Reciprocal expression of MADS-box genes and DNA methylation reconfiguration initiate bisexual cones in spruce

The naturally occurring bisexual cone of gymnosperms has long been considered a possible intermediate stage in the origin of flowers, but the mechanisms governing bisexual cone formation remain largely elusive. Here, we employed transcriptomic and DNA methylomic analyses, together with hormone measurement, to investigate the molecular mechanisms underlying bisexual cone development in the conifer Picea crassifolia. Our study reveals a "bisexual" expression profile in bisexual cones, especially in expression patterns of B-class, C-class and LEAFY genes, supporting the out of male model. GGM7 could be essential for initiating bisexual cones. DNA methylation reconfiguration in bisexual cones affects the expression of key genes in cone development, including PcDAL12, PcDAL10, PcNEEDLY, and PcHDG5. Auxin likely plays an important role in the development of female structures of bisexual cones. This study unveils the potential mechanisms responsible for bisexual cone formation in conifers and may shed light on the evolution of bisexuality.

[Adult-onset immunodeficiency induced by anti-interferon-γ autoantibodies: report of 13 cases]

Objective: To investigate the clinical characteristics of a group of patients with adult-onset immunodeficiency (AOID) induced by anti-interferon-γ autoantibodies (AIGA). Methods: Thirteen cases of AOID in a northern China medical center (Peking Union Medical College Hospital) from October 2020 to April 2022 were included. Data comprising clinical manifestations, laboratory results, infection sites and pathogens were collected. Results: Among the 13 patients, 5 were male. The median age of disease onset was 47 (14 to 71) years. The median time from symptom onset to diagnosis was 4 years (1 to 8 years). Four patients were from northern China, and 9 from southern China. Common symptoms included lymphadenopathy (13/13), fever (12/13), respiratory tract symptoms (12/13), and weight loss (11/13). Laboratory tests showed increased levels of white blood cell count (9/13), neutrophil count and proportion (9/13), erythrocyte sedimentation rate (ESR) (12/13), and C reactive protein (CRP) (11/13). The median plasma titers of AIGA upon diagnosis were 5681(3194, 13246). Sites of infection included lungs (12/13), lymph nodes (9/13), bones and joints (9/13), skin and soft tissue (7/13), blood flow and bone marrow (4/13), and glands (3/13). Most patients had nontuberculous mycobacteria (NTM) (12/13) infection. Seven patients had more than one pathogen. Conclusions: AOID also affects patients visiting northern China hospitals. AIGA screening is recommended among patients with disseminated NTM infections or recurrent infections.

A Comprehensive Evolutionary Study of Chloroplast RNA Editing in Gymnosperms: A Novel Type of G-to-A RNA Editing Is Common in Gymnosperms

Although more than 9100 plant plastomes have been sequenced, RNA editing sites of the whole plastome have been experimentally verified in only approximately 21 species, which seriously hampers the comprehensive evolutionary study of chloroplast RNA editing. We investigated the evolutionary pattern of chloroplast RNA editing sites in 19 species from all 13 families of gymnosperms based on a combination of genomic and transcriptomic data. We found that the chloroplast C-to-U RNA editing sites of gymnosperms shared many common characteristics with those of other land plants, but also exhibited many unique characteristics. In contrast to that noted in angiosperms, the density of RNA editing sites in ndh genes was not the highest in the sampled gymnosperms, and both loss and gain events at editing sites occurred frequently during the evolution of gymnosperms. In addition, GC content and plastomic size were positively correlated with the number of chloroplast RNA editing sites in gymnosperms, suggesting that the increase in GC content could provide more materials for RNA editing and facilitate the evolution of RNA editing in land plants or vice versa. Interestingly, novel G-to-A RNA editing events were commonly found in all sampled gymnosperm species, and G-to-A RNA editing exhibits many different characteristics from C-to-U RNA editing in gymnosperms. This study revealed a comprehensive evolutionary scenario for chloroplast RNA editing sites in gymnosperms, and reported that a novel type of G-to-A RNA editing is prevalent in gymnosperms.

Single Amino Acid Substitution the DNA Repairing Gene Radiation-Sensitive 4 Contributes to Ultraviolet Tolerance of a Plant Pathogen

To successfully survive and reproduce, all species constantly modify the structure and expression of their genomes to cope with changing environmental conditions including ultraviolet (UV) radiation. Thus, knowledge of species adaptation to environmental changes is a central theme of evolutionary studies which could have important implication for disease management and social-ecological sustainability in the future but is generally insufficient. Here, we investigated the evolution of UV adaptation in organisms by population genetic analysis of sequence structure, physiochemistry, transcription, and fitness variation in the radiation-sensitive 4 (RAD4) gene of the Irish potato famine pathogen Phytophthora infestans sampled from various altitudes. We found that RAD4 is a key gene determining the resistance of the pathogen to UV stress as indicated by strong phenotype-genotype-geography associations and upregulated transcription after UV exposure. We also found conserved evolution in the RAD4 gene. Only five nucleotide haplotypes corresponding to three protein isoforms generated by point mutations were detected in the 140 sequences analyzed and the mutations were constrained to the N-terminal domain of the protein. Physiochemical changes associated with non-synonymous mutations generate severe fitness penalty to mutants, which are purged out by natural selection, leading to the conserved evolution observed in the gene.

