[International multi-center evaluation of a rapid antigen test based on gold immunochromatographic assay for detection of severe acute respiratory syndrome coronavirus 2].

Objective: The gold immunochromatographic assay for detection of SARS-CoV-2 antigen was evaluated by international multi-center clinical trial. Methods: A total of 1 855 clinical parallel samples with valid test results (for nucleic acid and antigen tests, respectively) were collected from nine countries, including Germany, the United Kingdom, Ukraine, France, India, Thailand, Malaysia, the United States of America and Brazil, with sampling period from January 3 to September 22, 2021. These samples were detected by SARS-CoV-2 antigen test kit (colloidal gold immunochromatography assay) and nucleic acid detection kit (real-time fluorescent quantitative reverse transcription polymerase chain reaction). Positive coincidence rates [(number of antigen-positive cases/nucleic acid-positive cases)×100%], negative coincidence rates [(number of antigen-negative cases/nucleic acid-negative cases)×100%], total coincidence rates [(number of cases with consistent results for both antigen and nucleic acid detection/number of total cases) ×100%], as well as Kappa values were calculated. The differences of the above indictors among different countries were evaluated by the coefficient of variation. The detection rates of the antigen test for samples with different cycle threshold values (Ct values) for the nucleic acid detection, different characteristics and different mutant strains were analyzed. Results: For all samples, the positive, negative, and total coincidence rate between the antigen test and nucleic acid assay was 90.8% (569/627), 99.7% (1 224/1 228) and 96.7% (1 793/1 855), respectively, and the consistency coefficient Kappa value was 0.924. Among these countries, the coefficient of variation for positive coincidence rates (except for Malaysia with a lot of samples with Ct value>30), negative coincidence rates (except for France without negative samples) and total coincidence rates (except for France) was 6%,<1%, and 6%, respectively. When Ct values were less than 25, the detection rates of antigen test were 83.3%-100% for each countries (the coefficient of variation was 6%); the total detection rate and the coefficient of variation was 93.4% (428/458) and 5%, respectively, for asymptomatic infected persons and cases within 7 days post onset of symptoms; the total detection rate for various SARS-CoV-2 mutant strains was 97.5% (119/122); and it showed negative results for samples from cases infected with other viruses, including influenza A virus subtype H1N1, influenza B virus, respiratory syncytial virus subgroups A and B, coxsackievirus 16, human metapneumovirus, parainfluenza virus types 1 and 4, Epstein-Barr virus and adenovirus. Conclusion: The SARS-CoV-2 antigen test kit showed excellent authenticity, and there were few differences for its indictors among nine countries, therefore it can meet the needs of large-scale early screening of SARS-CoV-2 infection.

[International multi-center evaluation of a rapid antigen test based on gold immunochromatographic assay for detection of severe acute respiratory syndrome coronavirus 2].

