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1

Low dose gamma ray effect on inhancer of anther culture response in some spring wheat genotypes  

International Nuclear Information System (INIS)

In this investigation, the response of anther culture in three wheat genotypes (Tajan, Atila, R-12) after a treatment with a low dose of gamma ray was studied. Spikes of these genotypes were irradiated in doses of 2, 3 Gy, then cultured in the modified P4 medium, containing 200 mgl-1 Glutamine, 15% Ficol, 2 mgl-1 2,4-D, and 0.5 mgl-1 Kinitin. It was found that there is a significant difference between the genotypes, and also between the irradiated treatment levels and the non-irradiated treatment. All of the genotypes showed a low response to the anther culture meaning a decrease in the response with irradiation. 90% of Calli of Atila, 67% of R-12 and 46% of Tajan in control treatment produced plants. But the Calli of irradiated anthers did not produced any plant (green or albino). Generally by the gamma irradiation, we observed a low response in the Calli and plant let production.

2003-01-01

2

Response of anther culture in vitro to irradiation of spike and culturing with Al stress in barley  

International Nuclear Information System (INIS)

[en] Spikes of two barley lines treated with 60Co ?-radiation as anther culture materials, the callus induction and green plant regeneration were investigated on the media containing Al. The results showed that the frequency of callus induction was dramatically decreased by irradiation treatment and green plant regeneration was failed at a dose of 10 Gy. The calli was obtained from anthers cultured with Al-medium, and also green plants were regenerated even in higher Al concentration. The frequency of callus induction was reduced in culturing with higher stress of Al, and the green plant regeneration was also decreased. (authors)

2005-01-01

3

Evaluation of effect of different gamma ray doses on anther culture response in two Iranian wheat landraces  

International Nuclear Information System (INIS)

Wheat according to its importance as a source of food is the most important strategic agricultural product and has the highest level of under planting lands around the world. Double haploid induction methods are able to raise wheat breeding efficiency through decreasing length of breeding programming and increasing selection efficacy. In this experiment for determining the effect of gamma radiation of seeds on anther culture response of wheat, two recalcitrant Iranian wheat landraces, Graecum and Nigricum with no response to anther culture were chosen. Callus induction and plant regeneration traits from anther culture of these landraces and twenty of their random selected mutant genotypes which were produced through seed radiation with 100, 150, 200, 250Gy of gamma ray doses were evaluated. A factorial design based on completely randomized design with five replication was used to compare callus induction and plant regeneration percents of genotypes. Gamma ray doses levels and genotypes were two factors of this experiment which had a significant effect on both of callus induction and plant regeneration traits. An evaluation of the means revealed that the highest level of callus induction is noticed in 200Gy (12.5%) and that of plant induction is noticed in 150Gy (67.28%). the highest mean of callus induction (68.6%) was obtained in genotype L9.200.2 as a mutant of Nigricum landrace and The highest mean of plant induction (93.12%) was obtained in genotype L8.150.1 as a mutant of Graecum landrace. (author)

2008-01-01

4

Evaluation of gelling agents on anther culture: response of two soybean cultivars  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Anteras de duas cultivares de soja foram cultivadas em meio de cultura basal B5 longo gelificado com agarose ou Phytagel®. Análises citológicas das anteras foram conduzidas durante os primeiros 45 dias de cultura para avaliar a viabilidade e o estágio de desenvolvimento dos micrósporos. A freqüência de formação de calos foi analisada após 45 dias do início da cultura. A análise da variância da viabilidade do micrósporo mostrou interações significativas de (more) Cultivar X Agente Gelificante X Dias de Cultura. As freqüências de grãos de pólen viáveis diminuíram significativamente com o tempo de cultura, dentro de cada cultivar e agente gelificante testado. A interação Dia X Cultivar foi significante para as freqüências de grãos de pólen binucleados simétricos e estruturas multinucleados/multicelulares. O efeito do agente gelificante na freqüência de grãos de pólen binucleados simétricos e estruturas multinucleados/multicelulares não foi significante. Com relação às freqüências de calos e estruturas embriogênicas formadas, houve diferença significativa entre cultivares (IAS5= 14.8% e BRS 133=6.6%). O agente gelificante não mostrou efeito em tais freqüências. Abstract in english Anthers of two soybean cultivars were cultured in B5 long basal culture media gelled with agarose or PhytagelTM. Cytological examinations of the anthers were carried out during the first 45 days of culture to assay the viability and developmental stage of microspores. Frequency of callus formation was recorded at 45 days of culture. The analysis of variance of the microspore viability assay showed significant Cultivar X Gelling Agent X Day of Culture interactions. The fre (more) quencies of viable microspores decreased significantly with time of culture, within each cultivar and gelling agent tested. The interaction Day X Cultivar was significant for the frequencies of binucleate symmetrical grains and multinucleate/multicellular structures. The effect of gelling agents on the frequency of binucleate symmetrical pollens grains and multinucleate/multicellular structures was not significant. About the frequencies of calli and embryogenic calli formed, a significant difference was detected between the cultivars (IAS5= 14.8% and BRS 133=6.6%). Gelling agents showed no effect over these frequencies.

Cardoso, Milena Barcelos; Bodanese-Zanettini, Maria Helena; Mundstock, Elsa Cristina de; Kaltchuk-Santos, Eliane

2007-11-01

5

Induction of haploid morphogenic calluses from in vitro cultured anthers  

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Apricot (Prunus armeniaca) ‘Harcot’ anthers were cultured in vitro for the production of haploid plants. The best androgenic response was achieved with Nitsch and Nitsch (1969) medium, supplemented with 4.52 microM 2,4-D, 4.52 micoM zeatin, 2.85 microM IAA and 40 g l?1 sucrose. Cultures were maintai...

Peixe, Augusto; Barroso, João; Potes, Amely; Pais, Maria

6

Research progress and prospect on anther culture of tomato  

UK PubMed Central (United Kingdom)

In the breeding of tomato, haploid plants are obtained from anther culture. It may fix and analyze new genetic combination of hybrid plants in much less time than common breeding and establish pure tomato line. This paper summarizes research situation and progress on anther culture of tomato all over the world, and presents a prospect.

Si Jun; Li Chengqiong

2002-01-01

7

[Selective elimination of alleles in rice anther cultures].  

UK PubMed Central (United Kingdom)

The nature of heterosis is discussed and selective elimination of alleles (introduced in the hybrid genotype by the parental forms) in anther culture is shown. This supports the possibility of removing viability-reducing alleles (lethal, semilethal, and less effective alleles) from the genotypes of heterotic hybrids in anther culture.

Goncharova IuK

2013-02-01

8

The Direct Regeneration of Maize Haploids Through Anther Culture  

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Full Text Available The genetics of plants regenerated from anther-derived callus was investigated using single crosses & inbreds of maize. Anther culture in maize (Zea mays L.) usually follows an indirect procedure involving callus induction and differentiation on at least two different media. Alternatively, development of a direct procedure by which plantlets can be regenerated directly on one medium seems desirable, if acceptable frequency of plant regeneration could be obtained and an effective procedure of chromosome doubling of regenerated plantlets is available. Yupie (YP) and N6 were used as basal media and 10 growth regulators (2,4-D, kinetin, NAA, IAA, IBA, dicamba, pCPA, 6-BA, 2ip and hypoxanthine) were tested to evaluate the feasibility of direct regeneration of haploid plantlets of eight single cross hybrids and four inbred lines. The results indicated that the direct generation of plantlets is feasible through anther culture, though it is genotype and medium dependent. Ten plantlets were regenerated directly from single cross hybrid M60 X M96. The more effective medium was N6 basal medium plus 2,4-D (2.0 mg l-1) and kinetin (1.5 mg l-1). Regeneration frequency (percent of anthers producing plantlets) ranged from 1 to 4%.

L. Hassan; S.D. Ahmad; A. Okumus

2001-01-01

9

Improvement of bananas (Musa cvs.) through in vitro anther culture  

International Nuclear Information System (INIS)

Agricultural products play a great role in the Colombian economy, and the banana is one of the most important. Since 1981, one of the more serious problems effecting production of this crop is the fungus Mycosphaerella fijensis sp. difformis, that causes black sigatoka disease. Most of the recent efforts to control this disease have been directed towards the identification of clones tolerant or resistant to this disease. One alternative approach is the use of anther culture to obtain resistant haploid plants. Diploid clones (Musa - AA) have been used as a model in this study. The results presented here identify the most appropriate stage of anther development for callus induction and proliferation, and treatments that reduce tissue browning. (author). 12 refs, 1 fig., 1 tab

1995-01-01

10

Androgenetic plants of Anemone coronaria derived through anther culture  

UK PubMed Central (United Kingdom)

The genus Anemone (Ranunculaceae) includes many species cultivated for ornamental purposes. Most cut flower cultivars belong to A. coronaria L. and are multiplied by seed and sold for cultivation as 1-year-old tubers. As cultivars represent a population of hybrid individuals derived from crosses between heterozygous parents, the use of a true F? hybrid would improve the uniformity and quality of the product. As a first step towards the development of pure-breeding lines, anther cultures were established from elite cultivars of A. coronaria. Somatic embryos and plantlets were regenerated from five elite cultivars, and up to 16.9 regenerants per 100 cultured anthers were obtained. Cytological analysis identified that 11 of 19 regenerants had either a 2x = 16 karyotype, or were mixoploids. RAPD-based DNA fingerprinting showed that all the regenerants tested differed genetically from their anther donor, confirming their androgenetic origin. The shortening to 15 months for the time required to produce homozygous lines may convince seed companies to invest in F? hybrid breeding.

Laura M; Safaverdi G; Allavena A

2006-12-01

11

Obtaining barley haploid embryos and seedlings using anther culture technique  

International Nuclear Information System (INIS)

The effect of three barley genotypes (Igri, Arabi abiad, and Taqa 76), three irradiation doses (0, 5, and 10 Gy), and two media (FW, modified FW), on the number of formed embryos, and the ratio between regenerated embryos to green seedlings and albinos, were studied using anther culture. Also the study involved the compatibility between seedling morphology and chromosome number. results indicated significant differences among the genotypes, and media in callus and embryos formation and also in the ratio and albino seedlings. However, the effect of gamma rays dose was significant only on embryos regeneration. A high percentage of compatibility (90%) was obtained between the seedling morphology and chromosome number. (author).

2000-01-01

12

Cucumber mosaic virus resistant mutant from tobacco's anthers treated with ? ray through anther culture  

International Nuclear Information System (INIS)

Flower buds of Nicotiana tabacum cv. K326, NC89 and 8611, in which the microspore is in the phase of single nucleus and the nucleus is on the side, were irradiated with 60Co ?-ray. Plant lets from anther culture were transplanted and inoculated with poisonous fluid of CMV. The results showed that there was an orientation relation between the variation of disease resistance of plants of NC89, 8611 and the dose of 60Co ?-ray. The variation of leaves of plants was analogous to symptom of CMV when the dose was equal to or more than 4, which caused difficulty for selection. When dose was less than 2krad, there was no difference in disease resistance between the plants induced from irradiation of 60Co ?-ray and the control. However, when dose was equal to 2krad, the difference of disease resistance was at the level of significance. CMV-resistant mutants were selected from the population of haploid plant of NC89 and 8611 induced by 2.0 krad of 60Co ? ray

1999-01-01

13

Additives Promote Adventitious Buds Induction from Anther Culture of Bitter Melon (Momordica charantia L.)  

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Full Text Available The effects of growth regulators, Thidiazuron (TDZ), silver nitrate (AgNO3), triacontanol and glutaminate on adventitious buds induction from anther culture of bitter melon (Momordica charantia L.) were investigated. It was found that triacontanol was advantageous for buds development and adventitious buds differentiated from anther culture of bitter melon first time. On medium supplemented with glutaminate 0.1 mg L-1, protuberant structures differentiated on the surface of callus. AgNO3 and TDZ has no significant effect on promoting adventitious buds formation from anther culture of bitter melon.

Yi Tang; Huanxiu Li; Zesheng Yan; Jia Lai; Qian Luo; Li Zhang

2012-01-01

14

Evaluation of anther culture methods and androgenic capacity of wheat mutant lines  

International Nuclear Information System (INIS)

[en] Several experiments were conducted with the aim of obtaining haploid plants via anther culture of Chilean spring wheat genotypes. The first experiments compared five culture media and the effect of different incubation conditions on anthers of the genotypes Austral-UACH, Carahue-INIA, Dalcahue-INIA and Pavon 76. The low androgenic response obtained in these experiments, with a maximum of 1.78% callus induction, resulted in a change in methodology. In other experiments, the effect of P-4 callus induction medium and 190-2 plant regeneration medium on M2 and M3 mutant lines of As-Baer, Carahue-INIA, Dalcahue-INIA and Pavon 76 were compared. The effect of two sterilization systems was also studied. These experiments gave a maximum of 55.7% callus formation and a variable organogenesis in three genotypes. Dalcahue-INIA irradiated with 20 krad gamma rays (200 Gy) gave a good organogenic response. The percentage of albino plants ranged between 0 and 83.3% of the total regenerants. (author). 24 refs, 5 tabs

1996-01-01

15

Improvement of rice anther culture and application of the technique in mutation breeding  

International Nuclear Information System (INIS)

The ability of callus formation and green plant regeneration was very different for different rice type and varieties in anther culture. The differentiation and regeneration of green plants were obviously improved when the rice anthers at about 30 d after culture on induction medium were irradiated with 20 Gy of ?-rays and calli were cultured on the differentiation medium containing 30 mg/L colchicines. The stimulation effect of ?-irradiation combined with colchicines was much better than that of their single use. Mutation frequency and selective efficiency in M2 were obviously increased by application of the technique

2001-01-01

16

The effect of hormone on anther culture and chromosome doubling of Triticum×Triticale hybrid progeny  

UK PubMed Central (United Kingdom)

Anther culture of progenies from Triticum×Triticale hybird was carried out on C_(17) medium containing different kinds and levels of plant hormones. The data showed that the quality of callus, as well as the rate of differenciated green plants and frequency of chromosome doubling, on the medium containing 2.4-D 2 mg/L and 6BA 1 mg/L was obviously higher than that on other medium. It was revealed that hybrid progeny showed different sensitivity to different plant cytomins. As a plant hormone, 6BA was functional not only in callus differenciation. These results are useful in further theoretical research of anther culture.

Li Wenzhuo; Hao Zhengrong; Cui Jianping; Shen Daleng; Wu Genfa; Tao Jianqiu

1998-01-01

17

Induced mutations and Anther culture for sesame improvement  

International Nuclear Information System (INIS)

Seeds of two Sri Lankan sesame (Sesamum indicum L.) cultivars MI 2 and MI 3 and of UCR82-203 NS which has indehiscent capsules were treated with gamma rays, ethyl methanesulphonate and diethyl sulphate. Selections were made in segregating populations for improved yield components and morphological characters. Radiation sensitivity studies indicated that the seeds of MI 3 variety were more resistant to irradiation than MI 2. The M1 plants also showed varietal differences in growth reduction. Fifty percent growth reduction for plant height in MI 2 was in the range of 500 - 600 Gy and that for MI 3 was 750 - 1000 Gy. Promising mutants after screening in preliminary trials were tested for yield and adaptability in multilocational trials in different agro-climatic zones. A wide variation and increased mean values of yield and components were recorded in selected mutants in the preliminary trials. Two mutants, MB 29 and MB 33, consistently outyielded the recommended cultivar MI 3 in regional trials. The mutant MB 13 was also promising. MB 29 and MB 29w have a brittle seed coat easy for decortication. A number of mutants with improved characters have been isolated, characterized and included in the cross-breeding programmes. Mutants MB 29 and MB 33 recorded better germination than MI 2 under high osmotic pressure and should be tested for tolerance to drought at early growth phases. The shoot/root ratio was lease in MB 29, MB 1 and MB 1-1. The shortest and more synchronous flowering period recorded in MB 29 and C 10 is important in reducing shattering losses and escaping from drought at flowering stage, Two mutants which have lost the undesirable effects associated with the indehiscent character in UCR82-203 NS were later found to have lost the indehiscent character too, suggesting that the undesirable effects of the indehiscent (id id) locus are pleiotropic. Anther culture studies were undertaken with the objective of using doubled haploids for sesame improvement. 25 refs, 2 figs, 7 tabs.

1994-01-01

18

Development of multicellular pollen of Eriobotrya japonica Lindl. through anther culture  

Digital Repository Infrastructure Vision for European Research (DRIVER)

8 pages, 5 figures.-- Printed version published Dec 2006. , Eriobotrya japonica Lindl. is a worldwide known tree important for its use as horticultural and ornamental plant, especially in sub-tropical and Mediterranean countries. Microspore embryogenesis through in vitro anther culture is a widely used...

Germanà, María Antonietta; Chiancone, Benedetta; Guarda, Nathalie Levy; Sánchez-Testillano, Pilar; Risueño, María del Carmen

19

Additives Promote Adventitious Buds Induction from Anther Culture of Bitter Melon (Momordica charantia L.)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The effects of growth regulators, Thidiazuron (TDZ), silver nitrate (AgNO3), triacontanol and glutaminate on adventitious buds induction from anther culture of bitter melon (Momordica charantia L.) were investigated. It was found that triacontanol was advantageous for buds developm...

Yi Tang; Huanxiu Li; Zesheng Yan; Jia Lai; Qian Luo; Li Zhang

20

A Comparison between Wheat and Maize Cross and Anther Culture Method for Production of Wheat Haploid Plants  

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Full Text Available The significance of haploid plants as genetic and plant breeding tools has been recognized for a long time. Haploid production techniques including anther culture, isolated microspore culture and intergeneric hybridization between wheat × Hordeum bulbosum and wheat × maize have been used to produce homozygous lines which accelerate breeding programs. In this study, wheat × maize hybridization and anther culture techniques were used for haploid production in six wheat genotypes. The results showed that 70.7% of regenerated plants through anther culture were albino plants and only 29.2 % were green, while the plants produced through wheat × maize method were all green. Ploidy variation was not observed in plants regenerated through wheat × maize hybridization. It was concluded that wheat × maize crosses would be an appropriate and practical method for haploid production in different wheat genotypes, which in comparison with the anther culture method has a higher efficiency.

T. Mahmoodi-Ghehsareh; B. E. Sayed-Tabatabaei; C. Ghobadi; A. Mirlohi

2004-01-01

 
 
 
 
21

Combining Ability and Heritability of Callus Induction and Green-Plant Regeneration in Rice Anther Culture  

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Full Text Available This study was conducted to determine the inheritance of callus induction and plant regeneration in rice anther culture. Low efficiencies of callus induction and green-plant regeneration have limited the application of anther culture in plant breeding programs. Four parents along with six F1 genotypes derived from a four-parent incomplete diallel mating set of two commercial lines (Amol2 and Amol3) and two local cultivars (Ghasroddashti and Rashti) were evaluated for their callus induction and plant regeneration abilities. The results showed that the callus induction, green-plant regeneration and the effects of genotype and genotypexmedium interaction were significant (p<0.01). The local cultivars generally had a higher percent callus induction, plant regeneration and number of calli producing green plants than the commercial lines. The parents showed significant difference in anther callus formation, from 4.01% (Amol2) to 22.26% (Rashti). Combining ability analysis demonstrated the predominance of additive gene effects in the control of both characters with the local cultivars having higher combining ability for green-plant regeneration. Also gene action to be partially dominant for both characters. Combining ability analysis revealed that both additive and dominant gene effects are important in controlling callus induction and green-plant regeneration in rice.

N. Bagheri; N.B. Jelodar

2008-01-01

22

Initial segmentation patterns of microspores and pollen viability in soybean cultured anthers: indication of chromosome doubling  

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Full Text Available Anthers obtained from flowers buds of soybean cultivar IAS-5 were cultured in two basal culture media (B5 and B5 long). Cytological examinations of the in vitro anthers were performed during the first 20 days of culture to assay the viability (by propionic-carmine and fluorescein diacetate tests) and the stage of development of pollen grains. The frequencies of viable pollen grains varied significantly between bud sizes on the propionic-carmine analysis. The basal culture media and bud size had no clear effect on the frequencies of binucleate symmetrical and multinucleate pollen grains. Chromosome counts of metaphasic microspores throughout the culture period showed microspores with higher ploidy level in addition to normal chromosome number (n=20).Anteras obtidas de botões florais da cultivar IAS-5 de soja foram cultivadas em dois meios de cultura basais (B5 e B5 longo). Análises citológicas das anteras cultivadas in vitro foram realizadas durante os primeiros 20 dias de cultura, a fim de avaliar a viabilidade (por testes de carmim propiônico e FDA) e o estágio de desenvolvimento dos grãos de pólen. As freqüências de grãos de pólen viáveis variaram significativamente entre os tamanhos de botões florais na análise com carmim propiônico. O meio de cultura basal e o tamanho do botão floral não têm um claro efeito nas freqüências de pólens binucleados simétricos e multinucleados. Contagens cromossômicas de micrósporos metafásicos ao longo do período de cultura mostraram nível de ploidia superior ao normal (n=20).

Milena Barcelos Cardoso; Eliane Kaltchuk-Santos; Elsa Cristina de Mundstock; Maria Helena Bodanese-Zanettini

2004-01-01

23

The haploid embryoids development in anther culture of transformed tobacco (Nicotiana tabacum L.)  

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Full Text Available Induction of pollen embryogenesis was used for the test of cytokinin influence on the development of pollen grain. Gene for maize cytokinin-specific ?-glucosidase were introduced into tobacco genome together with the methotrexate resistance marker (Brzobohatý et al. 1994). Anther culture of T1 generation of transformed Nicotiana tabacum L. plants revealed that high activity of ?-glucosidase caused a reduced regeneration of pollen embryoids. The stages of pollen embryoid development were comparable with those of zygotic embryos. Optimal nutritive medium contained charcoal and chelated iron. The absence of iron in the initiation medium caused a distinct decrease of pollen embryoid regeneration.

Jaroslava Dubová

1996-01-01

24

In vitro Plant Regeneration Through Anther Culture of Five Rice Varieties  

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Full Text Available Anthers of five rice varieties viz. BR-5, BR-31, BR-34, BR-37 and BR-38 were cultured for callus induction and plant regeneration. Anthers were cultured on N6, Z2 and R2 media containing the same hormonal combination 2.5mg/l NAA, 0.5mg/l Kn and 0.5mg/l 2.4-D and incubated at 25 ± 1oC in dark for callus induction. All the varieties in Z2 medium, two varieties in N6 medium and only one variety in R medium produced callus. Out of all responding varieties BR-38 produced highest percentage of callus. Calli induced in different induction media were transferred to MS medium supplemented with 2.0 mg/l BAP + 0.5 mg/l Kn + 1.0 mg/l NAA and 1.0 mg/l Kn + 1.0 mg/l NAA and incubated at 25 ± 1oC in light for plantlet regeneration. Green plantlets appeared within 15-30 days of culture and highest number of regenerated green (33.32%) and albino (11.27%) plantlets were produced in BR-37.

M. Asaduzzaman; M.A. Bari; M.H. Rahman; N. Khatun; M.A. Islam; M. Rahman

2003-01-01

25

Development of a short duration upland rice mutant line through anther culture of gamma irradiated plants  

International Nuclear Information System (INIS)

[en] This experiment was conducted in the field and at the tissue culture laboratory of the Plant Physiology Division, CARI, Yezin from 1994 to 1997. Upland rice, Yar-2 was used as the test variety. Dried seeds (14% moisture content) were treated with gamma rays at doses of 0, 300, 350, 400 and 450 Gy respectively. These seeds were planted separately according to the gamma-ray treatment they received. At booting stage, tillers were cut. Anthers from the top and middle portion of the panicle were taken. The pollen, at developmental stage in each anther, was examined using Acetocarmine dye. Pollens at the uninucleate to early binucleare stage were selected. Tillers having pollens at the above-mentioned stage were placed in a dark room at 25(±) 1 C and 16 hours photoperiod. When plantlets were obtained from these media, well-developed green plantlets were selected and planted in Yoshida solution to attain vigorous root growth. Diploid and haploid plants were formed from the anther culture method. At the heading stage, haploid plants were treated with colchicines to promote development into diploid plants. At maturity, plants produced from materials treated with different gamma doses were harvested separately. These homozygous lines were planted in the field and the characters were compared with their parents grown at the same time. The highest callus induction rate was found in materials treated with 450 Gy of gamma rays, but the lowest green plant regeneration rate was also observed at this dose. Among the forty-five homozygous lines obtained of the above materials, 7 lines, all from the 450 Gy gamma rays treated material, flowered earlier than the parents. One of the 7 early flowering lines, mutant line No 18, matured 19 days earlier but had the same yield as the parent. All other lines had a lower yield than the parent. Comparisons of yield and yield components of mutant line 18 and Yar-2 (parent) and comparison of quality characters are shown in tables

2005-01-01

26

Initial segmentation patterns of microspores and pollen viability in soybean cultured anthers: indication of chromosome doubling  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Anteras obtidas de botões florais da cultivar IAS-5 de soja foram cultivadas em dois meios de cultura basais (B5 e B5 longo). Análises citológicas das anteras cultivadas in vitro foram realizadas durante os primeiros 20 dias de cultura, a fim de avaliar a viabilidade (por testes de carmim propiônico e FDA) e o estágio de desenvolvimento dos grãos de pólen. As freqüências de grãos de pólen viáveis variaram significativamente entre os tamanhos de botões florais (more) na análise com carmim propiônico. O meio de cultura basal e o tamanho do botão floral não têm um claro efeito nas freqüências de pólens binucleados simétricos e multinucleados. Contagens cromossômicas de micrósporos metafásicos ao longo do período de cultura mostraram nível de ploidia superior ao normal (n=20). Abstract in english Anthers obtained from flowers buds of soybean cultivar IAS-5 were cultured in two basal culture media (B5 and B5 long). Cytological examinations of the in vitro anthers were performed during the first 20 days of culture to assay the viability (by propionic-carmine and fluorescein diacetate tests) and the stage of development of pollen grains. The frequencies of viable pollen grains varied significantly between bud sizes on the propionic-carmine analysis. The basal culture (more) media and bud size had no clear effect on the frequencies of binucleate symmetrical and multinucleate pollen grains. Chromosome counts of metaphasic microspores throughout the culture period showed microspores with higher ploidy level in addition to normal chromosome number (n=20).

Cardoso, Milena Barcelos; Kaltchuk-Santos, Eliane; Mundstock, Elsa Cristina de; Bodanese-Zanettini, Maria Helena

2004-09-01

27

Evaluation of Effective Factors in Anther Culture of Iranian Rice (Oryza sativa L.) Cultivars  

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Full Text Available This study was conducted to develop the breeding method of anther culture for pure line induction in Iranian Rice cultivars. Several aspects were studied: the genotype factors, the culture medium, the date of sampling and the kind and content of sugar in culture medium. Results showed that the first date of sampling (middle July)had better callus induction than the second one and has led to increased callus induction of cultivars to 8.1 percent. In the investigation of carbon source, callus induction medium with 4% maltose was significantly better than others of sugar treatments. Also, different treatments of sugar had positive effects on cultivars regeneration, but there were not significant. Results indicated that there were significant differences in callus production among the different cultivars, and the average of callus induction ability ranged from 2.13% to 23.38%. Rashti had the highest callus induction and Amol3 and Amol2 had the lowest callus induction. Reciprocal effects of genotype and medium were significant (p<0.05). N6, Fj1 and G1 media had the highest callus induction, respectively. The average of regeneration ranged from 0.0 to 15.2 percent. The maximum plant regeneration percentage was obtained in M5 regeneration medium

Nadali BAGHERI; Nadali BABAEIAN-JELODAR; Ali GHANBARI

2009-01-01

28

Cultivo de anteras en dos clones de yuca/ Anther culture in two cassava clones  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El cultivo de anteras de yuca, Manihot esculenta Crantz, es una estrategia de mejoramiento genético para la producción de plantas haploides, permitiendo la selección de clones mejorados y la detección de genes favorables mediante las técnicas moleculares. No se ha precisado un protocolo que asegure la producción de plantas haploides en el cultivo, para ello se evaluó la respuesta morfogénica de dos clones de yuca: UCV-2726 (dulce) y UCV2375 (amarga), para tal fin (more) se evalúo el tamaño del botón floral (1-1,5mm y 2-2,5mm) que determinará la fase de desarrollo óptimo de la microspora. Se evaluaron dos medios de cultivo: Murashige y Skoog (MS) y Chu et al., (N6) ambos suplementados con dos concentraciones de auxina. Se estableció un diseño completamente aleatorizado en un arreglo factorial 3², y realizando la prueba de media de Duncan. Se observaron microsporas en tétrada y en fase uninucleada para el tamaño de botón 1-1,5 mm. Durante la inducción de callos se encontraron diferencias para el tamaño del botón, siendo mayor el número de callos formados para el tamaño de 1-1,5 mm en el medio de MS. El ANAVAR no arrojó diferencias significativas entre el tipo de clon y la respuesta al medio de cultivo, sin embargo, hubo diferencias en cuanto al tamaño del botón floral. Se generaron dos grupos de medias indicando que ambas longitudes generan diferentes números de callos. El tejido calloso se diferenció morfogénicamente en raíces, esto pudiera estar asociado con las auxinas aplicadas al medio. Abstract in english Cassava anther culture is a strategical tool for breeding programs in order to obtain haploid plants, allowing selection of improved clones and detection of very important genes through molecular markers. A complete protocol for cassava haploid plant production has not been developed, therefore we evaluated morphogenic response in two cassava clones: sweet (UCV-2726) and bitter (UCV-2375), for two different sizes (1-1.5 mm and 2-2,5 mm) of floral buds selected in order to (more) ascertain the optimal developmental phase of the microspore. Murashige and Skoog and Chu et al. media were evaluated, supplied with two different auxin concentrations. A factorial 3² completely randomized design and Duncan test were used as statistical methods. For floral bud size of 1-1.5 mm, tetrad and uninucleated microspores were observed. During callus induction, differences were found for bud size with the highest number of calluses formed for 1-1.5 mm in MS medium. The ANAVAR did not show significant differences between clone types and culture media. There were two different mean groups for callus number. Callus tissue differentiated morphogenically into roots; this might be associated with auxins applied to the medium.

Chirinos, Marilú; Velásquez S, Rosalía; Noguera, Arnaldo; Pérez, Miguel; Mata, Jonás; Polanco, Delia

2006-12-01

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A comparison of RFLP maps based on anther culture derived, selfed, and hybrid progenies of Solanum chacoense.  

UK PubMed Central (United Kingdom)

Comparative RFLP linkage maps were constructed using five segregating populations derived from two self-incompatible lines (termed PI 230582 and PI 458314) of diploid tuber-bearing Solanum chacoense Bitt. The analysis was based on 84 RFLP loci identified by 73 different cDNA clones. Distortion of expected Mendelian segregation ratios was observed; less than 10% of the markers showed a skewed segregation in the gametes forming the F1, hybrid population compared with 30% in the selfed population and 46 and 70% in the two populations produced by anther culture. For the anther culture derived populations, most of the skewed loci were scattered throughout the genome, whereas in the populations derived from selfing, they were found primarily in linkage group 1, around the S locus. In this study, we also found that the rate of meiotic recombination could differ between the male and female gametes produced by our parental lines. Thus, male gametes of line PI 458314 showed significantly less recombination as assessed by the total length of the map (206 cM for male gametes vs. 375 cM for female gametes) and the phenomenon was genome-wide. In contrast, the maps from the gametes of PI 230582 had about the same length, but some linkage groups were longer in the female gametes, while others were longer in the male gametes. Key words : Solanum chacoense, RFLP, anther culture, skewed segregation, self-incompatibility, sex differences in recombination.

Rivard SR; Cappadocia M; Landry BS

1996-08-01

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GENETIC DIVERSITY ANALYSIS OF ANTHER CULTURE DERIVED RICE PLANTS USING MOLECULAR MARKERS  

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Full Text Available Random amplified polymorphic DNA (RAPD) analysis and inter-simple sequence repeats (ISSR) primers were used to determine the occurrence and extent of variation in rice (Oryza sativa L.) plants regenerated from anther culture. Genetic diversity among 27 regenerants of the cross CO43/Nootripathu and their parents were assessed using 25 RAPD primers and 19 ISSR primers. RAPD primers used in the study produced 285 polymorphic markers (81.65% polymorphism) and ISSR primers produced 201 polymorphic markers (79.37% polymorphism). The number of markers produced per primer ranged from 4-27 in case of RAPD with a mean of 14.04 and 7-23 in case of ISSR with a mean of 13.05. Dendrograms were constructed using similarity index values. RAPD markers grouped the 27 regenerants (A0 generation) and their parents into four clusters and ISSR markers into three clusters. The Polymorphism information content (PIC) values ranged from 0.702 to 0.952 with a mean of 0.887 for RAPD markers. In ISSR analysis, the mean PIC value was 0.891 and the highest and lowest PIC values were 0.940 and 0.832 respectively. In the present study, RAPD markers were able to reveal greater genetic diversity among the regenerants screened than ISSR markers.

Hemaprabha K; Hemalatha T; UmaMaheswari T; Anbukkarasi K; Shanmugasundaram P

2013-01-01

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Effects of Genotype on Induction of Callus and Plant Regeneration Potential in vitro Anther Culture of Rice (Oryza sativa L.)  

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Full Text Available The present studies were carried out to evaluate the response of anthers of six rice genotypes to callus induction and plant regeneration. For callus induction Z2 media supplemented with 2, 4-D 0.5 mg l-1, NAA 2.5 mg l-1 and Kinetin 0.5 mg l- was used. Of the six genotypes, five gave good callusing response. Highest callus induction was observed in BRRI Dhan-29 (8.06%) and lowest in BR-10 (1.42%). Callus induction frequency varied from 1.42-8.06% depending on genotypes. Modified MS medium supplemented with Kinetin 0.5 mg l-1, BAP 2 mg l-1 and NAA 1.0 mg l-1 was used for plant regeneration. The results showed a significant genotypic difference in callus induction and plant regeneration. The regeneration of plantlet from anther derived calli ranged from 57-75% conclusion.

Sharmin Shahnewaz; M.A. Bari; N.A. Siddique; M.H. Rahman

2004-01-01

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Restriction fragment length polymorphism (RFLP) analyses of plants produced by in vitro anther culture of Solanum chacoense Bitt.  

UK PubMed Central (United Kingdom)

In this study, a novel approach was used to characterize the genetic architecture of plants produced by in vitro anther culture of two lines of self-incompatible Solanum chacoense Bitt. (2n=2x=24). We used cytological observations to determine the ploidy level of the regenerated plants and scanned genomic DNA of the anther donor plants to identify heterozygous sequences. Restriction fragment length polymorphism (RFLP) analyses permitted the visualization of DNA variations. Several heterozygous DNA markers were found within single anther donor plants. Completely homozygous lines could be easily identified. Somatically derived plants could be separated from diploid plants produced from 2n (unreduced) microspores. Our results demonstrate first division restitution (FDR) as the mechanism operating during the production of 2n microspores in one of our S. chacoense line. Potential applications of RFLP analyses for genetic mapping, identification of lethal alleles and quantitative trait loci (QTL) with haploid or homozygous diploid plants and determination of gene-centromere distance with diploid plants derived from 2n microspores will be discussed.

Rivard SR; Cappadocia M; Vincent G; Brisson N; Landry BS

1989-01-01

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Plant regeneration from in vitro culture of anthers of Solanum chacoense Bitt. and interspecific diploid hybrids Solanum tuberosum L. X. Solanum chacoense Bitt.  

UK PubMed Central (United Kingdom)

Production of plants from cultured anthers of Solanum chacoense clone IP 33, of its interspecific diploid hybrids with S. tuberosum clones IP 354 and IP 372, and of a complex Solanum hybrid containing in its genome S. ajanhuiri is reported. Genotypic differences were found to influence both the induction phase and the regeneration process. Hybrids derived from clone IP 354 of S. tuberosum were much more responsive in culture than hybrids from clone IP 372. Altogether, 507 plants were regenerated and 309 were cytologically analyzed. Of these, 52% were haploid, 47% diploid and 1% mixoploid or tetraploid. A number of diploid plants probably originated from unreduced microspores and some genetic consequences of this event are discussed.

