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101.
Cre-mediated recombination, a method widely used in mice for tissue-specific inactivation of endogenous genes or activation of transgenes, is critically dependent on the availability of mouse lines in which Cre recombinase functions in the tissue of interest or its progenitors. Here we describe a transgenic mouse line, Osr1-cre, in which Cre is active from embryonic day (E)11.5 in a few specific tissues. These include the endoderm of the posterior foregut, midgut, hindgut, and developing urogenital system, the heart left atrium, extra-ocular muscle progenitors, and mesenchyme in particular regions of the limb. Furthermore, starting at E12.5, Cre functions in limb interdigital mesenchyme. Within the urogenital system, recombination appears to be virtually complete in the epithelium of the bladder and urethra just posterior to it by E14.5. In males, some of these urethral cells form the prostate. The spatiotemporal pattern of Cre activity in Osr1-cre makes it a unique resource among the lines available for Cre-mediated recombination experiments. 相似文献
102.
103.
Three iridoid glycosides 6-O-(3'-O-benzoyl)-alpha-l-rhamnopyranosylcatalpol (1a), 6-O-(3'-O-trans-cinnamoyl)-alpha-l-rhamnopyranosylcatalpol (2a) and 6-O-(3'-O-cis-cinnamoyl)-alpha-l-rhamnopyranosylcatalpol (3a) were isolated from aerial parts of Gmelina arborea and structures were elucidated by spectral analysis. Additionally a known iridoid 6-O-(3', 4'-O-dibenzoyl)-alpha-l-rhamnopyranosylcatalpol (4) was also isolated and identified. 相似文献
104.
105.
Manoj K. Rai Pooja Asthana Shashi Kant Singh V.S. Jaiswal U. Jaiswal 《Biotechnology advances》2009,27(6):641-679
Encapsulation technology is an exciting and rapidly growing area of biotechnological research. This has drawn tremendous attention in recent years because of its wide use in conservation and delivery of tissue cultured plants of commercial and economic importance. Production of synthetic seeds by encapsulating somatic embryos, shoot buds or any other meristmatic tissue helps in minimizing the cost of micropropagated plantlets for commercialization and final delivery. In most of fruit crops, seed propagation has not been successful because of heterozygosity of seeds, minute seed size, presence of reduced endosperm, low germination rate, and also some are having seedless varieties. Many species have desiccation-sensitive intermediate or recalcitrant seeds and can be stored for only a few weeks or months. Under these circumstances, increasing interest has been shown recently to use encapsulation technology for propagation and conservation. Many fruit plants are studied worldwide for breeding, genetic engineering, propagation, and pharmaceutical purposes. In this context, synthetic seeds would be more applicable in exchange of elite and axenic plant material between laboratories and extension centers due to small bead size and ease in handling. Due to these advantages, interest in using encapsulation technology has continuously been increasing in several fruit plant species. The purpose of this review is to focus upon current information on development of synthetic seeds in several fruit crops. 相似文献
106.
A. K. Adhya V. Mahesha R. Srinivasan R. Nijhawan A. Rajwanshi V. Suri L. K. Dhaliwal 《Cytopathology》2009,20(6):375-379
Objectives: To perform an audit of all smears reported as atypical glandular cells (AGC) using the Bethesda system (TBS) 2001.
Methods: A total of 18 376 cervical smears were screened from January 2005 to June 2007, of which 65 cases were reported as AGC. Follow-up histology was available in 31 cases (47.7%), in whom a detailed cytological/histological correlation was carried out.
Results: AGC constituted 0.35% of all Pap smears. Follow-up histology was normal or benign in 20 cases, whereas a squamous or glandular abnormality was seen in 11 cases. Squamous abnormalities included one case each of cervical intraepithelial neoplasia (CIN)1, CIN2 and CIN3 and five cases of squamous cell carcinoma. All glandular epithelial abnormalities were endometrial in origin and included two endometrial adenocarcinomas and one uterine serous carcinoma. Neither in situ nor invasive adenocarcinoma of the endocervix was observed. Review of smears and reclassification as AGC, not otherwise specified and favour neoplasia revealed a higher proportion of abnormality in the latter group, reaffirming the utility of subtyping. The median age of women with AGC was 41 years. The outcome was analysed with respect to the median age. In women aged equal or more than 40 years, AGC reflected a high-grade squamous or glandular epithelial abnormality in 50% of cases compared with none in those less than 40 years old ( P = 0.010).
Conclusion: The age of the woman as well as the subtype of atypical glandular cells influences outcome and hence must be taken into consideration while formulating an acceptable management strategy in these women in a low-resource setting. 相似文献
Methods: A total of 18 376 cervical smears were screened from January 2005 to June 2007, of which 65 cases were reported as AGC. Follow-up histology was available in 31 cases (47.7%), in whom a detailed cytological/histological correlation was carried out.
Results: AGC constituted 0.35% of all Pap smears. Follow-up histology was normal or benign in 20 cases, whereas a squamous or glandular abnormality was seen in 11 cases. Squamous abnormalities included one case each of cervical intraepithelial neoplasia (CIN)1, CIN2 and CIN3 and five cases of squamous cell carcinoma. All glandular epithelial abnormalities were endometrial in origin and included two endometrial adenocarcinomas and one uterine serous carcinoma. Neither in situ nor invasive adenocarcinoma of the endocervix was observed. Review of smears and reclassification as AGC, not otherwise specified and favour neoplasia revealed a higher proportion of abnormality in the latter group, reaffirming the utility of subtyping. The median age of women with AGC was 41 years. The outcome was analysed with respect to the median age. In women aged equal or more than 40 years, AGC reflected a high-grade squamous or glandular epithelial abnormality in 50% of cases compared with none in those less than 40 years old ( P = 0.010).