Objective: The gold immunochromatographic assay for detection of SARS-CoV-2 antigen was evaluated by international multi-center clinical trial. Methods: A total of 1 855 clinical parallel samples with valid test results (for nucleic acid and antigen tests, respectively) were collected from nine countries, including Germany, the United Kingdom, Ukraine, France, India, Thailand, Malaysia, the United States of America and Brazil, with sampling period from January 3, 2021 to September 22, 2021. These samples were detected by SARS-CoV-2 antigen test kit (colloidal gold immunochromatography assay) and nucleic acid detection kit (real-time fluorescent quantitative reverse transcription polymerase chain reaction). Positive coincidence rates [(number of antigen-positive cases/nucleic acid-positive cases)×100%], negative coincidence rates [(number of antigen-negative cases/nucleic acid-negative cases)×100%], total coincidence rates [(number of cases with consistent results for both antigen and nucleic acid detection/number of total cases) ×100%], as well as Kappa values were calculated. The differences of the above indictors among different countries were evaluated by the coefficient of variation. The detection rates of the antigen test for samples with different cycle threshold values (Ct values) for the nucleic acid detection, different characteristics and different mutant strains were analyzed. Results: For all samples, the positive, negative, and total coincidence rate between the antigen test and nucleic acid assay was 90.8% (569/627), 99.7% (1 224/1 228) and 96.7% (1 793/1 855), respectively, and the consistency coefficient Kappa value was 0.924. Among these countries, the coefficient of variation for positive coincidence rates (except for Malaysia with a lot of samples with Ct value>30), negative coincidence rates (except for France without negative samples) and total coincidence rates (except for France) was 6%,<1%, and 6%, respectively. When Ct values were less than 25, the detection rates of antigen test were 83.3%-100% for each countries (the coefficient of variation was 6%); The total detection rate and the coefficient of variation was 93.4% (428/458) and 5%, respectively, for asymptomatic infected persons and cases within 7 days post onset of symptoms; the total detection rate for various SARS-CoV-2 mutant strains was 97.5% (119/122); and it showed negative results for samples from cases infected with other viruses, including influenza A virus subtype H1N1, influenza B virus, respiratory syncytial virus subgroups A and B, coxsackievirus 16, human metapneumovirus, parainfluenza virus types 1 and 4, Epstein-Barr virus and adenovirus. Conclusion: The SARS-CoV-2 antigen test kit showed excellent authenticity, and there were few differences for its indictors among nine countries, therefore it can meet the needs of large-scale early screening of SARS-CoV-2 infection.

Low expression of lncRNA TUBA4B promotes proliferation and inhibits apoptosis of colorectal cancer cells via regulating P15 and P16 expressions.

OBJECTIVE: To explore the expression, function, and regulation mechanism of the long non-coding ribonucleic acid (lncRNA) tubulin alpha 4b (TUBA4B) in colorectal cancer (CRC) tissues and cells. PATIENTS AND METHODS: Cancer and adjacent tissues were collected from 60 CRC patients. CRC cell lines SW480, SW620, HCT116, Caco-2, DLD-1 and HT29, and colonic epithelial cell line CCD841 were also enrolled. Then, the expression of TUBA4B in CRC tissues and cell lines was detected via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). In vitro assays [cell counting kit-8 (CCK-8) assay, clone formation assay, and flow cytometry] were performed to study the biological function of TUBA4B in CRC. Additionally, the downstream regulatory targets of TUBA4B were investigated through Western blotting analysis and qRT-PCR assay. RESULTS: The results of qRT-PCR revealed that compared with adjacent tissues, the expression of TUBA4B was down-regulated in 47/60 CRC tissues (47/60, 78.3%). According to in vitro assays (CCK-8 assay, clone formation assay, and flow cytometry), over-expression of TUBA4B inhibited the proliferation and promoted the apoptosis of CRC cells. TUBA4B remarkably regulated mRNA and protein levels of p15 and p16. CONCLUSIONS: LncRNA TUBA4B is down-regulated expression in CRC tissues and cells, which facilitates CRC cell proliferation and suppresses apoptosis by regulating the expressions of p15 and p16.

Titanium carbide sheet: metallic 2D structure with intrinsic and high catalytic activity for the hydrogen evolution reaction.

Searching for a metallic material that possesses intrinsic and high catalytic activity is interesting for the hydrogen evolution reaction (HER) in the electrochemical reduction of water. In this work, via density functional theory, we identified a promising two-dimensional (2D) catalyst material, namely TiC (1 0 0) sheet, which is composed of two atomic layers. Phonon spectrum calculation shows that all vibrational modes of the TiC (1 0 0) sheet are real. Even at 1200 K, the geometrical structure of TiC (1 0 0) sheet is still well kept. Interestingly, TiC (1 0 0) sheet is metallic, which means that TiC (1 0 0) sheet can possess high conductivity. Moreover, the Gibbs free energy ([Formula: see text]) of hydrogen on TiC (1 0 0) sheet at a low coverage is about 0.13 eV, which can be further optimized to an ideal value of 0 eV by introducing a strain. Besides, the effect of thickness on its catalytic activity is also assessed. We observed that TiC (1 0 0) sheet with a large thickness is also metallic. Calculated values of [Formula: see text] for four-layered and six-layered TiC (1 0 0) sheets at a moderate coverage can be about -0.06 and -0.04 eV, respectively. Our results highlight a new promising 2D catalyst material for the HER in the electrochemical reduction of water.