Cappadocia M; Cheng DSK; Ludlum-Simonette R

1984-12-01

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Breeding of a new early season indica rice variety Ganzaoxian 56 by irradiation, anther culture and hybridization  

International Nuclear Information System (INIS)

Ganzaoxian 56 is a new early season indica rice variety, which was bred in the College of Agronomy of Jiangxi Agricultural University by the integrative breeding techniques of radiation, anther culture and hybridization. Its main characteristics were as follows: super quality, high yield, high tolerance to heat-forced maturity, suitable maturity and high resistance to rice blast. It was registered by Crop Cultivar Registration Committee of Jiangxi Province on March 19, 2004. The breeding process of Ganzaoxian 56, main characteristics and the value of its exploitation and application were described in this paper. (authors)

2005-01-01

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Callus and Green Spot Formation From Anther Culture of Chili Mutant Lines (Capsicum Annum.L) Using in-vitro Culture  

International Nuclear Information System (INIS)

[en] Callus and green spot formation from anther culture of chili mutant lines (Capsicum annum.L) were carried out using in-vitro culture. Two kinds of different media based on hormonal composition were used for callus induction. A half of an quantities were directly cultured on callus induction medium, while rest of them were treated with cold shock (4oC) for 3 and 6 days subsequently cultured on callus induction medium. The highest callus formation was observed in culture from Ac medium containing I mg/l 2,4-D and 0,1 mg/l kinetin and were obtained from 0 days cold shock with chili without irradiation (Kr 0) 30%, chili mutant lines with irradiation dose 20 Krad (Kr 20) 25% and chili mutant lines with irradiation dose 40 Krad (Kr 40) 30% respectively. While cold shock for 3 days increasing 15 % callus formation from Kr 40 mutant lines

2002-01-01

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Adequação de meios de cultura de anteras e testes de genótipos de trigo Culture medium, microenvironment and genotype effects on wheat anther culture  

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Full Text Available Realizaram-se dois experimentos, o primeiro visando conhecer a capacidade androgênica de variedades de trigo e identificar as melhores condições para alcançar aquele objetivo, em termos de meios de cultura e microclima. No segundo, estudou-se maior número de variedades. No primeiro experimento, foram testadas as seguintes: PF 853031 e IAC 24, a primeira, usada como padrão; dois meios de cultura básicos, batata-2 e N6; duas auxinas, IAA e 2,4-D, nas doses de 3, 9 e 27 ìmol/L, e cinetina, nas doses de 2, 6, 12 e 24 ìmol/L. As anteras plaqueadas foram acondicionadas em sala fotoperiódica: (a) com 14 h de luz, 60 ìmol.m-2.s-1 (3.200 lux), à temperatura de 25°C, e (b) submetidas a pré-tratamento por quatro dias a 6°C e, em seguida, retornadas à condição a. Notou-se que a melhor combinação de tratamentos para a variedade IAC 24 foi o meio batata-2, 2,4-D a 27 .ìmol/L e cinetina 2 a 6 ìmol/L, por promover maior indução de estruturas androgênicas. Já para a variedade PF 853031, a mesma combinação de tratamentos, exceto 2,4-D a 9 µmol/L, promoveu também maior indução de estruturas androgênicas. Por outro lado, o pré-tratamento de quatro dias de frio causou maior indução de estruturas androgênicas em ambas as variedades. No segundo experimento, foram estudadas cinco variedades: PF 853048, usada como padrão, IAC 21, BH 1146, IAC 60 e Anahuac; dois meios de cultura básicos: batata-2 e N6; duas combinações hormonais: CH1 (10 µmol/L IAA e 30 ìmol/L de cinetina), e CH2 (10 ìmol/L de 2,4-D e 3,0 ìmol/L de cinetina). Observou-se maior indução de estruturas androgênicas para a 'PF 853048', seguida da 'Anahuac'. Todavia, somente foram obtidas plantas para a primeira. Essa constatação sugere que a capacidade androgênica seja controlada geneticamente no trigo. Na combinação hormonal 10 ìmol/L de 2,4-D e 3 ìmol/L de cinetina houve maior formação de estruturas androgênicas. Transplantaram-se as plantas regeneradas para vasos contendo solo, alocando-as em casa de vegetação para aclimatação, crescimento e florescimento. As plantas mostraram-se inférteis, mas produziram sementes após a duplicação pela técnica da colchicina.Experiments were carried out to establish conditions and to access varietal effects for wheat androgenesis. The varieties PF 853031, a standard known for androgenic capacity, and the IAC 24 of high agronomic value, were tested in two culture mediums, potato-2 and N6, including two auxins, IAA and 2.4-D, at 3, 9 and 27 ìmol/L, and kinetin, at 2, 6, 12 and 24 µmol/L. The experiment was installed in factorial design with six blocks and 20 anthers per plate (a block). About 5,760 anthers were plated per variety. The experiment was left in a photoperiodic room with (a) 14 h of cool fluorescent light, 60 ìmol.m-2.s-1 (3,200 lux), at temperature of 25°C, and (b) pretreated in dark at 6°C for four days, then backed to a. The variety IAC 24 showed higher androgenic capacity than the PF 853031 variety, in medium potato-2, 2.4-D at 27 ìmol/L and kinetin from 2 to 6 µmol/L. Cold treatment for four days was beneficial in improving androgenesis to both varieties. Five other varieties were studied, PF 853048, as a androgenic control, IAC 21, BH 1146, IAC 60 and Anahuac; two culture mediums, potato-2 and N6, along with two hormonal combinations, CH1 (IAA 10 µmol/L and kinetin 30 µmol/L) and CH2 (2.4-D 10µmol/L and kin 3 .mol/L) in the condition as (b) above. The standard variety PF 853048 ranked first and Anahuac, the second in terms of androgenic response. However, plants were only obtained from PF 853048. It is likely that the androgenic effect is under genotype control in wheat. The hormonal combination 10 µmol/L of 2.4-D and 3 µmol/L of kinetin were observed to induce higher androgenic response. Regenerated plants were potted and left to flower. All of them showed to be infertile, but produced seeds after colchicine treatment.

Luis Carlos da Silva Ramos; Erica Yumi Yokoo; Carlos Eduardo de Oliveira Camargo

1994-01-01

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Anther development stage and gamma radiation effects on tomato anther-derived callus formation  

International Nuclear Information System (INIS)

Two experiments were carried (I) to determine tomato anther development stage influence on callus production; and (II) to investigate gamma radiation effects on anther culture. In the first experiment, anthers of a tomato hybrid (IPA 5 x Rotam 4-F1) were grown on three media. Although calli were induced at all stages of anther development, varying from prophase I to mono nucleate microspore, callus frequency decreased as anther development progressed and calli induction were not significantly affected by all media tested. Anthers containing prophase I meiocytes produced the highest calli frequency. Anther and flower bud length both were significantly correlated with anther development stage. In the second experiment, seed and floral buds of tomato hybrids IPA 5 x Rotam 4 (F2), IPA 6 x Rotam 4 (F2) and IPA 8 x 217.1 (F2) were submitted to gamma-ray and anthers were plated on two media described by Gresshoff and Doy (1972) supplemented with 2.0 mg L-1 NAA + 5.0 mg L-1 KIN and 2.0 mg L-1 NAA + 1.0 mg L-1 KIN. No significant differences for genotype and dosage testes were found for calli formation. (author)

1999-01-01

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Histochemical and immunohistochemical identification of laticifer cells in callus cultures derived from anthers of Hevea brasiliensis.  

Science.gov (United States)

Laticifers are highly specialized cells present in over 20 plant families. They are well defined in planta. In vitro development of laticifers was also observed in some plants, but uncertain in the callus cultures of rubber tree, one of the most economically important latex producing plants. In the present study, we provide evidence that laticifer cells present in the callus cultures of rubber tree by histochemical and immunohistochemical studies. They present in the callus mainly as separate non-elongated form, a novel morphology different from the morphology of laticifer cells in planta, excluding their origin from explants. The occurring frequency of laticifer cells in the callus was genotype-dependent and negatively correlated with the somatic embryogenetic ability, suggesting that the presence of laticifer cells in the callus inhibit somatic embryogenesis in tissue culture of rubber tree. The genotypes PR107, RRIM600, Reyan8-79, and Reyan7-33-97 with lower embryogenetic ability compared to Haiken 2 had more laticifer cells, and laticifer clusters were only observed in these genotypes. PMID:21301851

Tan, Deguan; Sun, Xuepiao; Zhang, Jiaming

2011-02-08

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Histochemical and immunohistochemical identification of laticifer cells in callus cultures derived from anthers of Hevea brasiliensis.  

UK PubMed Central (United Kingdom)

Laticifers are highly specialized cells present in over 20 plant families. They are well defined in planta. In vitro development of laticifers was also observed in some plants, but uncertain in the callus cultures of rubber tree, one of the most economically important latex producing plants. In the present study, we provide evidence that laticifer cells present in the callus cultures of rubber tree by histochemical and immunohistochemical studies. They present in the callus mainly as separate non-elongated form, a novel morphology different from the morphology of laticifer cells in planta, excluding their origin from explants. The occurring frequency of laticifer cells in the callus was genotype-dependent and negatively correlated with the somatic embryogenetic ability, suggesting that the presence of laticifer cells in the callus inhibit somatic embryogenesis in tissue culture of rubber tree. The genotypes PR107, RRIM600, Reyan8-79, and Reyan7-33-97 with lower embryogenetic ability compared to Haiken 2 had more laticifer cells, and laticifer clusters were only observed in these genotypes.

Tan D; Sun X; Zhang J

2011-06-01

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Callus cultures from seeds and anthers of Sesamum indicum L./ Cultura in vitro de sementes e anteras de Sesamum indicum L.  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Sementes de gergelin (Sesamum indicum L.) foram cultivadas in vitro em meio de cultura de Wetherall contendo 0,5 mg/l de 2,4-D e em seguida transferidas para meio de Murashige e Skoog (MS) contendo 0,1 mg/l de 2,4-D e 100 mg/l de inositol. Ambos, 2,4-D e inositol mostraram-se ser necessários para o desenvolvimento de calos a partir de sementes, do mesmo modo que para o contínuo crescimento dos meios em cultura. Foram também obtidos calos de explantes de anteras, cotiledones e de hipocotilo de Sesamum utilizando-se o meio MS com a ocorrência de estruturas globulares. Abstract in english Continuously growing Sesamum hypocotyl callus cultures were successfully initiated from hypocotyl tissues of seeds cultured on Wetherall's Medium containing 0.5 mg/l 2,4-D and subcultured on Murashige and Skoog (MS) medium containing 0.1 mg/1 2,4-D and 100 mg/l inositol. Both 2,4-D and inositol appear to be essential for maintenance of continous growth. Callus cultures were likewise established from explants of anthers, cotyledon, and hypocotyl on the MS medium with the occurrence of arrested globular structures in some cultures.

Caldas, L.S.; Sharp, W.R.; Crocomo, O.J.

1979-01-01

 
 
 
 
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RFLP analyses and segregation of molecular markers in plants produced by in vitro anther culture, selfing, and reciprocal crosses of two lines of self-incompatible Solanum chacoense.  

UK PubMed Central (United Kingdom)

RFLP analyses were used to characterize several plant populations of Solanum chacoense Bitt. developed to investigate the generation of new S alleles at the self-incompatibility locus. The plant material consisted of two diploid parental lines, their anther culture derived (AC) progenies, their selfed progenies, and their reciprocal F1 hybrids. The RFLP analyses on the AC plants (121 individuals in total) permitted unambiguous identification of their origin. In particular, a distinction between plants originated from reduced (n) or unreduced (2n) microspores could be made. All the AC plants produced by gametic embryogenesis showed distinct RFLP patterns, whereas a number of clones (i.e., plants with identical RFLP patterns) were found among those regenerated via callus. The analyses conducted on the selfed progenies (69 plants) and the F1 hybrids (66 plants) showed only one case of accidental outcross. Segregation studies of the RFLP markers revealed significant deviations from expected Mendelian ratios in both AC-derived populations, as well as in the selfed progenies. Such deviations, however, were rare in the reciprocal F1 hybrids. These results are discussed in relation to the possible presence of genetic sieves operating during AC, illegitimate selfing, or during normal fertilization.

Rivard SR; Saba-El-Leil MK; Landry BS; Cappadocia M

1994-10-01

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AMS-dependent and independent regulation of anther transcriptome and comparison with those affected by other Arabidopsis anther genes  

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Full Text Available Abstract Background In flowering plants, the development of male reproductive organs is controlled precisely to achieve successful fertilization and reproduction. Despite the increasing knowledge of genes that contribute to anther development, the regulatory mechanisms controlling this process are still unclear. Results In this study, we analyzed the transcriptome profiles of early anthers of sterile mutants aborted microspores (ams) and found that 1,368 genes were differentially expressed in ams compared to wild type anthers, affecting metabolism, transportation, ubiquitination and stress response. Moreover, the lack of significant enrichment of potential AMS binding sites (E-box) in the promoters of differentially expressed genes suggests both direct and indirect regulation for AMS-dependent regulation of anther transcriptome involving other transcription factors. Combining ams transcriptome profiles with those of two other sterile mutants, spl/nzz and ems1/exs, expression of 3,058 genes were altered in at least one mutant. Our investigation of expression patterns of major transcription factor families, such as bHLH, MYB and MADS, suggested that some closely related homologs of known anther developmental genes might also have similar functions. Additionally, comparison of expression levels of genes in different organs suggested that anther-preferential genes could play important roles in anther development. Conclusion Analysis of ams anther transcriptome and its comparison with those of spl/nzz and ems1/exs anthers uncovered overlapping and distinct sets of regulated genes, including those encoding transcription factors and other proteins. These results support an expanded regulatory network for early anther development, providing a series of hypotheses for future experimentation.

Ma Xuan; Feng Baomin; Ma Hong

2012-01-01

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Anther development stage and gamma radiation effects on tomato anther-derived callus formation; Efeitos do estadio de desenvolvimento da antera e da radiacao gama na formacao de calos derivados de anteras de tomate  

Energy Technology Data Exchange (ETDEWEB)

Two experiments were carried (I) to determine tomato anther development stage influence on callus production; and (II) to investigate gamma radiation effects on anther culture. In the first experiment, anthers of a tomato hybrid (IPA 5 x Rotam 4-F{sub 1}) were grown on three media. Although calli were induced at all stages of anther development, varying from prophase I to mono nucleate microspore, callus frequency decreased as anther development progressed and calli induction were not significantly affected by all media tested. Anthers containing prophase I meiocytes produced the highest calli frequency. Anther and flower bud length both were significantly correlated with anther development stage. In the second experiment, seed and floral buds of tomato hybrids IPA 5 x Rotam 4 (F{sub 2}), IPA 6 x Rotam 4 (F{sub 2}) and IPA 8 x 217.1 (F{sub 2}) were submitted to gamma-ray and anthers were plated on two media described by Gresshoff and Doy (1972) supplemented with 2.0 mg L{sup -1} NAA + 5.0 mg L{sup -1} KIN and 2.0 mg L{sup -1} NAA + 1.0 mg L{sup -1} KIN. No significant differences for genotype and dosage testes were found for calli formation. (author)

Brasileiro, Ana Christina R.; Willadino, Lilia [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Lab. de Cultura de Tecidos Vegetais. E-mail: lilia@truenet.com.br; Guerra, Marcelo [Pernambuco Univ., Recife, PE (Brazil). Dept. de Botanica. Lab. de Citogenetica Vegetal; Colaco, Waldeciro [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear. Lab. de Radioagronomia; Meunier, Isabelle [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Dept. de Engenharia Florestal; Camara, Terezinha R. [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Dept. de Quimica. Lab. de Cultura de Tecidos Vegetais

1999-12-01

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Effect of Genotype and Callus Induction Medium on Green Plant Regeneration from Anther of Nepalese Rice Cultivars  

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Full Text Available Effects of genotype and medium composition on the frequency of callus induction and green plant regeneration from anther of Nepalese rice were investigated. Cold pretreated anthers from six rice genotypes at 8±2°C for seven days were cultured on three different callus induction media designated as Callus Induction Medium (CIM 1): N6 mineral salts + N6 vitamins (2 mg L-1 each) + myoinositol (100 mg L-1) + 2,4-D (2.5 mg L-1) + KI (0.5 mg L-1) + AgNO3 (10 mg L-1) + maltose (50 g L-1), CIM 2: N6 mineral salts + MS organic salts + NAA (4 mg L-1) + Kinetin (KI) (2 mg L-1) + Silver nitrate (AgNO3) (5 mg L-1) and sucrose 60 (g L-1) and CIM 3: CIM 2 without AgNO3.. The callus induction frequency was significantly affected by rice genotypes and genotype x medium interactions. The efficiency of callus induction (calli/anther) was higher in CIM 1 (14.1%) followed by CIM 2 (12.54%) and CIM 3 (10.3%). CIM 2 was found to be superior for the recovery of green plants. Among genotypes, only the calli from Chandanath -3 and Khumal-4 were able to differentiate into green plants. In this study the calli induced on medium containing 2, 4-Dichloroacetic acid (2, 4-D) had lower regeneration ability than the medium supplied with ?-naptthalene acetic acid (NAA). This study also revealed that the temperate cultivars (hill rice) were more responsive to anther culture than the tropical ones (terai rice).

R.K. Niroula; H.P. Bimb

2009-01-01

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Microarray and differential display identify genes involved in jasmonate-dependent anther development.  

UK PubMed Central (United Kingdom)

Jasmonate (JA) is a signaling compound essential for anther development and pollen fertility in Arabidopsis. Mutations that block the pathway of JA synthesis result into male sterility. To understand the processes of anther and pollen maturation, we used microarray and differential display approaches to compare gene expression pattern in anthers of wild-type Arabidopsis and the male-sterile mutant, opr3. Microarray experiment revealed 25 genes that were up-regulated more than 1.8-fold in wild-type anthers as compared to mutant anthers. Experiments based on differential display identified 13 additional genes up-regulated in wild-type anthers compared to opr3 for a total of 38 differentially expressed genes. Searches of the Arabidopsis and non-redundant databases disclosed known or likely functions for 28 of the 38 genes identified, while 10 genes encode proteins of unknown function. Northern blot analysis of eight representative clones as probes confirmed low expression in opr3 anthers compared with wild-type anthers. JA responsiveness of these same genes was also investigated by northern blot analysis of anther RNA isolated from wild-type and opr3 plants, In these experiments, four genes were induced in opr3 anthers within 0.5-1 h of JA treatment while the remaining genes were up-regulated only 1-8 h after JA application. None of these genes was induced by JA in anthers of the coil mutant that is deficient in JA responsiveness. The four early-induced genes in opr3 encode lipoxygenase, a putative bHLH transcription factor, epithiospecifier protein and an unknown protein. We propose that these and other early components may be involved in JA signaling and in the initiation of developmental processes. The four late genes encode an extensin-like protein, a peptide transporter and two unknown proteins, which may represent components required later in anther and pollen maturation. Transcript profiling has provided a successful approach to identify genes involved in anther and pollen maturation in Arabidopsis.

Mandaokar A; Kumar VD; Amway M; Browse J

2003-07-01

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Proteomic analysis of rice anthers under salt stress.  

UK PubMed Central (United Kingdom)

Salinity is a major factor that limits rice production worldwide. Rice is considered generally to be sensitive to salt stress during the reproductive stage. To determine the molecular mechanisms of salt tolerance at the reproductive stage, anther proteomic patterns for two contrasting rice genotypes IR64 (salt sensitive) and Cheriviruppu (salt tolerant) under salt stress were compared. Plants were grown in a greenhouse and salt stress (100 mM NaCl) was imposed at the booting stage. Anther samples were collected from control and salt-treated plants at the anthesis stage. The Na(+)/K(+) ratio in IR64 anthers under salt stress was >1.7 times greater than that under control conditions, whereas no significant change was observed in Cheriviruppu. We also observed an 83% reduction in IR64 pollen viability, whereas this reduction was only 23% in Cheriviruppu. Of 454 protein spots detected reproducibly on two-dimensional electrophoresis gels, 38 showed significant changes in at least one genotype in response to stress. Using Mass spectrometry (MALDI TOF/TOF) analysis, we identified 18 protein spots that were involved in several processes that might increase plant adaptation to salt stress, such as carbohydrate/energy metabolism, anther wall remodelling and metabolism, and protein synthesis and assembly. Three isoforms of fructokinase-2 were upregulated only in Cheriviruppu under salt stress. This upregulation might result in increased starch content in pollen, which would support pollen growth and development under salt stress. The results also suggested that anther and pollen wall remodelling/metabolism proteins contribute to the tolerance of rice to salt stress.

Sarhadi E; Bazargani MM; Sajise AG; Abdolahi S; Vispo NA; Arceta M; Nejad GM; Singh RK; Salekdeh GH

2012-09-01

47

Proteomic analysis of rice anthers under salt stress.  

Science.gov (United States)

Salinity is a major factor that limits rice production worldwide. Rice is considered generally to be sensitive to salt stress during the reproductive stage. To determine the molecular mechanisms of salt tolerance at the reproductive stage, anther proteomic patterns for two contrasting rice genotypes IR64 (salt sensitive) and Cheriviruppu (salt tolerant) under salt stress were compared. Plants were grown in a greenhouse and salt stress (100 mM NaCl) was imposed at the booting stage. Anther samples were collected from control and salt-treated plants at the anthesis stage. The Na(+)/K(+) ratio in IR64 anthers under salt stress was >1.7 times greater than that under control conditions, whereas no significant change was observed in Cheriviruppu. We also observed an 83% reduction in IR64 pollen viability, whereas this reduction was only 23% in Cheriviruppu. Of 454 protein spots detected reproducibly on two-dimensional electrophoresis gels, 38 showed significant changes in at least one genotype in response to stress. Using Mass spectrometry (MALDI TOF/TOF) analysis, we identified 18 protein spots that were involved in several processes that might increase plant adaptation to salt stress, such as carbohydrate/energy metabolism, anther wall remodelling and metabolism, and protein synthesis and assembly. Three isoforms of fructokinase-2 were upregulated only in Cheriviruppu under salt stress. This upregulation might result in increased starch content in pollen, which would support pollen growth and development under salt stress. The results also suggested that anther and pollen wall remodelling/metabolism proteins contribute to the tolerance of rice to salt stress. PMID:22868211

Sarhadi, Elham; Bazargani, Mitra Mohammadi; Sajise, Andres Godwin; Abdolahi, Shapour; Vispo, Naireen Aiza; Arceta, Marydee; Nejad, Ghasem Mohammadi; Singh, Rakesh Kumar; Salekdeh, Ghasem Hosseini

2012-07-23

48

Efeitos de meios de cultura na formação de calos a partir de anteras de aspargo (Asparagus officinalis L.)/ Effects of the culture media on the calli formation from Asparagus officinalis L. anthers  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Técnicas auxiliares, como a cultura de anteras, possibilitam melhor eficiência na obtenção de novos genótipos de aspargo. Neste trabalho, foram utilizadas anteras contendo grãos de pólen, no estágio uninucleado, dos híbridos 56x22-8 e 47x22-8, em meio MS, semi-sólido e líquido, com diferentes concentrações de reguladores de crescimento: meio A - 0,5 mg/l BAP + 0,1 mg/l ANA + 0,5 mg/l 2,4-D + 20 g/l sacarose + 20 g/l glicose; meio B - 0,5 mg/l 2,4-D + 30 g/l s (more) acarose; meio C - 3,0 mg/l ANA + 0,5 mg/l Kin + 30 g/l sacarose e meio D - 2,0 mg/l ANA + 0,5 mg/l Kin + 30 g/l sacarose. A formação de calos variou com o genótipo e o meio. Os meios líquidos apresentaram melhor eficiência na indução de calos do que os meios semi-sólidos. Para o híbrido 56x22-8 os melhores meios foram o A2 (líquido) com 80,5% de indução de calos e dentre os meios semi-sólidos, o meio D1 com 41,6% de calos formados. Para o híbrido 47x22-8, o mais eficiente foi o meio D2 (líquido), com 68,1% de calos formados e, dentre os meios semi-sólidos, o D2, com 15,2%. Não ocorreram diferenças significativas, estatisticamente, entre os meios líquidos nem entre os meios semi-sólidos. Abstract in english Anther culture is an auxiliary technique to obtain new genotypes. In this work, anthers with pollen grains in the uninucleated stage of hybrids 56x22-8 and 47x22-8 were cultured in MS medium, semi-solid and liquid, with different concentrations of growth regulators: medium A - 0,5 mg/l BAP + 0,1 mg/l NAA + 0,5 mg/1 2,4-D + 20 g/l sucrose + 20 g/l glucose; medium B - 0,5 mg/1 2,4-D + 30 g/l sucrose; medium C - 3,0 mg/l NAA + 0,5 mg/l Kin + 30 g/l sucrose and medium D - 2,0 (more) mg/l NAA + 0,5 mg/l Kin + 30 g/l sucrose. Callus formation varied with the genotype and the medium. Liquid media showed more efficiency in callus development than the semi-solids. For the hybrids 56x22-8 the best media were the liquid A2 with 80,5% of callus induction and among the semi-solids the D1, with 41,6%. For the hybrid 47x22-8 were liquid D2 with 68,1% and semi solid D1 with 15,2%. No significant differences were observed among the liquid media nor among the semi-solidones.

Bobrowski, Vera Lúcia; Peters, José Antônio; Augustin, Eliane; Viégas, Judith

1995-07-01

49

Efeitos de meios de cultura na formação de calos a partir de anteras de aspargo (Asparagus officinalis L.) Effects of the culture media on the calli formation from Asparagus officinalis L. anthers  

Directory of Open Access Journals (Sweden)

Full Text Available Técnicas auxiliares, como a cultura de anteras, possibilitam melhor eficiência na obtenção de novos genótipos de aspargo. Neste trabalho, foram utilizadas anteras contendo grãos de pólen, no estágio uninucleado, dos híbridos 56x22-8 e 47x22-8, em meio MS, semi-sólido e líquido, com diferentes concentrações de reguladores de crescimento: meio A - 0,5 mg/l BAP + 0,1 mg/l ANA + 0,5 mg/l 2,4-D + 20 g/l sacarose + 20 g/l glicose; meio B - 0,5 mg/l 2,4-D + 30 g/l sacarose; meio C - 3,0 mg/l ANA + 0,5 mg/l Kin + 30 g/l sacarose e meio D - 2,0 mg/l ANA + 0,5 mg/l Kin + 30 g/l sacarose. A formação de calos variou com o genótipo e o meio. Os meios líquidos apresentaram melhor eficiência na indução de calos do que os meios semi-sólidos. Para o híbrido 56x22-8 os melhores meios foram o A2 (líquido) com 80,5% de indução de calos e dentre os meios semi-sólidos, o meio D1 com 41,6% de calos formados. Para o híbrido 47x22-8, o mais eficiente foi o meio D2 (líquido), com 68,1% de calos formados e, dentre os meios semi-sólidos, o D2, com 15,2%. Não ocorreram diferenças significativas, estatisticamente, entre os meios líquidos nem entre os meios semi-sólidos.Anther culture is an auxiliary technique to obtain new genotypes. In this work, anthers with pollen grains in the uninucleated stage of hybrids 56x22-8 and 47x22-8 were cultured in MS medium, semi-solid and liquid, with different concentrations of growth regulators: medium A - 0,5 mg/l BAP + 0,1 mg/l NAA + 0,5 mg/1 2,4-D + 20 g/l sucrose + 20 g/l glucose; medium B - 0,5 mg/1 2,4-D + 30 g/l sucrose; medium C - 3,0 mg/l NAA + 0,5 mg/l Kin + 30 g/l sucrose and medium D - 2,0 mg/l NAA + 0,5 mg/l Kin + 30 g/l sucrose. Callus formation varied with the genotype and the medium. Liquid media showed more efficiency in callus development than the semi-solids. For the hybrids 56x22-8 the best media were the liquid A2 with 80,5% of callus induction and among the semi-solids the D1, with 41,6%. For the hybrid 47x22-8 were liquid D2 with 68,1% and semi solid D1 with 15,2%. No significant differences were observed among the liquid media nor among the semi-solidones.

Vera Lúcia Bobrowski; José Antônio Peters; Eliane Augustin; Judith Viégas

1995-01-01

50

Estudios preliminares referidos a la herencia de la resistencia a la Piriculariosis de líneas isogénicas de arroz obtenidas por cultivo de anteras/ Piriculariosis resistance inheritance of rice isogenic lines obtained from anthers culture  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish En el campo experimental de la Unidad Científico Tecnológica de Base «Los Palacios» fueron sembradas semillas de las plantas cosechadas de la primera generación de líneas isogénicas de arroz, procedentes del cultivo in vitro de anteras de plantas F2 de los cruces Amistad´82/2077, 2077/Amistad´82, Amistad´82/IR759-54-2-2 y Moroberekan/Amistad´82, con el objetivo de evaluar su comportamiento frente a infecciones naturales de P. grisea. Al parecer, no hay presenci (more) a de genes dominantes actuando en la herencia de la resistencia a la Piriculariosis y el comportamiento pudiera estar regido por la acción de genes mayores en homocigosis y de genes menores con efecto aditivo, lográndose la selección de cuatro líneas isogénicas resistentes a la enfermedad y de buen comportamiento agronómico, las que constituyen la base para la obtención de nuevos cultivares. Abstract in english In the Base Technological Scientist Unit «Los Palacios» seeds first generation of harvested rice isogenic lines, coming from F2 in vitro anthers culture from crossings Amistad´82/2077, 2077/Amistad´82, Amistad´82/IR759-54-2-2 and Moroberekan/Amistad´82, were sowed in field, with the objective to evaluate their behaviour in natural Blast field infection. The absence of dominant genes in heterocigosis involved in the inheritance to Blast was confirmed and, apparently, (more) the behaviour could be governed by major genes in homocigosis and small genes with additive effect. Four isogenic lines wit good agronomic behaviour and Blast resistant were selected. The same will be very useful to obtain new varieties.

Pérez León, Noraida de J; Castro Menduiña, Rodolfo; González Cepero, Maria Caridad; Álvarez Gil, Marta; Aguilar Portero, Manuel

2013-03-01

51

Cross Section Through the Dehisced Anther of Xylopia collina  

Science.gov (United States)

Cross section through the dehisced anther of Xylopia collina of the pawpaw family (Annonaceae). Species of the genus Xylopia, as well as other members of this family, produce large pollen that is shed in units of four or sometimes even 32 grains (some tetrads visible in illustration). Associated with these compound pollen units in most genera are layers of sterile tissue, called septa, that separate the grains into chambers within each anther. Tsou and Johnson investigated the variation and development of the septa of Annonaceae, and found that despite variability in appearance, the septal tissues of all species were formed by the same developmental pathway. They propose that these tissues may have evolved in Annonaceae in response to a requirement for extra nutrients and support tissues for large pollen units.

Chih-Hua Tsou (Institute of Botany;Academia Sinica ADR;POSTAL)

2004-03-09

52

Ação do etileno em combinação com thidiazuron, nitrato de prata e ácido acetilsalicílico na cultura de anteras de pimentão/ Ethylene action in combination with Thidiazuron (TDZ), silver nitrate (AgNO3) and acetylsalicylic acid on sweet pepper anther culture  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Verificou-se o efeito do etileno em combinação com o thidiazuron (TDZ), nitrato de prata (AgNO3) e ácido acetilsalicílico (AAS), na indução e regeneração de embriões em anteras de pimentão, genótipos F1 (PIX21C12#35 x Agronômico 08), (PIX21C04#4 x Linha 004), (PIX22C#31 x Linha 004), (PIX21C15#45 x Ikeda) e (PIX22C#21 x Ikeda). Os botões foram coletados quando sépalas e pétalas tinham tamanhos aproximadamente iguais, correspondendo ao estádio de anteras co (more) m micrósporos uninucleados. As anteras foram inoculadas em placa de Petri contendo meio de cultura C adicionado de 4,5 mM de TDZ; meio C acrescido de 0,05 mM de 2,4-D, 0,05 mM de cinetina e 88,8 mM de AAS; meio C acrescido de 0,05 mM de 2,4-D, 0,05 mM de cinetina e 5,0 mg/L de AgNO3. Em seguida, foram colocadas em ambiente escuro a 35ºC durante oito dias e enriquecido com ethephon, por 0; 2; 4; 6 ou 8 dias num esquema fatorial com quatro repetições, sendo cada placa considerada uma parcela contendo 20 a 24 anteras.O período de permanência de quatro dias, em ambiente enriquecido com ethephon, e os meios com TDZ e AgNO3, foram os mais favoráveis à indução de anteras. O TDZ também promoveu maior indução de calos embriogênicos. As maiores taxas de necrose ocorreram no meio com AAS. Só ocorreu regeneração direta em plântulas no meio C acrescido de 5 mg/L de AgNO3, sendo oito dias o melhor período. Os genótipos mais responsivos foram PIX22C#31 x linha 004 e PIX22C#21 x Ikeda. Observou-se a formação de plântulas haplóides e diplóides mediante análise da ponta de raíz. Considerando-se que a regeneração foi direta, sem passar por calos, supõe-se que as plântulas diplóides obtidas sejam provenientes dos micrósporos, devendo portanto ter ocorrido uma diploidização in vitro. Abstract in english The influence of ethylene used in combination with Thidiazuron (TDZ), silver nitrate (AgNO3) and acetylsalicylic acid (ASA) was evaluated on sweet pepper androgenesis of F1 genotypes (PIX21C12#35 x Agronômico 08, PIX21C04#4 x Line 004, PIX22C#31 x Line 004, PIX21C15#45 x Ikeda and PIX22C#21 x Ikeda). Floral buds were collected when sepals and petals were approximately of equal size, corresponding to the uninucleated stage of microspores. Anthers were placed in Petri dish (more) es containing three mediums: C medium supplemented with TDZ (4.5mM); C medium plus 2,4-D (0,05mM), Kinetin (0.5mM) and ASA (88,8mM) or AgNO3 (5.0 mg/L). After inoculation, the anthers were kept in the environment with ethephon for 0, 2, 4, 6 or 8 days at 35ºC for eight days in the dark. The experiment was conducted in a factorial design with four replications. Each replicate consisted of one Petri dish containing 20-24 anthers. TDZ and AgNO3 were most effective for inducing somatic embryos after four days with Ethrel. The greatest rates of necrosis took place on the medium with AAS. Direct regeneration of plantlets occurred only on medium supplemented with 5 mg/L of AgNO3 after an eight-day treatment with Ethrel. The most responsive genotypes were PIX22C#31 x Line 004 and PIX22C#21 x Ikeda. Chromosome number of the seedlings was verified through the root tip analysis which indicated the presence of haploid and diploid chromosome number. Since regeneration was direct, ie without going through callus phase, it is hypothesized that the diploid seedlings came from in vitro diploidization.

Luz, José Magno Q.; Pinto, José Eduardo B. P.; Ehlert, Polyana Aparecida D.; Cerqueira, Estér Solange; Bedin, Ivan

1999-11-01

53

Ação do etileno em combinação com thidiazuron, nitrato de prata e ácido acetilsalicílico na cultura de anteras de pimentão Ethylene action in combination with Thidiazuron (TDZ), silver nitrate (AgNO3) and acetylsalicylic acid on sweet pepper anther culture  

Directory of Open Access Journals (Sweden)

Full Text Available Verificou-se o efeito do etileno em combinação com o thidiazuron (TDZ), nitrato de prata (AgNO3) e ácido acetilsalicílico (AAS), na indução e regeneração de embriões em anteras de pimentão, genótipos F1 (PIX21C12#35 x Agronômico 08), (PIX21C04#4 x Linha 004), (PIX22C#31 x Linha 004), (PIX21C15#45 x Ikeda) e (PIX22C#21 x Ikeda). Os botões foram coletados quando sépalas e pétalas tinham tamanhos aproximadamente iguais, correspondendo ao estádio de anteras com micrósporos uninucleados. As anteras foram inoculadas em placa de Petri contendo meio de cultura C adicionado de 4,5 mM de TDZ; meio C acrescido de 0,05 mM de 2,4-D, 0,05 mM de cinetina e 88,8 mM de AAS; meio C acrescido de 0,05 mM de 2,4-D, 0,05 mM de cinetina e 5,0 mg/L de AgNO3. Em seguida, foram colocadas em ambiente escuro a 35ºC durante oito dias e enriquecido com ethephon, por 0; 2; 4; 6 ou 8 dias num esquema fatorial com quatro repetições, sendo cada placa considerada uma parcela contendo 20 a 24 anteras.O período de permanência de quatro dias, em ambiente enriquecido com ethephon, e os meios com TDZ e AgNO3, foram os mais favoráveis à indução de anteras. O TDZ também promoveu maior indução de calos embriogênicos. As maiores taxas de necrose ocorreram no meio com AAS. Só ocorreu regeneração direta em plântulas no meio C acrescido de 5 mg/L de AgNO3, sendo oito dias o melhor período. Os genótipos mais responsivos foram PIX22C#31 x linha 004 e PIX22C#21 x Ikeda. Observou-se a formação de plântulas haplóides e diplóides mediante análise da ponta de raíz. Considerando-se que a regeneração foi direta, sem passar por calos, supõe-se que as plântulas diplóides obtidas sejam provenientes dos micrósporos, devendo portanto ter ocorrido uma diploidização in vitro.The influence of ethylene used in combination with Thidiazuron (TDZ), silver nitrate (AgNO3) and acetylsalicylic acid (ASA) was evaluated on sweet pepper androgenesis of F1 genotypes (PIX21C12#35 x Agronômico 08, PIX21C04#4 x Line 004, PIX22C#31 x Line 004, PIX21C15#45 x Ikeda and PIX22C#21 x Ikeda). Floral buds were collected when sepals and petals were approximately of equal size, corresponding to the uninucleated stage of microspores. Anthers were placed in Petri dishes containing three mediums: C medium supplemented with TDZ (4.5mM); C medium plus 2,4-D (0,05mM), Kinetin (0.5mM) and ASA (88,8mM) or AgNO3 (5.0 mg/L). After inoculation, the anthers were kept in the environment with ethephon for 0, 2, 4, 6 or 8 days at 35ºC for eight days in the dark. The experiment was conducted in a factorial design with four replications. Each replicate consisted of one Petri dish containing 20-24 anthers. TDZ and AgNO3 were most effective for inducing somatic embryos after four days with Ethrel. The greatest rates of necrosis took place on the medium with AAS. Direct regeneration of plantlets occurred only on medium supplemented with 5 mg/L of AgNO3 after an eight-day treatment with Ethrel. The most responsive genotypes were PIX22C#31 x Line 004 and PIX22C#21 x Ikeda. Chromosome number of the seedlings was verified through the root tip analysis which indicated the presence of haploid and diploid chromosome number. Since regeneration was direct, ie without going through callus phase, it is hypothesized that the diploid seedlings came from in vitro diploidization.