[Hypomethylation of DAPL1 associated with prognosis of lung cancer patients with EGFR Del19 mutation]

Objective: To investigate the effect of apoptosis-associated protein kinase-like 1 (DAPL1) hypomethylation on prognosis of lung cancer patients with epidermal growth factor receptor gene exon 19 deletion (EGFR Del19) mutation. Methods: The clinicopathological data of lung cancer patients in databases of genomic data sharing (GDC) TCGA lung adenocarcinoma, TCGA lung adenocarcinoma, and TCGA lung cancer were collected to analyze the effect of DAPL1 methylation level on the prognosis of patients with EGFR Del19 mutation. Linear regression model was used for correlation analysis, Kaplan-Meier method was used to draw the survival curve, and the difference of survival curve between the two groups was tested by Log rank. Results: In GDC TCGA lung adenocarcinoma, TCGA lung adenocarcinoma and TCGA lung cancer databases, the 5-year survival rates of lung cancer patients with high DAPL1 expression (31.9%, 27.5% and 33.0%, respectively) were higher than those with low DAPL1 expression (11.0%, 11.6% and 13.8%, respectively). The differences were statistically significant (P=0.006, 0.028 and 0.025, respectively). The median expression levels of DAPL1 in patients with EGFR Del19 mutation (12.8, 2.75 and 2.9, respectively) were higher than those in patients with other EGFR mutations (11.6, 1.75 and 1.8, respectively, P<0.05). In TCGA lung adenocarcinoma and TCGA lung cancer database, the 5-year survival rate of lung cancer patients with lower DAPL1 methylation levels (22.4% and 16.4%, respectively) were higher than those of lung cancer patients with higher DAPL1 methylation levels (15.1% and 14.2%, respectively), with statistical significance (P<0.05). The expression level of DAPL1 was positively correlated with the EGFR mutant subtype (r=0.909, P<0.05), and negatively correlated with DNA methylation (r=-0.891, P<0.05). The expression of DAPL1 in lung cancer patients was regulated by DNA methylation, which affected the prognosis of lung cancer patients. Conclusion: High DAPL1 expression, or hypomethylation, is associated with lung cancer EGFR Del19 mutation subtype, and DAPL1 hypomethylated lung cancer patients have longer overall survival.

The importance of the iron valence state in NiCoFe nanosheet array catalysts for the oxygen evolution reaction

The catalytic performances of NiCoFe nanosheet array catalysts for the OER are strongly dependent on the valence state of iron cations in the precursors.

Phylotranscriptomics reveals the complex evolutionary and biogeographic history of the genus Tsuga with an East Asian-North American disjunct distribution

The disjunct distribution between East Asia and North America is one of the best established biogeographic patterns. A robust phylogeny is fundamental for understanding the biogeographic histories of taxa with this distribution pattern. Tsuga (hemlock) is a genus of Pinaceae with a typical intercontinental disjunct distribution in East Asia and eastern and western North America, and its phylogeny has not been completely reconstructed in previous studies. In this study, we reconstructed a highly resolved phylogeny of Tsuga using 881 nuclear genes, 60 chloroplast genes and 23 mitochondrial genes and explored its biogeographic and reticulate evolutionary history. The results of phylogenetic analysis, molecular dating and ancestral area reconstruction indicate that Tsuga very likely originated from North America in the late Oligocene and dispersed from America to East Asia via the Bering Land Bridge during the middle Miocene. In particular, we found complex reticulate evolutionary pattern among the East Asian hemlock species. T. sieboldii possibly originated from hybridization with the ancestor of T. chinensis from mainland China and T. forrestii as the paternal donor and the ancestor of T. diversifolia and T. ulleungensis as the maternal donor. T. chinensis (Taiwan) could have originated by hybridization together with T. sieboldii and then evolved independently after dispersal to the Taiwan Island, subsequently experiencing mitochondrial DNA introgression with T. chinensis from mainland China. Moreover, our study found that T. chinensis from western China is more closely related to T. forrestii than to T. chinensis from eastern China. The nonmonophyletic T. chinensis needs taxonomic reconsideration.