Exploring the effect of nanoholes on arsenene: a density functional theory study.

Effectively modulating the electronic and magnetic properties of a two-dimensional system is critical for the application of it in nanoscale devices. In this work, we explore the effect of nanohole on arsenene on the basis of density functional theory calculations. Our calculations show that, except slight distortion at the corner of nanoholes, geometries of both un-hydrogenated nanohole-embedded arsenene (As-NH) structure and hydrogenated nanohole-embedded arsenene (H-As-NH) structure are well maintained after optimization. Interestingly, the As-NH structure can be magnetized so that it can represent ferromagnetic, ferrimagnetic or antiferromagnetic behavior depending on the shape of the nanoholes. Furthermore, As-NH structure with triangle nanoholes is expected to exhibit remarkable magnetism. Besides, owning to the induction of flat defect levels by the nanoholes, As-NH structure can represent a relatively small band gap. In contrast, the H-As-NH structure is shown to lack the magnetism due to the saturation of unpaired As atoms. In this case, the H-As-NH structure exhibits a relatively large band gap due to the quantum confinement effect. These results indicate an opportunity for the design of arsenene-based nanoscale devices with potential applications in spintronic and optical fields.

Polyphasic taxonomy of Aspergillus section Aspergillus (formerly Eurotium), and its occurrence in indoor environments and food.

Aspergillus section Aspergillus (formerly the genus Eurotium) includes xerophilic species with uniseriate conidiophores, globose to subglobose vesicles, green conidia and yellow, thin walled eurotium-like ascomata with hyaline, lenticular ascospores. In the present study, a polyphasic approach using morphological characters, extrolites, physiological characters and phylogeny was applied to investigate the taxonomy of this section. Over 500 strains from various culture collections and new isolates obtained from indoor environments and a wide range of substrates all over the world were identified using calmodulin gene sequencing. Of these, 163 isolates were subjected to molecular phylogenetic analyses using sequences of ITS rDNA, partial ß-tubulin (BenA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) genes. Colony characteristics were documented on eight cultivation media, growth parameters at three incubation temperatures were recorded and micromorphology was examined using light microscopy as well as scanning electron microscopy to illustrate and characterize each species. Many specific extrolites were extracted and identified from cultures, including echinulins, epiheveadrides, auroglaucins and anthraquinone bisanthrons, and to be consistent in strains of nearly all species. Other extrolites are species-specific, and thus valuable for identification. Several extrolites show antioxidant effects, which may be nutritionally beneficial in food and beverages. Important mycotoxins in the strict sense, such as sterigmatocystin, aflatoxins, ochratoxins, citrinin were not detected despite previous reports on their production in this section. Adopting a polyphasic approach, 31 species are recognized, including nine new species. ITS is highly conserved in this section and does not distinguish species. All species can be differentiated using CaM or RPB2 sequences. For BenA, Aspergillus brunneus and A. niveoglaucus share identical sequences. Ascospores and conidia morphology, growth rates at different temperatures are most useful characters for phenotypic species identification.

[Effects of trabecular metal augments for the reconstruction of Paprosky type â ¢ acetabulum bone defects].