José Magno Q. Luz; José Eduardo B. P. Pinto; Polyana Aparecida D. Ehlert; Estér Solange Cerqueira; Ivan Bedin

1999-01-01

54

Foster cultural responsiveness on your unit.  

UK PubMed Central (United Kingdom)

As patient populations become more diverse, the challenge for nurse managers to ensure delivery of individualized, patient-centered care intensifies. Every patient presents with unique healthcare beliefs, values, behaviors, and lived experiences, and their culture shapes and influences health decisions and perceptions of healthcare encounters. Although cultural responsiveness resources and capabilities are influenced by a health organization's leaders and policies, they're directly implemented by nurse managers, nurses, and staff in each patient and family interaction. Equipping your staff with cultural responsiveness knowledge and skills, and helping them to internalize and consistently demonstrate culturally responsive behaviors, will improve patient satisfaction and quality care outcomes on your unit.

Roberts D; Moussa M; Sherrod D

2011-09-01

55

Pollen and Anther Development in Onobrychis schahuensis Bornm.(Fabaceae)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Young buds and flowers of Onobrychis schahuensis were removed at different stages of anther development and sectioned with micotome after preparation. The anther and pollen development were studied with light microscopy after staining. Results showed that some ultrastructural characters o...

Abdolkarim Chehregani; Nayereh Tanaomi; Massoud Ranjbar

56

Aligning collaborative and culturally responsive evaluation approaches.  

UK PubMed Central (United Kingdom)

The authors, three African-American women trained as collaborative evaluators, offer a comparative analysis of collaborative evaluation (O'Sullivan, 2004) and culturally responsive evaluation approaches (Frierson, Hood, & Hughes, 2002; Kirkhart & Hopson, 2010). Collaborative evaluation techniques immerse evaluators in the cultural milieu of the program, systematically engage stakeholders and integrate their program expertise throughout the evaluation, build evaluation capacity, and facilitate the co-creation of a more complex understanding of programs. However, the authors note that without explicit attention to considerations raised in culturally responsive evaluation approaches (for example, issues of race, power, and privilege), the voices and concerns of marginalized and underserved populations may be acknowledged, but not explicitly or adequately addressed. The intentional application of collaborative evaluation techniques coupled with a culturally responsive stance enhances the responsiveness, validity and utility of evaluations, as well as the cultural competence of evaluators.

Askew K; Beverly MG; Jay ML

2012-11-01

57

Culture and Crisis Response in New Zealand  

Science.gov (United States)

New Zealand is a bicultural nation, founded on the signing of the Treaty of Waitangi by the native Maori and the British Crown. It is also home to people from many countries, cultures and ethnicities. Therefore, culturally-relevant response to crisis events has become a significant aspect of the Ministry of Education's interdisciplinary Traumatic…

Annan, Jean; Dean, Shelley; Henry, Geoff; McGhie, Desiree; Phillipson, Roger

2010-01-01

58

Culturally divergent responses to mortality salience.  

Science.gov (United States)

Two experiments compared the effects of death thoughts, or mortality salience, on European and Asian Americans. Research on terror management theory has demonstrated that in Western cultural groups, individuals typically employ self-protective strategies in the face of death-related thoughts. Given fundamental East-West differences in self-construal (i.e., the independent vs. interdependent self), we predicted that members of Eastern cultural groups would affirm other people, rather than defend and affirm the self, after encountering conditions of mortality salience. We primed European Americans and Asian Americans with either a death or a control prime and examined the effect of this manipulation on attitudes about a person who violates cultural norms (Study 1) and on attributions about the plight of an innocent victim (Study 2). Mortality salience promoted culturally divergent responses, leading European Americans to defend the self and Asian Americans to defend other people. PMID:21705518

Ma-Kellams, Christine; Blascovich, Jim

2011-06-24

59

Culturally divergent responses to mortality salience.  

UK PubMed Central (United Kingdom)

Two experiments compared the effects of death thoughts, or mortality salience, on European and Asian Americans. Research on terror management theory has demonstrated that in Western cultural groups, individuals typically employ self-protective strategies in the face of death-related thoughts. Given fundamental East-West differences in self-construal (i.e., the independent vs. interdependent self), we predicted that members of Eastern cultural groups would affirm other people, rather than defend and affirm the self, after encountering conditions of mortality salience. We primed European Americans and Asian Americans with either a death or a control prime and examined the effect of this manipulation on attitudes about a person who violates cultural norms (Study 1) and on attributions about the plight of an innocent victim (Study 2). Mortality salience promoted culturally divergent responses, leading European Americans to defend the self and Asian Americans to defend other people.

Ma-Kellams C; Blascovich J

2011-08-01

60

Efeitos do estádio de desenvolvimento da antera e da radiação gama na formação de calos derivados de anteras de tomate Anther development stage and gamma radiation effects on tomato anther-derived callus formation  

Directory of Open Access Journals (Sweden)

Full Text Available Este trabalho foi conduzido visando: (I) determinar a influência do estádio de desenvolvimento de anteras de tomate sobre a formação de calos e (II) analisar o efeito da radiação gama no cultivo in vitro de anteras. No primeiro experimento, anteras de híbridos de tomate IPA 5 x Rotam 4 (F1) foram cultivadas em três meios nutritivos. Apesar da formação de calos ter sido induzida em todos os estádios de desenvolvimento, variando de prófase I à micrósporo mononucleado, a freqüência de calos produzidos decresceu com o avanço do estádio de desenvolvimento e se apresentou de forma semelhante nos meios testados. Anteras contendo meiócitos em estádio de prófase I mostraram maior freqüência de formação de calos. Tanto o comprimento da antera quanto o do botão floral apresentaram correlação significativa com o estádio de desenvolvimento. No segundo experimento, sementes e botões florais dos híbridos IPA 5 x Rotam 4 (F2), IPA 6 x Rotam 4 (F2) e IPA 8 x 217.1 (F2) foram submetidos à radiação gama e suas anteras foram cultivadas em dois meios descritos por Gresshoff & Doy (1972), contendo 2,0 mg L-1 de ANA + 5,0 mg L-1 de cinetina e 2,0 mg L-1 de ANA + 1,0 mg L-1 de cinetina. Não foram constatadas diferenças significativas, no que se refere à formação de calos, para os genótipos e doses estudadas - 200 Gy, para sementes e 20 Gy, para botões florais.Two experiments were carried (I) to determine tomato anther development stage influence on callus production; and (II) to investigate gamma radiation effects on anther culture. In the first experiment, anthers of a tomato hybrid (IPA 5 x Rotam 4 - F1) were grown on three media. Although calli were induced at all stages of anther development, varying from prophase I to mononucleate microspore, callus frequency decreased as anther development progressed and calli induction were not significantly affected by all media tested. Anthers containing prophase I meiocytes produced the highest calli frequency. Anther and flower bud length both were significantly correlated with anther development stage. In the second experiment, seeds and floral buds of tomato hybrids IPA 5 x Rotam 4 (F2), IPA 6 x Rotam 4 (F2) and IPA 8 x 217.1 (F2) were submitted to gamma-ray and anthers were plated on two media described by Gresshoff & Doy (1972) supplemented with 2.0 mg L-1 NAA + 5.0 mg L-1 KIN and 2.0 mg L-1 NAA + 1.0 mg L-1 KIN. No significant differences for genotype and dosage tested were found for calli formation.

Ana Christina R. Brasileiro; Lilia Willadino; Marcelo Guerra; Waldeciro Colaço; Isabelle Meunier; Terezinha R. Camara

1999-01-01

 
 
 
 
61

Culture and listeners' gaze responses to stuttering.  

UK PubMed Central (United Kingdom)

BACKGROUND: It is frequently observed that listeners demonstrate gaze aversion to stuttering. This response may have profound social/communicative implications for both fluent and stuttering individuals. However, there is a lack of empirical examination of listeners' eye gaze responses to stuttering, and it is unclear whether cultural background plays a role in regulating listeners' eye gaze response to stuttering. AIM: To examine listeners' eye gaze responses to stuttering speech relative to fluent speech in three cultural groups. METHODS & PROCEDURES: Eighteen African-American, 18 European-American and 18 Chinese adults were audiovisually presented with three stuttering and three fluent speech samples, when an eye-tracking device simultaneously recorded their gaze behaviours. The targets of listeners' eye gaze included four regions of interest (ROIs) on the speaker's face: eyes, nose, mouth and outside (i.e., everything else). Listeners' per cent of gaze time, gaze fixation count and average duration of gaze fixation were analysed with repeated-measures ANOVAs regarding each ROI as functions of the speaker's fluency status and listeners' cultural background. OUTCOMES & RESULTS: When observing stuttering speech, listeners tended to reduce gaze fixation duration on the speaker's eyes and increase their gaze time on the mouth. However, different from the two American groups, the Chinese group reduced their gaze time on the speaker's mouth. In addition, the Chinese participants' gaze behaviours were more focused on the ROI of outside, whereas the two American groups showed a similar focus on the ROIs of eyes and mouth. CONCLUSIONS & IMPLICATIONS: All groups of listeners responded to stuttering with gaze aversions mainly contributed to by a reduction in gaze fixation duration rather than gaze fixation number. This pattern of gaze aversion suggests that stuttering oppresses listeners with an emotional and/or cognitive overload. Attention shift and compensation strategies for speech signal degradation may also account for listeners' gaze responses to stuttering. Cultural differences in eye gaze responses to stuttering were observed mainly between Chinese and American listeners.

Zhang J; Kalinowski J

2012-07-01

62

Biosynthesis of anther cuticle and pollen exine in rice  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The lipidic structures, anther cuticle (outer anther surface) and pollen exine (outer pollen wall), play a key protective role for the male gametophyte and pollen grain development. We recently identified ancient cytochrome P450 family member CYP704B2 in rice and proposed a common fatty acid ?-hydro...

Li, Hui; Zhang, Dabing

63

Pollen and Anther Development in Onobrychis schahuensis Bornm.(Fabaceae)  

Directory of Open Access Journals (Sweden)

Full Text Available Young buds and flowers of Onobrychis schahuensis were removed at different stages of anther development and sectioned with micotome after preparation. The anther and pollen development were studied with light microscopy after staining. Results showed that some ultrastructural characters of anther and pollen grains were different from other Fabaceae members. The undifferentiated anther is ovoid-shaped and tetrasporangiated. The anther wall development follows the dicotyledonous type, which is composed of an epidermal layer, an endothelial layer, one middle layer and tapetum. The tapetum is secretory and its cells are uniseriate and uninucleate but some of them are binucleate. The microspore tetrads are tetrahedral. Pollen grains are ovate, tricolporate and shed at a bicellular stage.

Abdolkarim Chehregani; Nayereh Tanaomi; Massoud Ranjbar

2008-01-01

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Cell Culture Assay for Human Noroviruses [response  

Energy Technology Data Exchange (ETDEWEB)

We appreciate the comments provided by Leung et al., in response to our recently published article “In Vitro Cell Culture Infectivity Assay for Human Noroviruses” by Straub et al. (1). The specific aim of our project was to develop an in vitro cell culture infectivity assay for human noroviruses (hNoV) to enhance risk assessments when they are detected in water supplies. Reverse transcription (RT) qualitative or quantitative PCR are the primary assays for waterborne NoV monitoring. However, these assays cannot distinguish between infectious vs. non-infectious virions. When hNoV is detected in water supplies, information provided by our infectivity assay will significantly improve risk assessment models and protect human health, regardless of whether we are propagating NoV. Indeed, in vitro cell culture infectivity assays for the waterborne pathogen Cryptosporidium parvum that supplement approved fluorescent microscopy assays, do not result in amplification of the environmentally resistant hard-walled oocysts (2). However, identification of life cycle stages in cell culture provides evidence of infectious oocysts in a water supply. Nonetheless, Leung et al.’s assertion regarding the suitability of our method for the in vitro propagation of high titers of NoV is valid for the medical research community. In this case, well-characterized challenge pools of virus would be useful for developing and testing diagnostics, therapeutics, and vaccines. As further validation of our published findings, we have now optimized RT quantitative PCR to assess the level of viral production in cell culture, where we are indeed finding significant increases in viral titer. The magnitude and time course of these increases is dependent on both virus strain and multiplicity of infection. We are currently preparing a manuscript that will discuss these findings in greater detail, and the implications this may have for creating viral challenge pools

Straub, Tim M.; Honer Zu Bentrup, Kerstin; Orosz Coghlan, Patricia; Dohnalkova, Alice; Mayer, Brooke K.; Bartholomew, Rachel A.; Valdez, Catherine O.; Bruckner-Lea, Cindy J.; Gerba, Charles P.; Abbaszadegan, Morteza A.; Nickerson, Cheryl A.

2007-07-01

65

El turismo cultural. ¿Un negocio responsable? Cultural Tourism. A Responsible Business?  

Directory of Open Access Journals (Sweden)

Full Text Available Cuestiones como la degradación el medioambiente, la pérdida de la diversidad cultural y especialmente lo considerado como patrimonio cultural y la ecología, son actualmente aspectos consustanciales a la vida cotidiana, a la política, a la planificación y a los negocios. En la Cumbre de la Tierra (Río de Janeiro, 1992) se acuña el concepto Turismo Responsable en un intento de impulsar el respeto y la preservación, implicando en la tarea a todos los actores. Bajo el paraguas de la responsabilidad, uno de los productos con mayor crecimiento y demanda en la última década ha sido el turismo cultural, planteado ahora como una de las fórmulas para la consecución del desarrollo integral de los pueblos. En este artículo se repasa el turismo cultural como producto, su importancia en el nuevo orden turístico y su alcance, constatando como a través de él el sistema turístico ha tendido a implicarse en la gestión de la cultura y condicionarla por su rentabilidad.Environmental degradation, the loss of cultural diversity and especially what is considered cultural heritage and ecology, are actually the main issues of every day life, politics, planning and business. During the Rio Meeting (Rio de Janeiro, 1992) the concept of Responsible Tourism was born in an attempt to enhance respect and preservation with all actors involved. Under the umbrella of responsibility, cultural tourism was one product that showed the biggest growth under the premises of the formula of all-embracing development of society. This article presents a revision of cultural tourism as a product, its importance for the new tourist order and its range and establishing in which way the tourist system had a tendency to get involved in cultural management and therefore as conditioned its profitability.

Agustín Santana Talavera

2008-01-01

66

El turismo cultural. ¿Un negocio responsable?/ Cultural Tourism. A Responsible Business?  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Cuestiones como la degradación el medioambiente, la pérdida de la diversidad cultural y especialmente lo considerado como patrimonio cultural y la ecología, son actualmente aspectos consustanciales a la vida cotidiana, a la política, a la planificación y a los negocios. En la Cumbre de la Tierra (Río de Janeiro, 1992) se acuña el concepto Turismo Responsable en un intento de impulsar el respeto y la preservación, implicando en la tarea a todos los actores. Bajo el (more) paraguas de la responsabilidad, uno de los productos con mayor crecimiento y demanda en la última década ha sido el turismo cultural, planteado ahora como una de las fórmulas para la consecución del desarrollo integral de los pueblos. En este artículo se repasa el turismo cultural como producto, su importancia en el nuevo orden turístico y su alcance, constatando como a través de él el sistema turístico ha tendido a implicarse en la gestión de la cultura y condicionarla por su rentabilidad. Abstract in english Environmental degradation, the loss of cultural diversity and especially what is considered cultural heritage and ecology, are actually the main issues of every day life, politics, planning and business. During the Rio Meeting (Rio de Janeiro, 1992) the concept of Responsible Tourism was born in an attempt to enhance respect and preservation with all actors involved. Under the umbrella of responsibility, cultural tourism was one product that showed the biggest growth unde (more) r the premises of the formula of all-embracing development of society. This article presents a revision of cultural tourism as a product, its importance for the new tourist order and its range and establishing in which way the tourist system had a tendency to get involved in cultural management and therefore as conditioned its profitability.

Santana Talavera, Agustín

2008-12-01

67

Callus induction and plant regeneration of tomato (Lycopersicon esculentum cv. IPA 5) via anther culture Indução de calos e regeneração de plantas a partir do cultivo in vitro de anteras de tomate (Lycopersicon esculentum cv. IPA 5)  

Directory of Open Access Journals (Sweden)

Full Text Available Different growth regulators combinations were tested on the production of anther callus in tomato cultivar IPA 5. Calli were induced on media supplemented with 1.0mgL-1 gibberellic acid (GA3), 0.05mgL-1 alpha-naphthaleneacetic acid (NAA) plus 0.1mgL-1 6-benzylaminopurine (BAP), or with 1.0mgL-1 BAP plus 1.0mgL-1 NAA. The medium containing 1.0mgL-1 BAP and 1.0mgL-1 NAA produced the highest calli frequency, and promoted plant regeneration by indirect organogenesis, when calli were transferred to 0.01mgL-1 BAP and 0.001mgL-1 NAA. Plants regenerated presented tetraploid cells and rare diploid cells. These tetraploid plants could be used as source for further obtainment of trisomic lines, for the purpose of genic localization studies and protein compounds analysis.Diferentes combinações de reguladores de crescimento foram testadas na produção de calos a partir do cultivo de anteras de tomate cultivar IPA 5. Calos foram induzidos no meio suplementado com 1,0mgL-1 de ácido giberélico (GA3) + 0,05mgL-1 de alfa-ácido naftalenoacético (ANA) + 0,1mgL-1 de 6-benzilaminopurina (BAP), ou com 1,0mgL-1 de BAP + 1,0mgL-1 de ANA. O meio contendo 1,0mgL-1 de BAP e 1,0mgL-1 de ANA produziu a maior freqüência de calos e promoveu a regeneração de plantas através de organogênese indireta, quando os calos foram transferidos para 0,01mgL-1 de BAP e 0,001mgL-1 de ANA. As plantas regeneradas apresentaram células tetraplóides e, raramente, células diplóides. Estas plantas tetraplóides podem servir como fonte para posterior obtenção de linhagens trissômicas, para serem utilizadas em estudos de localização gênica e em análises de compostos protéicos.

Ana Christina Rabello Brasileiro; Lilia Willadino; Gianna Griz Carvalheira; Marcelo Guerra

1999-01-01

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Ustilago maydis reprograms cell proliferation in maize anthers.  

Science.gov (United States)

The basidiomycete Ustilago maydis is a ubiquitous pathogen of maize (Zea mays), one of the world's most important cereal crops. Infection by this smut fungus triggers tumor formation in aerial plant parts within which the fungus sporulates. Using confocal microscopy to track U. maydis infection on corn anthers for 7 days post-injection, we found that U. maydis is located on the epidermis during the first 2 days, and has reached all anther lobe cell types by 3 days post-injection. Fungal infection alters cell-fate specification events, cell division patterns, host cell expansion and host cell senescence, depending on the developmental stage and cell type. Fungal effects on tassel and plant growth were also quantified. Transcriptome profiling using a dual organism microarray identified thousands of anther genes affected by fungal infection at 3 days post-injection during the cell-fate specification and rapid cell proliferation phases of anther development. In total, 4147 (17%) of anther-expressed genes were altered by infection, 2018 fungal genes were expressed in anthers, and 206 fungal secretome genes may be anther-specific. The results confirm that U. maydis deploys distinct genes to cause disease in specific maize organs, and suggest mechanisms by which the host plant is manipulated to generate a tumor. PMID:23795972

Gao, Li; Kelliher, Timothy; Nguyen, Linda; Walbot, Virginia

2013-08-08

69

Ustilago maydis reprograms cell proliferation in maize anthers.  

UK PubMed Central (United Kingdom)

The basidiomycete Ustilago maydis is a ubiquitous pathogen of maize (Zea mays), one of the world's most important cereal crops. Infection by this smut fungus triggers tumor formation in aerial plant parts within which the fungus sporulates. Using confocal microscopy to track U. maydis infection on corn anthers for 7 days post-injection, we found that U. maydis is located on the epidermis during the first 2 days, and has reached all anther lobe cell types by 3 days post-injection. Fungal infection alters cell-fate specification events, cell division patterns, host cell expansion and host cell senescence, depending on the developmental stage and cell type. Fungal effects on tassel and plant growth were also quantified. Transcriptome profiling using a dual organism microarray identified thousands of anther genes affected by fungal infection at 3 days post-injection during the cell-fate specification and rapid cell proliferation phases of anther development. In total, 4147 (17%) of anther-expressed genes were altered by infection, 2018 fungal genes were expressed in anthers, and 206 fungal secretome genes may be anther-specific. The results confirm that U. maydis deploys distinct genes to cause disease in specific maize organs, and suggest mechanisms by which the host plant is manipulated to generate a tumor.

Gao L; Kelliher T; Nguyen L; Walbot V

2013-09-01

70

Organizational culture during the accident response process  

International Nuclear Information System (INIS)

The ability of an organization to effectively move from an anticipatory to an ad hoc strategy may well depend on the organization having the ability to balance these two apparently dichotomous cultural styles. The organization which is most capable of making the necessary transition in an optimal manner may well exhibit some aspects of both cultural styles during normal operations. Data collected at one NPP does exhibit this pattern of results, with the organization exhibiting a clear hierarchical chain of command and perceived conventional behavioral expectations as well as exhibiting a more decentralized and collegial approach to decisionmaking, a team work orientation, and informal communications. Thus, it is expected that this organization possesses the capabilities to make a successful transition from an anticipatory to an ad hoc strategy. Data collected at a second NPP more strongly exhibits the traditional style suggested as being important during the anticipatory strategy, with more formal communications and bureaucratically controlled decision-making. This organization may experience difficulty if faced with the need to make a transition from an anticipatory to an ad hoc strategy. These conclusions are further validated based on observation of Emergency Preparedness Exercise Inspections, which suggest that the more anticipatory types of behaviors actually inhibit successful performance during an ad hoc response. The final validation of these hypotheses needs to be demonstrated with cultural data collected during emergency simulations. The mechanism to obtain such data during these types of situations is an area for future research

1992-01-01

71

Organizational culture during the accident response process  

Energy Technology Data Exchange (ETDEWEB)

The ability of an organization to effectively move from an anticipatory to an ad hoc strategy may well depend on the organization having the ability to balance these two apparently dichotomous cultural styles. The organization which is most capable of making the necessary transition in an optimal manner may well exhibit some aspects of both cultural styles during normal operations. Data collected at one NPP does exhibit this pattern of results, with the organization exhibiting a clear hierarchical chain of command and perceived conventional behavioral expectations as well as exhibiting a more decentralized and collegial approach to decisionmaking, a team work orientation, and informal communications. Thus, it is expected that this organization possesses the capabilities to make a successful transition from an anticipatory to an ad hoc strategy. Data collected at a second NPP more strongly exhibits the traditional style suggested as being important during the anticipatory strategy, with more formal communications and bureaucratically controlled decision-making. This organization may experience difficulty if faced with the need to make a transition from an anticipatory to an ad hoc strategy. These conclusions are further validated based on observation of Emergency Preparedness Exercise Inspections, which suggest that the more anticipatory types of behaviors actually inhibit successful performance during an ad hoc response. The final validation of these hypotheses needs to be demonstrated with cultural data collected during emergency simulations. The mechanism to obtain such data during these types of situations is an area for future research.

Shurberg, D.A.; Haber, S.B.

1992-08-01

72

Organizational culture during the accident response process  

Energy Technology Data Exchange (ETDEWEB)

The ability of an organization to effectively move from an anticipatory to an ad hoc strategy may well depend on the organization having the ability to balance these two apparently dichotomous cultural styles. The organization which is most capable of making the necessary transition in an optimal manner may well exhibit some aspects of both cultural styles during normal operations. Data collected at one NPP does exhibit this pattern of results, with the organization exhibiting a clear hierarchical chain of command and perceived conventional behavioral expectations as well as exhibiting a more decentralized and collegial approach to decisionmaking, a team work orientation, and informal communications. Thus, it is expected that this organization possesses the capabilities to make a successful transition from an anticipatory to an ad hoc strategy. Data collected at a second NPP more strongly exhibits the traditional style suggested as being important during the anticipatory strategy, with more formal communications and bureaucratically controlled decision-making. This organization may experience difficulty if faced with the need to make a transition from an anticipatory to an ad hoc strategy. These conclusions are further validated based on observation of Emergency Preparedness Exercise Inspections, which suggest that the more anticipatory types of behaviors actually inhibit successful performance during an ad hoc response. The final validation of these hypotheses needs to be demonstrated with cultural data collected during emergency simulations. The mechanism to obtain such data during these types of situations is an area for future research.

Shurberg, D.A.; Haber, S.B.

1992-01-01

73

Becoming Culturally Responsive Teachers in Today's Diverse Classroom  

Science.gov (United States)

In an invitational learning environment (Purkey, 1991; Schmidt, 2004), 7 teachers began the process of identifying their cultural identity and perspectives, naming ways that they used their cultural identity with their culturally diverse students, and discovering culturally responsive teaching pedagogies that they could use in their classrooms. In…

Mitchell, Laura A.

2009-01-01

74

Haplodiploid androgenetic breeding in oat: genotypic variation in anther size and microspore development stage/ Melhoramento por haplodiploidização androgenética: variação genotípica no tamanho das anteras e no estágio de desenvolvimento dos micrósporos em aveia  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A aveia (Avena spp.) tem sido pouco responsiva à haplodiploidização, um processo que aumenta a eficiência da seleção no melhoramento por gerar, em uma etapa, linhas puras homozigóticas. A fase mononucleada do micrósporo é critica para o sucesso da androgênese in vitro nos cereais de inverno e, em geral, pode ser inferida pelo tamanho da antera. Foram medidas anteras e analisados citológicamente micrósporos das cultivares de Avena sativa UPF 7, UPF 18, UFRGS 14 (more) , Stout e da linhagem CAV 3361 de Avena sterilis, cultivadas em câmaras de crescimento sob temperaturas dia-noite variando de 16ºC a 9ºC e 12 horas de intensidade luminosa de 300 mol m-2 s-1. O tamanho das anteras em cada fase de desenvolvimento dos micrósporos variou significativamente entre genótipos e de acordo com a região de inserção das espiguetas na panícula. A variação na arquitetura da panícula e a maturação não linear das espiguetas aumentam as dificuldades para a identificação das anteras potencialmente androgenéticas e podem explicar, em parte, os baixos resultados da androgênese na aveia. Os dados mostram a necessidade de uma análise citológica prévia para auxiliar a determinar a fase ideal de desenvolvimento dos micrósporos potencialmente responsivos à cultura de anteras, para o uso da androgenese na aveia. Abstract in english Oat (Avena spp.) is poorly responsive to the haplodiploidization process, which leads to the production of homozygous lines in one step, increasing breeding efficiency. Androgenetic haploids in small grain cereal crops are obtained from microspores cultured at the mononucleate stage, which can be identified by the size of anthers. In order to identify the appropriate anther size for in vitro culture, microspore cytological analyses were made in Avena sativa cultivars UPF (more) 7, UPF 18, UFRGS 14, Stout and Avena sterilis CAV 3361, cultivated in growth chamber under controlled light and temperature conditions. Variation was observed within and among genotypes for anther size at each microspore developmental stage and according to the position of spikelets in the panicle. Architecture variation in panicle shape and non-linear microsporogenesis maturation increased the challenge of identifying potentially androgenetic oat anthers. Cytological screening before culture is critical in identifying microspores at the right stage for oat androgenesis.

Cesaro, Taniela De; Baggio, Maria Irene; Zanetti, Silvia Andréia; Suzin, Marilei; Augustin, Lizete; Brammer, Sandra Patussi; Iorczeski, Edson Jair; Milach, Sandra Cristina Kothe

2009-02-01

75

Spirituality, Cultural Identity, and Epistemology in Culturally Responsive Teaching in Higher Education  

Science.gov (United States)

This article focuses on how spirituality connects to cultural identity and how it relates to culturally responsive teaching in higher education. It focuses on the development of a culturally responsive epistemology that suggests research and teaching is both a spiritual and intellectual pursuit. For critical multicultural teaching to have…

Tisdell, Elizabeth J.

2006-01-01

76

EFFECTS OF CRY1AB-EXPRESSING CORN ANTHERS ON MONARCH BUTTERFLY LARVAE  

Science.gov (United States)

Previous studies suggest that exposure to Bacillus thuringiensis (Bt) corn anthers may have adverse effects on populations of the monarch butterfly, Danaus plexippus (L.). To explore the risk of Bt-corn anthers to monarch butterflies, studies were designed to quantify anther distribution in space an...

77

Culturally Responsive Instruction for English Language Learners With Learning Disabilities.  

UK PubMed Central (United Kingdom)

This case study describes the culturally responsive instruction of one special education teacher with Latino English language learners (ELLs) with learning disabilities in an urban elementary school setting. This study was situated in a social constructivist research based framework. In investigating this instruction with ELLs, this study focused on how one teacher's knowledge of culturally responsive pedagogy affected her special education instruction. Findings resulted in three major themes that were aligned with the current literature in this area: Cultural Aspects of Teaching Reading, Culturally Relevant Skills-Based Instruction, and Collaborative Agency Time. The results indicated that the success of special education with ELLs at the elementary education level might be dependent on how well the special education teacher integrates culturally responsive instruction with ELLs' cultural and linguistic needs.

Orosco MJ; O'Connor R

2013-02-01

78

A milestone in the doubled haploid pathway of cassava : A milestone in the doubled haploid pathway of cassava (Manihot esculenta Crantz): cellular and molecular assessment of anther-derived structures.  

UK PubMed Central (United Kingdom)

This study was aimed at inducing androgenesis in cultured anthers of cassava (Manihot esculenta Crantz) to develop a protocol for the production of doubled haploids. Microspore reprogramming was induced in cassava by cold or heat stress of anthers. Since the anthers contain both haploid microspores and diploid somatic cells, it was essential to verify the origin of anther-derived calli. The origin of anther-derived calli was assessed by morphological screening followed by histological analysis and flow cytometry (FCM). Additionally, simple sequence repeat (SSR) and amplified fragmented length polymorphism (AFLP) assays were used for the molecular identification of the microspore-derived calli. The study clearly demonstrated the feasibility of producing microspore-derived calli using heat- or cold-pretreated anthers. Histological studies revealed reprogramming of the developmental pathway of microspores by symmetrical division of the nucleus. Flow cytometry analysis revealed different ploidy level cell types including haploids, which confirmed their origin from the microspores. The SSR and AFLP marker assays independently confirmed the histological and FCM results of a haploid origin of the calli at the DNA level. The presence of multicellular microspores in the in vitro system indicated a switch of developmental program, which constitutes a crucial step in the design of protocols for the regeneration of microspore-derived embryos and plants. This is the first detailed report of calli, embryos, and abnormal shoots originated from the haploid cells in cassava, leading to the development of a protocol for the production of doubled haploid plants in cassava.

Perera PI; Ordoñez CA; Lopez-Lavalle LA; Dedicova B

2013-09-01

79

The Skin That We Sing: Culturally Responsive Choral Music Education  

Science.gov (United States)

This article describes ways that music education can be made more culturally responsive, or congruent with the orientations of culturally diverse students. Music education in the United States has historically been based on Eurocentric frameworks that may no longer be applicable in an increasingly multicultural society. For the many teachers…

Shaw, Julia

2012-01-01

80

Cultured articular chondrocytes sheets for partial thickness cartilage defects utilizing temperature-responsive culture dishes  

Directory of Open Access Journals (Sweden)

Full Text Available The extracellular matrix (ECM) of articular cartilage has several functions that are unique to joints. Although a technique for transplanting cultured chondrocytes has already been introduced, it is difficult to collect intact ECM when using enzymes to harvest samples. Temperature-responsive culture dishes have already been clinically applied in the fields of myocardial and corneal transplantation. Earlier studies have shown that a sheet of cultured cells with intact ECM and adhesive factors can be harvested using such culture dishes, which allow the surface properties of the dish to be reversibly altered by changing the temperature. Human chondrocytes were subjected to enzymatic digestion and then were seeded in temperature-responsive culture dishes. A sheet of chondrocytes was harvested by only reducing the temperature after the cultured cells reached confluency. A real-time PCR analysis of the chondrocyte sheets confirmed that type II collagen, aggrecan, and fibronectin were present. These results suggested that, although chondrocytes undergo dedifferentiation in a monolayer culture, multilayer chondrocyte sheets grown in a similar environment to that of three-dimensional culture may be able to maintain a normal phenotype. A histological examination suggested that multilayer chondrocyte sheets could thus prevent the loss of proteoglycans because the area covered by the sheets was well stained by safranin-O. The present experiments suggested that temperature-responsive culture dishes are useful for obtaining cultured chondrocytes, which may then be clinically employed as a substitute for periosteal patches because such sheets can be applied without a scaffold.

N Kaneshiro; M Sato; M Ishihara; G Mitani; H Sakai; T Kikuchi; J Mochida

2007-01-01

 
 
 
 
81

Early anther ablation triggers parthenocarpic fruit development in tomato.  

UK PubMed Central (United Kingdom)

Fruit set and fruit development in tomato is largely affected by changes in environmental conditions, therefore autonomous fruit set independent of fertilization is a highly desirable trait in tomato. Here, we report the production and characterization of male-sterile transgenic plants that produce parthenocarpic fruits in two tomato cultivars (Micro-Tom and Moneymaker). We generated male-sterility using the cytotoxic gene barnase targeted to the anthers with the PsEND1 anther-specific promoter. The ovaries of these plants grew in the absence of fertilization producing seedless, parthenocarpic fruits. Early anther ablation is essential to trigger the developing of the transgenic ovaries into fruits, in the absence of the signals usually generated during pollination and fertilization. Ovaries are fully functional and can be manually pollinated to obtain seeds. The transgenic plants obtained in the commercial cultivar Moneymaker show that the parthenocarpic development of the fruit does not have negative consequences in fruit quality. Throughout metabolomic analyses of the tomato fruits, we have identified two elite lines which showed increased levels of several health promoting metabolites and volatile compounds. Thus, early anther ablation can be considered a useful tool to promote fruit set and to obtain seedless and good quality fruits in tomato plants. These plants are also useful parental lines to be used in hybrid breeding approaches.

Medina M; Roque E; Pineda B; Cañas L; Rodriguez-Concepción M; Beltrán JP; Gómez-Mena C

2013-08-01

82

Fine Division of Rice Anther Development by Cytological Morphology  

Directory of Open Access Journals (Sweden)

Full Text Available A cytological and morphological study was conducted on the anther of a hybrid rice (Oryza Sativa L. indica) strain, Chuan You 9527. To sutdy the growth procedures of pollen and anther wall, their development processes from stamen primordia initiation to pollen maturation were observed and divided into stages. Rice spikelets ranging from approx. 1.0 millimeter to approx. 10.0 millimeter were chosen; loading films of anthers were prepared by using the techniques of paraffin section, and they were observed and then photographed with digital camera system for optical microscopy (Nikon DS-Ril-U2). The results showed that the whole development process of anther could be divided into thirteen fine stages, based on the significant alterations in the morphological characteristics of cells and tissues. The thirteen stages are archesporial cell stage, bi-parietal stage, tri-parietal stage, pollen mother cell forming stage (the above four stages together are known as microsporocyte forming stage), early pollen mother cell meiosis stage, mid pollen mother cell meiosis stage, pollen mother cell dayad stage, pollen mother cell tetrad stage( the above four stages are known collectively as microsporocyte meiosis stage), early microspore stage, mid microspore stage, late microspore stage, bi-cellular pollen stage, and mature pollen stage.