[Epidemiological and virus molecular characterization of dengue fever outbreak in Hunan province, 2018]

Objective: To analyze the epidemiological and etiological characteristics of a dengue fever outbreak in Hunan province in 2018. Methods: Real-time PCR assay was performed for the laboratory diagnosis of 8 suspected dengue fever cases. Etiological surveillance was performed in 186 suspected dengue fever cases and fever cases who had close contacts with dengue fever patients. C6/36 cells was used for the virus isolation from acute phase serum. By sequencing the full length of E genes of 15 dengue virus strains, phylogenetic analysis was performed based on the sequences obtained, including reference sequences from the NCBI GenBank database, the serotypes and gene subtypes of the virus were analyzed to trace the possible source of transmission. An emergency monitoring of vector density and a retrospective survey of sero-epidemiology in healthy population were conducted in the epidemic area. Results: In the serum samples of 8 suspected patients, 6 were dengue virus RNA positive, and 4 were NS1 antigen positive. In 186 suspected patients, 96 were dengue virus nucleic acid, NS1 antigen or antibody positive in etiological test. A total of 64 dengue virus strains were isolated. The phylogenetic analysis showed that all the dengue virus strains belonged to type 2, which might be from Guangdong or Zhejiang provinces. The Bretub index was up to 65, indicating an extremely high risk of transmission. The positive rate of the dengue virus IgG antibody was 0.53%(2/377) in retrospective survey of 377 healthy people. Conclusion: The field epidemiologic and the molecular genetics analyses showed the outbreak of dengue fever in Hunan in 2018 was caused by imported cases and dengue virus 2.

The flattened and needlelike leaves of the pine family (Pinaceae) share a conserved genetic network for adaxial-abaxial polarity but have diverged for photosynthetic adaptation

Background

Leaves have highly diverse morphologies. However, with an evolutionary history of approximately 200 million years, leaves of the pine family are relatively monotonous and often collectively called “needles”, although they vary in length, width and cross-section shapes. It would be of great interest to determine whether Pinaceae leaves share similar morpho-physiological features and even consistent developmental and adaptive mechanisms.

Results

Based on a detailed morpho-anatomical study of leaves from all 11 Pinaceae genera, we particularly investigated the expression patterns of adaxial-abaxial polarity genes in two types of leaves (needlelike and flattened) and compared their photosynthetic capacities. We found that the two types of leaves share conserved spatial patterning of vasculatures and genetic networks for adaxial-abaxial polarity, although they display different anatomical structures in the mesophyll tissue differentiation and distribution direction. In addition, the species with needlelike leaves exhibited better photosynthetic capacity than the species with flattened leaves.

Conclusions

Our study provides the first evidence for the existence of a conserved genetic module controlling adaxial-abaxial polarity in the development of different Pinaceae leaves.

[Clinical application of self-made drainage tubes in different layers of soft tissue for negative-pressure wound therapy in 33 patients]

From January 2014 to June 2018, 28 patients with different types of deep soft tissue injury or infection were admitted to the Affiliated Jiangyin Hospital of Medical College of Southeast University; 5 patients were admitted to the Zhengzhou First People's Hospital. There were 24 males and 9 females, aged 18-89 (40±20) years. Disposable suction tubes with holes cut on side walls were used as self-made drainage tubes. The authors placed the self-made drainage tubes on different deep soft tissue layers and wound surfaces after debridement. The effective drainage sections of the wound surface drainage tubes were wrapped with silver ion antimicrobial functional active dressings. Bio-permeable membrane was used to close the operative area. The drainage tubes in the deep layer of wound and wound surface were connected in parallel by a tee and connected to wall-hanging medical negative-pressure suction device to conduct negative-pressure wound treatment at -20.0 to -10.6 kPa. The deep drainage tubes were usually removed or changed 4 or 5 days after surgery.The drainage tubes in the wound surface were synchronously replaced when removing or replacing he drainage tubes in the deep layer of wound. On 4 to 15 days after surgery, the deep drainage tubes were removed. On 8 to 25 days after surgery, the wound surface drainage tubes were removed. Then the treatment was changed to a conventional dressing change until the wounds were completely healed or the wound bed was ready for skin grafts or tissue flaps. The indwelling time of deep drainage tubes in this group of patients was (6.2±2.8) days, and the indwelling time of wound surface drainage tubes was (12.0±3.0) days. The wound healing time was (22±5) days, the hospital stay time was (29±7) days, and wound bacteria were reduced from 6 species and 11 strains before treatment to 3 species and 4 strains after treatment. No adverse events such as wound bleeding, irritative pain, and chronic sinus occurred during treatment. Twenty-three patients were followed up for 13 to 28 months, no treatment-related complications were observed.

[Acute respiratory failure due to Pneumocystis pneumonia in connective tissue disease patients: clinical manifestation and prognostic factors related to hospital mortality]