Objective: To investigate the methods and short-time clinical results of reconstruction of Paprosky type Ⅲ acetabulum bone defects by using tantalum augments. Methods: A total of 17 patients (17 hips) with Paprosky type Ⅲ acetabulum bone defects, treated with tantalum augments in revision of total hip arthroplasty at Department of Orthopedics Surgery in General Hospital of Chinese People's Liberation Army were retrospectively analyzed from March 2014 to May 2016.There were 6 males and 11 females aged from 23 to 74 years with an average of (50.2±16.3) years. Tantalum augments or TM-Cup augment (the cup-on-cup technique) were used to reconstruct the defects.The TM-Cup augment was the tantalum revision cup which was removed titanium ring. The cup-on-cup technique combined TM-Cup augment and biological acetabulum cup. Augments were served as the nonresorptive structural allograft in revision of total hip arthroplasty. Harris hip score was used to evaluate clinical effects. The vertical position of the rotation center was measured and analyzed. Radiographic assessments of the acetabular components were performed by DeLee-Charnley and the Anderson criteria and recorded postoperative complications. Results: All the patients were followed up from 3 to 29 months with an average of (16.2±5.4) months, tantalum augments and biological acetabulum cup were used in 13 patients, the TM-Cup augment and biological acetabulum cup were used in 4 patients. At the time of the latest follow-up, the mean Harris hip score increased compared to preoperatively (86.8±8.3 vs. 30.0±12.0) (t=12.78, P<0.01), the average vertical location of the center of rotation was decreased ((25.3±9.8) mm vs.(47.6±10.5)) mm (t=4.95, P<0.01). All the tantalum augments and biological acetabulum cups were stable, there were no infection, dislocation and other complications. Conclusions: The use of tantalum augments could be considered as an effective management of Paprosky type Ⅲ defects providing good clinical and radiographic outcomes in the short term.The cup-on-cup technique which was used in reconstruction of severe superior-invagination acetabular bone defects and restoration relatively normal center of rotation had special application value.

Adenosine A2A receptor inactivation alleviates early-onset cognitive dysfunction after traumatic brain injury involving an inhibition of tau hyperphosphorylation.

Tau is a microtubule-associated protein, and the oligomeric and hyperphosphorylated forms of tau are increased significantly after neurotrauma and considered important factors in mediating cognitive dysfunction. Blockade of adenosine A2A receptors, either by caffeine or gene knockout (KO), alleviates cognitive dysfunction after traumatic brain injury (TBI). We postulated that A2AR activation exacerbates cognitive impairment via promoting tau hyperphosphorylation. Using a mouse model of moderate controlled cortical impact, we showed that TBI induced hyperphosphorylated tau (p-tau) in the hippocampal dentate gyrus and spatial memory deficiency in the Morris water maze test at 7 days and 4 weeks after TBI. Importantly, pharmacological blockade (A2AR antagonist ZM241385 or non-selective adenosine receptor antagonist caffeine) or genetic inactivation of A2ARs reduced the level of tau phosphorylation at Ser404 and alleviated spatial memory dysfunction. The A2AR control of p-tau is further supported by the observations that a KO of A2AR decreased the activity of the tau phosphorylation kinases, glycogen synthase kinase-3ß (GSK-3ß) and protein kinase A (PKA) after TBI, and by that CGS21680 (A2AR agonist) exacerbated okadaic acid-induced tau hyperphosphorylation in cultured primary hippocampal neurons. Lastly, CGS21680-induced neuronal tau hyperphosphorylation and axonal injury were effectively alleviated by individual treatments with ZM241385 (A2AR antagonist), H89 (PKA antagonist) and SB216763 (GSK-3ß antagonist), or by the combined treatment with H89 and SB216763. Our findings suggest a novel mechanism whereby A2AR activation triggers cognitive dysfunction by increasing the phosphorylation level of tau protein after TBI and suggest a promising therapeutic and prophylactic strategy by targeting aberrant A2AR signaling via tau phosphorylation.

Molecular characterization, expression, and functional analysis of chicken TRAF6.