LI Gui-jie

2011-01-01

83

Legal Response to the Destruction of Cultural, Religious and Historical  

Directory of Open Access Journals (Sweden)

Full Text Available Now, certainly, we know that since ancient times, humans experience their own personal and work them into forms that our cultural, religious, historical know have reflected and also know that it works, and plays an important role in human social life. Cultural, historic and religious monuments in the definition shooting, said: Construction works and objects that are placed on them due to the relatively long time interest in history has a nation belongs to them, cultural, religious, historical, say. In this research, the legal response to the destruction of cultural, historic and religious studies, which have included the following cases: Part I: Defining cultural, religious, and historical examples of it, Part II: cultural, religious, and historical background, Part III: Cultural Heritage, Part IV: cultural, religious, historical association and dissociation with the heritage – religious, Part V: The ways of identifying cultural, religious, historical. So, must be said that the cultural, religious and historical heritage of the people who understand the law and the media to inform the public and appropriate legislation should be prevented from destroying them.

Amir Ahmadi; Alireza Shakarbigi; Yoseph Niazi

2013-01-01

84

Anther and pollen development in some species of Poaceae (Poales).  

Science.gov (United States)

Anther and pollen development were studied in Olyra humilis Nees, Sucrea monophylla Soderstr, (Bambusoideae), Axonopus aureus P. Beauv., Paspalum polyphyllum Nees ex Trin. (Panicoideae), Eragrostis solida Nees, and Chloris elata Desv. (Chloridoideae). The objective of this study was to characterise, embryologically, these species of subfamilies which are considered basal, intermediate and derivate, respectively. The species are similar to each other and to other Poaceae. They present the following characters: tetrasporangiate anthers; monocotyledonous-type anther wall development, endothecium showing annular thickenings, secretory tapetum; successive microsporogenesis; isobilateral tetrads; spheroidal, tricellular, monoporate pollen grains with annulus and operculum. Nevertheless, the exine patterns of the species studied are distinct. Olyra humilis and Sucrea monophylla (Bambusoideae) show a granulose pattern, whereas in the other species, it is insular. In addition, Axonopus aureus and Paspalum polyphyllum (Panicoideae) have a compactly insular spinule pattern, while Chloris elata and Eragrostis solida (Chloridoideae) show a sparsely insular spinule pattern. The exine ornamentation may be considered an important feature at the infrafamiliar level. PMID:20552147

Nakamura, A T; Longhi-Wagner, H M; Scatena, V L

2010-03-19

85

Anther and pollen development in some species of Poaceae (Poales).  

UK PubMed Central (United Kingdom)

Anther and pollen development were studied in Olyra humilis Nees, Sucrea monophylla Soderstr, (Bambusoideae), Axonopus aureus P. Beauv., Paspalum polyphyllum Nees ex Trin. (Panicoideae), Eragrostis solida Nees, and Chloris elata Desv. (Chloridoideae). The objective of this study was to characterise, embryologically, these species of subfamilies which are considered basal, intermediate and derivate, respectively. The species are similar to each other and to other Poaceae. They present the following characters: tetrasporangiate anthers; monocotyledonous-type anther wall development, endothecium showing annular thickenings, secretory tapetum; successive microsporogenesis; isobilateral tetrads; spheroidal, tricellular, monoporate pollen grains with annulus and operculum. Nevertheless, the exine patterns of the species studied are distinct. Olyra humilis and Sucrea monophylla (Bambusoideae) show a granulose pattern, whereas in the other species, it is insular. In addition, Axonopus aureus and Paspalum polyphyllum (Panicoideae) have a compactly insular spinule pattern, while Chloris elata and Eragrostis solida (Chloridoideae) show a sparsely insular spinule pattern. The exine ornamentation may be considered an important feature at the infrafamiliar level.

Nakamura AT; Longhi-Wagner HM; Scatena VL

2010-05-01

86

Pollen and anther ontogeny in Cabomba caroliniana (Cabombaceae, Nymphaeales).  

UK PubMed Central (United Kingdom)

Cabomba is a small water lily genus that is native to the New World. Studies of pollen development and associated changes in the anther yield valuable characters for considering the evolution of reproductive biology in seed plants. Here we characterized the complete ontogenetic sequence for pollen in Cabomba caroliniana. Anthers at the microspore mother cell, tetrad, free microspore, and mature pollen grain stages were studied using scanning electron, transmission electron, and light microscopy. Tetragonal and decussate tetrads both occur in C. caroliniana, indicating successive microsporogenesis. The exine is tectate-columellate, and the infratectal columellae are the first exine elements to form, followed by a continuous tectum and a thin foot layer. A lamellate endexine initiates in the early free microspore stage, but becomes compressed in mature grains. Tectal microchannels and sculptural rods also initiate during the early free microspore stage, and significant pollenkitt deposition follows, supporting the hypothesis that these elements function in entomophily. The tapetum is morphologically amoeboid, with migratory tapetal cells directly contacting developing free microspores within the anther locule. Results from this study illustrate the importance of including ontogenetic data in analyzing pollen characters and in developing evolutionary and ecological hypotheses. The new palynological data also emphasize the character plasticity that occurs in basal angiosperms.

Taylor ML; Gutman BL; Melrose NA; Ingraham AM; Schwartz JA; Osborn JM

2008-04-01

87

Pollen and anther ontogeny in Cabomba caroliniana (Cabombaceae, Nymphaeales).  

Science.gov (United States)

Cabomba is a small water lily genus that is native to the New World. Studies of pollen development and associated changes in the anther yield valuable characters for considering the evolution of reproductive biology in seed plants. Here we characterized the complete ontogenetic sequence for pollen in Cabomba caroliniana. Anthers at the microspore mother cell, tetrad, free microspore, and mature pollen grain stages were studied using scanning electron, transmission electron, and light microscopy. Tetragonal and decussate tetrads both occur in C. caroliniana, indicating successive microsporogenesis. The exine is tectate-columellate, and the infratectal columellae are the first exine elements to form, followed by a continuous tectum and a thin foot layer. A lamellate endexine initiates in the early free microspore stage, but becomes compressed in mature grains. Tectal microchannels and sculptural rods also initiate during the early free microspore stage, and significant pollenkitt deposition follows, supporting the hypothesis that these elements function in entomophily. The tapetum is morphologically amoeboid, with migratory tapetal cells directly contacting developing free microspores within the anther locule. Results from this study illustrate the importance of including ontogenetic data in analyzing pollen characters and in developing evolutionary and ecological hypotheses. The new palynological data also emphasize the character plasticity that occurs in basal angiosperms. PMID:21632364

Taylor, Mackenzie L; Gutman, Benjamin L; Melrose, Natalie A; Ingraham, Angela M; Schwartz, Julie A; Osborn, Jeffrey M

2008-04-01

88

Activity of carbon dioxide fixation by anthers and leaves of cereal grains  

International Nuclear Information System (INIS)

[en] This paper gives a comparative evaluation of the photosynthetic activity of anthers and flag leaves in winter wheat, rye, and triticale. The content of chlorophylls in anthers and leaves was determined. The activity of 14CO2 fixation by anthers and leaf disks was determined by the radiometric method in a chamber floating on mercury under standard exposure conditions (0.1% concentration of 14CO2, illumination of 15,000 1x, temperature of 23 C). Analyses were conducted in three replications and the results of typical biological experiments are cited. Data show that chlorophyll is actively synthesized in the anthers of cereal grains

1986-01-01

89

Activity of carbon dioxide fixation by anthers and leaves of cereal grains  

Energy Technology Data Exchange (ETDEWEB)

This paper gives a comparative evaluation of the photosynthetic activity of anthers and flag leaves in winter wheat, rye, and triticale. The content of chlorophylls in anthers and leaves was determined. The activity of /sup 14/CO/sub 2/ fixation by anthers and leaf disks was determined by the radiometric method in a chamber floating on mercury under standard exposure conditions (0.1% concentration of /sup 14/CO/sub 2/, illumination of 15,000 1x, temperature of 23 C). Analyses were conducted in three replications and the results of typical biological experiments are cited. Data show that chlorophyll is actively synthesized in the anthers of cereal grains.

Kirichenko, E.B.; Chernyad' ev, I.I.; Doman, N.G.; Talibullina, K.K.; Voronkova, T.V.

1986-05-01

90

Cultural variations in motivational responses to felt misunderstanding.  

UK PubMed Central (United Kingdom)

Three studies examined cultural variations in the motivational consequences of being misunderstood by others. Study 1 found that European American students who felt misunderstood by others performed progressively better academically, whereas Asian and Asian American students who felt misunderstood by others performed progressively worse. In Studies 2 and 3, felt misunderstanding was experimentally manipulated, and motivational responses were measured with a handgrip task (Study 2) and prefrontal electroencephalography (EEG) asymmetry (Study 3). Across the two studies, Asians and Asian Americans showed more withdrawal-related responses but European Americans showed either no difference (Study 2) or more motivated responses (Study 3) after being misunderstood versus being understood. Together, these studies demonstrate systematic cultural variations in motivational responses to felt misunderstanding.

Lun J; Oishi S; Coan JA; Akimoto S; Miao FF

2010-07-01

91

Cultural variations in motivational responses to felt misunderstanding.  

Science.gov (United States)

Three studies examined cultural variations in the motivational consequences of being misunderstood by others. Study 1 found that European American students who felt misunderstood by others performed progressively better academically, whereas Asian and Asian American students who felt misunderstood by others performed progressively worse. In Studies 2 and 3, felt misunderstanding was experimentally manipulated, and motivational responses were measured with a handgrip task (Study 2) and prefrontal electroencephalography (EEG) asymmetry (Study 3). Across the two studies, Asians and Asian Americans showed more withdrawal-related responses but European Americans showed either no difference (Study 2) or more motivated responses (Study 3) after being misunderstood versus being understood. Together, these studies demonstrate systematic cultural variations in motivational responses to felt misunderstanding. PMID:20495092

Lun, Janetta; Oishi, Shigehiro; Coan, James A; Akimoto, Sharon; Miao, Felicity F

2010-05-21

92

Influence of culture conditions on metal-induced responses in a cultured rainbow trout gill epithelium.  

UK PubMed Central (United Kingdom)

A primary culture technique for rainbow trout (Oncorhynchus mykiss) gill cells was optimized to better represent the intact gill in vivo in response to waterborne toxic metals. Modifications in cell seeding density and culture conditions resulted in a gill epithelial cell culture model, which displayed classic in vivo responses to toxic metals. Metallothionein-A (MTA), metallothionein-B (MTB), zinc transporter-1 (ZnT-1), glutathione-S-transferase (GST), and glucose-6-phosphate-dehydrogenase (G6PD) all showed dose-dependent increases in expression at the mRNA level in response to waterborne zinc. Of these genes, the change in zinc-induced expression relative to the control was greatest for MTA, MTB, and ZnT-1. MT expression was also induced by silver, lead, copper, and cadmium. Cells cultured with freshwater on the apical side maintained the net transepithelial influx of Ca2+ displayed by freshwater trout gills in vivo, and there was an active inward movement of Ca2+. Waterborne zinc applied to the apical compartment reduced the net uptake of Ca2+ by stimulating the efflux component. The use of endogenous metal-responsive gene expression and inhibition of ion transport in the developed cell culture system will facilitate studies of metal-gill interactions and may prove to have future practical applications within biomonitoring of natural waters.

Walker PA; Bury NR; Hogstrand C

2007-09-01

93

Retaining Latino Students: Culturally Responsive Instruction in Colleges and Universities  

Science.gov (United States)

|In this article the authors define and describe culturally responsive teaching (CRT) in college and university courses. Whereas, the Latino population in our K-12 schools has grown rapidly, we have not seen such growth in the population of Latino students in our postsecondary schools. It is the authors' position that CRT can be a tool in helping…

Pappamihiel, N. Eleni; Moreno, Marcio

2011-01-01

94

Addressing the Disproportionate Representation of Culturally and Linguistically Diverse Students in Special Education through Culturally Responsive Educational Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this article, we present a conceptual framework for addressing the disproportionate representation of culturally and linguistically diverse students in special education. The cornerstone of our approach to addressing disproportionate representation is through the creation of culturally responsive...

Janette K. Klingner; Alfredo J. Artiles; Elizabeth Kozleski; Beth Harry; Shelley Zion; William Tate; Grace Zamora Durán

95

Geoethics and geological culture: awareness, responsibility and challenges  

Directory of Open Access Journals (Sweden)

Full Text Available The international debate in the field of geoethics focuses on some of the most important environmental emergencies, while highlighting the great responsibilities of geoscientists, whatever field they work in, and the important social, cultural and economic repercussions that their choices can have on society. The GeoItalia 2009 and 2011 conferences that were held in Rimini and Turin, respectively, and were organized by the Italian Federation of Earth Science, were two important moments for the promotion of geoethics in Italy. They were devoted to the highlighting of how, and with what tools and contents, can the geosciences contribute to the cultural renewal of society. They also covered the active roles of geoscientists in the dissemination of scientific information, contributing in this way to the correct construction of social knowledge. Geology is culture, and as such it can help to dispel misconceptions and cultural stereotypes that concern natural phenomena, disasters, resources, and land management. Geological culture consists of methods, goals, values, history, ways of thinking about nature, and specific sensitivity for approaching problems and their solutions. So geology has to fix referenced values, as indispensable prerequisites for geoethics. Together, geological culture and geoethics can strengthen the bond that joins people to their territory, and can help to find solutions and answers to some important challenges in the coming years regarding natural risks, resources, and climate change. Starting from these considerations, we stress the importance of establishing an ethical criterion for Earth scientists, to focus attention on the issue of the responsibility of geoscientists, and the need to more clearly define their scientific identity and the value of their specificities.

Silvia Peppoloni; Giuseppe Di Capua

2012-01-01

96

Isolation and culture of soybean (Glycine max L. Merrill) microspores and pollen grains  

Directory of Open Access Journals (Sweden)

Full Text Available In the last three decades, research on soybean microspore embryogenesis was restricted to anther culture, which presents limitations such as the small number of responsive microspores and the high embryogenic potential of sporophytic tissues. Therefore, a sequence of studies was performed to establish appropriate conditions for the isolation and culture of soybean microspores and pollen grains as an alternative to anther culture. First, a pollen and microspore isolation technique was developed using floral buds from four soybean cultivars (Bragg, IAS 5, MG/BR-46 Conquista and BRSMT Uirapuru). This technique allowed the establishment of cultures with satisfactory density and characteristics. Subsequently, different culture conditions were tested. Although B5 and MS media have been currently recommended for soybean anther culture, the best result was obtained in PTA-15 modified medium, with the formation of enlarged microspores and 0.4% of multicellular pollen grains in the cultivar BRSMT Uirapuru.Nas últimas três décadas, a pesquisa em embriogênese do micrósporo de soja restringiu-se ao cultivo in vitro de anteras, com inúmeras limitações, como o pequeno número de micrósporos responsivos e o alto potencial embriogênico dos tecidos esporofíticos. Por isso, foi executada uma seqüência de testes visando ao estabelecimento de condições adequadas para o isolamento e o cultivo in vitro de micrósporos e grãos de pólen, como um sistema alternativo ao cultivo de anteras. Inicialmente, uma técnica de isolamento foi desenvolvida usando botões florais de quatro cultivares de soja (Bragg, IAS 5, MG/BR-46 Conquista e BRSMT Uirapuru), a qual possibilitou o estabelecimento de cultivos com características e densidade satisfatórias. Posteriormente, diferentes condições de cultivo foram testadas. Apesar de os meios B5 e MS serem recomendados para o cultivo de anteras de soja, o melhor resultado foi obtido em meio PTA-15 modificado, como o aumento do tamanho dos micrósporos e a formação de 0,4% de grãos de pólen multicelulares na cultivar BRSMT Uirapuru.

Lia Rosane Rodrigues; Bianca de Camargo Forte; Maria Helena Bodanese-Zanettini

2006-01-01

97

Isolation and culture of soybean (Glycine max L. Merrill) microspores and pollen grains  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Nas últimas três décadas, a pesquisa em embriogênese do micrósporo de soja restringiu-se ao cultivo in vitro de anteras, com inúmeras limitações, como o pequeno número de micrósporos responsivos e o alto potencial embriogênico dos tecidos esporofíticos. Por isso, foi executada uma seqüência de testes visando ao estabelecimento de condições adequadas para o isolamento e o cultivo in vitro de micrósporos e grãos de pólen, como um sistema alternativo ao cu (more) ltivo de anteras. Inicialmente, uma técnica de isolamento foi desenvolvida usando botões florais de quatro cultivares de soja (Bragg, IAS 5, MG/BR-46 Conquista e BRSMT Uirapuru), a qual possibilitou o estabelecimento de cultivos com características e densidade satisfatórias. Posteriormente, diferentes condições de cultivo foram testadas. Apesar de os meios B5 e MS serem recomendados para o cultivo de anteras de soja, o melhor resultado foi obtido em meio PTA-15 modificado, como o aumento do tamanho dos micrósporos e a formação de 0,4% de grãos de pólen multicelulares na cultivar BRSMT Uirapuru. Abstract in english In the last three decades, research on soybean microspore embryogenesis was restricted to anther culture, which presents limitations such as the small number of responsive microspores and the high embryogenic potential of sporophytic tissues. Therefore, a sequence of studies was performed to establish appropriate conditions for the isolation and culture of soybean microspores and pollen grains as an alternative to anther culture. First, a pollen and microspore isolation t (more) echnique was developed using floral buds from four soybean cultivars (Bragg, IAS 5, MG/BR-46 Conquista and BRSMT Uirapuru). This technique allowed the establishment of cultures with satisfactory density and characteristics. Subsequently, different culture conditions were tested. Although B5 and MS media have been currently recommended for soybean anther culture, the best result was obtained in PTA-15 modified medium, with the formation of enlarged microspores and 0.4% of multicellular pollen grains in the cultivar BRSMT Uirapuru.

Rodrigues, Lia Rosane; Forte, Bianca de Camargo; Bodanese-Zanettini, Maria Helena

2006-07-01

98

Analysis of anther transcriptomes to identify genes contributing to meiosis and male gametophyte development in rice  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background In flowering plants, the anther is the site of male gametophyte development. Two major events in the development of the male germline are meiosis and the asymmetric division in the male gametophyte that gives rise to the vegetative and generative cells, and the following mitotic division in the generative cell that produces two sperm cells. Anther transcriptomes have been analyzed in many plant species at progressive stages of development by using microarray and sequence-by synthesis-technologies to identify genes that regulate anther development. Here we report a comprehensive analysis of rice anther transcriptomes at four distinct stages, focusing on identifying regulatory components that contribute to male meiosis and germline development. Further, these transcriptomes have been compared with the transcriptomes of 10 stages of rice vegetative and seed development to identify genes that express specifically during anther development. Results Transcriptome profiling of four stages of anther development in rice including pre-meiotic (PMA), meiotic (MA), anthers at single-celled (SCP) and tri-nucleate pollen (TPA) revealed about 22,000 genes expressing in at least one of the anther developmental stages, with the highest number in MA (18,090) and the lowest (15,465) in TPA. Comparison of these transcriptome profiles to an in-house generated microarray-based transcriptomics database comprising of 10 stages/tissues of vegetative as well as reproductive development in rice resulted in the identification of 1,000 genes specifically expressed in anther stages. From this sub-set, 453 genes were specific to TPA, while 78 and 184 genes were expressed specifically in MA and SCP, respectively. The expression pattern of selected genes has been validated using real time PCR and in situ hybridizations. Gene ontology and pathway analysis of stage-specific genes revealed that those encoding transcription factors and components of protein folding, sorting and degradation pathway genes dominated in MA, whereas in TPA, those coding for cell structure and signal transduction components were in abundance. Interestingly, about 50% of the genes with anther-specific expression have not been annotated so far. Conclusions Not only have we provided the transcriptome constituents of four landmark stages of anther development in rice but we have also identified genes that express exclusively in these stages. It is likely that many of these candidates may therefore contribute to specific aspects of anther and/or male gametophyte development in rice. In addition, the gene sets that have been produced will assist the plant reproductive community in building a deeper understanding of underlying regulatory networks and in selecting gene candidates for functional validation.

Deveshwar Priyanka; Bovill William D; Sharma Rita; Able Jason A; Kapoor Sanjay

2011-01-01

99

Research on cotton anther development of three male-sterile lines  

International Nuclear Information System (INIS)

Pollens of Sumian 22 were irradiated by 60Co ?-rays at a dose of 20Gy, then fertilized to pistil and harvested seed. Three male-sterile lines were selected from M1 plants, their anther observed by paraffin slice technique. Although there were some different characteristics during the abortion anther development, the abortion was consistent: the abortion stage from the development periods of pollen mother cells to microspore, pollen mother cells, tapetum, middle layer cells and the shape of anther were affected, the results contained micronucleus and double nucleus, cytoplasm expansion during the period of meiosis, tapetum and middle layer cells and so on were abnormal. (authors)

2009-01-01

100

Calogênese in vitro em anteras de coffea arabica L./ In vitro callogenesis in anthers of Coffea arabica L.  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O café é um dos mais importantes produtos do mercado internacional; porém, o tempo gasto e os recursos despendidos são fatores limitantes para o melhoramento do cafeeiro por meio de métodos convencionais. Contudo, a cultura de anteras surge como uma alternativa viável e de curto prazo para solução desses problemas. Com o presente trabalho, objetivou-se a produção de dihaplóides com a cultura de anteras do cafeeiro (androgênese indireta), buscando um protocolo (more) para a fase de indução de calos. Para tanto, foi efetuada a assepsia dos botões florais e das anteras, que, em seguida, foram inoculadas em meio IC e mantidas no escuro por 8 semanas, sob temperatura de 25ºC ± 1. Para induzir a calogênese em anteras da cv. Acaiá Cerrado, foram testadas as concentrações de 2,4-D (0, 1, 2 e 4 mg.L-1) x cinetina (0, 2, 4 e 8 mg.L-1) e 2,4-D (0; 0,5; 1 e 2 mg.L-1) x AIB (0; 0,5; 1 e 2 mg.L-1) mais 2iP (2 mg.L-1) e, para a cv. Rubi, as concentrações de 2,4-D (0, 1, 2 e 4 mg.L-1) x cinetina (0, 2, 4 e 8 mg.L-1). Foi observado que a maior porcentagem de indução de calogênese em anteras na cv. Acaiá Cerrado ocorre com as combinações de 2,4-D (2 mg.L-1) + cinetina (1,9 mg.L-1) e 2,4-D (0,86 mg.L-1) + AIB (1 mg.L-1)+ 2iP (2 mg.L-1); para cv. Rubi, a combinação de 2,4-D (1,9 mg.L-1) e cinetina (4 mg.L-1). Abstract in english The coffee is one of the most important products of the international market, however the time and money wasted in breeding programs are limiting factors for its improvement. However, the anther culture appears as a viable alternative for a short time period solution for this problem. This work aimed to obtain the double haploids production from anther cultures of the coffee plant (indirect androgenesis) aiming to optimize a protocol calluse induction. For this purpose, a (more) sseptic conditions of the flower budsand anthers were accomplished, folowed by inoculationin IC medium and the tissue were kept for eight weeks at 25ºC ± 1 in the dark. To induce callogenesis in anthers of the 'Acaiá Cerrado' there were tested 2,4-D (0, 1, 2 and 4 mg.L-1) x kinetin (0, 2, 4 and 8 mg.L-1) and 2,4-D (0; 0,5; 1 and 2mg.L-1) x AIB (0; 0,5; 1 and 2mg.-1) plus 2 iP (2 mg.L-1) concentrations and for the 'Rubi' 2,4-D (0, 1, 2 and 4 mg.L-1) x kinetin (0, 2, 4 and 8 mg.L-1) concentrations. It was observed that the highest percentage of callogenesis induction in anthers of the 'Acaiá Cerrado' was provenient from 2,4-D (2 mg.L-1) + kinetin (1,9 mg.L-1) and 2,4-D (0,86 mg.L-1) + AIB (1 mg.L-1)+ 2iP (2mg.L-1) combinations for 'Rubi' 2,4-D (1,9 mg.L-1) and kinetin (4 mg.L-1).

Palú, Ednamar Gabriela; Silva, Adriano Bortolotti da; Pasqual, Moacir

2004-08-01

 
 
 
 
101

Modulation of insulin responses in cultured cells by calmodulin  

International Nuclear Information System (INIS)

[en] The main impetus of this work was to analyze the possible association of Ca++/calmodulin with the ? subunit tyrosine kinase of the insulin receptor in whole cells, and to correlate this association to insulin dependent biological responses. Initial in vitro assays with IM-9 lymphocyte receptor preparations demonstrated that calmodulin augments insulin-stimulated receptor autophosphorylation in a calcium dependent manner. Furthermore, the specific calmodulin inhibitors calmidazolium and agent W-7 were effective at inhibiting insulin stimulated receptor autophosphorylation at concentrations reported to inhibit other calmodulin regulated systems. Utilizing the insulin-responsive cultured muscle cell line BC3H-1, we have investigated the effects of these calmodulin antagonists on insulin receptor autophosphorylation, insulin-stimulated DNA synthesis, and insulin-stimulated hexose uptake in intake in intact cells. Confluent BC3H-1 myocytes were assayed for responsiveness to insulin in the presence and absence of increasing concentrations of calmidazolium or W-7 at 37 degree C. Insulin-stimulated receptor tyrosine autophosphorylation of the 95 kDa ?-subunit was inhibited by both agents with IC50 values for each of ?30 ?M. 3H-thymidine incorporation into DNA was also inhibited with an IC50 value for each of 20-30 ?M. Insulin-stimulated 3H-2-deoxyglucose uptake was not specifically affected by calmidazolium and demonstrated inhibition by W-7 only at concentrations indication that the effect is not modulated by a calmodulin dependent mechanism

1989-01-01

102

Social responses to climate change: Political cultures and social plasticity  

Energy Technology Data Exchange (ETDEWEB)

Working Group III of the Intergovernmental Panel on Climate Change cautiously observes that {open_quotes}The value of better information about climate change processes and impacts and society`s responses to them is likely to be great.{close_quotes} Global-scale problems involve an infinite number of social complexities, so a fundamental analytic need is a metric to facilitate cross-cultural comparison of sets of attitudes or worldviews relevant to coping with climate change. Enhanced climate change is a salient example of the synergistic character of anthropogenic and natural processes, but the very fact that not everyone sees {open_quotes}anthropogenic{close_quotes} and {open_quotes}natural{close_quotes} as dichotomous, or agrees on the implications of either alternative, indicates the presence of competing worldviews. There is a consensus that a high level of environmental quality is a collective good, so a general failure to provide it needs explaining. Is the problem inherent to collective action or is it a function of the global politico-economic system? The premises of some worldviews lead to doubt that collective action problems can be resolved in a system dominated by sovereign states, and insist that nothing short of radical systemic revision is required. Other premises produce fear of concentrations of power in supranational or international organizations. What elements predispose people and groups to accept or reject one or the other of these views? This research uses cultural theory to explore socioeconomic and political implications of diverse worldviews. Responses of a sample of over 500 people to politically and environmentally relevant statements are classified, scaled and clustered. Implications for social adaptability, or plasticity, are suggested.

Pendergraft, C.A.

1997-12-31

103

Cd/sup 2 +/ responses of cultured human blood cells  

Energy Technology Data Exchange (ETDEWEB)

Cd/sup 2 +/ cytotoxicity, uptake, and partitioning, and Cd/sup 2 +/-induced metallothioneine synthesis were studied in cultured peripheral human blood cells. Mononuclear cells were found to resist relatively high levels of Cd/sup 2 +/. Few cells were killed below 50 ..mu..M Cd/sup 2 +/. Above this value, survival decreased exponentially with dose. The mean LD50 for mononuclear cells cultured in Cd/sup 2 +/ for 40 hr was 100 ..mu..M. Polymorphonuclear cells (granulocytes) were found to be more resistant, with a significantly higher threshold and LD50, and a more complex dose response. Most of the Cd/sup 2 +/ incorporated by blood cells was taken up by nucleated cells. Despite their greater resistance, polymorphonuclear cells incorporated more Cd/sup 2 +/ at higher doses (50 to 150 ..mu..M) than did mononuclear cells. No Cd/sup 2 +/ was bound to metallothioneine in polymorphonuclear cells following exposure to Cd/sup 2 +/ for even extended periods of time (18 hr) at high doses of /sup 109/Cd/sup 2 +/ (25 ..mu..M). Instead Cd/sup 2 +/ appeared in a Sephadex G-75 peak of approximately 60,000 Da, as well as in the void peak. No significant amount of preexisting metallothioneine (MT) or metallothioneine mRNA was found in the mononuclear cells. However, MT synthesis was induced rapidly following exposure to Cd/sup 2 +/. (/sup 109/Cd/sup 2 +/)MT appeared within 1 hr following exposure to 50 ..mu..M /sup 109/Cd/sup 2 +/, and MT synthesis rates measured from (/sup 35/S)cysteine incorporation were found to be maximal within 4 hr.

Enger, M.D.; Hildebrand, C.E.; Stewart, C.C.

1983-01-01

104

Characterization of callase (?-1,3-d-glucanase) activity during microsporogenesis in the sterile anthers of Allium sativum L. and the fertile anthers of A. atropurpureum  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We examined callase activity in anthers of sterile Allium sativum (garlic) and fertile Allium atropurpureum. In A. sativum, a species that produces sterile pollen and propagates only vegetatively, callase was extracted from the thick walls of A. sativum microspore tetrads exhibited maximum activity ...

Winiarczyk, Krystyna; Jaroszuk-?cise?, Jolanta; Kupisz, Kamila

105

The "Simmie" Side of Life: Old Order Amish Youths' Affective Response to Culturally Prescribed Deviance.  

Science.gov (United States)

Analyzed the counterintuitive affective response Old Order Amish youth make to unique cultural prescriptions for adolescent deviance (constructed by adult Amish culture). Interview data supported the basic principles of Terror Management Theory in an unexpected, indirect fashion. Rather than functioning as a specialized cultural-anxiety buffer…

Reiling, Denise M.

2002-01-01

106

Culturally Responsive Schooling for Indigenous Youth: A Review of the Literature  

Science.gov (United States)

|This article reviews the literature on culturally responsive schooling (CRS) for Indigenous youth with an eye toward how we might provide more equitable and culturally responsive education within the current context of standardization and accountability. Although CRS for Indigenous youth has been advocated for over the past 40 years, schools and…

Castagno, Angelina E.; Brayboy, Bryan McKinley Jones

2008-01-01

107

Characterization of chondrocyte sheets prepared using a co-culture method with temperature-responsive culture inserts.  

UK PubMed Central (United Kingdom)

Conventional culture methods using temperature-responsive culture dishes require 4-5 weeks to prepare layered chondrocyte sheets that can be used in articular cartilage repair and regeneration. This study investigated whether the use of synovial tissue obtained from the same joint as the chondrocyte nutritive supply source could more quickly facilitate the preparation of chondrocyte sheets. After culturing derived synoviocytes and chondrocytes together (i.e. combined culture or co-culture) on temperature-responsive inserts, chondrocyte growth was assessed and a molecular analysis of the chondrocyte sheets was performed. Transplantable tissue could be obtained more quickly using this method (average 10.5 days). Real-time polymerase chain reaction and immunostaining of the three-layer chondrocyte sheets confirmed the significant expression of genes critical to cartilage maintenance, including type II collagen (COL2), aggrecan-1 and tissue metallopeptidase inhibitor 1. However, the expression of COL1, matrix metalloproteinase 3 (MMP3), MMP13 and A-disintegrin and metalloproteinase with thrombospondin motifs 5 was suppressed. The adhesive factor fibronectin-1 (FN1) was observed in all sheet layers, whereas in sheets generated using conventional preparation methods positive FN1 immunostaining was observed only on the surface of the sheets. The results indicate that synoviocyte co-cultures provide an optimal environment for the preparation of chondrocyte sheets for tissue transplantation and are particularly beneficial for shortening the required culture period. Copyright © 2013 John Wiley & Sons, Ltd.

Kokubo M; Sato M; Yamato M; Mitani G; Kutsuna T; Ebihara G; Okano T; Mochida J

2013-07-01

108

Androgenic response of barley accessions and F1s with Fusarium head blight resistance.  

UK PubMed Central (United Kingdom)

Most Fusarium head blight (FHB) resistant barley (Hordeum vulgare L.) accessions perform relatively poorly from an agronomic point of view. Due to the polygenic inheritance of FHB resistance, introgression of this complex trait into well-adapted elite germplasm will likely require multiple cycles of hybridization and selection to combine resistance and agronomic performance. The use of anther culture to produce doubled haploids would seem well justified to reduce the time required to achieve this goal. Unfortunately, little is known concerning the androgenic response of the small number of genotypes with known partial FHB resistance. To make the best use of such FHB resistance donors in a barley improvement program, we first characterized the FHB resistance of eight reported FHB resistance sources (Chevron, Gobernadora, Seijo II, Shyri, Svanhals, Zhedar I, F104-250-9 and C97-21-38-3) in our own FHB nursery in Quebec City (QC, Canada). In parallel, we assessed the androgenic response of these same eight lines with that of three cultivars (ACCA, Léger and Cadette) of known androgenic response. Finally, the androgenic response of F(1) hybrids involving some of these genotypes used as parents was measured and compared to that of the parental genotypes. Very large and significant differences were observed in the number of green plants produced by the different accessions and F(1)s. Although anther culture seemed very promising for some accessions, for others, the androgenic response was so low that a conventional approach would seem more appropriate.

Marchand S; Fonquerne G; Clermont I; Laroche L; Huynh TT; Belzile FJ

2008-03-01

109

Androgenic response of barley accessions and F1s with Fusarium head blight resistance.  

Science.gov (United States)

Most Fusarium head blight (FHB) resistant barley (Hordeum vulgare L.) accessions perform relatively poorly from an agronomic point of view. Due to the polygenic inheritance of FHB resistance, introgression of this complex trait into well-adapted elite germplasm will likely require multiple cycles of hybridization and selection to combine resistance and agronomic performance. The use of anther culture to produce doubled haploids would seem well justified to reduce the time required to achieve this goal. Unfortunately, little is known concerning the androgenic response of the small number of genotypes with known partial FHB resistance. To make the best use of such FHB resistance donors in a barley improvement program, we first characterized the FHB resistance of eight reported FHB resistance sources (Chevron, Gobernadora, Seijo II, Shyri, Svanhals, Zhedar I, F104-250-9 and C97-21-38-3) in our own FHB nursery in Quebec City (QC, Canada). In parallel, we assessed the androgenic response of these same eight lines with that of three cultivars (ACCA, Léger and Cadette) of known androgenic response. Finally, the androgenic response of F(1) hybrids involving some of these genotypes used as parents was measured and compared to that of the parental genotypes. Very large and significant differences were observed in the number of green plants produced by the different accessions and F(1)s. Although anther culture seemed very promising for some accessions, for others, the androgenic response was so low that a conventional approach would seem more appropriate. PMID:18026956

Marchand, Suzanne; Fonquerne, Gaudéric; Clermont, Isabelle; Laroche, Liette; Huynh, Tung Thanh; Belzile, François J

2007-11-20

110

Engendering cultural responsive care: a reflective model for nurse education  

Directory of Open Access Journals (Sweden)

Full Text Available A significant outcome of globalization has been a greater movement of peoples. As a consequence societies around the world are increasingly becoming multicultural. Multiculturalism, therefore, is a major characteristic of modern societies and one which has significant implications for health care delivery and health care systems. Many of these implications arise from differing health beliefs and values. Different cultural groups will, therefore, have values and attitudes consistent with that culture. Within health care the norms of the host culture tend to dominate resulting in ethnocentrism. This ethnocentric approach to delivery of health care has led to inequities, with immigrant groups reporting dissatisfaction with health care provision. This paper explores the ways in which health belief systems and values are constructed. It then goes on to consider how differing health beliefs have led to health disparities, amongst differing cultural groups, within the United Kingdom. A model of reflection specifically designed to facilitate the exploration of health care values within a pre-registration nursing curriculum is proposed as one way of promoting culturally sensitive care within nursing students.

Derek Chambers; Susan Thompson; Aru Narayanasamy

2013-01-01

111

Oviposition Attractancy of Bacterial Culture Filtrates: response of Culex quinquefasciatus  

Directory of Open Access Journals (Sweden)

Full Text Available Oviposition attractants could be used for monitoring as well as controlling mosquitoes by attracting them to lay eggs at chosen sites. In the present study, culture filtrates of seven bacterial species were tested for their attractancy against gravid females of Culex quinquefasciatus. When their oviposition active indices (OAI) were studied, the culture filtrates of Bacillus cereus and Pseudomonas fluorescens exhibited oviposition attractancy (OAI = >0.3) at 100 ppm and the OAI were respectively 0.70 and 0.47. Culture filtrates of B. thuringiensis var. israelensis (wild type), B. t. var. israelensis (mutant) and B. sphaericus showed attractancy at 2000 ppm with OAI of respectively 0.71, 0.59 and 0.68. However, the OAI of B. megaterium as well as Azospirillum brasilense was 0.13 (at 2000 ppm), which was less than 0.3 required to be considered them as attractants. When the oviposition attractancy of the bacterial culture filtrates were compared with that of a known oviposition attractant, p-cresol (at 10 ppm), the culture filtrates of B. t. var. israelensis (wild type) and B. cereus were found to be more active than p-cresol, respectively with 64.2 and 54.3% oviposition.