Objective: To investigate the clinical manifestations and prognostic factors of hospital death in connective tissue disease patients with acute respiratory failure caused by pneumocystis pneumonia (PCP) admitted to two medical intensive care units(MICU). Methods: A retrospective review was conducted for all connective tissue disease (CTD) patients with acute respiratory failure from PCP in MICU of 2 academic medical centers between 2010 and 2015. The patients were divided into survivors and non-survivors. Demographic and clinical data, including laboratory, radiological and microbiological findings, as well as therapy, clinical course, mortality and prognostic factors of hospital mortality were included in the analysis. Logistic regression models were used to determine the effect of prognostic factors on hospital death after adjusting for covariates of which the p values were less than 0.1. Results: A total of 41 patients with connective tissue disease were identified. The PaO(2)/FiO(2) ratio (PFR) on ICU admission was 120 mmHg(55-180 mmHg, 1 mmHg=0.133 kPa). Common clinical features included dyspnea (90.2%, 37/41), fever (87.8%, 36/41) and dry cough(65.9%, 30/41). 58.5%(24/41) and 17.1%(7/41) patients were co-infected by CMV and aspergillus, respectively. The overall mortality rate was 75.6%(31/41). Compared with survivors, the age, APACHEⅡ score and incidence of barotrauma in non-survivors were higher (39±17 vs 58±15, t=3.018, P=0.002), (15±6 vs 19±5, t=2.528, P=0.019), (0/10 vs 12/31, χ(2)=5.473, P=0.021), while PFR on ICU admission was lower in non-survivors (172±68 vs 116±49, t=-1.893, P=0.007). Logistic analysis showed that PFR on ICU admission was the independent risk factor for hospital death (OR=1.004, 95%CI: 1.002-1.006, P=0.048). Conclusions: Mortality rate among patients with acute respiratory failure secondary to CTD related PCP is still high, and the poor prognostic factors of hospital mortality included PFR on ICU admission and barotrauma.

hPCL3s Promotes Hepatocellular Carcinoma Metastasis by Activating β-Catenin Signaling

Two isoforms of human Polycomb-like protein 3 (hPCL3) have been reported as components of the nuclear Polycomb repressive complex 2 (PRC2), with the short isoform (hPCL3s) showing a dominant cytoplasmic localization. The function of cytoplasmic hPCL3s has, however, not been addressed. In this study, we report that hPCL3s is upregulated in clinical hepatocellular carcinoma (HCC) samples and its expression correlated with HCC clinical features. hPCL3s positively regulated the migration, invasion, and metastasis of HCC cells. hPCL3s interacted with components of the cytoplasmic β-catenin destruction complex, inhibited β-catenin degradation, and activated β-catenin/T-cell factor signaling. Downstream of the β-catenin cascade, IL6 mediated the motility-promoting functions of hPCL3s. Forced expression of hPCL3s in the liver of a HCC mouse model promoted tumorigenesis and metastasis. Taken together, these data show that hPCL3s promotes the metastasis of HCC by activating the β-catenin/IL6 pathway.Significance: hPCL3s has an oncogenic role in hepatocellular carcinoma by activating the β-catenin/IL6 signaling axis to promote metastasis. Cancer Res; 78(10); 2536-49. ©2018 AACR.

Microstructural visual pathway abnormalities in patients with primary glaucoma: 3 T diffusion kurtosis imaging study

AIM

To evaluate microstructural visual pathway damage in patients with primary glaucoma (PG) by using 3 T diffusion kurtosis imaging (DKI).

MATERIALS AND METHODS

The study was approved by the ethics committee, and all participants provided written informed consent. Ten patients with PG were examined. Twenty healthy individuals served as control subjects. DKI was performed with a GE Silent 3 T magnetic resonance imaging (MRI) unit. Mean diffusivity (MD), fractional anisotropy (FA), and mean kurtosis (MK) maps were automatically created. Mean MK, MD, and FA values were calculated for each part of the visual pathway.

RESULTS

No abnormalities in the shape and signal intensity were observed along the entire visual pathway in patients and the control group on the conventional MRI. Higher MD, and lower MK and FA were observed in the optic nerves (ON), lateral geniculate nucleus (LGN), optic radiations (OR), and visual cortex (VCx) of PG patients, as compared with control subjects. A significantly higher MD was observed in the ON (p<0.01), and significantly lower FA was observed in OR (p<0.05). Additionally, significantly lower MK was observed in the ON, LGN, and VCx, except for OR (p<0.01). Changes of DKI parameters in the ON were the most distinct.

CONCLUSION

Glaucoma is a complex neurological disease that affects the entire visual pathway. MK derived from DKI would be a better biomarkers than FA and MD in detecting microstructural damage.

A role of tumor susceptibility gene 101 (TSG101) in innate immune response of crayfish Procambarus clarkii

Tumor susceptibility gene 101 (TSG101) is a multi-functional gene involved in cell growth and proliferation in vertebrates. However, its role in the innate immune response of crustaceans remains unclear. Here, a TSG101 gene was identified in crayfish Procambarus clarkii with an open reading frame of 1320 bp that encoded a predicted 48.3-kDa protein highly homologous to those in other invertebrates. TSG101 mRNA was highly expressed in stomach and hepatopancreas, and its expression was induced significantly in different tissues (hemocytes, gills and intestine) by lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid (poly I: C) with various expression patterns. Recombinant TSG101 protein was expressed in Escherichia coli, and a possible protein-protein interaction between TSG101 and hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) was explored by far-western blotting. RNA interference of TSG101 affected the gene expression of members of the Toll pathway. These results suggest that TSG101 is involved in the innate immune responses of P. clarkii.