Conclusion: The age of the woman as well as the subtype of atypical glandular cells influences outcome and hence must be taken into consideration while formulating an acceptable management strategy in these women in a low-resource setting. 相似文献
107.
The aerobic nitrogen fixing xylanolytic bacterium Paenibacillus pabuli strain ATSKP produces loosely attached capsular polysaccharide KP-EPS. On 0.5% birchwood xylan 70 ± 5.02 mg of KP-EPS was
produced per gram dry weight of cells by the fourth day of growth in the absence of combined nitrogen source at 30°C. It was
separated and purified using centrifugation, cold acetone precipitation and dialysis and is a sulfate containing heteropolymer
as revealed by FT-IR spectrometry and elemental analysis. CHN analysis revealed the presence of 37.50% carbon, 5.90% hydrogen
and 8.28% nitrogen in KP-EPS. Absence of phosphorus was confirmed by 31P NMR. ICP-OES analysis showed the presence of various metals in small concentrations. Specific binding with aniline blue
suggested the presence of (1,3)-β-d-glucan. Thermal gravimetric analysis and differential scanning calorimetric analysis confirmed its thermal stability as high
as 200°C. The EPS was not pseudo plastic and the viscosity was less than xanthan. The intrinsic viscosity did not reduce drastically
when dissolved in 0.1 M NaCl. 相似文献
108.
Traditional concealed information paradigms rely on the idea that stimuli that are meaningful to a person (critical items)
will draw attentional resources disproportionately, relative to stimuli that are not (irrelevant items), generating detectable
differences on a suitable dependent variable (behavioral, psychophysiological, or neural). Here, we introduce a behavioral
paradigm that could be used to reveal concealed information by exploiting the link between concealed information and attentional
processes more directly. This novel paradigm is based on the attentional blink phenomenon in which detection of a stimulus
reduces detection accuracy rates of subsequent target stimuli within a 200–500 ms time window. We hypothesized that a well-known
face used as a critical item could capture attentional resources automatically, making it harder to detect the occurrence
of a subsequently presented target face. The results confirmed this hypothesis, and showed that concealed knowledge of a famous
face could be detected in 9 out of 12 individuals by looking for a relative dip in target detection accuracy after the presentation
of a critical item. 相似文献
109.
Parvinder Pal Singh Naveed Ahmed Qazi Syed Shafi D. Mahendhar Reddy Abid H. Banday P. Bhaskar Reddy K.A. Suri B.D. Gupta N.K. Satti Basant P. Wakhloo H.M. Sampath Kumar G.N. Qazi 《Journal of Molecular Catalysis .B, Enzymatic》2009,56(1):46-54
Lipase catalyzed regio-selective acylation of five iridoid glycosides viz., picroside I&II, catalpol, agnuside and negundoside in the presence of various acyl donors such as vinyl acetate and p-nitrophenyl alkanoates was studied. The regio-selectivity of enzymatic acylation and yields were found to vary amongst different substrates. Monoacylated products were isolated with all the substrates under scrutiny indicating high regio-selective nature of such transformations. A series of acyl esters of picroside-I, picroside-II, catalpol, agnuside and negundoside have been synthesized by this enzymatic trans-esterification methodology. 相似文献
110.
Jason J. Paxman Natalie A. Borg James Horne Philip E. Thompson Yanni Chin Pooja Sharma Jamie S. Simpson Jerome Wielens Susannah Piek Charlene M. Kahler Harry Sakellaris Mary Pearce Stephen P. Bottomley Jamie Rossjohn Martin J. Scanlon 《The Journal of biological chemistry》2009,284(26):17835-17845
Oxidative protein folding in Gram-negative bacteria results in the formation of disulfide bonds between pairs of cysteine residues. This is a multistep process in which the dithiol-disulfide oxidoreductase enzyme, DsbA, plays a central role. The structure of DsbA comprises an all helical domain of unknown function and a thioredoxin domain, where active site cysteines shuttle between an oxidized, substrate-bound, reduced form and a DsbB-bound form, where DsbB is a membrane protein that reoxidizes DsbA. Most DsbA enzymes interact with a wide variety of reduced substrates and show little specificity. However, a number of DsbA enzymes have now been identified that have narrow substrate repertoires and appear to interact specifically with a smaller number of substrates. The transient nature of the DsbA-substrate complex has hampered our understanding of the factors that govern the interaction of DsbA enzymes with their substrates. Here we report the crystal structure of a complex between Escherichia coli DsbA and a peptide with a sequence derived from a substrate. The binding site identified in the DsbA-peptide complex was distinct from that observed for DsbB in the DsbA-DsbB complex. The structure revealed details of the DsbA-peptide interaction and suggested a mechanism by which DsbA can simultaneously show broad specificity for substrates yet exhibit specificity for DsbB. This mode of binding was supported by solution nuclear magnetic resonance data as well as functional data, which demonstrated that the substrate specificity of DsbA could be modified via changes at the binding interface identified in the structure of the complex. 相似文献