Poonam S; Paily KP; Balaraman K

2002-01-01

112

Effects of Cry1Ab-Expressing Corn Anthers on the Movement of Monarch Butterfly Larvae  

Science.gov (United States)

Studies have shown that anthers from Bacillus thuringiensis (Bt) corn, Zea mays L., do not pose a significant risk to the monarch butterfly, Danaus plexippus (L.). However, adverse effects (decreased feeding and weight) have been detected after 4 days of exposure in the laboratory to a high density ...

113

Examination of Meiosis Anomalies in Anthers of Vitis vinifera L. cv. Cavus  

Directory of Open Access Journals (Sweden)

Full Text Available Meiotic anomalies in pollen mother cells in anthers of Vitis vinifera L. cv. Cavus (2n = 38) were examined by light microscopy. In most microspore mother cells, the course of meiosis is regular. In some cells irregularities were observed, including chromosome bridges, univalents and fragments. Microspore tetrads are isobilateral and tetrahedral.

Erol Kodak; H. Nurhan Buyukkartal

2005-01-01

114

Examination of Meiosis Anomalies in Anthers of Vitis vinifera L. cv. Cavus  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Meiotic anomalies in pollen mother cells in anthers of Vitis vinifera L. cv. Cavus (2n = 38) were examined by light microscopy. In most microspore mother cells, the course of meiosis is regular. In some cells irregularities were observed, including chromosome bridges, univalents and fragments...

Erol Kodak; H. Nurhan Buyukkartal

115

Analysis of anther transcriptomes to identify genes contributing to meiosis and male gametophyte development in rice  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background In flowering plants, the anther is the site of male gametophyte development. Two major events in the development of the male germline are meiosis and the asymmetric division in the male gametophyte that gives rise to the vegetative and generative cells, and the f...

Deveshwar Priyanka; Bovill William D; Sharma Rita; Able Jason A; Kapoor Sanjay

116

Rice SIZ1, a SUMO E3 ligase, controls spikelet fertility through regulation of anther dehiscence.  

UK PubMed Central (United Kingdom)

• Sumoylation, a post-translational modification, has important functions in both animals and plants. However, the biological function of the SUMO E3 ligase, SIZ1, in rice (Oryza sativa) is still under investigation. • In this study, we employed two different genetic approaches, the use of siz1 T-DNA mutant and SIZ1-RNAi transgenic plants, to characterize the function of rice SIZ1. • Genetic results revealed the co-segregation of single T-DNA insertional recessive mutation with the observed phenotypes in siz1. In addition to showing reduced plant height, tiller number and seed set percentage, both the siz1 mutant and SIZ1-RNAi transgenic plants showed obvious defects in anther dehiscence, but not pollen viability. The anther indehiscence in siz1 was probably a result of defects in endothecium development before anthesis. Interestingly, rice orthologs of AtIRX and ZmMADS2, which are essential for endothecium development during anther dehiscence, were significantly down-regulated in siz1. Compared with the wild-type, the sumoylation profile of high-molecular-weight proteins in mature spikelets was reduced significantly in siz1 and the SIZ1-RNAi line with notably reduced SIZ1 expression. The nuclear localization signal located in the SIZ1 C-terminus was sufficient for its nuclear targeting in bombarded onion epidermis. • The results suggest the functional role of SIZ1, a SUMO E3 ligase, in regulating rice anther dehiscence.

Thangasamy S; Guo CL; Chuang MH; Lai MH; Chen J; Jauh GY

2011-02-01

117

Rice SIZ1, a SUMO E3 ligase, controls spikelet fertility through regulation of anther dehiscence.  

Science.gov (United States)

• Sumoylation, a post-translational modification, has important functions in both animals and plants. However, the biological function of the SUMO E3 ligase, SIZ1, in rice (Oryza sativa) is still under investigation. • In this study, we employed two different genetic approaches, the use of siz1 T-DNA mutant and SIZ1-RNAi transgenic plants, to characterize the function of rice SIZ1. • Genetic results revealed the co-segregation of single T-DNA insertional recessive mutation with the observed phenotypes in siz1. In addition to showing reduced plant height, tiller number and seed set percentage, both the siz1 mutant and SIZ1-RNAi transgenic plants showed obvious defects in anther dehiscence, but not pollen viability. The anther indehiscence in siz1 was probably a result of defects in endothecium development before anthesis. Interestingly, rice orthologs of AtIRX and ZmMADS2, which are essential for endothecium development during anther dehiscence, were significantly down-regulated in siz1. Compared with the wild-type, the sumoylation profile of high-molecular-weight proteins in mature spikelets was reduced significantly in siz1 and the SIZ1-RNAi line with notably reduced SIZ1 expression. The nuclear localization signal located in the SIZ1 C-terminus was sufficient for its nuclear targeting in bombarded onion epidermis. • The results suggest the functional role of SIZ1, a SUMO E3 ligase, in regulating rice anther dehiscence. PMID:21083564

Thangasamy, Saminathan; Guo, Cian-Ling; Chuang, Ming-Hsiang; Lai, Ming-Hsing; Chen, Jychian; Jauh, Guang-Yuh

2010-11-16

118

Influence of Microsperma Lentil Genotypes on Tissue Culture Responses  

Directory of Open Access Journals (Sweden)

Full Text Available In vitro growth responses of various lentil genotypes varied. The best callussing response was noticed in variety ILL- 4605. The genotype AARI-L-89503 had a tendency for embryogenesis. The genotype AARI-L-86642 had the best rooting ability. This genotype also showed in vitro flowering response. Masoor-85 and Pant-L-406 had moderate morphogenic responses. Meristem multiplication, shoot development, shoot bud formation from callus and adventitious rooting from shoot cuttings was obtained under appropriate growth regulators combinations.

N. Altaf; J. Iqbal; M. S. Ahmad

1998-01-01

119

Contrasting Nephropathic Responses to Oral Administration of Extract of Cultured Penicillium polonicum in Rat and Primate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Liquid- or solid substrate-cultured Penicillium polonicum administered in feed to rats over several days evokes a histopathological response in kidney involving apoptosis and abnormal mitosis in proximal tubules. The amphoteric toxin is yet only partly characterized, but can be isolated from culture...

Peter G. Mantle; Katharine M. McHugh; John E. Fincham

120

Social Justice and Cultural Responsiveness: Innovative Teaching Strategies for Group Work  

Science.gov (United States)

This article presents a teaching strategy for group work that enhances the social justice consciousness of course participants by increasing their knowledge of their own cultural identity, worldview, acculturation, privilege, and oppression to improve their cultural responsiveness and understanding of social justice issues. The focus is on group…

Ibrahim, Farah A.

2010-01-01

 
 
 
 
121

Addressing the Disproportionate Representation of Culturally and Linguistically Diverse Students in Special Education through Culturally Responsive Educational Systems  

Directory of Open Access Journals (Sweden)

Full Text Available In this article, we present a conceptual framework for addressing the disproportionate representation of culturally and linguistically diverse students in special education. The cornerstone of our approach to addressing disproportionate representation is through the creation of culturally responsive educational systems. Our goal is to assist practitioners, researchers, and policy makers in coalescing around culturally responsive, evidence-based interventions and strategic improvements in practice and policy to improve students’ educational opportunities in general education and reduce inappropriate referrals to and placement in special education. We envision this work as cutting across three interrelated domains: policies, practices, and people. Policies include those guidelines enacted at federal, state, district, and school levels that influence funding, resource allocation, accountability, and other key aspects of schooling. We use the notion of practice in two ways, in the instrumental sense of daily practices that all cultural beings engage in to navigate and survive their worlds, and also in a technical sense to describe the procedures and strategies devised for the purpose of maximizing students’ learning outcomes. People include all those in the broad educational system: administrators, teacher educators, teachers, community members, families, and the children whose opportunities we wish to improve.

Janette K. Klingner; Alfredo J. Artiles; Elizabeth Kozleski; Beth Harry; Shelley Zion; William Tate; Grace Zamora Durán; David Riley

2005-01-01

122

[Response surface methodology to optimize marine microbe culture for producing fungi fibrinolytic compound].  

UK PubMed Central (United Kingdom)

Response surface methodology was applied to optimize the fermentation conditions of FGFC1 (Fungi fibrinolytic compound 1). On the basis of single factor tests, response surface analysis was designed by Design-Expert, and the effects of culture time, ornithine hydrochloride addition and culture temperature on the yield of FGFC1 were studied, the predicted value and measured value were also contrasted. The results show the optimal culture conditions as follows: the culture time is 7 d, ornithine hydrochloride addition is 0.5% (M/V), culture temperature is 28 degrees C. Under these conditions, the yield of FGFC1 is 1 978.33 mg/L, which is consistent with the predicted value. It shows that the experiment is effective.

Su T; Bao B; Yan T; Zhang C; Bu Y; Wu W

2013-06-01

123

Collateral Learning in Science: Students' Responses to a Cross-Cultural Unit of Work  

Science.gov (United States)

The purpose of this study was to investigate the nature of students' responses to a cross-cultural science unit entitled "Maintaining health." The unit was designed to help students to build bridges between their traditional practices and beliefs and western science concepts. This paper reports students' responses to a pre-test and post-test, and…

Herbert, Susan

2008-01-01

124

Spatial and temporal activity of upstream regulatory regions of rice anther-specific genes in transgenic rice and Arabidopsis.  

UK PubMed Central (United Kingdom)

Upstream regulatory regions (URRs) of rice anther-specific genes, namely OSbHLH (coding for basic helix-loop-helix-containing protein) and OSFbox (F-box protein encoding gene), selected from the microarray data have been cloned to control expression of GUS and GFP reporter genes in stably transformed rice. Quantitative real time PCR analysis shows maximum transcript accumulation of these two genes in the meiotic anthers. Analysis of OSbHLH and OSFbox URRs by PLACE database reveal the presence of known pollen-specific cis elements. The URRs of both OSbHLH and OSFbox genes have maximum activity in the meiotic anther stage in rice, but confer constitutive expression in the heterologous dicot system, Arabidopsis, indicative of monocot specificity. Another rice gene (OSIPK; with homology to genes encoding calcium-dependent protein kinases) URR already reported to have anther-specific activity in Arabidopsis and tobacco also confers anther-specific expression in rice and is active in the pollen tubes, suggesting it belongs to the category of late expressed genes. The spatial activity of three URRs has also been analysed by histochemical evaluation of GUS activity in different anther cells/tissues. The activity of OSIPK URR in rice is strongest among the three URRs.

Khurana R; Kapoor S; Tyagi AK

2013-02-01

125

Effects of cortisol on the primary response of mouse spleen cell cultures to heterologous erythrocytes  

International Nuclear Information System (INIS)

[en] Cell viability and the production of direct PFC were studied in mouse spleen cell cultures after cortisol treatment in vivo or in vitro at various times relative to primary stimulation with SRBC in vitro. Cortisol treatment in vivo reduced spleen cell numbers by 88 percent after 48 hr, but cultures of the remaining cells produced as many PFC in vitro as did cultures of equal numbers of normal spleen cells. In normal spleen cell cultures incubated with cortisol for 4 hr prior to the addition of antigen, peak responses of PFC/culture and PFC/106 cells occurred 24 hr later than in controls and averaged, respectively, 27 and 141 percent of control values. Minimum viable cell numbers were observed in cortisol-treated cultures after 3 days; thereafter cell numbers gradually increased. These results were not significantly altered when cultures were treated simultaneously with cortisol and antigen. The response was not suppressed if the addition of antigen preceded that of cortisol by more than 4 hr. Suppression was also considerably reduced if fetal calf serum was used when preparing cells for culture

1974-01-01

126

Effect of 60Co ?-rays irradiation pretreatment on callus inductivity and differentiation of strawberry anther  

International Nuclear Information System (INIS)

Strawberry buds, in which a majority of pollen had single nuclear keeping to the side, were pretreated by 60Co ?-rays irradiation at different doses. The irradiation effect on the callus inductivity and plant differentiation rate of strawberry anther were studied. The results indicated that the pretreatment by 60Co ?-rays could increase the anther callus inductivity and plant differentiation rate significantly, and 20 Gy was the best dose. The callus inductivity of Akihime and Toyonoka increased by 39.09% and 35.68%, respectively, compared with the no-pretreatment materials. On the same media, the plant differentiation rate of Akihime and Toyonoka were also increased by 6.67%-6.72% and 4.73%-6.45%, respectively, compared with the two varieties of no-pretreatment. (authors)

2007-01-01

127

Observation on flower's morphological and anther's anatomy character of three {\\sl Allium} plants  

UK PubMed Central (United Kingdom)

Allium mongolicum, Allium tenuissimum and Allium ramosum are great favor as wide vegetable in recently. Some experts paid attention to the studies on these three Allium plants, but the study on anatomy character is not reported. According to farming observation and paraffin section method the flower's morphological and anther's anatomy character of three Allium plants are observed, the results show that the flower's morphological is obvious difference; the pollen's shape is also diversity: Allium mongolicum is semi-round, Allium tenuissimum is ovoid, Allium ramosum is long-ovoid. As for the size of pollen, Allium ramosum is the biggest, the second is Allium mongolicum, and Allium tenuissimum is the smallest. The studies indicate the anther's anatomy character of threes plants and provide further theoretical evident for Allium's classification, relationship determining and reproduction.

Hao Lizhen; Yang Zhongren; Wang Liuying; Zhao Qingyan; Zhang Fenglan

2005-01-01

128

Dose response of tracheal epithelial cells to ionizing radiation in air-liquid interface cultures  

Energy Technology Data Exchange (ETDEWEB)

The dose-response relationships of tracheal epithelial cells to ionizing radiation was examined in air-liquid interface cultures, which were developed for the purpose of simulating in vivo conditions. The cultures investigated in this study were expected to be advantageous for the performance of irradiation experiments using short-range {alpha} rays. The level of dose response of air-liquid interface cultures to ionizing radiation proved to be the same as that for in vivo conditions. This result indicates that air-liquid interface cultures will prove most useful, to facilitate future studies for the investigation of the biological effects induced in tracheal epithelial cells by ionizing radiation, especially by {alpha}-rays. (orig.)

Fukutsu, K.; Yamada, Y.; Shimo, M. [National Inst. of Radiological Sciences, Chiba (Japan)

2002-03-01

129

Dose response of tracheal epithelial cells to ionizing radiation in air-liquid interface cultures  

International Nuclear Information System (INIS)

The dose-response relationships of tracheal epithelial cells to ionizing radiation was examined in air-liquid interface cultures, which were developed for the purpose of simulating in vivo conditions. The cultures investigated in this study were expected to be advantageous for the performance of irradiation experiments using short-range ? rays. The level of dose response of air-liquid interface cultures to ionizing radiation proved to be the same as that for in vivo conditions. This result indicates that air-liquid interface cultures will prove most useful, to facilitate future studies for the investigation of the biological effects induced in tracheal epithelial cells by ionizing radiation, especially by ?-rays. (orig.)

2002-01-01

130

The effects of corporate social responsibility on employees' affective commitment: a cross-cultural investigation.  

Science.gov (United States)

This study investigated the moderating effects of several Global Leadership and Organizational Behavior Effectiveness (GLOBE) cultural value dimensions on the relationship between employees' perceptions of their organization's social responsibility and their affective organizational commitment. Based on data from a sample of 1,084 employees from 17 countries, results showed that perceived corporate social responsibility (CSR) was positively related to employees' affective commitment (AC), after controlling for individual job satisfaction and gender as well as for nation-level differences in unemployment rates. In addition, several GLOBE value dimensions moderated the effects of CSR on AC. In particular, perceptions of CSR were more positively related to AC in cultures higher in humane orientation, institutional collectivism, ingroup collectivism, and future orientation and in cultures lower in power distance. Implications for future CSR research and cross-cultural human resources management are discussed. PMID:23067337

Mueller, Karsten; Hattrup, Kate; Spiess, Sven-Oliver; Lin-Hi, Nick

2012-10-15

131

The effects of corporate social responsibility on employees' affective commitment: a cross-cultural investigation.  

UK PubMed Central (United Kingdom)

This study investigated the moderating effects of several Global Leadership and Organizational Behavior Effectiveness (GLOBE) cultural value dimensions on the relationship between employees' perceptions of their organization's social responsibility and their affective organizational commitment. Based on data from a sample of 1,084 employees from 17 countries, results showed that perceived corporate social responsibility (CSR) was positively related to employees' affective commitment (AC), after controlling for individual job satisfaction and gender as well as for nation-level differences in unemployment rates. In addition, several GLOBE value dimensions moderated the effects of CSR on AC. In particular, perceptions of CSR were more positively related to AC in cultures higher in humane orientation, institutional collectivism, ingroup collectivism, and future orientation and in cultures lower in power distance. Implications for future CSR research and cross-cultural human resources management are discussed.

Mueller K; Hattrup K; Spiess SO; Lin-Hi N

2012-11-01

132

The molecular basis for uv response of cultured human cells  

Energy Technology Data Exchange (ETDEWEB)

During the past year we have analyzed the mechanism by which UV and H{sub 2}O{sub 2} increase the activity of AP-1 in HeLa cells. AP-1 is a dimeric protein complex composed of the fos and jun gene products. After UV irradiation of HeLa cells (or exposure to H{sub 2}O{sub 2}) expression of the c-jun gene rapidly increases at least 50-fold. This induction occurs through the previously identified AP-1 site in the c-jun promoter. This positive autoregulation is mediated by AP-1 complexes that are composed mostly of cJun. cJun is a phosphoprotein that undergoes complex changes in its phosphorylation state following exposure to phorbol esters, growth factors or transforming oncogenes. We show that UV irradiation causes increases in the phosphorylation of cJun. We have been trying to determine the common signal by which DNA damaging agents lead to activation of the UV response. We present evidence that oxidative stress may serve as a signal for AP-1 induction during the UV response. We are also trying to purify and characterize UVIC, a factor secreted from UV damaged cells which protects non-irradiated cells from damage. We have identified UVIC as a 17 kDa polypeptide that retains radioprotective activity after SDS-PAGE and renaturation. We are currently scaling up the isolation and purification process. 4 refs. (MHB)

Karin, M.

1991-12-01

133

The molecular basis for uv response of cultured human cells  

Energy Technology Data Exchange (ETDEWEB)

During the past year we have analyzed the mechanism by which UV and H{sub 2}O{sub 2} increase the activity of AP-1 in HeLa cells. AP-1 is a dimeric protein complex composed of the fos and jun gene products. After UV irradiation of HeLa cells (or exposure to H{sub 2}O{sub 2}) expression of the c-jun gene rapidly increases at least 50-fold. This induction occurs through the previously identified AP-1 site in the c-jun promoter. This positive autoregulation is mediated by AP-1 complexes that are composed mostly of cJun. cJun is a phosphoprotein that undergoes complex changes in its phosphorylation state following exposure to phorbol esters, growth factors or transforming oncogenes. We show that UV irradiation causes increases in the phosphorylation of cJun. We have been trying to determine the common signal by which DNA damaging agents lead to activation of the UV response. We present evidence that oxidative stress may serve as a signal for AP-1 induction during the UV response. We are also trying to purify and characterize UVIC, a factor secreted from UV damaged cells which protects non-irradiated cells from damage. We have identified UVIC as a 17 kDa polypeptide that retains radioprotective activity after SDS-PAGE and renaturation. We are currently scaling up the isolation and purification process. 4 refs. (MHB)

Karin, M.

1991-01-01

134

Intra and interspecific variability of in vitro culture response in Lycopersicon (tomatoes)  

Directory of Open Access Journals (Sweden)

Full Text Available Intra and interspecific variability was measured in the genus Lycopersicon for the traits: productivity rate (PR, total number of regenerated shoots/total number of cultures), regeneration percentage (%R, number of cultures regenerating shoots or primordia/total number of cultures) and callus percentage (%C, number of cultures only producing callus/total number of cultures). Leaf explants from various genotypes of L. esculentum, L. esculentum var. cerasiforme, L. pimpinellifolium and L. peruvianum were placed on Murashige and Skoog (Physiol. Plant. 15: 473-493, 1962) medium + 0.175 mg/l IAA + 2.25 mg/l BA. Significant differences among species and among genotypes within the same species were found, while genotypes from different species showed similar responses.

Pratta Guillermo; Zorzoli Roxana; Picardi Liliana Amelia

1997-01-01

135

Immunolocalization of Lipoxygenase in the Anther Wall Cells of Lathyrus undulatus Boiss. during Programmed Cell Death  

Directory of Open Access Journals (Sweden)

Full Text Available Lipoxygenase catalyzes oxygenation of long chain fatty acids to hydroperoxides and is involved in the degradation of membranes occuring in some types of programmed cell death (PCD). The localization of lipoxygenase in the anther wall layers of L. undulatus during cellular degradation was analyzed by immunogold labeling technique at young and vacuolated pollen stage, due to the close relation between lipoxygenase activity and membrane degradation in programmed cell death. Immunoreaction to lipoxygenase was monitored slightly at young pollen stage in the anther wall cells. As programmed cell death signals progress, lipoxygenase revealed in anther wall cells intensely. At vacuolated pollen stage tapetal cells came forward with ultrastructural changes such as cell, organelle and membrane disintegration. At the indicated stage immunogold particles indicating sites of LOX PAb-binding epitopes were located in the nucleus (chromatin was condensed and lined at the periphery), cytoplasm and close to long dilated rough endoplasmic reticulum (RER) cisterna. In conclusion lipoxygenase increase which has a role in the membrane degeneration, possibly induced the collapse of tonoplast, nuclear and plasma membrane and triggered programmed cell death in the tapetal cells of L. undulatus as well as the other wall cells.

Filiz VARDAR; Meral ÜNAL

2011-01-01

136

Identification of an Arabidopsis plasma membrane-located ATP transporter important for anther development.  

UK PubMed Central (United Kingdom)

ATP acts as an extracellular signal molecule in plants. However, the nature of the mechanisms that export this compound into the apoplast are under debate. We identified the protein PM-ANT1 as a candidate transporter able to mediate ATP export. PM-ANT1 joins the mitochondrial carrier family, lacks an N-terminal amino acid extension required for organelle localization, and locates to the plasma membrane. Recombinant PM-ANT1 transports ATP, and the gene is substantially expressed in mature pollen grains. Artificial microRNA (amiRNA) mutants show reduced silique length and less seeds per silique but increased seed weight associated with unchanged pollen viability. Anthers from amiRNA mutants exhibited a normal early development, but stomium breakage is inhibited, leading to impaired anther dehiscence. This results in reduced self-pollination and thus decreased fertilization efficiency. amiRNA pollen grains showed increased intracellular ATP levels but decreased extracellular ATP levels. The latter effects are in line with transport properties of recombinant PM-ANT1, supporting in planta that functional PM-ANT1 resides in the plasma membrane and concur with the PM-ANT1 expression pattern. We assume that PM-ANT1 contributes to ATP export during pollen maturation. ATP export may serve as an extracellular signal required for anther dehiscence and is a novel factor critical for pollination and autogamy.

Rieder B; Neuhaus HE

2011-05-01

137

Identification of an Arabidopsis plasma membrane-located ATP transporter important for anther development.  

Science.gov (United States)

ATP acts as an extracellular signal molecule in plants. However, the nature of the mechanisms that export this compound into the apoplast are under debate. We identified the protein PM-ANT1 as a candidate transporter able to mediate ATP export. PM-ANT1 joins the mitochondrial carrier family, lacks an N-terminal amino acid extension required for organelle localization, and locates to the plasma membrane. Recombinant PM-ANT1 transports ATP, and the gene is substantially expressed in mature pollen grains. Artificial microRNA (amiRNA) mutants show reduced silique length and less seeds per silique but increased seed weight associated with unchanged pollen viability. Anthers from amiRNA mutants exhibited a normal early development, but stomium breakage is inhibited, leading to impaired anther dehiscence. This results in reduced self-pollination and thus decreased fertilization efficiency. amiRNA pollen grains showed increased intracellular ATP levels but decreased extracellular ATP levels. The latter effects are in line with transport properties of recombinant PM-ANT1, supporting in planta that functional PM-ANT1 resides in the plasma membrane and concur with the PM-ANT1 expression pattern. We assume that PM-ANT1 contributes to ATP export during pollen maturation. ATP export may serve as an extracellular signal required for anther dehiscence and is a novel factor critical for pollination and autogamy. PMID:21540435

Rieder, Benjamin; Neuhaus, H Ekkehard

2011-05-03

138

Observation on the development of anther and microspore in Hevea brasiliensis  

UK PubMed Central (United Kingdom)

The development of anther and microspore in Hevea seedling and in Hevea clones BRIM600 and GT-1 were observed?and the results are as follows; 1. Anther wall of seedling tree consists of four layers of cells and its formation is of dicotyledonous type. In later development stages some fibrous thickenings appear on the walls of endothecium cells, in which the protoplast remains until anther dehiscence. The middle layer consists of one layer of cells or two ayers of irregular cells and disappears in monokaryon stage. Tapetal cells being of secretory type have one or two nuclei and disappear in 3-celled stage. Meiosis of microspore mother cell is of simultaneous type. The mature pollen comprises three cells, among them the sperm cells are spherical in shape and the cytoplasmic sheath and nucleolus are unable to be recognized under light microscope. 2.In RRIM600 the development of microspore is similar to that in the seedling tree, but in the later stage most of them become aborted pollens with different sizes and only a few grow normally;besides, some flowers degenerate entirely. 3. For GT-1?in the meiosis stage of microspore mothercell, the tapetal cells become peculiarly enlarged and vacuoled?as the result?the microspores disintegrate inside the tetrad or segregate into empty pollens.

Xie Shiwen; Qiu Debo; Wang Zhekui; Kong Weiming

1993-01-01

139

Culture.  

UK PubMed Central (United Kingdom)

This article summarizes the definitions, means, and research of adapting psychotherapy to clients' cultural backgrounds. We begin by reviewing the prevailing definitions of cultural adaptation and providing a clinical example. We present an original meta-analysis of 65 experimental and quasi-experimental studies involving 8,620 participants. The omnibus effect size of d = .46 indicates that treatments specifically adapted for clients of color were moderately more effective with that clientele than traditional treatments. The most effective treatments tended to be those with greater numbers of cultural adaptations. Mental health services targeted to a specific cultural group were several times more effective than those provided to clients from a variety of cultural backgrounds. We recommend a series of research-supported therapeutic practices that account for clients' culture, with culture-specific treatments being more effective than generally culture-sensitive treatments.

Smith TB; Rodríguez MD; Bernal G

2011-02-01

140

A preclinical medical student curriculum to introduce health disparities and cultivate culturally responsive care.  

UK PubMed Central (United Kingdom)

PURPOSE: To evaluate the efficacy of a newly reformed curriculum for teaching culturally responsive care and to build awareness of health and health care disparities in first-year medical students. Secondary outcomes were to determine if a progressive approach to teaching this content would improve not only knowledge of vulnerable groups but also awareness of inherent personal biases and cultural assumptions, which contribute to inequitable care. PROCEDURES: Students enrolled in Social and Cultural Issues in Health Care from October 2009 through December 2009, who agreed to participate, completed pretests and posttests that assessed their awareness and knowledge of culturally responsive care and health disparities. FINDINGS: In 3 of the questions assessing cultural awareness, the participants improved significantly after the course compared to before the course. Participants also significantly improved in 6 of the 7 knowledge-based questions. CONCLUSIONS: Our findings demonstrate that this innovative curriculum was successful in improving students' knowledge of vulnerable populations and health disparities. Our progressive curricular approach also successfully increased participant awareness of health disparities by requiring students to assess the socioeconomic and environmental factors of inequitable care. Additionally, it emphasized a process of continuous self-appraisal in delivering culturally responsive care.

Jarris YS; Bartleman A; Hall EC; Lopez L

2012-09-01

 
 
 
 
141

[Cytological observation of anther abortion and starch distribution of a cytoplasm male sterile pepper (Capsicum annum L.)].  

Science.gov (United States)

A cytoplasm male sterile pepper (Capsicum annum L.) was examined using cytochemical method to study its pollen abortion. Thick sections of both anthers of male sterility line 8214A and its maintainer 8214B at different stages were stained using Periodic Acid-Schiff's (PAS) reaction to detect starch distribution. Anther structure and starch distribution in both anthers of male sterility and maintainer line were similar before the meiosis of microspore mother cells. After meiosis, the size of tapetal cells of fertile anthers of maintainer line increased and became high vacuolation. Abundant small starches appeared in the connective cells from tetrad stage to early stage of microspore development. At the late stage of microspore, the tapetal cells began to degenerate and the starches in the connective cells became large. Bi-cellular pollen synthesized starches after the large vacuole of vegetative cell disappeared, and abundant starches were stored in the mature pollen. In the anthers of male sterile line, meiosis of microspore mother could occurred and the tetrads could be formed in the locule, but the tetrads were extruded together because the locule could not enlarge its space. Finally, the tetrad microspores degenerated. The development of vascular tissue of the sterile anthers was normal and abundant starches were stored in the connective cells, which suggested that the function of plant transporting polysaccharide into anther was normal but tapetum could not transport the polysaccharide into locule. According to our result, the pollen abortion occurred in the tetrad stage and the abnormal development of tapetal cells might be the reason which induced tetrad microspore abortion in this male sterile pepper. PMID:18959002

Qiu, Yi Lan; Liu, Zhu Li; Li, Hong; Chen, Song; Chen, Liang Bi; Tian, Hui Qiao

2008-08-01

142

[Cytological observation of anther abortion and starch distribution of a cytoplasm male sterile pepper (Capsicum annum L.)].  

UK PubMed Central (United Kingdom)

A cytoplasm male sterile pepper (Capsicum annum L.) was examined using cytochemical method to study its pollen abortion. Thick sections of both anthers of male sterility line 8214A and its maintainer 8214B at different stages were stained using Periodic Acid-Schiff's (PAS) reaction to detect starch distribution. Anther structure and starch distribution in both anthers of male sterility and maintainer line were similar before the meiosis of microspore mother cells. After meiosis, the size of tapetal cells of fertile anthers of maintainer line increased and became high vacuolation. Abundant small starches appeared in the connective cells from tetrad stage to early stage of microspore development. At the late stage of microspore, the tapetal cells began to degenerate and the starches in the connective cells became large. Bi-cellular pollen synthesized starches after the large vacuole of vegetative cell disappeared, and abundant starches were stored in the mature pollen. In the anthers of male sterile line, meiosis of microspore mother could occurred and the tetrads could be formed in the locule, but the tetrads were extruded together because the locule could not enlarge its space. Finally, the tetrad microspores degenerated. The development of vascular tissue of the sterile anthers was normal and abundant starches were stored in the connective cells, which suggested that the function of plant transporting polysaccharide into anther was normal but tapetum could not transport the polysaccharide into locule. According to our result, the pollen abortion occurred in the tetrad stage and the abnormal development of tapetal cells might be the reason which induced tetrad microspore abortion in this male sterile pepper.

Qiu YL; Liu ZL; Li H; Chen S; Chen LB; Tian HQ

2008-08-01

143

OsC6, encoding a lipid transfer protein, is required for postmeiotic anther development in rice.  

UK PubMed Central (United Kingdom)

Synthesis of lipidic components in anthers, including of the pollen exine, is essential for plant male reproductive development. Plant lipid transfer proteins (LTPs) are small, abundant lipid-binding proteins that have the ability to exchange lipids between membranes in vitro. However, their biological role in male reproductive development remains less understood. Here, we report the crucial role of OsC6 in regulating postmeiotic anther development in rice (Oryza sativa). Found in monocots, OsC6 belongs to a distinct clade from previously identified LTP1 and LTP2 family members found in both dicots and monocots. OsC6 expression is mainly detectable in tapetal cells and weakly in microspores from stage 9 to stage 11 of anther development. Immunological assays indicated that OsC6 is widely distributed in anther tissues such as the tapetal cytoplasm, the extracellular space between the tapetum and middle layer, and the anther locule and anther cuticle. Biochemical assays indicated that recombinant OsC6 has lipid binding activity. Moreover, plants in which OsC6 was silenced had defective development of orbicules (i.e. Ubisch bodies) and pollen exine and had reduced pollen fertility. Furthermore, additional evidence is provided that the expression of OsC6 is positively regulated by a basic helix-loop-helix transcription factor, Tapetum Degeneration Retardation (TDR). Extra granule-like structures were observed on the inner surface of the tdr tapetal layer when the expression of OsC6 was driven by the TDR promoter compared with the tdr mutant. These data suggest that OsC6 plays a crucial role in the development of lipidic orbicules and pollen exine during anther development in rice.

Zhang D; Liang W; Yin C; Zong J; Gu F; Zhang D

2010-09-01

144

OsC6, encoding a lipid transfer protein, is required for postmeiotic anther development in rice.  

Science.gov (United States)

Synthesis of lipidic components in anthers, including of the pollen exine, is essential for plant male reproductive development. Plant lipid transfer proteins (LTPs) are small, abundant lipid-binding proteins that have the ability to exchange lipids between membranes in vitro. However, their biological role in male reproductive development remains less understood. Here, we report the crucial role of OsC6 in regulating postmeiotic anther development in rice (Oryza sativa). Found in monocots, OsC6 belongs to a distinct clade from previously identified LTP1 and LTP2 family members found in both dicots and monocots. OsC6 expression is mainly detectable in tapetal cells and weakly in microspores from stage 9 to stage 11 of anther development. Immunological assays indicated that OsC6 is widely distributed in anther tissues such as the tapetal cytoplasm, the extracellular space between the tapetum and middle layer, and the anther locule and anther cuticle. Biochemical assays indicated that recombinant OsC6 has lipid binding activity. Moreover, plants in which OsC6 was silenced had defective development of orbicules (i.e. Ubisch bodies) and pollen exine and had reduced pollen fertility. Furthermore, additional evidence is provided that the expression of OsC6 is positively regulated by a basic helix-loop-helix transcription factor, Tapetum Degeneration Retardation (TDR). Extra granule-like structures were observed on the inner surface of the tdr tapetal layer when the expression of OsC6 was driven by the TDR promoter compared with the tdr mutant. These data suggest that OsC6 plays a crucial role in the development of lipidic orbicules and pollen exine during anther development in rice. PMID:20610705

Zhang, Dasheng; Liang, Wanqi; Yin, Changsong; Zong, Jie; Gu, Fangwei; Zhang, Dabing

2010-07-07

145

Exploring the influence of cultural familiarity and expertise on neurological responses to music.  

UK PubMed Central (United Kingdom)

Contemporary music education in many countries has begun to incorporate not only the dominant music of the culture, but also a variety of music from around the world. Although the desirability of such a broadened curriculum is virtually unquestioned, the specific function of these musical encounters and their potential role in children's cognitive development remain unclear. We do not know if studying a variety of world music traditions involves the acquisition of new skills or an extension and refinement of traditional skills long addressed by music teachers. Is a student's familiarity with a variety of musical traditions a manifestation of a single overarching "musicianship" or is knowledge of these various musical styles more similar to a collection of discrete skills much like learning a second language? Research on the comprehension of spoken language has disclosed a neurologically distinct response among subjects listening to their native language rather than an unfamiliar language. In a recent study comparing Western subjects' responses to music of their native culture and music of an unfamiliar culture, we found that subjects' activation did not differ on the basis of the cultural familiarity of the music, but on the basis of musical expertise. We discuss possible interpretations of these findings in relation to the concept of musical universals, cross-cultural stimulus characteristics, cross-cultural judgment tasks, and the influence of musical expertise. We conclude with suggestions for future research.

Demorest SM; Morrison SJ

2003-11-01

146

Exploring the influence of cultural familiarity and expertise on neurological responses to music.  