Iron overload in hereditary tyrosinemia type 1 induces liver injury through the Sp1/Tfr2/hepcidin axis

BACKGROUND & AIMS

Iron is an essential metal for fundamental metabolic processes, but little is known regarding the involvement of iron in other nutritional disorders. In the present study, we investigated disordered iron metabolism in a murine model of hereditary tyrosinemia type I (HT1), a disease of the tyrosine degradation pathway.

METHODS

We analysed the status of iron accumulation following NTBC withdrawal from Fah(-/-) mice, a murine model for HT1. Liver histology and serum parameters were used to assess the extent of liver injury and iron deposition. To determine the physiological significance of iron accumulation, mice were subjected to a low-iron food intake to reduce the iron accumulation. Mechanistic studies were performed on tissues and cells using immunoblotting, qRT-PCR, adenovirus transfection and other assays.

RESULTS

Severe iron overload was observed in the murine model of HT1 with dramatically elevated hepatic and serum iron levels. Mechanistic studies revealed that downregulation and dysfunction of Tfr2 decreased hepcidin, leading to iron overload. The Fah(-/-) hepatocytes lost the ability of transferrin-sensitive induction of hepcidin. Forced expression of Tfr2 in the murine liver reduced the iron accumulation. Moreover, transcription factor Sp1 was downregulated and identified as a new regulator of Tfr2 here. Additionally, low-iron food intake effectively reduced the iron deposits, protected the liver and prolonged the survival in these mice.

CONCLUSIONS

Iron was severely overloaded in the HT1 mice via the Sp1/Tfr2/Hepcidin axis. The iron overload induced liver injury in the HT1 mice, and reduction of the iron accumulation ameliorated liver injury.

LAY SUMMARY

Primary and secondary iron overload is an abnormal status affecting millions of people worldwide. Here, we reported severe iron overload in a murine model of HT1, a disease of the tyrosine degradation pathway, and elucidated the mechanistic basis and the physiological significance of iron overload in HT1. These studies are of general interest not only with respect to secondary iron-induced liver injury in HT1 but also are important to elucidate the crosstalk between the two metabolic pathways.

Dealloyed PdAg core Pt monolayer shell electrocatalyst for oxygen reduction reaction

A core–shell nanostructure with dealloyed PdAg nanoparticles as the core and a Pt monolayer as the shell shows much higher catalytic properties for oxygen reduction reaction as compared with its counterpart with alloyed PdAg as the core.

Sorafenib enriches epithelial cell adhesion molecule-positive tumor initiating cells and exacerbates a subtype of hepatocellular carcinoma through TSC2-AKT cascade

Sorafenib is a specific adenosine triphosphate-competitive RAF inhibitor used as a first-line treatment of advanced hepatocellular carcinoma (HCC). However, the responses are variable, reflecting heterogeneity of the disease, while the resistance mechanism remains poorly understood. Here, we report that sorafenib treatment can exacerbate disease progression in both patient-derived xenografts and cell line-derived xenografts and that the therapeutic effect of the drug inversely covaries to the ratio of epithelial cell adhesion molecule-positive cells, which may be tumor initiating cells in HCC. The TSC2-AKT cascade mediates this sorafenib resistance. In response to sorafenib treatment, formation of the TSC1/2 complex is enhanced, causing increased phosphorylation of AKT, which contributes to up-regulation of "stemness"-related genes in epithelial cell adhesion molecule-positive cells and enhancement of tumorigenicity. The expression of TSC2 negatively correlated with prognosis in clinical sorafenib therapy. Furthermore, all-trans retinoic acid decreased AKT activity, reduced the epithelial cell adhesion molecule-positive cell population enriched by sorafenib, and potentiated the therapeutic effect of sorafenib in the patient-derived xenograft model.

CONCLUSION

Our findings suggest that a subtype of HCC is not suitable for sorafenib therapy; this resistance to sorafenib can be predicted by the status of TSC2, and agents inducing differentiation of tumor initiating cells (e.g., all-trans retinoic acid) should improve the prognosis of this subtype of HCC.

Loop-locked coherent population trapping magnetometer based on a fiber electro-optic modulator

We have set up a coherent population trapping (CPT)-based magnetometer prototype with the D1 line of ⁸⁷Rb atoms. The dichromatic light field is derived from a fiber electro-optic modulator (FEOM) connected to an external cavity laser diode. A CPT resonance signal with a 516 Hz linewidth is observed. By feeding back the derivative of the resonance curve to the FEOM with a proportional integral controller, of which the voltage output is directly converted to the measured magnetic field intensity, the resonance peak is locked to the environmental magnetic field. The measurement data we have achieved are well matched with the data measured by a commercial fluxgate magnetometer within 2 nT, and the sensitivity is better than 8 pT/√Hz in a parallel B field.