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is a crucial adaptor molecule of the interleukin-1 receptor/Toll-like receptor (IL-1/TLR) superfamily, which can trigger downstream signaling cascades involved in innate immunity. The function of TRAF6 has been clarified in mammals but is poorly understood in chicken. In our study, we investigated TRAF6 function in birds, particularly in chicken innate immune responses, by cloning and characterizing chicken TRAF6 (chTRAF6). The full-length coding sequence of chTRAF6 comprised 1638 bp and encoded a 545-amino acid protein, which shares high sequence similarity with TRAF6 of other species and consists of four structurally conserved domains. Quantitative real-time polymerase chain reaction revealed that chTRAF6 was widely expressed in all tested tissues and its expression was induced in chicken embryo fibroblast cells treated with poly(I:C) and poly(dA:dT). Increased expression of chTRAF6 was observed both in vitro and in vivo following infection with Newcastle disease virus in chickens. Taken together, these results suggest that chTRAF6 plays a vital role in host defense against viral infection in chicken.

New Talaromyces species from indoor environments in China.

Talaromyces contains both asexual and sexually reproducing species. This genus is divided in seven sections and currently has 105 accepted species. In this study we investigated the Talaromyces isolates that were obtained during a study of indoor air collected in Beijing, China. These indoor Talaromyces strains are resolved in four sections, seven of them are identified as T. islandicus, T. aurantiacus, T. siamensis and T. albobiverticillius according to BenA sequences, while 14 isolates have divergent sequences and are described here as nine new species. The new species are placed in four sections, namely sections Helici, Islandici, Talaromyces and Trachyspermi. They are described based on sequence data (ITS, BenA, CaM and RPB2) in combination with phenotypic and extrolite characters. Morphological descriptions and notes for distinguishing similar species are provided for each new species. The recently described T. rubrifaciens is synonymised with T. albobiverticillius based on presented phylogenetic results.

Electronic and magnetic properties of C-adsorbed graphene: a first-principles study.

Using density functional theory, we consider the adsorption of C on graphene, which gives rise to many interesting phenomena. A single-C at the bridge site shows a clearly covalent-bond feature with graphene, in which the metallic state occurs and a magnetic moment of 0.36 µ(B) was determined. For both-sided adsorption, the magnetic moment is remarkably larger than that in one-sided adsorption, and increases with concentration up to a coverage of 12.5%. High spin polarization obtained at the Fermi level indicates a high degree of passage of preferred spin, which is important for developing spin filters.

Electronic and magnetic properties of substituted BN sheets: a density functional theory study.

Using density functional calculations, we investigate the geometries, electronic structures and magnetic properties of hexagonal BN sheets with 3d transition metal (TM) and nonmetal atoms embedded in three types of vacancies: V(B), V(N), and V(B+N). We show that some embedded configurations, except TM atoms in V(N) vacancy, are stable in BN sheets and yield interesting phenomena. For instance, the band gaps and magnetic moments of BN sheets can be tuned depending on the embedded dopant species and vacancy type. In particular, embedment such as Cr in V(B+N), Co in V(B), and Ni in V(B) leads to half-metallic BN sheets interesting for spin filter applications. From the investigation of Mn-chain (C(Mn)) embedments, a regular 1D structure can be formed in BN sheets as an electron waveguide, a metal nanometre wire with a single atom thickness.

QTL consistency and meta-analysis for grain yield components in three generations in maize.