Science.gov (United States)

Contemporary music education in many countries has begun to incorporate not only the dominant music of the culture, but also a variety of music from around the world. Although the desirability of such a broadened curriculum is virtually unquestioned, the specific function of these musical encounters and their potential role in children's cognitive development remain unclear. We do not know if studying a variety of world music traditions involves the acquisition of new skills or an extension and refinement of traditional skills long addressed by music teachers. Is a student's familiarity with a variety of musical traditions a manifestation of a single overarching "musicianship" or is knowledge of these various musical styles more similar to a collection of discrete skills much like learning a second language? Research on the comprehension of spoken language has disclosed a neurologically distinct response among subjects listening to their native language rather than an unfamiliar language. In a recent study comparing Western subjects' responses to music of their native culture and music of an unfamiliar culture, we found that subjects' activation did not differ on the basis of the cultural familiarity of the music, but on the basis of musical expertise. We discuss possible interpretations of these findings in relation to the concept of musical universals, cross-cultural stimulus characteristics, cross-cultural judgment tasks, and the influence of musical expertise. We conclude with suggestions for future research. PMID:14681123

Demorest, Steven M; Morrison, Steven J

2003-11-01

147

Dynamic cultural modulation of neural responses to one's own and friend's faces.  

UK PubMed Central (United Kingdom)

Long-term cultural experiences influence neural response to one's own and friend's faces. The present study investigated whether an individual's culturally specific pattern of neural activity to faces can be modulated by temporary access to other cultural frameworks using a self-construal priming paradigm. Event-related potentials were recorded from British and Chinese adults during judgments of orientations of one's own and friend's faces after they were primed with independent and interdependent self-construals. We found that an early frontal negative activity at 220-340?ms (the anterior N2) differentiated between one's own and friend's faces in both cultural groups. Most remarkably, for British participants, priming an interdependent self-construal reduced the default anterior N2 to their own faces. For Chinese participants, however, priming an independent self-construal suppressed the default anterior N2 to their friend's faces. These findings indicate fast modulations of culturally specific neural responses induced by temporary access to other cultural frameworks.

Sui J; Hong YY; Hong Liu C; Humphreys GW; Han S

2013-03-01

148

Culture shapes a mesolimbic response to signals of dominance and subordination that associates with behavior.  

UK PubMed Central (United Kingdom)

It has long been understood that culture shapes individuals' behavior, but how this is accomplished in the human brain has remained largely unknown. To examine this, we made use of a well-established cross-cultural difference in behavior: American culture tends to reinforce dominant behavior whereas, conversely, Japanese culture tends to reinforce subordinate behavior. In 17 Americans and 17 Japanese individuals, we assessed behavioral tendencies towards dominance versus subordination and measured neural responses using fMRI during the passive viewing of stimuli related to dominance and subordination. In Americans, dominant stimuli selectively engaged the caudate nucleus, bilaterally, and the medial prefrontal cortex (mPFC), whereas these were selectively engaged by subordinate stimuli in Japanese. Correspondingly, Americans self-reported a tendency towards more dominant behavior whereas Japanese self-reported a tendency towards more subordinate behavior. Moreover, activity in the right caudate and mPFC correlated with behavioral tendencies towards dominance versus subordination, such that stronger responses in the caudate and mPFC to dominant stimuli were associated with more dominant behavior and stronger responses in the caudate and mPFC to subordinate stimuli were associated with more subordinate behavior. The findings provide a first demonstration that culture can flexibly shape functional activity in the mesolimbic reward system, which in turn may guide behavior.

Freeman JB; Rule NO; Adams RB Jr; Ambady N

2009-08-01

149

Response of cellulase activity in pH-controlled cultures of the filamentous fungus Acremonium cellulolyticus.  

Science.gov (United States)

Cellulase production was investigated in pH-controlled cultures of Acremonium cellulolyticus. The response to culture pH was investigated for three cellulolytic enzymes, carbomethyl cellulase (CMCase), avicelase, and beta-glucosidase. Avicelase and beta-glucosidase showed similar profiles, with maximum activity in cultures at pH 5.5-6. The CMCase activity was highest in a pH 4 culture. At an acidic pH, the ratios of CMCase and avicelase activity to cellulase activity defined by filter paper unit were high, but at a neutral pH, the beta-glucosidase ratio was high. The pH 6.0 culture showed the highest cellulase activity within the range of pH 3.5-6.5 cultures. The saccharification activity from A. cellulolyticus was compared to those of the cellulolytic enzymes from other species. The A. cellulolyticus culture broth had a saccharification yield comparable to those of the Trichoderma enzymes GC220 and Cellulosin T2, under conditions with the same cellulase activity. The saccharification yields from Solka floc, Avicel, and waste paper, measured as the percent of released reducing sugar to dried substrate, were greater than 80% after 96 h of reaction. The yields were 16% from carboxymethylcellulose and 26% from wood chip refiner. Thus, the A. cellulolyticus enzymes were suitable for converting cellulolytic biomass to reducing sugars for biomass ethanol production. This study is a step toward the establishment of an efficient system to reutilize cellulolytic biomass. PMID:19882113

Prasetyo, Joni; Sumita, Shyuuhei; Okuda, Naoyuki; Park, Enoch Y

2009-11-01

150

Response of cellulase activity in pH-controlled cultures of the filamentous fungus Acremonium cellulolyticus.  

UK PubMed Central (United Kingdom)

Cellulase production was investigated in pH-controlled cultures of Acremonium cellulolyticus. The response to culture pH was investigated for three cellulolytic enzymes, carbomethyl cellulase (CMCase), avicelase, and beta-glucosidase. Avicelase and beta-glucosidase showed similar profiles, with maximum activity in cultures at pH 5.5-6. The CMCase activity was highest in a pH 4 culture. At an acidic pH, the ratios of CMCase and avicelase activity to cellulase activity defined by filter paper unit were high, but at a neutral pH, the beta-glucosidase ratio was high. The pH 6.0 culture showed the highest cellulase activity within the range of pH 3.5-6.5 cultures. The saccharification activity from A. cellulolyticus was compared to those of the cellulolytic enzymes from other species. The A. cellulolyticus culture broth had a saccharification yield comparable to those of the Trichoderma enzymes GC220 and Cellulosin T2, under conditions with the same cellulase activity. The saccharification yields from Solka floc, Avicel, and waste paper, measured as the percent of released reducing sugar to dried substrate, were greater than 80% after 96 h of reaction. The yields were 16% from carboxymethylcellulose and 26% from wood chip refiner. Thus, the A. cellulolyticus enzymes were suitable for converting cellulolytic biomass to reducing sugars for biomass ethanol production. This study is a step toward the establishment of an efficient system to reutilize cellulolytic biomass.

Prasetyo J; Sumita S; Okuda N; Park EY

2010-09-01

151

Investigating the effect of heavy metals on developmental stages of anther and pollen in Chenopodium botrys L. (Chenopodiaceae).  

UK PubMed Central (United Kingdom)

Excessive amounts of heavy metals adversely affect plant growth and development. Whereas some regions naturally contain high levels of heavy metals, anthropogenic release of heavy metals into the environment continuously increases soil contamination. Preliminary studies have shown that Chenopodium botrys can grow in some heavy metal contaminated soils and is a high accumulator plant species for Cu and moderately accumulator plant species for Fe, Mn, and Zn, thus, was considered as an important species in this study. Based on that, in this species, we studied the individual effects of heavy metals on the formation, development, and structure of anther and pollen. To achieve this purpose, surrounding area of Hame-Kasi iron and copper mine (Hamedan, Iran) was chosen as a polluted area where the amount of some heavy metals was several times higher than the natural soils. Flowers and young pods were removed from non-polluted and polluted plants, fixed in FAA 70, and subjected to developmental studies. Analysis of anther development in plants from contaminated sites showed general similarities in the pattern of pollen formation with those from non-polluted ones, but also deviation from typical form of major stages of anther and pollen development was seen in plants from polluted ones. Stabilizing of tapetum layer, increasing in tapetum layer numbers, thickening callose wall in the microspore mother cell stage, changing the anther shape, and decreasing the size of anther were the effects of heavy metals. Reduction of pollen number was also seen in the plants collected from polluted area.

Yousefi N; Chehregani A; Malayeri B; Lorestani B; Cheraghi M

2011-06-01

152

Developing Sociopolitical Consciousness at Freedom Schools: Implications for Culturally Responsive Teacher Preparation  

Science.gov (United States)

This article describes the programmatic ways in which the Children's Defense Fund Freedom Schools[R] program develops culturally responsive teaching practices amongst its summer interns, particularly in the area of developing sociopolitical consciousness. This paper places specific focus on the role that historical knowledge, the acknowledgement…

Jackson, Tambra O.

2011-01-01

153

Writing the Male Abuser in Cultural Responses to Domestic Violence in Spain  

Science.gov (United States)

The article analyzes the portrayal of the male perpetrator of heterosexual domestic violence in a selection of contemporary Spanish texts (novel, drama, and autobiography) that form part of a clearly discernible cultural response to the issue of intimate partner violence in Spain today. It reads the figure of the abuser in conjunction with a range…

Godsland, Shelley

2012-01-01

154

Fabrication of transplantable corneal epithelial and oral mucosal epithelial cell sheets using a novel temperature-responsive closed culture device.  

UK PubMed Central (United Kingdom)

Temperature-responsive culture surfaces make it possible to harvest transplantable carrier-free cell sheets. Here, we applied temperature-responsive polymer for polycarbonate surfaces with previously developed closed culture devices for an automated culture system in order to fabricate transplantable stratified epithelial cell sheets. Histological and immunohistochemical analyses and colony-forming assays revealed that corneal epithelial and oral mucosal epithelial cell sheets could be harvested with the temperature-responsive closed culture devices. The results were similar to those obtained using temperature-responsive culture inserts. These results indicate that the novel temperature-responsive closed culture device is useful for fabricating transplantable stratified epithelial cell sheets. Copyright © 2013 John Wiley & Sons, Ltd.

Nakajima R; Kobayashi T; Kikuchi T; Kitano Y; Watanabe H; Mizutani M; Nozaki T; Senda N; Saitoh K; Takagi R; Yamato M; Okano T; Takeda S

2013-03-01

155

EFFECTS ON FITNESS AND BEHAVIOR OF MONARCH BUTTERFLY LARVAE EXPOSED TO A COMBINATION OF CRY1AB-EXPRESSING CORN ANTHERS AND POLLEN  

Science.gov (United States)

Anthers and pollen from corn, Zea mays L., expressing Bacillus thuringiensis (Bt) derived protein frequently fall onto common milkweed, Asclepias syriaca L., growing in and near corn fields. Previous studies have shown that alone, Bt anthers do not pose a significant risk to the monarch butterfly, D...

156

Enhancing cultural responsiveness: the development of a pilot transcultural secondary consultation program.  

UK PubMed Central (United Kingdom)

OBJECTIVE: This paper describes the development of a pilot secondary consultation program by a state-wide transcultural psychiatry unit, Victorian Transcultural Mental Health (VTMH), in partnership with a rural mental health service, Goulburn Valley Area Mental Health Service (GVAMHS), and the responses of the clinicians who participated. METHOD: A series of eight consultations were facilitated by the VTMH in 2010 and attended by a total of 57 GVAMHS clinicians; five sessions were conducted face-to-face and three by videoconference. Facilitators recorded the details of discussions at each session. Participants and facilitators offered feedback that was analysed to improve the quality of cultural responsiveness at GVAMHS. RESULTS: Participants from a range of disciplines provided consistently positive feedback. The sessions provided an effective forum for discussing cultural formulations and culturally sensitive approaches to working with individuals and their families. CONCLUSIONS: This pilot secondary consultation program provided clinicians in a rural area with a forum in which to reflect on cross-cultural mental health issues. This pilot has informed the development of subsequent VTMH cultural consultation services.

McDonough S; Chopra P; Tuncer C; Schumacher B; Bhat R

2013-08-01

157

CULTURE  

UK PubMed Central (United Kingdom)

Provided is an aquiculture device using wet fog in which culture fluid and pure water are alternately sprayed by two spraying device, room humidification effect is provided by device of spraying pure water, and device of spraying the culture fluid is washed with water, and thus vibrator is not impaired by the culture fluid. The aquiculture device comprises a body(1) a water storage part(2) for storing a pure water at the bottom of the body(1) a culture fluid storage part(3) at the upper part of one side of the body(1) a culturing room(4) formed at the upper part of the other side of the body(1) a double structure of support layer(41) and a filtering layer(42) which have space(43) therebetween a first spray device(5) and a second spray device(6) installed in the water storage part(2). In the device, pure water and culture fluid are alternately supplied from the water storage part(2) and the culture fluid storage part(3).

CHOI JIN YOUNG; PARK DEOK JAE

158

Callus induction and embryo regeneration in Coffea arabica L. anthers by silver nitrate and ethylene/ Indução de calos e regeneração de embriões em anteras de Coffea arabica L. por nitrato de prata e etileno  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O melhoramento genético do cafeeiro por métodos convencionais é um processo demorado para aquisição de uma nova cultivar. Através da cultura de anteras podem-se obter linhagens homozigóticas rapidamente, oriundas de dihaplóides. O objetivo foi utilizar na cultura de anteras na cv. Catuaí Vermelho 99 de Coffea arabica L., nitrato de prata (AgNO3) e etileno para induzir a formação de calos e regenerar plântulas dihaplóides. As anteras foram inoculadas em meio M (more) S acrescido de 2 mg L-1 de 2,4-D com e sem AgNO3 (5 mg L-1), juntamente com etileno por diferentes dias: (testemunha; 2; 4; 6, e 8). Ao final de 12 dias, estas foram transferidas para o meio de regeneração, acrescido de 0,108 mg L-1 de cinetina. Foi observada uma oxidação e intumescimento maior nos primeiros dias de inoculação em exposição ao etileno, e a cv. Catuaí Vermelho 99 respondeu a formação de calos e também a embriogênese direta na presença do etileno. Abstract in english The genetic breeding of coffee by conventional methods to obtain new cultivars is time-consuming. Anther culture can yield homozygous lines quickly from bi-haploids. This study used anther cultures of Coffea arabica L. cv. Catuaí Vermelho 99, and tested the effect of silver nitrate (AgNO3) and ethylene in callus-formation induction and bi-haploid seedling regeneration. The anthers were inoculated in MS to which 2 mg L-1 2,4-D had been added with AgNO3 (5 mg L-1) together (more) with ethylene being introduced or not, for different periods (the control, 2, 4, 6, and 8 days). At the end of 12 days, the anthers were transferred to the regeneration medium, to which 0.108 mg L-1 kinetin had been added. Greater oxidation and intumescence were observed in the first days after exposure to ethylene; the cultivar Catuaí Vermelho 99 responded to callus formation and also direct embryogenesis in the presence of ethylene.

Silva, Adelaide Siqueira; Luz, José Magno Queiroz; Rodrigues, Tatiana Michlovská; Bittar, Cecília Alves; Lino, Leandro de Oliveira

2011-12-01

159

In vitro culture response of barley (Hordeum vulgare) ethylene synthesis mutant MC 169  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Although it is generally accepted that plant in vitro culture response is influenced by the donor genotype, the genetic and molecular bases of this phenomenon are barely known. As a consequence, the optimization of tissue culture protocols is mainly empirically done. Researchers of the IGEAF studied the genetic basis of the in vitro regeneration of various plant species, including the tissue culture response of artificially induced barley mutants. One barley mutant, MC 16 (more) 9, carries a nuclear gene, recently described controlling the root growth in hydroponic cultivation. Under this condition, the roots of MC 169 mutant plants were longer than those of the original wild type line MC 182, a fact that was associated with a reduced ethylene biosynthesis. On the other hand, it is known that ethylene accumulation is inhibitory for in vitro regeneration of several plant species. In this study, we compared the in vitro culture response of mutant MC 169 with that of its mother line MC 182. The data about induction and regeneration of calli as well as those of habituated calli formation demonstrated that mutant MC 169 and its mother line MC 182 show a similar in vitro behaviour.

Biagioli, Carolina; Rios, Raúl; Basso, Alicia; Franzone, Pascual; Prina, Alberto

2006-06-01

160

Nutritional lipid supply can control the heat shock response of B16 melanoma cells in culture.  

UK PubMed Central (United Kingdom)

The in vitro culture of cells offers an extremely valuable method for probing biochemical questions and many commonly-used protocols are available. For mammalian cells a source of lipid is usually provided in the serum component. In this study we examined the question as to whether the nature of the lipid could become limiting at high cell densities and, therefore, prospectively influence the metabolism and physiology of the cells themselves. When B16 mouse melanoma cells were cultured, we noted a marked decrease in the proportions of n-3 and n-6 polyunsaturated fatty acids (PUFAs) with increasing cell density. This was despite considerable quantities of these PUFAs still remaining in the culture medium and seemed to reflect the preferential uptake of unesterified PUFA rather than other lipid classes from the media. The reduction in B16 total PUFA was reflected in changes in about 70% of the molecular species of membrane phosphoglycerides which were analysed by mass spectrometry. The importance of this finding lies in the need for n-3 and n-6 PUFA in mammalian cells (which cannot synthesize their own). Although the cholesterol content of cells was unchanged the amount of cholesterol enrichment in membrane rafts (as assessed by fluorescence) was severely decreased, simultaneous with a reduced heat shock response following exposure to 42°C. These data emphasize the pivotal role of nutrient supply (in this case for PUFAs) in modifying responses to stress and highlight the need for the careful control of culture conditions when assessing cellular responses in vitro.

Péter M; Balogh G; Gombos I; Liebisch G; Horváth I; Török Z; Nagy E; Maslyanko A; Benk? S; Schmitz G; Harwood JL; Vígh L

2012-11-01

 
 
 
 
161

Primary culture of adult mouse lung fibroblasts in serum-free medium: responses to growth factors.  

UK PubMed Central (United Kingdom)

We report a completely serum-free system for primary culture of fibroblasts from explants of adult mouse lung tissue which permits bioassays for cytokine activity to be performed using unselected populations of cells at low passage number, without interference by serum binding proteins or interacting growth factors. Cultures were established on collagen-coated surfaces in medium MCDB 201 containing albumin, transferrin, epidermal growth factor, lipids, prostaglandin E1, vitamin E, and reducing agents. The cells were morphologically and ultrastructurally typical of fibroblasts in culture and demonstrated expression of vimentin and induction of expression of desmin in culture. Proliferation of the cells was reproducible between different primary cultures and was growth factor dependent. Both cycling and growth-arrested cells exhibited increased DNA synthesis when stimulated with epidermal growth factor, platelet-derived growth factor, or basic fibroblast growth factor, which functioned as complete mitogens, but did not respond to insulin, tumor necrosis factor or interleukin-1 beta. Maximal induction of DNA synthesis by epidermal growth factor required the continued presence of the mitogen in the culture medium. These results cannot be satisfactorily explained by the competence-progression model of responses to mitogenic stimuli but support and extend the findings of other studies using diploid fibroblasts.

Kumar RK; O'Grady R; Li W; Smith LW; Rhodes GC

1991-04-01

162

Primary culture of adult mouse lung fibroblasts in serum-free medium: responses to growth factors.  

Science.gov (United States)

We report a completely serum-free system for primary culture of fibroblasts from explants of adult mouse lung tissue which permits bioassays for cytokine activity to be performed using unselected populations of cells at low passage number, without interference by serum binding proteins or interacting growth factors. Cultures were established on collagen-coated surfaces in medium MCDB 201 containing albumin, transferrin, epidermal growth factor, lipids, prostaglandin E1, vitamin E, and reducing agents. The cells were morphologically and ultrastructurally typical of fibroblasts in culture and demonstrated expression of vimentin and induction of expression of desmin in culture. Proliferation of the cells was reproducible between different primary cultures and was growth factor dependent. Both cycling and growth-arrested cells exhibited increased DNA synthesis when stimulated with epidermal growth factor, platelet-derived growth factor, or basic fibroblast growth factor, which functioned as complete mitogens, but did not respond to insulin, tumor necrosis factor or interleukin-1 beta. Maximal induction of DNA synthesis by epidermal growth factor required the continued presence of the mitogen in the culture medium. These results cannot be satisfactorily explained by the competence-progression model of responses to mitogenic stimuli but support and extend the findings of other studies using diploid fibroblasts. PMID:2004652

Kumar, R K; O'Grady, R; Li, W; Smith, L W; Rhodes, G C

1991-04-01

163

Endothelial invasive response in a co-culture model with physically-induced osteodifferentiation.  

UK PubMed Central (United Kingdom)

Manipulation of stem cells using physicochemical stimuli has emerged as an important tool in regenerative medicine. While 2D substrates with tunable elasticity have been studied for control of stem cell differentiation, we recently developed a stratified co-culture model of angiogenesis of human mesenchymal stem cells (hMSCs) that differentiate on a tunable polydimethylsiloxane (PDMS) substrate, thereby creating a physiologic context for elasticity-induced differentiation. Endothelial cells (EC) were cultured on top of the hMSC construct on a collagen gel to monitor network formation. Media composition influenced EC invasion due to the conditioning media, the reduction of serum and supplemental growth factors, and the addition of recombinant growth factors. Conditioned media, recombinant growth factors and direct co-culture were compared for endothelial cell invasive response using quantitative image analysis. As anticipated, use of recombinant vascular endothelial growth factor (VEGF) induced the deepest EC invasions while direct co-culture caused shallow invasions compared to other conditions. However, endothelial cells displayed lumen-like morphology, suggesting that cell-cell interaction in the co-culture model could mimic sprouting behaviour. In summary, an engineered suitable biochemical and physical environment facilitated endothelial cells to form 3D vessel structures onto hMSCs. These structures were plated on a stiff surface known to induce osteodifferentiation of stem cells. This low cost co-culture system, with its minimal chemical supplementation and physically controllable matrix, could potentially model in vivo potential in engineered and pre-vascularized bone grafts.

Traphagen SB; Titushkin I; Sun S; Wary KK; Cho M

2013-08-01

164

Small Business Responsiveness and Organizational Culture in the Context of a Developing Economy  

Directory of Open Access Journals (Sweden)

Full Text Available The paper examines the relationship between two important variables that define small and medium-sized enterprises: organizational culture and responsiveness. Firms operating in Romania were selected for the study. The country offers a business context with many changes over the last two decades, a challenge and an opportunity for researchers. Results show that the combination of entrepreneurial characteristics and planning and goal oriented managerial styles suits best successful companies. The market-driven type of culture has the best coordination and is best positioned to deliver customer-centered versatility, while adhocracy helps businesses respond fast to changes in the market environment.

Michael STOICA; Liviu FLOREA; Edit LUKÁCS

2012-01-01

165

On the Value of Traditional Confucian Culture And the Value of Modern Corporate Social Responsibility  

Directory of Open Access Journals (Sweden)

Full Text Available The core values of the Chinese Confucian Culture such as “humanity, righteousness, harmony, courtesy, honesty and cleanness” represent the soul of five-thousand-years Chinese traditional culture, which may represent the value of maintaining the balanced social benefits and harmonious development of the whole society from the prospective of a whole society, and which may also have some important uses for reference and roles of enlightenment for establishing the values of modern corporate social responsibility if it is effectively integrated into the practice of modern business management.

Wenzhong Zhu; Yucheng Yao

2009-01-01

166

Writing the male abuser in cultural responses to domestic violence in Spain.  

UK PubMed Central (United Kingdom)

The article analyzes the portrayal of the male perpetrator of heterosexual domestic violence in a selection of contemporary Spanish texts (novel, drama, and autobiography) that form part of a clearly discernible cultural response to the issue of intimate partner violence in Spain today. It reads the figure of the abuser in conjunction with a range of primarily Spanish studies on domestic aggression, with the aim of showing how and why the chosen authors engage with bodies of theory that address battery. The study concludes that some cultural producers devise a strategy of eliding the male aggressor in an attempt to subvert the power he wields over the female victim.

Godsland S

2012-01-01

167

Exploring the Relationship between Self-Awareness and Student Commitment and Understanding of Culturally Responsive Social Work Practice.  

UK PubMed Central (United Kingdom)

This study explores the relationship between self-awareness and social work students' commitment and understanding of culturally responsive social work practice. Data consisted of assigned papers (N = 23), submitted by graduate social work students, which asked them to describe their ethnic/racial background and ancestors' process of assimilation, and to reflect on their ethnic and racial identity as a means toward increased self-awareness and future culturally responsive practice. Content analysis revealed 11 themes, including students' enlightenment of their privilege, experiences of cultural loss, and acknowledgment of biases as integral parts of culturally responsive practice. Implications for social work education and research are addressed.

Bender K; Negi N; Fowler DN

2010-01-01

168

The Effect of Institutional Culture on Change Strategies in Higher Education: Universal Principles or Culturally Responsive Concepts?  

Science.gov (United States)

This study examined the impact of institutional culture on the change process within colleges and universities. It used an ethnographic approach and two tiered cultural frameworks to investigate comprehensive change at six institutions. The conceptual frameworks of culture used were Berquist's theory of institutional archetypes of culture and…

Kezar, Adrianna; Eckel, Peter

169

Proteome analysis of the wild and YX-1 male sterile mutant anthers of wolfberry (Lycium barbarum L.).  

Science.gov (United States)

Pollen development is disturbed in the early tetrad stage of the YX-1 male sterile mutant of wolfberry (Lycium barbarum L.). The present study aimed to identify differentially expressed anther proteins and to reveal their possible roles in pollen development and male sterility. To address this question, the proteomes of the wild-type (WT) and YX-1 mutant were compared. Approximately 1760 protein spots on two-dimensional differential gel electrophoresis (2D-DIGE) gels were detected. A number of proteins whose accumulation levels were altered in YX-1 compared with WT were identified by mass spectrometry and the NCBInr and Viridiplantae EST databases. Proteins down-regulated in YX-1 anthers include ascorbate peroxidase (APX), putative glutamine synthetase (GS), ATP synthase subunits, chalcone synthase (CHS), CHS-like, putative callose synthase catalytic subunit, cysteine protease, 5B protein, enoyl-ACP reductase, 14-3-3 protein and basic transcription factor 3 (BTF3). Meanwhile, activities of APX and GS, RNA expression levels of apx and atp synthase beta subunit were low in YX-1 anthers which correlated with the expression of male sterility. In addition, several carbohydrate metabolism-related and photosynthesis-related enzymes were also present at lower levels in the mutant anthers. In contrast, 26S proteasome regulatory subunits, cysteine protease inhibitor, putative S-phase Kinase association Protein 1(SKP1), and aspartic protease, were expressed at higher levels in YX-1 anthers relative to WT anthers. Regulation of wolfberry pollen development involves a complex network of differentially expressed genes. The present study lays the foundation for future investigations of gene function linked with wolfberry pollen development and male sterility. PMID:22860020

Zheng, Rui; Sijun Yue; Xu, Xiaoyan; Liu, Jianyu; Xu, Qing; Wang, Xiaolin; Han, Lu; Yu, Deyue

2012-07-30

170

Proteome analysis of the wild and YX-1 male sterile mutant anthers of wolfberry (Lycium barbarum L.).  

UK PubMed Central (United Kingdom)

Pollen development is disturbed in the early tetrad stage of the YX-1 male sterile mutant of wolfberry (Lycium barbarum L.). The present study aimed to identify differentially expressed anther proteins and to reveal their possible roles in pollen development and male sterility. To address this question, the proteomes of the wild-type (WT) and YX-1 mutant were compared. Approximately 1760 protein spots on two-dimensional differential gel electrophoresis (2D-DIGE) gels were detected. A number of proteins whose accumulation levels were altered in YX-1 compared with WT were identified by mass spectrometry and the NCBInr and Viridiplantae EST databases. Proteins down-regulated in YX-1 anthers include ascorbate peroxidase (APX), putative glutamine synthetase (GS), ATP synthase subunits, chalcone synthase (CHS), CHS-like, putative callose synthase catalytic subunit, cysteine protease, 5B protein, enoyl-ACP reductase, 14-3-3 protein and basic transcription factor 3 (BTF3). Meanwhile, activities of APX and GS, RNA expression levels of apx and atp synthase beta subunit were low in YX-1 anthers which correlated with the expression of male sterility. In addition, several carbohydrate metabolism-related and photosynthesis-related enzymes were also present at lower levels in the mutant anthers. In contrast, 26S proteasome regulatory subunits, cysteine protease inhibitor, putative S-phase Kinase association Protein 1(SKP1), and aspartic protease, were expressed at higher levels in YX-1 anthers relative to WT anthers. Regulation of wolfberry pollen development involves a complex network of differentially expressed genes. The present study lays the foundation for future investigations of gene function linked with wolfberry pollen development and male sterility.

Zheng R; Sijun Yue; Xu X; Liu J; Xu Q; Wang X; Han L; Yu D

2012-01-01

171

Rat Sertoli cells acquire a. beta. -adrenergic response during primary culture  

Energy Technology Data Exchange (ETDEWEB)

Two-dimensional polyacrylamide gel electrophoresis and the radioligand (-)-(/sup 125/I)iodopindolol (/sup 125/I-Pin) have been used to study isoproterenol-dependent protein phosphorylation and ..beta..-adrenergic receptor availability, respectively, in cultured Sertoli cells and freshly isolated seminiferous tubular segments of sexually immature and mature rats. Sertoli cells prepared from sexually immature rats show progressive /sup 125/I-Pin binding in primary cultures that correlates with isoproterenol-induced cell shape changes, redistribution of immunoreactive vimentin, and phosphorylation of this intermediate filament protein. Seminiferous tubules do not show significant isoproterenol-dependent vimentin phosphorylation nor /sup 125/I-Pin binding. However, vimentin phosphorylation can be induced by follicle-stimulating hormone or a cyclic nucleotide analog. This study stresses the need for correlating pharmacological-induced responses observed in Sertoli cell primary cultures with those in the intact seminiferous tubule.

Kierszenbaum, A.L.; Spruill, W.A.; White, M.G.; Tres, L.L.; Perkins, J.P.

1985-04-01

172

The response of mineralizing culture systems to microtextured and polished titanium surfaces.  

Science.gov (United States)

The surface texture of titanium has a predictable effect on peri-implant tissue formation in vivo. When implanted in an osseous environment, smooth surfaces (R(a) 1.0 mm) are generally apposed by osseous tissue. Thus in vitro study assessed the mineralization and proliferation response of TF274, MC3T3-E1, murine femoral stromal cells and canine stromal cells to tissue culture plastic (R(a) = 0.001 mm), polished (R(a) = 0.01 mm) and irregularly textured (R(a) = 3.26 mm) titanium surfaces. Amongst all culture systems, proliferation was significantly decreased on textured vs. smooth surfaces. Midway through the culture of the canine marrow cells, the cell layer detached from the tissue culture plastic and polished titanium surfaces. The TF274, MC3T3-E1, murine femoral stromal cell systems formed a mineralized matrix on the tissue culture plastic and polished titanium surfaces which was not observed with the canine stromal cell system. Compared to the tissue culture plastic and polished titanium surfaces, matrix mineralization was significantly reduced on the textured titanium surfaces for the TF274, MC3T3-E1, murine femoral stromal systems, a result which was differed significantly in comparison to the canine stromal system. These results were surprising given the large number of reports concerning the in vivo response to titanium in clinical and pre-clinical studies. Further work is required to determine if the TF274, MC3T3-E1 and murine femoral stromal systems are suitable for the in vitro investigation of the effects of titanium surface texture on osteoblast activity. PMID:18404719

Hacking, S Adam; Harvey, Edward; Roughley, Peter; Tanzer, Michael; Bobyn, John

2008-10-01

173

Responsive hydrogels produced via organic sol-gel chemistry for cell culture applications.  

UK PubMed Central (United Kingdom)

In this study, we report the synthesis of novel environmentally responsive polyurea hydrogel networks prepared via organic sol-gel chemistry and demonstrate that the networks can stabilize pH while releasing glucose both in simple aqueous media and in mammalian cell culture settings. Hydrogel formulations have been developed based on the combination of an aliphatic triisocyanate with pH-insensitive amine functional polyether and pH-sensitive poly(ethyleneimine) segments in a minimally toxic solvent suitable for the sol-gel reaction. The polyether component of the polyurea network is sufficiently hydrophilic to give rise to some level of swelling independent of environmental pH, while the poly(ethyleneimine) component contains tertiary amine groups providing pH sensitivity to the network in the form of enhanced swelling and release under acidic conditions. The reaction of these materials to form a network is rapid and requires no catalyst. The resultant material exhibits the desired pH-responsive swelling behavior and demonstrates its ability to simultaneously neutralize lactic acid and release glucose in both cell-free culture media and mammalian cell culture, with no detectable evidence of cytotoxicity or changes in cell behavior, in the case of either SA-13 human hybridomas or mouse embryonic stem cells. Furthermore, pH is observed to have a clear effect on the rate at which glucose is released from the hydrogel network. Such characteristics promise to maintain a favorable cell culture environment in the absence of human intervention.

Patil S; Chaudhury P; Clarizia L; McDonald M; Reynaud E; Gaines P; Schmidt DF

2012-08-01

174

Enzymatic responses to radiation in cultured vascular endothelial and smooth muscle cells  

Energy Technology Data Exchange (ETDEWEB)

Confluent monolayers of bovine aortic endothelial and smooth muscle cells were exposed to 0-5.0 Gy of /sup 60/Co ..gamma.. rays. From 0 to 72 hr after irradiation, the monolayer and culture medium were analyzed for cell (nuclei) number, DNA and protein content, the activities of angiotensin converting enzyme (ACE), lactate dehydrogenase (LDH), and superoxide dismutase (SOD), and LDH isoenzyme profile. Irradiated endothelial cells exhibited a time- and dose-dependent increase in cell detachment, decreased DNA and protein content and reduced ACE activity per attached cell, increased LDH and SOD activities per microgram of DNA, and increased LDH activity in the culture medium. The release of LDH activity, observed after 0.5 Gy, was the most sensitive endothelial response, and occurred independent of or preceding cell detachment. Vascular smooth muscle cells contained two or three times more SOD activity than did endothelial cells and exhibited no significant responses to 5.0 Gy.

Rubin, D.B.; Drab, E.A.; Ward, W.F.; Smith, L.J.; Fowell, S.M.

1984-08-01

175

Temperament trait of sensory processing sensitivity moderates cultural differences in neural response.  

Science.gov (United States)

This study focused on a possible temperament-by-culture interaction. Specifically, it explored whether a basic temperament/personality trait (sensory processing sensitivity; SPS), perhaps having a genetic component, might moderate a previously established cultural difference in neural responses when making context-dependent vs context-independent judgments of simple visual stimuli. SPS has been hypothesized to underlie what has been called inhibitedness or reactivity in infants, introversion in adults, and reactivity or responsivness in diverse animal species. Some biologists view the trait as one of two innate strategies-observing carefully before acting vs being first to act. Thus the central characteristic of SPS is hypothesized to be a deep processing of information. Here, 10 European-Americans and 10 East Asians underwent functional magnetic resonance imaging while performing simple visuospatial tasks emphasizing judgments that were either context independent (typically easier for Americans) or context dependent (typically easier for Asians). As reported elsewhere, each group exhibited greater activation for the culturally non-preferred task in frontal and parietal regions associated with greater effort in attention and working memory. However, further analyses, reported here for the first time, provided preliminary support for moderation by SPS. Consistent with the careful-processing theory, high-SPS individuals showed little cultural difference; low-SPS, strong culture differences. PMID:20388694

Aron, Arthur; Ketay, Sarah; Hedden, Trey; Aron, Elaine N; Rose Markus, Hazel; Gabrieli, John D E

2010-04-13

176

Temperament trait of sensory processing sensitivity moderates cultural differences in neural response.  

UK PubMed Central (United Kingdom)

This study focused on a possible temperament-by-culture interaction. Specifically, it explored whether a basic temperament/personality trait (sensory processing sensitivity; SPS), perhaps having a genetic component, might moderate a previously established cultural difference in neural responses when making context-dependent vs context-independent judgments of simple visual stimuli. SPS has been hypothesized to underlie what has been called inhibitedness or reactivity in infants, introversion in adults, and reactivity or responsivness in diverse animal species. Some biologists view the trait as one of two innate strategies-observing carefully before acting vs being first to act. Thus the central characteristic of SPS is hypothesized to be a deep processing of information. Here, 10 European-Americans and 10 East Asians underwent functional magnetic resonance imaging while performing simple visuospatial tasks emphasizing judgments that were either context independent (typically easier for Americans) or context dependent (typically easier for Asians). As reported elsewhere, each group exhibited greater activation for the culturally non-preferred task in frontal and parietal regions associated with greater effort in attention and working memory. However, further analyses, reported here for the first time, provided preliminary support for moderation by SPS. Consistent with the careful-processing theory, high-SPS individuals showed little cultural difference; low-SPS, strong culture differences.

Aron A; Ketay S; Hedden T; Aron EN; Rose Markus H; Gabrieli JD

2010-06-01

177

[Functions of ANAC092 involved in regulation of anther development in Arabidopsis thaliana].  