Note: Generation of Raman laser beams based on a sideband injection-locking technique using a fiber electro-optical modulator

Two phase-coherent Raman laser beams with a frequency offset of 6.835 GHz were generated by sideband injection-locking technique. A master diode laser was phase-modulated at 6.835 GHz by a fiber electro-optic modulator. A slave diode was injection-locked to the -1 sideband of the phase-modulated beam, and another diode was locked to the master laser carrier. This method produced stable and spatially separated Raman lasers with a large frequency shift range (>180 MHz). The relative linewidth of these two beams was ∼1 Hz, and the unwanted carrier mode was suppressed down to -24 dB. Stimulated Raman transitions and Ramsey fringes were driven by Raman lasers in a cold atomic beam.

The effective method for investigation meridian tropism theory in rats

This present work describes an effective new method for study traditional Chinese medicine (TCM) on meridian tropism (MT) theory, which plays an essential role in clinical selection of TCM according to syndromes and strengthens the therapeutic effects. The new thread included material basis foundation and its tissue distribution study. Xiheliu, the most popular TCM on heart tropism, was investigated by simple and accurate high performance liquid chromatography (HPLC) method. The analysis of plasma after oral administration the total flavonoid of Xiheliu (TFX) exhibited that tamarixetin and kaempferide had the highest concentration and approximately the highest level within 25 min. The mixture of them could last accelerating the urine excretion more than 7 h after a single dose and could not cause the disorder of ion in rats, which was observed in diuretic activity experiment. In view of the reported biological activities was consistent with the effects of Xiheliu, tamarixetin and kaempferide were likely to be the material basis of it. Tissue distribution study showed that the highest level of analytes was in heart, lung, kidney and liver, and most tissues reached maximum level at 30 min post-dose. Since liver was the most important blood-supply tissue, the result of this experiment was in accordance with the MT record of Xiheliu and confirmed that tamarixetin and kaempferide was the material bases of it on MT. This is the first report for the illumination of material basis and the mechanism of Xiheliu on MT by analysis the record of Xiheliu in Compendium of Materia Medica and experimental study.

RACK1 suppresses gastric tumorigenesis by stabilizing the β-catenin destruction complex

BACKGROUND & AIMS

Dysregulation of Wnt signaling has been involved in gastric tumorigenesis by mechanisms that are not fully understood. The receptor for activated protein kinase C (RACK1, GNB2L1) is involved in development of different tumor types, but its expression and function have not been investigated in gastric tumors.

METHODS

We analyzed expression of RACK1 in gastric tumor samples and their matched normal tissues from 116 patients using immunohistochemistry. Effects of knockdown with small interfering RNAs or overexpression of RACK1 in gastric cancer cell lines were evaluated in cell growth and tumor xenograft. RACK1 signaling pathways were investigated in cells and zebrafish embryos using immunoblot, immunoprecipitation, microinjection, and in situ hybridization assays.

RESULTS

Expression of RACK1 was reduced in gastric tumor samples and correlated with depth of tumor infiltration and poor differentiation. Knockdown of RACK1 in gastric cancer cells accelerated their anchorage-independent proliferation in soft agar, whereas overexpression of RACK1 reduced their tumorigenicity in nude mice. RACK1 formed a complex with glycogen synthase kinase Gsk3β and Axin to promote the interaction between Gsk3β and β-catenin and thereby stabilized the β-catenin destruction complex. On stimulation of Wnt3a, RACK1 repressed Wnt signaling by inhibiting recruitment of Axin by Dishevelled 2 (Dvl2). Moreover, there was an inverse correlation between expression of RACK1 and localization of β-catenin to the cytoplasm/nucleus in human gastric tumor samples.

CONCLUSIONS

RACK1 negatively regulates Wnt signaling pathway by stabilizing the β-catenin destruction complex and act as a tumor suppressor in gastric cancer cells.

Catalytic Pt-on-Au nanostructures: why Pt becomes more active on smaller Au particles

Platinum is a widely used precious metal in many catalytic nanostructures. Engineering the surface electronic structure of Pt-containing bi- or multimetallic nanostructure to enhance both the intrinsic activity and dispersion of Pt has remained a challenge. By constructing Pt-on-Au (Pt^Au) nanostructures using a series of monodisperse Au nanoparticles in the size range of 2-14 nm, we disclose herein a new approach to steadily change both properties of Pt in electrocatalysis with downsizing of the Au nanoparticles. A combined tuning of Pt dispersion and its surface electronic structure is shown as a consequence of the changes in the size and valence-band structure of Au, which leads to significantly enhanced Pt mass-activity on the small Au nanoparticles. Fully dispersed Pt entities on the smallest Au nanoparticles (2 nm) exhibit the highest mass-activity to date towards formic acid electrooxidation, being 2 orders of magnitude (75-300 folds) higher than conventional Pt/C catalyst. Fundamental relationships correlating the Pt intrinsic activity in Pt^Au nanostructures with the experimentally determined surface electronic structures (d-band center energies) of the Pt entities and their underlying Au nanoparticles are established.