Grain yield is the most important and complex trait in maize. In this study, a total of 258 F(9) recombinant inbred lines (RIL), derived from a cross between dent corn inbred Dan232 and popcorn inbred N04, were evaluated for eight grain yield components under four environments. Quantitative trait loci (QTL) and their epistatic interactions were detected for all traits under each environment and in combined analysis. Meta-analysis was used to integrate genetic maps and detected QTL across three generations (RIL, F(2:3) and BC(2)F(2)) derived from the same cross. In total, 103 QTL, 42 pairs of epistatic interactions and 16 meta-QTL (mQTL) were detected. Twelve out of 13 QTL with contributions (R(2)) over 15% were consistently detected in 3-4 environments (or in combined analysis) and integrated in mQTL. Only q100GW-7-1 was detected in all four environments and in combined analysis. 100qGW-1-1 had the largest R(2) (19.3-24.6%) in three environments and in combined analysis. In contrast, 35 QTL for 6 grain yield components were detected in the BC(2)F(2) and F(2:3) generations, no common QTL across three generations were located in the same marker intervals. Only 100 grain weight (100GW) QTL on chromosome 5 were located in adjacent marker intervals. Four common QTL were detected across the RIL and F(2:3) generations, and two between the RIL and BC(2)F(2) generations. Each of five important mQTL (mQTL7-1, mQTL10-2, mQTL4-1, mQTL5-1 and mQTL1-3) included 7-12 QTL associated with 2-6 traits. In conclusion, we found evidence of strong influence of genetic structure and environment on QTL detection, high consistency of major QTL across environments and generations, and remarkable QTL co-location for grain yield components. Fine mapping for five major QTL (q100GW-1-1, q100GW-7-1, qGWP-4-1, qERN-4-1 and qKR-4-1) and construction of single chromosome segment lines for genetic regions of five mQTL merit further studies and could be put into use in marker-assisted breeding.

Electronic and magnetic properties of metal-doped BN sheet: A first-principles study.

The electronic and magnetic properties of a BN sheet doped with 3d transition metals (Fe, Co and Ni) have been investigated using ab initio calculations. Our calculations show many interesting physical properties in a metal-doped BN sheet. A Fe-doped BN sheet is a half-metal with the magnetic moment of 2.0 micro(B), and Co-doped BN sheet becomes a narrow-gap semiconductor with a magnetic moment of 1.0 micro(B). However, no magnetic moment is induced on a Ni-doped BN sheet, which has the same band gap as a pristine BN sheet. Furthermore, Fe atom easily forms an isolated particle on the BN sheet, while Ni and Co atoms are likely to form a sheet-supported metal nanotemplate. These results are useful for spintronics application and could help in the development of magnetic nanotructures and metallic nanotemplate at room temperature.

Oxygen-induced magnetic properties and metallic behavior of a BN sheet.

In this paper, an ab initio method has been employed to study the adsorption energies, electronic structures and magnetic properties of a BN sheet functionalized by an oxygen (O) atom. The adsorption process is typically exothermic, and some unusual properties can be revealed with different adsorption sites. The energy gap of the BN sheet narrows due to the strong hybridization between O and BN electronic states when the O locates above a BN bond or a nitrogen atom. Upon the adsorption of O above a B3N3 ring or a boron atom, the electrons of the O-adsorbed BN system are polarized, which gives rise to a magnetic moment of 2.0 µ(B). In this case, the Fermi level crosses the valence band, resulting in the O-adsorbed BN system being metallic. Furthermore, potential energy curve analysis shows that the magnetism and metallicity of the BN system can be modulated by the external temperature and pressure.

c-Ski promotes skin fibroblast proliferation but decreases type I collagen: implications for wound healing and scar formation.