UK PubMed Central (United Kingdom)

NAC family is a class of transcription factors that have been typically found in plant with various functions. This type of genes plays a key regulatory role in secondary plant growth, cell division, senescence, especially in the hormone and signaling pathways. ANAC092 was reported to function in relation to lateral root development and senescence. The promoter and in situ hybridization analyses showed that ANAC092 was expressed temporally in the process of anther development. The gene was expressed in tapetum at stages 8-11 of anther development and reached the highest amount at stages 9-10, which was overlapped with the expression period of AMS (Aborted microspores). In this study, we constructed ANAC092 over-expression system, and identified homozygous transgenic lines. Compared with the wild type, the number of pollen grains in the transgenic line was decreased significantly, but the length of pollen grain was increased. qRT-PCR analysis showed that the expression of genes related to pollen development, e.g., SPL, EMS1, DYT1, and AMS was in-creased in the over-expression plants. Bioinformatics results showed that ANAC092 promoter sequence possessed seven AMS binding sites. All the results showed that ANAC092 is possibly located in the downstream of AMS and plays an im-portant role in the process of pollen development.

Li J; Chen X; Luo LQ; Yu J; Ming F

2013-07-01

178

Functional monoecy due to delayed anther dehiscence: a novel mechanism in Pseuduvaria mulgraveana (Annonaceae).  

Science.gov (United States)

Unlike most genera in the early-divergent angiosperm family Annonaceae, Pseuduvaria exhibits a diversity of floral sex expression. Most species are structurally andromonoecious (or possibly androdioecious), although the hermaphroditic flowers have been inferred to be functionally pistillate, with sterile staminodes. Pseuduvaria presents an ideal model for investigating the evolution of floral sex in early-divergent angiosperms, although detailed empirical studies are currently lacking. The phenology and pollination ecology of the Australian endemic species Pseuduvaria mulgraveana are studied in detail, including evaluations of floral scent chemistry, pollen viability, and floral visitors. Results showed that the flowers are pollinated by small diurnal nitidulid beetles and are protogynous. Pollen from both hermaphroditic and staminate flowers are shown to be equally viable. The structurally hermaphroditic flowers are nevertheless functionally pistillate as anther dehiscence is delayed until after petal abscission and hence after the departure of pollinators. This mechanism to achieve functional unisexuality of flowers has not previously been reported in angiosperms. It is known that protogyny is widespread amongst early-divergent angiosperms, including the Annonaceae, and is effective in preventing autogamy. Delayed anther dehiscence represents a further elaboration of this, and is effective in preventing geitonogamy since very few sexually mature flowers occur simultaneously in an individual. We highlight the necessity for field-based empirical interpretations of functional floral sex expression prior to evaluations of evolutionary processes. PMID:23555844

Pang, Chun-Chiu; Scharaschkin, Tanya; Su, Yvonne C F; Saunders, Richard M K

2013-03-26

179

Method for RNA isolating from anthers of Xanthoceras sorbi-folia Bunge  

UK PubMed Central (United Kingdom)

Method for RNA isolating from anthers of Xanthoceras sorbifolia Bunge by the methods of TRIZOL ar-agent,Guanidine Thiocyanate and CTAB and estabilsh the method of RNA isolation suitable for anthers of Xan-thoceras sorbifolia Bunge through the rate of yield,purity,electrophoresis and DDRT-PCR of RNA.The result shows that there are three clear bands--28SrRNA,18s rRNA and 5S rRNA respectively--and ilttle RNA de-composes by the method of CTAB reagent,but,but RNAs isolated by the two other methods disperse in the pattern of small molecular instead of bands.And the purity of the former is higher than that of the altters.its ratio of A-260/A-280is1.944and the value of A-260/A-230 is 2.165 RNA isolated by the methods of TRIZOLreagent and Guani-dine Thiocyanate decompose seriously into lmall molecular,mixed with salt ion.Data of mRNA differential dis-play show that there are ideal amplified bands using the RNA isolated by the metnod of CTABreagent 14?

Du Xihua; Lu Hai; Gao Shumin; Li Fenglan

2003-01-01

180

Down-regulation of phosphatidylinositol response to BDNF and NT-3 in cultures of cortical neurons.  

Science.gov (United States)

The hydrolysis of phosphatidyl 4,5-bisphosphate (PI), which is involved in the transduction mechanism of neurotransmitters and growth factors, is stimulated by brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) in primary cultures of fetal brain neurons. In the present study we sought to examine the effect of pretreatment with these factors on their acute stimulation capabilities and, furthermore, to substantiate that the effects of BDNF and NT-3 reflect actions on neurons rather than glial cells. Pretreatment with BNDF and NT-3 for 4 days followed by 1 day without growth factor abolished the effect of an acute stimulation with these factors. The growth factors were mutually effective so that BDNF pretreatment abolished the acute response to NT-3 and vice versa. In contrast, the effects of bFGF (basic fibroblast growth factor, a non-neurotrophin growth factor) also stimulating PI hydrolysis in these culture systems, were not reduced by neurotrophin pretreatment. Pretreatment with K-252b, at concentrations known to inhibit trk receptors, did not alter the acute stimulation of PI hydrolysis induced by the neutrophins. PI hydrolysis stimulated by BDNF and NT-3 in cultures grown in presence of cytosine arabinoside C, containing > 95% neurons, was higher than in cultures containing non-neuronal cells, indicating that the neurotrophin stimulation occurs in neuronal cells. No stimulatory effect was detected in bFGF treated pure neuronal cultures. The findings suggest that prolonged exposure of responsive neurons to BDNF and NT-3 down-regulates their stimulatory effects on PI hydrolysis. PMID:8348325

Widmer, H R; Ohsawa, F; Knüsel, B; Hefti, F

1993-06-18

 
 
 
 
181

Down-regulation of phosphatidylinositol response to BDNF and NT-3 in cultures of cortical neurons.  

UK PubMed Central (United Kingdom)

The hydrolysis of phosphatidyl 4,5-bisphosphate (PI), which is involved in the transduction mechanism of neurotransmitters and growth factors, is stimulated by brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) in primary cultures of fetal brain neurons. In the present study we sought to examine the effect of pretreatment with these factors on their acute stimulation capabilities and, furthermore, to substantiate that the effects of BDNF and NT-3 reflect actions on neurons rather than glial cells. Pretreatment with BNDF and NT-3 for 4 days followed by 1 day without growth factor abolished the effect of an acute stimulation with these factors. The growth factors were mutually effective so that BDNF pretreatment abolished the acute response to NT-3 and vice versa. In contrast, the effects of bFGF (basic fibroblast growth factor, a non-neurotrophin growth factor) also stimulating PI hydrolysis in these culture systems, were not reduced by neurotrophin pretreatment. Pretreatment with K-252b, at concentrations known to inhibit trk receptors, did not alter the acute stimulation of PI hydrolysis induced by the neutrophins. PI hydrolysis stimulated by BDNF and NT-3 in cultures grown in presence of cytosine arabinoside C, containing > 95% neurons, was higher than in cultures containing non-neuronal cells, indicating that the neurotrophin stimulation occurs in neuronal cells. No stimulatory effect was detected in bFGF treated pure neuronal cultures. The findings suggest that prolonged exposure of responsive neurons to BDNF and NT-3 down-regulates their stimulatory effects on PI hydrolysis.

Widmer HR; Ohsawa F; Knüsel B; Hefti F

1993-06-01

182

Population-level variation in the expression of heterostyly in three species of Rubiaceae: does reciprocal placement of anthers and stigmas characterize heterostyly?  

UK PubMed Central (United Kingdom)

Heterostyly (i.e., reciprocal placement of anthers and stigmas between two or three floral morphs) is hypothesized to enhance outcrossing and reduce selfing. However, few studies have documented reciprocity among individual plants; instead, mean anther and stigma heights for floral morphs are usually reported, masking interindividual variation. We measured eight floral dimensions for individuals in five populations of three heterostylous Rubiaceae. The three methods used to quantify reciprocity yielded different conclusions regarding the degree to which populations conformed to expectations for heterostylous plants. Only Psychotria poeppigiana had stigma and, to a lesser degree, anther heights in discrete classes. Variation among plants of Bouvardia ternifolia and Psychotria chiapensis yielded a continuum of anther and stigma heights across populations. Comparison of distances between stigma and anthers indicated that only flowers of B. ternifolia had, as expected, a constant value for this distance. Finally, regression relationships between anther and stigma heights and corolla length showed that only in one population each of B. ternifolia and P. poeppigiana, and in P. chiapensis, was distance between anthers and stigmas the same across the range of corolla sizes for both floral morphs. Variation among these species in expression of heterostyly was not clearly linked to phylogenetic relationship or pollinator syndromes. Two approach herkogamous (AH) species were studied for comparison. Flowers of Psychotria brachiata were consistently AH, but flowers of P. pittieri were highly variable. Determining fitness consequences of population-level variation in sexual systems requires studies linking floral morphology to pollinator behavior and pollen transfer.

Faivre AE; McDade LA

2001-05-01

183

Nutritional lipid supply can control the heat shock response of B16 melanoma cells in culture.  

Science.gov (United States)

The in vitro culture of cells offers an extremely valuable method for probing biochemical questions and many commonly-used protocols are available. For mammalian cells a source of lipid is usually provided in the serum component. In this study we examined the question as to whether the nature of the lipid could become limiting at high cell densities and, therefore, prospectively influence the metabolism and physiology of the cells themselves. When B16 mouse melanoma cells were cultured, we noted a marked decrease in the proportions of n-3 and n-6 polyunsaturated fatty acids (PUFAs) with increasing cell density. This was despite considerable quantities of these PUFAs still remaining in the culture medium and seemed to reflect the preferential uptake of unesterified PUFA rather than other lipid classes from the media. The reduction in B16 total PUFA was reflected in changes in about 70% of the molecular species of membrane phosphoglycerides which were analysed by mass spectrometry. The importance of this finding lies in the need for n-3 and n-6 PUFA in mammalian cells (which cannot synthesize their own). Although the cholesterol content of cells was unchanged the amount of cholesterol enrichment in membrane rafts (as assessed by fluorescence) was severely decreased, simultaneous with a reduced heat shock response following exposure to 42°C. These data emphasize the pivotal role of nutrient supply (in this case for PUFAs) in modifying responses to stress and highlight the need for the careful control of culture conditions when assessing cellular responses in vitro. PMID:22583025

Péter, Mária; Balogh, Gábor; Gombos, Imre; Liebisch, Gerhard; Horváth, Ibolya; Török, Zsolt; Nagy, Enik?; Maslyanko, Andriy; Benk?, Sándor; Schmitz, Gerd; Harwood, John L; Vígh, László

2012-05-14

184

Construção e avaliação de um protótipo de máquina coletora de anteras/ Construction and evaluation of an anther collector prototype machine  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Um protótipo de máquina coletora de anteras foi projetado e construído, e seu desempenho foi avaliado, comparando - se com o método de coleta manual, em flores rosáceas e campanuladas de pessegueiro (Prunus persica). O trabalho foi conduzido utilizando-se do delineamento experimental inteiramente ao acaso, arranjado em um esquema bifatorial (2 métodos de remoção x 2 formas florais), com 12 repetições de 30 balões florais. O protótipo apresentou maior velocidad (more) e de processamento, sem diminuir a qualidade do pólen, mesmo sendo armazenadas anteras com maior quantidade de filetes e descartado maior número de anteras do que o método manual. Abstract in english An anther collector prototype machine was projected and built. Its performance was evaluated by comparisons between the use of the prototype and the traditional manual method, both for showy and non-showy peach-tree flowers (Prunus persica). The study was accomplished in August 2011 using a completely randomized experimental design, arranged in a bi-factorial scheme (2 collection methods x 2 flower forms), with 12 repetitions, each consisted by 30 flowers. The prototype p (more) roved to be faster in the anther extraction time without losses in the pollen quality, even harvesting anthers with higher fillet amounts and discarding a higher quantity of anthers than the manual method.

Tonet, Rodrigo; Sachet, Marcos Robson; Citadin, Idemir; Modolo, Alcir José

2013-03-01

185

Pollen packaging and dispensing: adaption of patterns of anther dehiscence and flowering traits to pollination in three Epimedium species.  

Science.gov (United States)

Pollen presentation theory (PPT) predicts that plant species typically pollinated by frequent and wasteful pollinators ought to be much more parsimonious and only gradually release pollen compared to plant species pollinated by infrequent pollinators that are efficient at delivering the pollen they remove. To test PPT, we compare the pollen presentation schedules and pollination systems in three related Epimedium species, having different pollinators. Results showed that differences in anther dehiscence and flowering traits resulted in different pollen packaging schedules. For E. sutchuenense and E. franchetii, a special 'roll-up' movement of the anther wall during anther dehiscence increased pollen removal compared to the dehiscence pattern in E. mikinorii, which lacked the 'roll-up' movement. Investigations revealed that honeybees had a higher pollen removal rate and lower stigmatic pollen load compared to bumblebees. In accordance with PPT, E. sutchuenense presents pollen sequentially and slowly for the frequent and wasteful honeybees. In comparison to E. sutchuenense, E. franchetii had a faster presentation rate and was adapted to the efficient and infrequent bumblebees. However, E. mikinorii was pollinated by both bumblebees and honeybees at high frequency and had the fastest pollen presentation. This pattern could reduce pollen wastage by honeybees and might be an adaptation to its short flower longevity (less than 1 day), to increase the chances of pollen deposition on stigmas. The study indicates that pollen presentation schedules can be a consequence of interactions among anther dehiscence, flowering traits and pollination environments for a given species. PMID:23614841

Li, X-X; Wang, H; Gituru, R W; Guo, Y-H; Yang, C-F

2013-04-24

186

Pollen packaging and dispensing: adaption of patterns of anther dehiscence and flowering traits to pollination in three Epimedium species.  

UK PubMed Central (United Kingdom)

Pollen presentation theory (PPT) predicts that plant species typically pollinated by frequent and wasteful pollinators ought to be much more parsimonious and only gradually release pollen compared to plant species pollinated by infrequent pollinators that are efficient at delivering the pollen they remove. To test PPT, we compare the pollen presentation schedules and pollination systems in three related Epimedium species, having different pollinators. Results showed that differences in anther dehiscence and flowering traits resulted in different pollen packaging schedules. For E. sutchuenense and E. franchetii, a special 'roll-up' movement of the anther wall during anther dehiscence increased pollen removal compared to the dehiscence pattern in E. mikinorii, which lacked the 'roll-up' movement. Investigations revealed that honeybees had a higher pollen removal rate and lower stigmatic pollen load compared to bumblebees. In accordance with PPT, E. sutchuenense presents pollen sequentially and slowly for the frequent and wasteful honeybees. In comparison to E. sutchuenense, E. franchetii had a faster presentation rate and was adapted to the efficient and infrequent bumblebees. However, E. mikinorii was pollinated by both bumblebees and honeybees at high frequency and had the fastest pollen presentation. This pattern could reduce pollen wastage by honeybees and might be an adaptation to its short flower longevity (less than 1 day), to increase the chances of pollen deposition on stigmas. The study indicates that pollen presentation schedules can be a consequence of interactions among anther dehiscence, flowering traits and pollination environments for a given species.

Li XX; Wang H; Gituru RW; Guo YH; Yang CF

2013-04-01

187

Defective Pollen Wall is Required for Anther and Microspore Development in Rice and Encodes a Fatty Acyl Carrier Protein Reductase  

Energy Technology Data Exchange (ETDEWEB)

Aliphatic alcohols naturally exist in many organisms as important cellular components; however, their roles in extracellular polymer biosynthesis are poorly defined. We report here the isolation and characterization of a rice (Oryza sativa) male-sterile mutant, defective pollen wall (dpw), which displays defective anther development and degenerated pollen grains with an irregular exine. Chemical analysis revealed that dpw anthers had a dramatic reduction in cutin monomers and an altered composition of cuticular wax, as well as soluble fatty acids and alcohols. Using map-based cloning, we identified the DPW gene, which is expressed in both tapetal cells and microspores during anther development. Biochemical analysis of the recombinant DPW enzyme shows that it is a novel fatty acid reductase that produces 1-hexadecanol and exhibits >270-fold higher specificity for palmiltoyl-acyl carrier protein than for C16:0 CoA substrates. DPW was predominantly targeted to plastids mediated by its N-terminal transit peptide. Moreover, we demonstrate that the monocot DPW from rice complements the dicot Arabidopsis thaliana male sterile2 (ms2) mutant and is the probable ortholog of MS2. These data suggest that DPWs participate in a conserved step in primary fatty alcohol synthesis for anther cuticle and pollen sporopollenin biosynthesis in monocots and dicots.

Shi, J.; Shanklin, J.; Tan, H.; Yu, X.-H.; Liu, Y.; Liang, W.; Ranathunge, K.; Franke, R. B.; Schreiber, L.; Wang, Y.; Kai, G.; Ma, H.; Zhang, D.

2011-06-01

188

Ethylene is involved in stress responses induced by fusicoccin in sycamore cultured cells.  

Science.gov (United States)

The phytohormone ethylene is involved in many physiological and developmental processes of plants, as well as in stress responses and in the development of disease resistance. Fusicoccin (FC) is a well-known phytotoxin, that in sycamore (Acer pseudoplatanus L.) cultured cells, induces a set of stress responses, including synthesis of ethylene. In this study, we investigated the possible involvement of ethylene in the FC-induced stress responses of sycamore cells by means of Co(2+), a well-known specific inhibitor of ethylene biosynthesis. Co(2+) inhibited the accumulation of dead cells in the culture, the production of nitric oxide (NO) and of the molecular chaperone Binding Protein (BiP) in the endoplasmic reticulum induced by FC. By contrast, Co(2+) was ineffective on the FC-induced accumulation of cells with fragmented DNA, production of H(2)O(2) and release of cytochrome c from the mitochondrion, and only partially reduced the accumulation of regulative 14-3-3 proteins in the cytosol. In addition, we compared the effect of FC on the above parameters with that of the ethylene-releasing compound ethephon (2-chloroethane phosphonic acid). The results suggest that ethylene is involved in several stress responses induced by FC in sycamore cells, including a form of cell death that does not show apoptotic features and possibly involves NO as a signaling molecule. PMID:20630615

Malerba, Massimo; Crosti, Paolo; Cerana, Raffaella

2010-07-13

189

Ethylene is involved in stress responses induced by fusicoccin in sycamore cultured cells.  

UK PubMed Central (United Kingdom)

The phytohormone ethylene is involved in many physiological and developmental processes of plants, as well as in stress responses and in the development of disease resistance. Fusicoccin (FC) is a well-known phytotoxin, that in sycamore (Acer pseudoplatanus L.) cultured cells, induces a set of stress responses, including synthesis of ethylene. In this study, we investigated the possible involvement of ethylene in the FC-induced stress responses of sycamore cells by means of Co(2+), a well-known specific inhibitor of ethylene biosynthesis. Co(2+) inhibited the accumulation of dead cells in the culture, the production of nitric oxide (NO) and of the molecular chaperone Binding Protein (BiP) in the endoplasmic reticulum induced by FC. By contrast, Co(2+) was ineffective on the FC-induced accumulation of cells with fragmented DNA, production of H(2)O(2) and release of cytochrome c from the mitochondrion, and only partially reduced the accumulation of regulative 14-3-3 proteins in the cytosol. In addition, we compared the effect of FC on the above parameters with that of the ethylene-releasing compound ethephon (2-chloroethane phosphonic acid). The results suggest that ethylene is involved in several stress responses induced by FC in sycamore cells, including a form of cell death that does not show apoptotic features and possibly involves NO as a signaling molecule.

Malerba M; Crosti P; Cerana R

2010-11-01

190

Microfluidic culture models to study the hydrodynamics of tumor progression and therapeutic response.  

UK PubMed Central (United Kingdom)

The integration of tissue engineering strategies with microfluidic technologies has enabled the design of in vitro microfluidic culture models that better adapt to morphological changes in tissue structure and function over time. These biomimetic microfluidic scaffolds accurately mimic native 3D microenvironments, as well as permit precise and simultaneous control of chemical gradients, hydrodynamic stresses, and cellular niches within the system. The recent application of microfluidic in vitro culture models to cancer research offers enormous potential to aid in the development of improved therapeutic strategies by supporting the investigation of tumor angiogenesis and metastasis under physiologically relevant flow conditions. The intrinsic material properties and fluid mechanics of microfluidic culture models enable high-throughput anti-cancer drug screening, permit well-defined and controllable input parameters to monitor tumor cell response to various hydrodynamic conditions or treatment modalities, as well as provide a platform for elucidating fundamental mechanisms of tumor physiology. This review highlights recent developments and future applications of microfluidic culture models to study tumor progression and therapeutic targeting under conditions of hydrodynamic stress relevant to the complex tumor microenvironment.

Buchanan C; Rylander MN

2013-08-01

191

Organizational Institutions and Their Responsible Behavioral-Cultural Gene Codes and A Measurement for Organizational Efficiency  

Directory of Open Access Journals (Sweden)

Full Text Available This essay has two goals. The first is to classify two different types of organizational institutions from the four-dimensional system-thinking perspective, and to identify the relationship between such organizational institutions and their relevant behavioral-cultural gene codes embedded within their (P-)individuals. Unlike the popular belief that authoritarian or totalitarian institutions are caused by ideologies or created/dominated by tyrannical leaders, the author defines a concept of behavioral-cultural gene code and extends the application of self-organization theory to suggest that behavioral-cultural gene codes carried by the members of the organization are responsible for the formation of, either democratic or authoritarian, institutions. Therefore, transformation of an authoritarian organization into a democratic one, no matter at the level of groups, of business enterprises, or of a government, must start from transforming behavioral-cultural gene codes. The second goal is to define Organizational Friction Coefficient for capturing the characteristics of these two types of organizational institutions, thus adding clarity to the widely used concept of organizational efficiency in the contexts of both business organizations and systems of government.

Jason Jixuan

2010-01-01

192

Comparison of tumour age response to radiation for cells derived from tissue culture or solid tumours  

International Nuclear Information System (INIS)

Direct comparison of the cell age response of 9L and KHT tumour cells derived either from tissue culture or solid tumours was achieved. Cells from dissociated KHT and 9L tumours (the latter implanted either subcutaneously or intracerebrally) and cells from tissue culture were separated into homogenous sized populations by centrifugal elutriation. In both tumour models these homogeneous sized populations correspond to populations enriched at different stages of the cell cycle. The survival of these elutriated cell populations was measured after a single dose of Cs-137 gamma rays. For cells isolated from 9L solid tumours, there was little variation in radiosensitivity throughout the cell cycle; however, a very small but significant increase in resistance was found in late G1 cells. This lack of a large variation in radiosensitivity through the cell cycle for 9L cells from solid tumours also was seen in 9L cells growing in monolayer tissue culture. When similar experiments were performed using the KHT sarcoma tumour model, the results showed that KHT cells in vitro exhibited a fairly conventional increase in radioresistance in both mid G1 and late S. However, the cell age response of KHT cells from solid tumours was different; particularly in the late S and G2 + M phases. (author)

1984-01-01

193

Comparison of tumour age response to radiation for cells derived from tissue culture or solid tumours  

Energy Technology Data Exchange (ETDEWEB)

Direct comparison of the cell age response of 9L and KHT tumour cells derived either from tissue culture or solid tumours was achieved. Cells from dissociated KHT and 9L tumours (the latter implanted either subcutaneously or intracerebrally) and cells from tissue culture were separated into homogenous sized populations by centrifugal elutriation. In both tumour models these homogeneous sized populations correspond to populations enriched at different stages of the cell cycle. The survival of these elutriated cell populations was measured after a single dose of Cs-137 gamma rays. For cells isolated from 9L solid tumours, there was little variation in radiosensitivity throughout the cell cycle; however, a very small but significant increase in resistance was found in late G/sub 1/ cells. This lack of a large variation in radiosensitivity through the cell cycle for 9L cells from solid tumours also was seen in 9L cells growing in monolayer tissue culture. When similar experiments were performed using the KHT sarcoma tumour model, the results showed that KHT cells in vitro exhibited a fairly conventional increase in radioresistance in both mid G/sub 1/ and late S. However, the cell age response of KHT cells from solid tumours was different; particularly in the late S and G/sub 2/ + M phases.

Keng, P.C.; Siemann, D.W. (Rochester Univ. Medical Center, NY (USA). Cancer Center; Rochester Univ., NY (USA). Dept. of Radiation Oncology; Rochester Univ., NY (USA). Dept. of Radiation Biology and Biophysics); Wheeler, K.T. (Kansas Univ., Lawrence (USA). Dept. of Radiation Biophysics)

1984-10-01

194

Spatial quantification and classification of skin response following perturbation using organotypic skin cultures.  

UK PubMed Central (United Kingdom)

MOTIVATION: For a mechanistic understanding of skin and its response to an induced perturbation, systems biology is gaining increasing attention. Unfortunately, quantitative and spatial expression data for skin, like for most other tissues, are almost not available. RESULTS: Integrating organotypic skin cultures, whole-slide scanning and subsequent image processing provides bioinformatics with a novel source of spatial expression data. We here used this approach to quantitatively describe the effect of treating organotypic skin cultures with sodium dodecyl sulphate in a non-corrosive concentration. We first measured the differentiation-related spatial expression gradient of Heat-Shock-Protein 27 in a time series of up to 24 h. Secondly, a multi-dimensional tissue classifier for predicting skin irritation was developed based on abstract features of these profiles. We obtained a high specificity of 0.94 and a sensitivity of 0.92 compared with manual classification. Our results demonstrate that the integration of tissue cultures, whole-slide scanning and image processing is well suited for both the standardized data acquisition for systems biological tissue models and a highly robust classification of tissue responses.

Pommerencke T; Westphal K; Ernst C; Safferling K; Dickhaus H; Steinberg T; Tomakidi P; Grabe N

2010-11-01

195

Consortia modulation of the stress response: proteomic analysis of single strain versus mixed culture.  

UK PubMed Central (United Kingdom)

The high complexity of naturally occurring microbial communities is the major drawback limiting the study of these important biological systems. In this study, a comparison between pure cultures of Pseudomonas reinekei sp. strain MT1 and stable community cultures composed of MT1 plus the addition of Achromobacter xylosoxidans strain MT3 (in a steady-state proportion 9:1) was used as a model system to study bacterial interactions that take place under simultaneous chemical and oxidative stress. Both are members of a real community isolated from a polluted sediment by enrichment in 4-chlorosalicylate (4CS). The analysis of dynamic states was carried out at the proteome, metabolic profile and population dynamic level. Differential protein expression was evaluated under exposure to 4CS and high concentrations of toxic intermediates (4-chlorocatechol and protoanemonin), including proteins from several functional groups and particularly enzymes of aromatic degradation pathways and outer membrane proteins. Remarkably, 4CS addition generated a strong oxidative stress response in pure strain MT1 culture led by alkyl hydroperoxide reductase, while the community showed an enhanced central metabolism response, where A. xylosoxidans MT3 helped to prevent toxic intermediate accumulation. A significant change in the outer membrane composition of P. reinekei MT1 was observed during the chemical stress caused by 4CS and in the presence of A. xylosoxidans MT3, highlighting the expression of the major outer membrane protein OprF, tightly correlated to 4CC concentration profile and its potential detoxification role.

Bobadilla Fazzini RA; Preto MJ; Quintas AC; Bielecka A; Dos Santos VA

2010-09-01

196

[Alteration of brown adipocyte Ca2+ responses in culture by adrenergic activation].  

UK PubMed Central (United Kingdom)

Thermogenic capability of brown adipose tissue is controlled by norepinephrine. Interaction of norepinephrine with adipocyte at- and P3-adrenergic receptors results in the increase of Ca2+ and cAMP concentrations. The [Ca2+]i changes initiated by norepinephrine and selective agonists of alpha1- and beta-adrenergic receptors, cirazolin and isoproterenol, were recorded in single cells of primary culture on the 1st, 3rd and 6th days in vitro. On the first day, isoproterenol-induced [Ca2+]i changes as compared to cirazolin-induced ones were characterized by greater amplitude and lesser impulse duration over the entire range of physiological concentrations used. These differences were negligible after 3 days and kinetic differences were practically absent after 6 days of cultivation. The agonist-induced [Ca2+]i changes in proliferating and differentiated cells differed significantly: in the process of cell growth in culture, the amplitude of calcium response increased, the duration of impulse signal decreased and the sensitivity to adrenergic agonists increased. The Ca2+ store in endoplasmic reticulum increased during the cell growth and development in culture, according to thapsigargin-induced Ca2+ response amplitude increase in Ca2+ free medium. The rate of Ca2+ pumping out of cell characterizing PMCA-activity also increased.

Turovski? EA; Konakov MV; Berezhnov AV; Zinchenko VP; Bronnikov GE; Dolgacheva LP

2011-01-01

197

Biological responses of xenobiotic metabolizing enzymes to lead exposure in cultured H4IIE rat cells.  

UK PubMed Central (United Kingdom)

This study was undertaken to investigate the constitutive response of xenobiotic metabolizing enzymes (XMEs) to lead (Pb2+) exposure in cultured rat liver (H4IIE) cell lines. Phase I enzymes such as CYP1A1 and CYP1A2 had mRNA expressions that were slightly induced after exposure to low concentrations of Pb2+; however, under higher concentrations of Pb2+, the mRNA expressions of CYP1A1 and CYP1A2 were significantly down-regulated. These effects were in correspondence with AhR mRNA expression. Phase II enzymes had mRNA expressions that were reduced upon exposure to Pb2+. Metallothionein mRNA expression was induced after treatment with Pb2+ in a dose-dependent trend. In conclusion, Phase I and II enzymes were significantly modulated upon lead exposure indicating some toxicological implications for lead exposure in cultured H4IIE cells.

Darwish WS; Ikenaka Y; Ishizuka M

2013-02-01

198

Increased synthesis of ajmalicine and catharanthine by cell suspension cultures of Catharanthus roseus in response to fungal culture-filtrates.  

UK PubMed Central (United Kingdom)

The ammonium sulfate-precipitated fraction from mycelia and culture-filtrates and the crude, cell-free culture filtrates from the growth medium of the fungi Chrysosporium palmorum, Eurotium rubrum, Micromucor isabellina, and Pythium aphanidermatum when aseptically added to cell suspensions of Cantharanthus roseus caused a rapid and dramatic increase in indole alkaloid biosynthesis. Up to 400 micrograms/L ajmalicine and 600 micrograms/L catharanthine were detected in C. roseus cell suspension grown in the presence of the M. isabellina fungal culture filtrate for 3 d. Untreated cells produced only trace levels of ajmalicine and catharanthine per liter of cell suspension after 15 d of culture.

DiCosmo F; Quesnel A; Misawa M; Tallevi SG

1987-03-01

199

Increased synthesis of ajmalicine and catharanthine by cell suspension cultures of Catharanthus roseus in response to fungal culture-filtrates.  

Science.gov (United States)

The ammonium sulfate-precipitated fraction from mycelia and culture-filtrates and the crude, cell-free culture filtrates from the growth medium of the fungi Chrysosporium palmorum, Eurotium rubrum, Micromucor isabellina, and Pythium aphanidermatum when aseptically added to cell suspensions of Cantharanthus roseus caused a rapid and dramatic increase in indole alkaloid biosynthesis. Up to 400 micrograms/L ajmalicine and 600 micrograms/L catharanthine were detected in C. roseus cell suspension grown in the presence of the M. isabellina fungal culture filtrate for 3 d. Untreated cells produced only trace levels of ajmalicine and catharanthine per liter of cell suspension after 15 d of culture. PMID:3619437

DiCosmo, F; Quesnel, A; Misawa, M; Tallevi, S G

1987-03-01

200

Antimicrobial peptide response to group B Streptococcus in human extraplacental membranes in culture.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Streptococcus agalactiae (GBS) is an important cause of chorioamnionitis. This study characterizes GBS colonization and stimulation of antimicrobial responses in human extraplacental membranes using an ex vivo transwell two-compartment system of full-thickness membranes and live GBS. STUDY DESIGN: Human extraplacental membranes were affixed to transwell frames (without synthetic membranes). Live GBS was added to the decidual side of membranes in transwell cultures, and cocultures were incubated for 4, 8 and 24 h. GBS recovery from homogenized membranes and culture medium was determined by enumerating colony forming units (CFU) on blood agar. Antimicrobial peptide expression was identified using immunohistochemistry and ELISA. GBS killing by HBDs was assessed in vitro by incubating GBS with different human beta defensins (HBDs) for 3 h, then enumerating CFU. RESULTS: GBS recovery from membranes markedly decreased over time (P < 0.05). The antimicrobial peptides HBD-1, HBD-2, HBD-3, and lactoferrin were expressed in both GBS-exposed and non-exposed tissues. Notably, a pattern of localized increased HBD-2 in the amnion of GBS-infected tissue was observed. Moreover, GBS-treated membranes released increased amounts of HBD-2 into the amniotic and decidual compartments of the transwell cultures after 24 h (P < 0.05). In bacterial cultures, HBD-2 decreased GBS viability in a concentration-dependent manner (P < 0.05). CONCLUSION: Innate immune responses in ex vivo human extraplacental membranes suppress GBS growth. HBD-2 was implicated in this GBS suppression with evidence of signal transduction across the tissue. Antimicrobial peptides may be important for innate immune defense against intrauterine GBS infections during pregnancy.

Boldenow E; Jones S; Lieberman RW; Chames MC; Aronoff DM; Xi C; Loch-Caruso R

2013-06-01

 
 
 
 
201

Complex responses to culture conditions in Pseudomonas syringae pv. tomato DC3000 continuous cultures: the role of iron in cell growth and virulence factor induction.  

Science.gov (United States)

The growth of a model plant pathogen, Pseudomonas syringae pv. tomato DC3000, was investigated using a chemostat culture system to examine environmentally regulated responses. Using minimal medium with iron as the limiting nutrient, four different types of responses were obtained in a customized continuous culture system: (1) stable steady state, (2) damped oscillation, (3) normal washout due to high dilution rates exceeding the maximum growth rate, and (4) washout at low dilution rates due to negative growth rates. The type of response was determined by a combination of initial cell mass and dilution rate. Stable steady states were obtained with dilution rates ranging from 0.059 to 0.086 h(-1) with an initial cell mass of less than 0.6 OD(600). Damped oscillations and negative growth rates are unusual observations for bacterial systems. We have observed these responses at values of initial cell mass of 0.9 OD(600) or higher, or at low dilution rates (multiple steady states.Iron, which was reported earlier as a growth limiting nutrient in a widely used minimal medium, enhances both growth and virulence factor induction in iron-supplemented cultures compared to unsupplemented controls. Intracellular iron concentration is correlated to the early induction (6 h) of virulence factors in both batch and chemostat cultures. A reduction in aconitase activity (a TCA cycle enzyme) and ATP levels in iron-limited chemostat cultures was observed compared to iron-supplemented chemostat cultures, indicating that iron affects central metabolic pathways. We conclude that DC3000 cultures are particularly dependent on the environment and iron is likely a key nutrient in determining physiology. PMID:19953673

Kim, Beum Jun; Schneider, David J; Cartinhour, Samuel W; Shuler, Michael L

2010-04-01

202

Lean culture for the construction industry building responsible and committed project teams  

CERN Multimedia

Given that the greatest risk factor on any project is manpower costs, problems resulting in delays, rework, or overtime will lower profits through increased labor costs. Most of these process-generated costs are fully preventable. An in-depth exploration of the application of Lean initiatives in the construction industry, Lean Culture for the Construction Industry: Building Responsible and Committed Project Teams addresses employee issues in terms of productivity and waste by applying behavioral psychology principles at both tactical and strategic levels. Written by a veteran consultant in the

Santorella, Gary

2010-01-01

203

The Generation X Librarian Essays on Leadership, Technology, Pop Culture, Social Responsibility and Professional Identity  

CERN Document Server

Generation X includes individuals born roughly between 1961 and 1981. This generation has faced major advances in technology, environmental degradation, and widening economic injustice, all of which affect libraries and librarians. This collection of critical essays highlights the special challenges that face Generation X librarians. Topics covered include management and leadership, rapidly changing technology, social attitudes and stereotypes within popular culture, and how Generation X librarians have responded to or developed in response to those themes. This work fills many of the gaps pre

Wallace, Martin K,; Estep, Erik Sean

2011-01-01

204

Rock crab predation of juvenile sea scallops: the functional response and its implications for bottom culture  

UK PubMed Central (United Kingdom)

The functional response describes how consumption rate of individual predators changes as prey density changes, and can have important implications for the bottom culture of scallops. We examined (i) the functional response of rock crabs (Cancer irroratus) preying on juvenile sea scallops (Placopecten magellanicus); (ii) the effect of substrate type and scallop size on the functional response; and (iii) the underlying behavioural mechanisms of observed functional responses. Specifically, we quantified predation rate and behaviours, such as the proportion of time spent searching for prey, encounter rate between predators and prey and the outcomes of encounters, when individual rock crabs were offered a range of scallop density (2-50 or 11-111 scallops m-²) and two size classes of scallops (~~25 and ~~35 mm shell height) on two different substrate types (“glass-bottom” and “granule”). We found that crab predation rate on small juvenile scallops increased at a decelerating rate with prey density to a plateau at high prey density on both substrates, indicating a hyperbolic (type II) functional response. Crab predation rate on large juvenile scallops was independent of prey density (i.e., no functional response evident), suggesting that crabs were at their satiation level. Prey density did not influence any behaviour except encounter rate on small juvenile scallops, which increased as prey density increased. Substrate type influenced crab predation: maximum predation rate of crabs on small juvenile scallops and encounter rate with either size of juvenile scallops was lower on granule than on glass-bottom. Our results in the laboratory suggest that crabs could potentially be swamped if scallops are seeded at a high density in the field. However, many factors in the field may influence the functional response. For example, the presence of multiple prey types may lead to sigmoid functional responses, while the presence of many crab individuals may lead to aggregation of crabs in areas of high prey density.