[Rapid determination of internal resistance in an electricigenic microorganism reaction system]

Internal resistance (R(int)) is an important parameter for kinetic studies on an electricigenic microorganism reaction system (EMRS). The traditional polarization curve measurement method is too laborious and tedious, usually leads to remarkable disturbance on system running. An improved method was put forward in this study, by decreasing the adjustment range of the external resistance value (R(ext)). In the situation of 10 omega of R(ext) step length and 1 min of voltage stabilization time, the whole test can be finished in 10 min, and the differences of the system current before and after R(int) determination were less than 20 microA. Different stabilization time has little influence on the results. Though to shorten the R(ext) step length can lessen the disturbance on the system running,it simultaneously leads to a larger measurement errors because of the multimeter precision limitation. The method advanced may be used to monitor the real-time R(int) change of EMRS.

Performance of tetramethoxyphenyl porphyrin cobalt(II) (CoTMPP) based stainless steel cathode in the electricigenic permeable reactive barrier for groundwater organic contamination remediation

An electricigenic permeable reactive barrier (EPRB) technology was brought forward for remediation of organic-contaminated groundwater, with a benefit that it overcame the limitations of electron acceptor addition in other groundwater remediation methods. To investigate performances of constructions and materials used in EPRB system, several kinds of reactors were designed and prepared in laboratory. Stainless steel wires, a kind of nontoxic, inexpensive and conductive material, were used as basic material of electrode. In order to improve cathodic oxygen reduction capability, a cathode based on tetramethoxyphenyl porphyrin cobalt (II) (CoTMPP) was prepared and studied in this paper. Results showed that a high catalytic activity for oxygen reduction was exhibited by the CoTMPP based cathode, with an electricity generation 3 times as high as that of the naked stainless steel cathode. Some evidence indicated that by loading on the surface of stainless steel wires and heat-treated under anaerobic conditions, epoxy resin, with its curing agents, might have got a catalytic capability for oxygen reduction.

Structural diversity and evolution of the Rf-1 locus in the genus Oryza

The Rf-1 locus in rice is agriculturally important as it restores fertility in plants with BT-type cytoplasmic male sterility (CMS). The Rf-1 locus contains several duplicated copies of the gene responsible for restoration of fertility. We analyzed the genomic structure of the Rf-1 locus in the genus Oryza to clarify the structural diversity and evolution of the locus. We identified six genes (Rf-1A to Rf-1F) with homology to Rf-1 at this locus in Oryza species with an AA genome. The Rf-1 locus structures in the rice accessions examined were very complex and fell into at least six classification types. The nucleotide sequences of the duplicated genes and their flanking regions were highly conserved suggesting that the complex Rf-1 locus structures were produced by homologous recombination between the duplicated genes. The fact that complex Rf-1 locus structures were common to Oryza species that have evolved independently indicates that a duplication of the ancestral Rf-1 gene occurred early in rice evolution and that homologous recombination resulted in the diversification of Rf-1 locus structures. Additionally, the amino acid sequences of each duplicated gene were conserved between species. This suggests that the duplicated genes in the Rf-1 locus may have divergent functions and may act by controlling mitochondrial gene expression in rice as occurs in the restoration of CMS.

Photoreactivation of Escherichia coli following medium-pressure ultraviolet disinfection and its control using chloramination

Ultraviolet (UV) disinfection is becoming increasingly popular as an alternative disinfection technology to chlorination in recent years. In this study, we investigated the photoreactivation of Escherichia coli following medium-pressure (MP) UV disinfection of synthetic water by a bench-scale collimated beam apparatus. The UV doses ranged from 1.6 -19.7 mWs/cm2 and photoreactivation was investigated for 6 hours under fluorescent light. In addition, chloramination was applied after UV disinfection to investigate its ability to control photoreactivation. It was found that photoreactivation occurred for all UV doses tested and the increase in bacteria numbers ranged from 0.04 to 1.35 log10. However, the degree of photoreactivation decreased with increased UV doses. Chloramination experiments revealed that the addition of 0.5 mg/l of monochloramine resulted in suppression of photoreactivation for 1 hour only. An increased monochloramine dose of 1 mg/l was found to prevent photoreactivation for the entire duration of the experiment. The results of this study have shown that photoreactivation occurs even after MP UV disinfection, although it is of a lesser extent at higher UV doses. This study has also established that secondary chloramination can effectively suppress and eliminate photoreactivation with a chloramine dose of 1 mg/l.

Effects of pH and temperature on the survival of coliphages MS2 and Qbeta

The RNA F-specific coliphages, MS2 and Qbeta, have been used as virus indicators in water and wastewater studies. It is therefore useful to have a good understanding concerning the effects of environmental factors on their survival in order to choose an appropriate candidate for assessing microbial safety in relation to water quality management. The effects of pH and temperature on the survival of these two coliphages were investigated. MS2 survived better in acidic conditions than in an alkaline environment. In contrast, Qbeta had a better survival rate in alkaline conditions than in an acidic environment. The inactivation rates of both coliphages were lowest within the pH range 6-8 and the temperature range 5-35 degrees C. The inactivation rates of both coliphages increased when the pH was decreased to below 6 or increased to above 8. The inactivation rates of both coliphages increased with increasing temperature. Qbeta behaved peculiarly in extreme pH buffers, i.e. it was inactivated very rapidly initially when subjected to an extreme pH environment, although the inactivation rate subsequently decreased. In general, MS2 was a better indicator than Qbeta. However, within the pH range 6-9 and at temperatures not above 25 degrees C, either MS2 or Qbeta could be used as a viral indicator.