BACKGROUND: Accelerating wound healing is always accompanied by excessive scar formation. The focus in chronic wounds has been promoting the proliferation of tissue repair cells while decreasing collagen deposition. Smad3 null mice display more rapid wound closure and reduced scar formation. We hypothesized that c-Ski, acting as a co-repressor of transforming growth factor-beta1/Smad3 in epithelial cells and as a complicated regulator of embryo fibroblast proliferation, may play such a role through modulation of skin fibroblast function. AIM: To investigate the effect of c-Ski on skin fibroblast proliferation, cell-cycle progression, type I collagen secretion and myofibroblast differentiation. The potential involvement of Smad3 was also investigated. METHODS: Cultured rat skin fibroblasts were used. Immunocytochemistry and reverse transcription (RT)-PCR was used to examine the localization and expression of c-Ski. Plasmid transfection technology was used to produce c-Ski or/and Smad3 overexpression. Cell proliferation was analysed by 5-bromo-2-deoxyuridine incorporation; cell cycle by fluorescence-activated cell sorting; type I collagen expression by immunocytochemistry, RT-PCR and western blotting; and myofibroblast differentiation by western blotting. RESULTS: c-Ski was expressed in cultured skin fibroblasts. Overexpression of c-Ski was able to promote skin fibroblast proliferation and accelerate cell-cycle progression through inhibiting Smad3 activity. It also decreased type I collagen protein and mRNA expression through inhibiting Smad3 activity. It did not affect fibroblast-myofibroblast differentiation. CONCLUSIONS: Because of the important role of fibroblast proliferation and collagen secretion in tissue repair and scar formation, we speculate that c-Ski may be a new candidate molecule for accelerating wound healing and decreasing scar formation.

[Cloning of AHA gene from Amaranthus hypochondriacus and it's aphid inhibitory effect in transgenic tabacco plants].

Using total DNA isolated from Amaranthus hypochondriacus as template, Amaranthus hypochondriacus agglutinin AHA gene was amplified by PCR and cloned. Sequence analysis results showed that this gene is consisted of 2453 base pairs including one 1538 bp intron and two exons of 212 bp and 703 bp respectively. After inverse PCR amplification, coding region of AHA gene was obtained. AHA gene with it's intron (AHAg) and withou intron (AHAc) were inserted downstream of 35S promotor in the binary vector pBin438 resulting in the construction of two plant expression vectors pBAHAg and pBAHAc repectively. Leave explants of Nicotinana tabacum var. SR1 were transformed with A. tumefaciens LBA4404 harbouring the above expression vectors. Results from PCR and Southern blot analysis showed that AHA genes were inserted into the genome of transformed tobacco plants. Immunodot blot analysis indicated that AHA was expressed in transgenic plants. The results from insect bioassay with peach aphid (Mizus persicae) showed that the transgenic plants of pBAHAg and pBAHAc were aphid resistant, evidenced by a 57%-48% reduction in insect population density, some plants were more than 85%. The aphid resistance of transgenic plants transformed with AHAg gene as judged by aphid inhibition rate was higher than that of plants transormed with AHAc gene indicating that the intron in AHAg may be favorable for expression of AHA in transgenic plants.

[RGS and the regulation of G protein signal transduction].

Regulators of G-protein signaling (RGSs) are recently identified negative regulator of G-protein signaling, most of the RGSs act as GTPase activating proteins (GAPs). RGSs can selectively act on Gas and their effects are scrupulously regulated in vivo. It is believed that we can learn more about regulation of signal transduction from the development of research on RGSs.

Carbon-11 labelled ketamine-synthesis, distribution in mice and PET studies in baboons.

No-carrier-added (NCA)[11C](+/-)-ketamine (2a) and its enantiomers (+)-2b and (-)-2c were synthesized by methylation of the corresponding norketamine (1a-c) with [11C]H3I in an overall radiochemical yield of 20% (EOB) with specific activities of 0.35-0.45 Ci/mumol at EOB in a synthesis time of 40 min from EOB. Compound 2a was metabolized rapidly in mouse brain and labeled metabolites appeared in baboon plasma. PET studies of compounds 2a-c in a baboon showed that influx of compounds 2a-c into the brain was high for the first few min but radioactivity then declined rapidly. Although the retention of radioactivity in the baboon striatum was not significantly different for 2a-c 20 min post-injection, graphical analysis of time-activity data for each enantiomer and for the racemate in baboon striatum suggested that (+)-ketamine may interact with receptors slightly more effectively than its (-)-enantiomer or racemate. However, due to its rapid metabolism in the brain and a similar uptake in the striatum and cerebellum, [11C]ketamine may not be an ideal tracer for studying NMDA receptor with PET.