sufficient to produce a 130%, significantly greater exacerbation of aortic atherosclerosis in LDLR-/- mice in the presence of a high cholesterol diet. Mice receiving a high cholesterol diet alone displayed a lesion area index of 18.2 +/- 6.1 (S.D.) while mice treated with both the high cholesterol diet and C. pneumoniae infection had a lesion area index of 41.8 +/- 15.2 (S.D.). However, the chlamydial infection did not significantly alter the mouse serum total cholesterol or the LDL levels induced by the high cholesterol diet. This study not only confirms our previous findings that C. pneumoniae infection can exacerbate aortic atherosclerosis lesion in the LDLR-/- mice, but also further optimizes the LDLR-/- mouse model for future mechanism studies.

A motif shared by TFIIF and TFIIB mediates their interaction with the RNA polymerase II carboxy-terminal domain phosphatase Fcp1p in Saccharomyces cerevisiae

Transcription by RNA polymerase II is accompanied by cyclic phosphorylation and dephosphorylation of the carboxy-terminal heptapeptide repeat domain (CTD) of its largest subunit. We have used deletion and point mutations in Fcp1p, a TFIIF-interacting CTD phosphatase, to show that the integrity of its BRCT domain, like that of its catalytic domain, is important for cell viability, mRNA synthesis, and CTD dephosphorylation in vivo. Although regions of Fcp1p carboxy terminal to its BRCT domain and at its amino terminus were not essential for viability, deletion of either of these regions affected the phosphorylation state of the CTD. Two portions of this carboxy-terminal region of Fcp1p bound directly to the first cyclin-like repeat in the core domain of the general transcription factor TFIIB, as well as to the RAP74 subunit of TFIIF. These regulatory interactions with Fcp1p involved closely related amino acid sequence motifs in TFIIB and RAP74. Mutating the Fcp1p-binding motif KEFGK in the RAP74 (Tfg1p) subunit of TFIIF to EEFGE led to both synthetic phenotypes in certain fcp1 tfg1 double mutants and a reduced ability of Fcp1p to activate transcription when it is artificially tethered to a promoter. These results suggest strongly that this KEFGK motif in RAP74 mediates its interaction with Fcp1p in vivo.

[Inner-hemangioma ligation and pingyangmycin injection in hemangioma (with 30 cases report)]

OBJECTIVE

To provide a simple and safe surgical approach in treating cavernous and racemose hemangioma.

METHODS

First cross-ligate the hemangioma, as to divide the tumor into independent compartments, them inject pingyangmycin into the compartments respectively.

RESULTS

There are 30 cases in this group (35 hemangiomas). Twenty-four cases (28 hemangiomas) were totally cured, accounting for 80%; Six cases were improved (7 hemangiomas) for 20%; There was no ineffective case.

CONCLUSION

"Inner-hemangioma ligation and injection of pingyangmycin" has broad surgical indications, with desirable outcome in treating cavernous and racemose hemangioma, especially those unsuitable for surgery, or ineffective simply by inner-hemangioma injection.

Degradation of transcription factor RFX5 during the inhibition of both constitutive and interferon gamma-inducible major histocompatibility complex class I expression in chlamydia-infected cells

We have previously shown that the obligate intracellular pathogen chlamydia can suppress interferon (IFN)-gamma-inducible major histocompatibility complex (MHC) class II expression in infected cells by degrading upstream stimulation factor (USF)-1. We now report that chlamydia can also inhibit both constitutive and IFN-gamma-inducible MHC class I expression in the infected cells. The inhibition of MHC class I molecule expression correlates well with degradation of RFX5, an essential downstream transcription factor required for both the constitutive and IFN-gamma-inducible MHC class I expression. We further demonstrate that a lactacystin-sensitive proteasome-like activity identified in chlamydia-infected cell cytosolic fraction can degrade both USF-1 and RFX5. This proteasome-like activity is dependent on chlamydial but not host protein synthesis. Host preexisting proteasomes may not be required for the unique proteasome-like activity. These observations suggest that chlamydia-secreted factors may directly participate in the proteasome-like activity. Efforts to identify the chlamydial factors are underway. These findings provide novel information on the molecular mechanisms of chlamydial evasion of host immune recognition.