Kinetics of beta-mannanase fermentation by Bacillus licheniformis

Bacterial growth, konjac powder utilization and beta-mannanase production by Bacillus licheniformis NK-27 in batch fermentation were used to develop a model of the process. The optimal set of parameters was estimated by fitting the model to experimental data. The results predicted by the model were in good agreement with the experimental data.

NOMENCLATURE

fs, fraction parameter; Kp, constant in Equation (6) (g l(-1)); Ks, Monod constant for bacteria growth (g l(-1)); m, maintenance coefficient (g g(-1) h(-1)); P, beta-mannanase concentration (g 1(-1)); qm, constant in Equation (6) (h(-1)); S, substrate concentration (g l(-1)); S0, initial substrate concentration (g l(-1)); Si, insoluble substrate concentration (g l(-1)); Ss, soluble substrate concentration (g l(-1)); t, fermentation time (h); tL, lag time (h); mu, specific growth rate (h(-1)); mu(max), maximum specific growth rate (h(-1)); X, biomass concentration (g l(-1)); YP/S, beta-mannanase yield on carbon substrate (g g(-1)); YX/S, biomass yield on carbon substrate (g g(-1)).

Removal of MS2 bacteriophage using membrane technologies

Removals of MS2 bacteriophage virus using different membrane materials under different operating pressures were investigated. The results obtained in this study suggested that a better log removal in terms of MS2 bacteriophage virus could be achieved using Polyamide RO membrane under the optimum operating pressure of 100 psi. It is further noted that variable MS2 influent concentration levels resulted in corresponding variable log removals of the bacteriophages by the Polyamide RO membrane. The presence of MS2 bacteriophage virus in the effluent could possibly be due to leakage of bacteriophages through the membranes structure. Investigations using SEM and AFM showed that there were gaps or pores present in the membrane structure which were sufficiently large for the MS2 viruses to pass through.

Fermentation of starch for enhanced alkaline protease production by constructing an alkalophilic Bacillus pumilus strain

A new engineering strain, Bacillus pumilus c172-14 (pBX 96), was obtained by introducing the pBX 96 plasmid, which carries the alpha-amylase amy gene, into the host strain of alkalophilic Bacillus pumilus c172 via transformation. The newly constructed strain was found to express the amy gene and could use starch instead of glucose or starch hydrolysate as carbon source for its fermentation of alkaline protease. The pBX 96 plasmid in the new host was found to be segregationally and structurally stable. The expression of amy gene did not affect the host strain's resistance to bacteriophages. Moreover, the level of alkaline protease was improved significantly compared with the parent strain. The constructed strain gave a maximum alkaline protease activity of 14,014 U/ml in shaking flask after 48 h cultivation when growing in a medium containing 6% corn meal, 4% soybean flour, 0.4% Na2HPO4, 0.03% KH2PO4, 0.02% MgCl2, 0.3% CaCl2, 0.25% Na2CO3, 0.1% glucose, and 20 microg/ml kanamycin (pH 7.0). The optimal pH value and temperature of the alkaline protease were 11.0 and 40 degrees C, respectively. This enzyme was stable over a pH range of 8-11. Its residual activity remained at 100% when treated under a temperature of less than 45 degrees C for 30 min. The corresponding residual activity reduced to 65% of its optimal value at 60 degrees C for 30 min. The alkaline protease was a kind of serine protease, which was demonstrated by the complete inactivation by PMSF (1 mM). This newly constructed strain will be useful in the alkaline protease industry.

Prognostic importance of left ventricular diastolic filling velocity profiles in dilated cardiomyopathy

To determine the prognostic importance of pulsed Doppler-derived left ventricular diastolic filling velocity profiles and the relationship between Doppler variables and clinical functional status, the follow-up outcome of 58 patients with dilated cardiomyopathy and symptoms of left ventricular dysfunction was analysed. During a mean follow-up period of 31.2 +/- 12.8 months, 23 died of either progressive pump failure or sudden death. Peak early filling velocity (E) was higher and late atrial filling velocity (A) lower in nonsurvivors than in survivors. The E/A ratio was higher and the deceleration time (DT) of early diastole shorter in nonsurvivors. The mortality was significantly higher in patients with an E/A ratio > 2 or a DT < 150 ms than in those without. Repeated Doppler echocardiographic examinations in 31 of 35 survivors after intense treatment showed decreased E, increased A, reduced E/A ratio and prolonged DT in 18 patients with clinical functional improvement, whereas these measurements were unaltered in the remaining 13 patients whose functional status was unchanged or deteriorated. This study suggests that pulsed Doppler-derived left ventricular diastolic filling variables may be important predictors of outcome in dilated cardiomyopathy and provide useful measures in observing the effects of therapy during long-term follow-up of the patients.