Wong MC; Barbeau MA

2006-08-01

205

Androgenesis-inducing stress treatments change phytohormone levels in anthers of three legume species (Fabaceae).  

UK PubMed Central (United Kingdom)

UNLABELLED: Legumes are recalcitrant to androgenesis and induction protocols were only recently developed for pea (Pisum sativum L.) and chickpea (Cicer arietinum L.), albeit with low regeneration frequencies. Androgenesis is thought to be mediated through abscisic acid (ABA) but other phytohormones, such as auxins, cytokinins, and gibberellins, have also been implicated. In view of improving induction protocols, the hormone content of pea, chickpea, and lentil anthers was measured after exposure to cold, centrifugation, electroporation, sonication, osmotic shock, or various combinations thereof using an analytical mass spectrometer. Indole-3-acetic acid (IAA) had a key function during the induction process. In pea, high concentrations of IAA-asparagine (IAA-Asp), a putative IAA metabolite, accumulated during the application of the different stresses. In chickpea, the IAA-Asp concentration increased 30-fold compared to pea but only during the osmotic shock treatment and likely as a result of the presence of exogenous IAA in the medium. In contrast, no treatment in lentil (Lens culinaris) invoked such an increase in IAA-Asp content. Of the various cytokinins monitored, only cis zeatin riboside increased after centrifugation and electroporation in pea and possibly chickpea. No bioactive gibberellins were detected in any species investigated, indicating that this hormone group is likely not linked to androgenesis in legumes. In contrast to the other stresses, osmotic shock treatment caused a reduction in the levels of all hormones analyzed, with the exception of IAA-Asp in chickpea. A short period of low hormone content might be a necessary transition phase for androgenesis induction of legumes. KEY MESSAGE: Five androgenesis-inducing stress treatments changed content of ABA, auxin and cytokinin in anthers of three legumes. Osmotic shock treatment differed because it reduced hormone content to very low levels.

Lulsdorf M; Yuan HY; Slater S; Vandenberg A; Han X; Zaharia LI

2012-07-01

206

The role of organic osmolytes in the response of cultured astrocytes to hyperosmolarity.  

UK PubMed Central (United Kingdom)

Idiogenic osmoles are volume-regulatory organic solutes that accumulate within a cell in response to hyperosmolar conditions such as those found in diabetic ketoacidosis or hypernatremic dehydration in infants. Intracellular metabolites known to play this role include certain amino acids and taurine, polyols, and trimethylamines. In this study, in vitro astrocyte cultures prepared from the cerebral cortices of 1-day-old Sprague-Dawley rats were exposed to graded conditions of hypernatremia (325-375 mOsm/kg), a range that can be observed in vivo, for 24, 48, and 72 hours. Cell survival and generation of idiogenic osmoles were determined. Next, we assessed the ability of selected exogenous osmoles to protect the cultured cells from the effects of hypernatremia. Significant cell loss occurred after 48 to 72 hours of exposure and was proportional to the degree of hyperosmolarity. Addition of myoinositol (1 mM) to the cultures reduced cell loss resulting from hypernatremia by approximately 50%. In agreement with previous studies, intracellular levels of myoinositol and taurine correlated with the degree of in vitro hypernatremic exposure and play a significant role in increasing survival of astrocytes subjected to hypertonic insult.

Hijab S; Havalad S; Snyder AK

2011-09-01

207

The role of organic osmolytes in the response of cultured astrocytes to hyperosmolarity.  

Science.gov (United States)

Idiogenic osmoles are volume-regulatory organic solutes that accumulate within a cell in response to hyperosmolar conditions such as those found in diabetic ketoacidosis or hypernatremic dehydration in infants. Intracellular metabolites known to play this role include certain amino acids and taurine, polyols, and trimethylamines. In this study, in vitro astrocyte cultures prepared from the cerebral cortices of 1-day-old Sprague-Dawley rats were exposed to graded conditions of hypernatremia (325-375 mOsm/kg), a range that can be observed in vivo, for 24, 48, and 72 hours. Cell survival and generation of idiogenic osmoles were determined. Next, we assessed the ability of selected exogenous osmoles to protect the cultured cells from the effects of hypernatremia. Significant cell loss occurred after 48 to 72 hours of exposure and was proportional to the degree of hyperosmolarity. Addition of myoinositol (1 mM) to the cultures reduced cell loss resulting from hypernatremia by approximately 50%. In agreement with previous studies, intracellular levels of myoinositol and taurine correlated with the degree of in vitro hypernatremic exposure and play a significant role in increasing survival of astrocytes subjected to hypertonic insult. PMID:20093923

Hijab, Samina; Havalad, Suresh; Snyder, Ann K

2011-09-01

208

Application of item response theory to achieve cross-cultural comparability of occupational stress measurement.  

UK PubMed Central (United Kingdom)

Our objective was to examine cross-cultural comparability of standard scales of the Effort-Reward Imbalance occupational stress scales by item response theory (IRT) analyses. Data were from 20,256 Japanese employees, 1464 Dutch nurses and nurses' aides, 2128 representative employees from post-communist countries, 963 Swedish representative employees, 421 Chinese female employees, 10,175 employees of the French national gas and electric company and 734 Spanish railroad employees, sanitary personnel and telephone operators. The IRT likelihood ratio model was used for differential item functioning (DIF) and differential test functioning (DTF) analyses. Despite the existence of DIF, most comparisons did not show discernible differences in the relations between Effort-Reward total score and level of the underlying trait across cultural groups. In the case that DTF was suspected, excluding an item with significant DIF improved the comparability. The full cross-cultural comparability of Effort-Reward Imbalance scores can be achieved with the help of IRT analysis.

Tsutsumi A; Iwata N; Watanabe N; de Jonge J; Pikhart H; Fernández-López JA; Xu L; Peter R; Knutsson A; Niedhammer I; Kawakami N; Siegrist J

2009-01-01

209

The topographical guidance of neurons cultured on holographic photo-responsive polymer.  

Science.gov (United States)

Neuronal cells to respond to submicron-scale groove structure. On the grooved structure of particular dimension, it has been reported that neuronal cells grew perpendicular to the groove direction. We used holographic photo-responsive polymer to form a submicron-scale surface relief grating structure. A sinusoidal groove pattern is built up by holographic interference of 488 nm Ar ion laser beams. The primary hippocampal neurons cultured on the surface of the polymer film grew extending their neurites in a perpendicular orientation to the groove direction. This suggests that laser holography can be used to control the neurites orientation and growth. The holographic grating and photo-responsive polymer will raise the possibility of controlling neural network formation between living cells by light. PMID:17271430

Kyoo Lee, Jae; Baac, Hyoungwon; Song, Sang-Ho; Lee, Sin-Doo; Park, Dongeun; June Kim, Sung

2004-01-01

210

Response to hypogravity of normal in vitro cultured follicular cells from thyroid.  

UK PubMed Central (United Kingdom)

Aim of this investigation is the study of molecular modifications occurring in differentiated mammalian cells exposed to gravitational changes. The test system chosen is a well characterized clone of differentiated, normal thyroid follicular cells (FRTL5) in long-term culture. As a follow-up to our recent experiment performed during the MASER-7 sounding rocket mission, flown for European Space Agency by Swedish Space Corporation in May 1996, we evaluated FRTL5 cells responses to Thyroid Stimulating Hormone dependent cAMP production under acute hypogravity conditions obtained in a fast rotating clinostat. Following this approach, we evaluated the FRTL5 cells response to TSH under microgravity conditions in order to optimize experimental tools and strategies in preparation to, and in between real flight missions.

Meli A; Perrella G; Curcio F; Ambesi-Impiombato FS

1998-01-01

211

Temperature stress differentially modulates transcription in meiotic anthers of heat-tolerant and heat-sensitive tomato plants  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Fluctuations in temperature occur naturally during plant growth and reproduction. However, in the hot summers this variation may become stressful and damaging for the molecular mechanisms involved in proper cell growth, impairing thus plant development and particularly fruit-set in many crop plants. Tolerance to such a stress can be achieved by constitutive gene expression or by rapid changes in gene expression, which ultimately leads to protection against thermal damage. We have used cDNA-AFLP and microarray analyses to compare the early response of the tomato meiotic anther transcriptome to moderate heat stress conditions (32°C) in a heat-tolerant and a heat-sensitive tomato genotype. In the light of the expected global temperature increases, elucidating such protective mechanisms and identifying candidate tolerance genes can be used to improve breeding strategies for crop tolerance to heat stress. Results The cDNA-AFLP analysis shows that 30 h of moderate heat stress (MHS) alter the expression of approximately 1% of the studied transcript-derived fragments in a heat-sensitive genotype. The major effect is gene down-regulation after the first 2 h of stress. The microarray analysis subsequently applied to elucidate early responses of a heat-tolerant and a heat-sensitive tomato genotype, also shows about 1% of the genes having significant changes in expression after the 2 h of stress. The tolerant genotype not only reacts with moderate transcriptomic changes but also exhibits constitutively higher expression levels of genes involved in protection and thermotolerance. Conclusion In contrast to the heat-sensitive genotype, the heat-tolerant genotype exhibits moderate transcriptional changes under moderate heat stress. Moreover, the heat-tolerant genotype also shows a different constitutive gene expression profile compared to the heat-sensitive genotype, indicating genetic differences in adaptation to increased temperatures. In the heat-tolerant genotype, the majority of changes in gene expression is represented by up-regulation, while in the heat-sensitive genotype there is a general trend to down-regulate gene expression upon MHS. The putative functions associated with the genes identified by cDNA-AFLP or microarray indicate the involvement of heat shock, metabolism, antioxidant and development pathways. Based on the observed differences in response to MHS and on literature sources, we identified a number of candidate transcripts involved in heat-tolerance.

Bita Craita E; Zenoni Sara; Vriezen Wim H; Mariani Celestina; Pezzotti Mario; Gerats Tom

2011-01-01

212

Studies in tissue culture of some indigenous rice (Oryza glaberrima Steud.) accessions in Ghana  

International Nuclear Information System (INIS)

A study was conducted with the aim of developing separate protocols for callus induction and plant regeneration from different parts of three O. glaberrima accessions indigenous to Ghana. The three O. glaberrima accessions, Guame, N/4 and SARI 1 were assessed for their callus induction and plant regeneration ability from leaf segments, mature dehusked seeds and anthers on different concentrations of plant growth regulators, incorporated into Murashige and Skoog, (1962) (MS) basal medium. For leaf segments, callus was induced on MS supplemented with (0-10) mg/l 2,4-D. Callus induction frequency was significantly (p?0.05) different among accessions, as well as among the 2,4-dichlorophenoxyacetic acid (2,4-D) levels tested. Highest callus induction frequency was exhibited at a concentration of 6 mg/l 2,4-D for all accessions tested. Callus obtained was sub-cultured on regeneration medium consisting of MS supplemented with (1:0-5) mg.l NAA:BAP. Plant regeneration was nil. Instead, prolific root formation was observed. For mature dehusked seeds, callus induction medium consisted of MS supplemented with (0-6) mg/l 2,4-D. All tested accessions exhibited highest callus frequency at 4 mg/l 2,4-D. Similarly callus induction frequency was significantly (p?0.05) different among accessions, as well as among concentrations of 2,4-D tested. Calli obtained were sub-cultured on MS medium supplemented with (0-2.5) mg/l 6-benzylaminopurine (BAP) and exhibited the highest regeneration frequency on medium containing 2.0 mg/l BAP. However, callus induced on a concentration of 3 mg/l 2,4-D and sub-cultured on a concentration of 2 mg/l BAP gave the best response n terms of shoot proliferation, growth and root development and therefore were considered to be the optimum concentrations for callus induction and plant regeneration respectively. Plantlet regeneration was achieved only in accession N/4 while Guame and SARI 1 exhibited poor regeneration response. Among the three rice accessions evaluated, N/4 was the most promising accession in terms of callus induction frequency and regeneration ability. The three accessions of O. glaberrima were again studied for their response to anther culture in terms of callus induction and frequency of plant regeneration using N, Garfish and D oy, MS and Nis tch tissue culture media, and supplemented with 2,4-D (1:(0-5) mg/l) were used for callus induction. No response to callus formation was obtained after 16 weeks of culture and a conclusion was drawn that all three accessions were recalcitrant to anther culture. (au)

2011-01-01

213

Effect of yeast culture supplementation on carcass yield and humoral immune response of broiler chicks  

Directory of Open Access Journals (Sweden)

Full Text Available Aim: A study was conducted to evaluate the effect of supplemental yeast culture (Diamond V XPC Yeast Culture; YC) in broiler diets on carcass characteristics and humoral immune response. Materials and Methods: A total of 240 one-day-old broiler chicks (Ross 308) were randomly assigned to four YC dietary treatments of 60 birds each. The dietary treatments were 0 (control), 1, 1.25 and 1.5 g YC/kg diet over 42 d. Results: The results revealed that the birds fed yeast cultures had statistically increased (P < 0.05) body weight from control birds only at 5-6 weeks of age. The highest inclusion level (1.5g/kg) recorded the best weight. The broiler chicks fed a diet supplemented with 1.25g/kg had the lowest mortality rate over the whole period of the experiment. The birds given the highest level of yeast (1.5g/kg) had significantly (P < 0.05) higher percentage of major and minor breast muscles compared with the others that fed a basal diet. A significantly (P < 0.01) increase in IgM titer was noticed in birds fed diet containing YC levels more than 1g/kg at 7 days post-injection with sheep red blood cells. Likewise, broilers fed a diet containing 1.25g/kg exhibited a higher level of antibody titer against Newcastle disease virus at latter age (on d 42) compared with the other groups. Conclusion: The data suggest improvement in growth performance, carcass yield and humoral immunity of broilers fed yeast culture supplementation diet. [Vet World 2012; 5(11.000): 651-657

M M Fathi; S Al-Mansour; A Al-Homidan; A Al-Khalaf; M Al-Damegh

2012-01-01

214

Flagellin from an incompatible strain of Pseudomonas avenae induces a resistance response in cultured rice cells.  

UK PubMed Central (United Kingdom)

The host range of Pseudomonas avenae is wide among monocotyledonous plants, but individual strains can infect only one or a few host species. The resistance response of rice cells to pathogens has been previously shown to be induced by a rice-incompatible strain, N1141, but not by a rice-compatible strain, H8301. To clarify the molecular mechanism of the host specificity in P. avenae, a strain-specific antibody that was raised against N1141 cells and then absorbed with H8301 cells was prepared. When a cell extract of strain N1141 was separated by SDS-polyacrylamide gel electrophoresis and immunostained with the N1141 strain-specific antibody, only a flagellin protein was detected. Purified N1141 flagellin induced the hypersensitive cell death in cultured rice cells within 6 h of treatment, whereas the H8301 flagellin did not. The hypersensitive cell death could be blocked by pretreatment with anti-N1141 flagellin antibody. Furthermore, a flagellin-deficient N1141 strain lost not only the induction ability of hypersensitive cell death but also the expression ability of the EL2 gene, which is thought to be one of the defense-related genes. These results demonstrated that the resistance response in cultured rice cells is induced by the flagellin existing in the incompatible strain of P. avenae but not in the flagellin of the compatible strain.

Che FS; Nakajima Y; Tanaka N; Iwano M; Yoshida T; Takayama S; Kadota I; Isogai A

2000-10-01

215

Induction of heme oxygenase: A general response to oxidant stress in cultured mammalian cells  

International Nuclear Information System (INIS)

Accumulation of heme oxygenase mRNA is strongly stimulated by treatment of cultured human skin fibroblasts with ultraviolet radiation, hydrogen peroxide, or the sulfhydryl reagent sodium arsenite. Since this will result in a transient reduction in the prooxidant state of cells, the phenomenon may represent an important inducible antioxidant defense mechanism. To examine the generality of the response, we have measured the accumulation of the specific mRNA in a variety of human and mammalian cell types after inducing treatments. Induction by sodium arsenite is observed in all additional human cell types tested. This includes primary epidermal keratinocytes and lung and colon fibroblasts as well as established cell lines such as HeLa, TK6 lymphoblastoid, and transformed fetal keratinocytes. Strong induction of heme oxygenase mRNA is also observed following sodium arsenite treatment of cell lines of rat, hamster, mouse, monkey, and marsupial origin. The agents which lead to induction in cultured human skin fibroblasts fall into two categories: (a) those which are oxidants or can generate active intermediates (ultraviolet A radiation, hydrogen peroxide, menadione, and the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate); (b) agents which are known to interact with or modify cellular glutathione levels (buthionine sulfoximine, sodium arsenite, iodoacetamide, diamide, and cadmium chloride). These observations strongly support the hypothesis that induction of the enzyme is a general response to oxidant stress in mammalian cells and are consistent with the possibility that the cellular redox state plays a key role.

1991-01-01

216

Induction of heme oxygenase: A general response to oxidant stress in cultured mammalian cells  

Energy Technology Data Exchange (ETDEWEB)

Accumulation of heme oxygenase mRNA is strongly stimulated by treatment of cultured human skin fibroblasts with ultraviolet radiation, hydrogen peroxide, or the sulfhydryl reagent sodium arsenite. Since this will result in a transient reduction in the prooxidant state of cells, the phenomenon may represent an important inducible antioxidant defense mechanism. To examine the generality of the response, we have measured the accumulation of the specific mRNA in a variety of human and mammalian cell types after inducing treatments. Induction by sodium arsenite is observed in all additional human cell types tested. This includes primary epidermal keratinocytes and lung and colon fibroblasts as well as established cell lines such as HeLa, TK6 lymphoblastoid, and transformed fetal keratinocytes. Strong induction of heme oxygenase mRNA is also observed following sodium arsenite treatment of cell lines of rat, hamster, mouse, monkey, and marsupial origin. The agents which lead to induction in cultured human skin fibroblasts fall into two categories: (a) those which are oxidants or can generate active intermediates (ultraviolet A radiation, hydrogen peroxide, menadione, and the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate); (b) agents which are known to interact with or modify cellular glutathione levels (buthionine sulfoximine, sodium arsenite, iodoacetamide, diamide, and cadmium chloride). These observations strongly support the hypothesis that induction of the enzyme is a general response to oxidant stress in mammalian cells and are consistent with the possibility that the cellular redox state plays a key role.

Applegate, L.A.; Luscher, P.; Tyrrell, R.M. (Swiss Institute for Experimental Cancer Research, Epalinges (Switzerland))

1991-02-01

217

Characterization of callase (?-1,3-D-glucanase) activity during microsporogenesis in the sterile anthers of Allium sativum L. and the fertile anthers of A. atropurpureum.  

UK PubMed Central (United Kingdom)

We examined callase activity in anthers of sterile Allium sativum (garlic) and fertile Allium atropurpureum. In A. sativum, a species that produces sterile pollen and propagates only vegetatively, callase was extracted from the thick walls of A. sativum microspore tetrads exhibited maximum activity at pH 4.8, and the corresponding in vivo values ranged from 4.5 to 5.0. Once microspores were released, in vitro callase activity peaked at three distinct pH values, reflecting the presence of three callase isoforms. One isoform, which was previously identified in the tetrad stage, displayed maximum activity at pH 4.8, and the remaining two isoforms, which were novel, were most active at pH 6.0 and 7.3. The corresponding in vivo values ranged from pH 4.75 to 6.0. In contrast, in A. atropurpureum, a sexually propagating species, three callase isoforms, active at pH 4.8-5.2, 6.1, and 7.3, were identified in samples of microsporangia that had released their microspores. The corresponding in vivo value for this plant was 5.9. The callose wall persists around A. sativum meiotic cells, whereas only one callase isoform, with an optimum activity of pH 4.8, is active in the acidic environment of the microsporangium. However, this isoform is degraded when the pH rises to 6.0 and two other callase isoforms, maximally active at pH 6.0 and 7.3, appear. Thus, factors that alter the pH of the microsporangium may indirectly affect the male gametophyte development by modulating the activity of callase and thereby regulating the degradation of the callose wall.

Winiarczyk K; Jaroszuk-?cise? J; Kupisz K

2012-06-01

218

Variability of affective responses to odors: culture, gender, and olfactory knowledge.  

UK PubMed Central (United Kingdom)

Emotion and odor scales (EOS) measuring odor-related affective feelings were recently developed for three different countries (Switzerland, United Kingdom, and Singapore). The first aim of this study was to investigate gender and cultural differences in verbal affective response to odors, measured with EOS and the usual pleasantness scale. To better understand this variability, the second aim was to investigate the link between affective reports and olfactory knowledge (familiarity and identification). Responses of 772 participants smelling 56-59 odors were collected in the three countries. Women rated odors as more intense and identified them better in all countries, but no reliable sex differences were found for verbal affective responses to odors. Disgust-related feelings revealed odor-dependent sex differences, due to sex differences in identification and categorization. Further, increased odor knowledge was related to more positive affects as reported with pleasantness and odor-related feeling evaluations, which can be related to top-down influences on odor representation. These top-down influences were thought, for example, to relate to beliefs about odor properties or to categorization (edible vs. nonedible). Finally, the link between odor knowledge and olfactory affect was generally asymmetrical and significant only for pleasant odors, not for unpleasant ones that seemed to be more resistant to cognitive influences. This study, for the first time using emotional scales that are appropriate to the olfactory domain, brings new insights into the variability of affective responses to odors and its relationship to odor knowledge.

Ferdenzi C; Roberts SC; Schirmer A; Delplanque S; Cekic S; Porcherot C; Cayeux I; Sander D; Grandjean D

2013-02-01

219

Intracellular calcium response to directly applied mechanical shearing force in cultured vascular endothelial cells.  

UK PubMed Central (United Kingdom)

We studied the responses of cultured endothelial cells to mechanical shearing force directly applied to those cells in vitro to determine changes in the concentration of intracellular calcium ion (Ca++), one of the factors that transfers information within the cell. Cultured bovine fetal aortic endothelial cells containing the Ca++ fluorescence indicator, Fura-2, were rubbed with a latex balloon in a specially designed system, and changes in the fluorescence of Fura-2 caused by this shear stimulation were determined by photometric fluorescence microscopy. Immediately after shear stimulation, the concentration of Ca++ in the cells was increased and reached a peak (511 +/- 165 nM, n = 12) within 15 seconds after stimulation. After the peak, the concentration was gradually restored to the resting level (55 +/- 17 nM, n = 12). The magnitude of the Ca++ response was dependent on the intensity of the shear force applied. Analysis of fluorescence images of Fura-2 revealed that the cells showed this Ca++ reaction without being injured or desquamated, although there were slight differences in the degree and duration of reaction among cells. This reaction appeared even when the cells were placed in the air with no contact with the fluid. This result suggests that neither the fluid flow associated with the balloon movement nor chemical substances in the fluid are involved in the reaction, but that pure physical force alone is responsible for the Ca++ reaction. Further, it suggests that endothelial cells have the ability to perceive such physical stimulation as shear force and to transfer this information to the interior of the cell via changes in the intracellular Ca++ concentration.

Ando J; Ohtsuka A; Katayama Y; Korenaga R; Ishikawa C; Kamiya A

1994-01-01

220

Traditional Chinese medicine anther cap for controlling cardiovascular and cerebrovascular diseases, preparing method and quality control method thereof  

UK PubMed Central (United Kingdom)

The invention relates to a traditional Chinese medicine anther cap for controlling cardiovascular and cerebrovascular diseases, a preparing method and a quality control method thereof. The preparing method comprises the following steps of: proportioning and grinding astragalus root, salvia miltiorrhia, safflower, ginseng, shizandra, scorpin, cassia seed, hemlock parsley, borneol, chrysanthemum, rhizome gastrodiae, dogwood fruit, medlar, fructus alpiniae oxyphyllae, grass-leaved sweetflag, caulis polygoni multiflori and rhizome anemarrhenae powder sieving uniformly mixing uniformly spraying onto a cloth liner which is manufactured in advance coating and sewing into an anther cap core placing in a cap top interlayer and sealing. The invention is suitable for the apoplexy symptoms in each period, and cardiovascular and cerebrovascular diseases of hypertension, atherosclerosis, headache and dizziness, neurasthenia, and the like, and is used for preventing apoplexy.

TAO ZHAO

 
 
 
 
221

Traditional Chinese medicine anther cap for controlling cardiovascular and cerebrovascular diseases, preparing method and quality control method thereof  

UK PubMed Central (United Kingdom)

The invention relates to a traditional Chinese medicine anther cap for controlling cardiovascular and cerebrovascular diseases, a preparing method and a quality control method thereof. The preparing method comprises the following steps of: proportioning and grinding astragalus root, salvia miltiorrhia, safflower, ginseng, shizandra, cassia seed, hemlock parsley, borneol, chrysanthemum, rhizome gastrodiae, dogwood fruit, medlar, fructus alpiniae oxyphyllae, grass-leaved sweetflag, caulis polygoni multiflori and rhizome anemarrhenae powder sieving uniformly mixing uniformly spraying onto a cloth liner which is manufactured in advance coating and sewing into an anther cap core placing in a cap top interlayer and sealing. The invention is suitable for the apoplexy symptoms in each period, and cardiovascular and cerebrovascular diseases of hypertension, atherosclerosis, headache and dizziness, neurasthenia, and the like, and is used for preventing apoplexy.

TAO ZHAO

222

Mercuric chloride induces a stress response in cultured astrocytes characterized by mitochondrial uptake of iron.  

UK PubMed Central (United Kingdom)

Mercury exerts a variety of toxic effects on both neurons and glia. Mercury induces aberrations in microtubules, ion channels and mitochondria presumably by binding to sulfhydryl groups. Indirect evidence further suggests that mercury targeted to mitochondria may induce iron-catalyzed oxygen radical production. We have previously shown that the mitochondria of astrocytes subjected to oxidative stress accumulate redox active transition metals that may catalyze the formation of cytotoxic oxygen free radicals. In the present study we have investigated the effect of mercuric chloride on astrocytes in monolayer culture in order to determine whether mercury accumulates in astrocytic mitochondria and whether mercury exposure triggers a stress response-associated uptake of iron. Our results indicate that mercuric chloride exposure initiates the constellation of changes in mitochondrial structure that typifies the response of these cells to oxidative stress. Energy dispersive Xray microspectroscopy demonstrates that these altered mitochondria concentrate both mercury and iron. Concurrent with these changes, mercuric chloride treatment activates transcription of the heme oxygenase-1 (HO-1) gene in a dose dependent manner, further indicating an oxidative stress response. Thus, mercury-induced stress may transform innocuous astrocytes into potentially lethal sources of cytotoxic oxygen free radicals.

Brawer JR; McCarthy GF; Gornitsky M; Frankel D; Mehindate K; Schipper HM

1998-12-01

223

Mercuric chloride induces a stress response in cultured astrocytes characterized by mitochondrial uptake of iron.  

Science.gov (United States)

Mercury exerts a variety of toxic effects on both neurons and glia. Mercury induces aberrations in microtubules, ion channels and mitochondria presumably by binding to sulfhydryl groups. Indirect evidence further suggests that mercury targeted to mitochondria may induce iron-catalyzed oxygen radical production. We have previously shown that the mitochondria of astrocytes subjected to oxidative stress accumulate redox active transition metals that may catalyze the formation of cytotoxic oxygen free radicals. In the present study we have investigated the effect of mercuric chloride on astrocytes in monolayer culture in order to determine whether mercury accumulates in astrocytic mitochondria and whether mercury exposure triggers a stress response-associated uptake of iron. Our results indicate that mercuric chloride exposure initiates the constellation of changes in mitochondrial structure that typifies the response of these cells to oxidative stress. Energy dispersive Xray microspectroscopy demonstrates that these altered mitochondria concentrate both mercury and iron. Concurrent with these changes, mercuric chloride treatment activates transcription of the heme oxygenase-1 (HO-1) gene in a dose dependent manner, further indicating an oxidative stress response. Thus, mercury-induced stress may transform innocuous astrocytes into potentially lethal sources of cytotoxic oxygen free radicals. PMID:9863766

Brawer, J R; McCarthy, G F; Gornitsky, M; Frankel, D; Mehindate, K; Schipper, H M

1998-12-01

224

Defense/stress responses activated by chitosan in sycamore cultured cells.  

Science.gov (United States)

Chitosan (CHT) is a natural, non-toxic, and inexpensive compound obtained by partial alkaline deacetylation of chitin, the main component of the exoskeleton of crustaceans and other arthropods. The unique physiological and biological properties of CHT make this polymer useful for a wide range of industries. In agriculture, CHT is used to control numerous pre- and postharvest diseases on various horticultural commodities. In recent years, much attention has been devoted to CHT as an elicitor of defense responses in plants, which include raising of cytosolic Ca(2+), activation of MAP kinases, callose apposition, oxidative burst, hypersensitive response, synthesis of abscisic acid, jasmonate, phytoalexins, and pathogenesis-related proteins. In this work, we investigated the effects of different CHT concentrations on some defense/stress responses of sycamore (Acer pseudoplatanus L.) cultured cells. CHT induced accumulation of dead cells, and of cells with fragmented DNA, production of H(2)O(2) and nitric oxide, release of cytochrome c from the mitochondrion, accumulation of regulative 14-3-3 proteins in the cytosol and of HSP70 molecular chaperone binding protein in the endoplasmic reticulum, accompanied by marked modifications in the architecture of this cell organelle. PMID:21327845

Malerba, Massimo; Crosti, Paolo; Cerana, Raffaella

2011-02-14

225

Defense/stress responses activated by chitosan in sycamore cultured cells.  

UK PubMed Central (United Kingdom)

Chitosan (CHT) is a natural, non-toxic, and inexpensive compound obtained by partial alkaline deacetylation of chitin, the main component of the exoskeleton of crustaceans and other arthropods. The unique physiological and biological properties of CHT make this polymer useful for a wide range of industries. In agriculture, CHT is used to control numerous pre- and postharvest diseases on various horticultural commodities. In recent years, much attention has been devoted to CHT as an elicitor of defense responses in plants, which include raising of cytosolic Ca(2+), activation of MAP kinases, callose apposition, oxidative burst, hypersensitive response, synthesis of abscisic acid, jasmonate, phytoalexins, and pathogenesis-related proteins. In this work, we investigated the effects of different CHT concentrations on some defense/stress responses of sycamore (Acer pseudoplatanus L.) cultured cells. CHT induced accumulation of dead cells, and of cells with fragmented DNA, production of H(2)O(2) and nitric oxide, release of cytochrome c from the mitochondrion, accumulation of regulative 14-3-3 proteins in the cytosol and of HSP70 molecular chaperone binding protein in the endoplasmic reticulum, accompanied by marked modifications in the architecture of this cell organelle.

Malerba M; Crosti P; Cerana R

2012-01-01

226

Responses of cultured neural retinal cells to substratum-bound laminin and other extracellular matrix molecules.  

UK PubMed Central (United Kingdom)

The responses of cultured chick embryo retinal neurons to several extracellular matrix molecules are described. Retinal cell suspensions in serum-free medium containing the "N1" supplement (J. E. Bottenstein, S. D. Skaper, S. Varon, and J. Sato, 1980, Exp. Cell Res. 125, 183-190) were seeded on tissue culture plastic surfaces pretreated with polyornithine (PORN) and with one of the factors to be tested. Substantial cell survival could be observed after 72 hr in vitro on PORN pretreated with serum or laminin, whereas most cells appeared to be degenerating on untreated PORN, PORN-fibronectin, and PORN-chondronectin. Cell attachment, although quantitatively similar for all these substrata, was temperature-dependent on serum and laminin but not on fibronectin or untreated PORN. In a short-term bioassay, neurite development was abundant on laminin, scarce on serum and fibronectin, and absent on PORN. No positive correlation between cell spreading and neurite production could be seen: cell spreading was more extensive on PORN and fibronectin than on laminin or serum, while on laminin-treated dishes, spreading was similar for neurite-bearing and non-neurite-bearing cells. Laminin effects on retinal neurons were clearly substratum dependent. When bound to tissue culture plastic, laminin showed a dose-dependent inhibitory effect on cell attachment and did not stimulate neurite development. PORN-bound laminin, on the other hand, did not affect cell attachment but caused marked stimulation of neurite development, suggesting that laminin conformation and/or the spatial distribution of active sites play an important role in the neurite-promoting function of this extracellular matrix molecule. Investigation of the embryonic retina with ELISA and immunocytochemical methods showed that laminin is present in this organ during development. Therefore, in vivo and in vitro observations are consistent with the possibility that laminin might influence neuronal development in the retina.

Adler R; Jerdan J; Hewitt AT

1985-11-01

227

Isolation and characterization of CaMF3, an anther-specific gene in Capsicum annuum L.  

Directory of Open Access Journals (Sweden)

Full Text Available Previous work on gene expression analysis based on RNA sequencing identified a variety of differentially expressed cDNA fragments in the genic male sterile-fertile line 114AB of Capsicum annuum L. In this work, we examined the accumulation of one of the transcript-derived fragments (TDFs), CaMF3 (male fertile 3), in the flower buds of a fertile line. The full genomic DNA sequence of CaMF3 was 1,951 bp long and contained 6 exons and 5 introns, with the complete sequence encoding a putative 25.89 kDa protein of 234 amino acids. The predicted protein of CaMF3 shared sequence similarity with members of the isoamyl acetate-hydrolyzing esterase (IAH1) protein family. CaMF3 expression was detected only in flower buds at stages 7 and 8 and in open flowers of a male fertile line; no expression was observed in any organs of a male sterile line. Fine expression analysis revealed that CaMF3 was expressed specifically in anthers of the fertile line. These results suggest that CaMF3 is an anther-specific gene that may be essential for anther or pollen development in C. annuum.

Xuefeng Hao; Changming Chen; Guoju Chen; Bihao Cao; Qinghua Chen; Jianjun Lei

2012-01-01

228

Ketamine attenuates the lipopolysaccharide-induced inflammatory response in cultured N2a cells.  

Science.gov (United States)

The use of ketamine is recommended in patients with sepsis undergoing surgery due to its anti-inflammatory effects. However, a paucity of data exists with regard to the anti-inflammatory effects of ketamine in the central nervous system. Therefore, the present study aimed to investigate the effect of ketamine on lipopolysaccharide (LPS)?induced inflammatory responses in cultured Neuro2a (N2a) cells and to elucidate its potential mechanism of action. N2a cells were randomly divided into the following 3 groups (n=6): The DMEM culture solution administration alone group, the 0.5 µmol/l LPS administration alone group and the 1 µmol/l ketamine plus 0.5 µmol/l LPS administration group. The expression levels of interleukin (IL)-1?, IL-6, tumor necrosis factor (TNF)-?, nuclear factor (NF)-?B and inducible nitric oxide synthase (iNOS) were determined. LPS-treated N2a cells exhibited a significant increase in the expression levels of IL-1?, IL-6, TNF-?, NF-?B and iNOS, while the administration of ketamine eliminated the LPS-induced production of IL-1?, IL-6, TNF-?, NF-?B and iNOS. Based on our data, we hypothesized that the anti-inflammatory effect exerted by ketamine on N2a cells was potentially due to the inhibition of NF-?B and iNOS. PMID:23660699

Yang, Chun; Jiang, Ri-Yue; Shen, Jiang; Hong, Tao; Liu, Ning; Ding, Liang-Cai; Wang, Da-Ming; Chen, Lu-Jun; Xu, Bin; Zhu, Bin

2013-05-08

229

Ketamine attenuates the lipopolysaccharide-induced inflammatory response in cultured N2a cells.  

UK PubMed Central (United Kingdom)

The use of ketamine is recommended in patients with sepsis undergoing surgery due to its anti-inflammatory effects. However, a paucity of data exists with regard to the anti-inflammatory effects of ketamine in the central nervous system. Therefore, the present study aimed to investigate the effect of ketamine on lipopolysaccharide (LPS)?induced inflammatory responses in cultured Neuro2a (N2a) cells and to elucidate its potential mechanism of action. N2a cells were randomly divided into the following 3 groups (n=6): The DMEM culture solution administration alone group, the 0.5 µmol/l LPS administration alone group and the 1 µmol/l ketamine plus 0.5 µmol/l LPS administration group. The expression levels of interleukin (IL)-1?, IL-6, tumor necrosis factor (TNF)-?, nuclear factor (NF)-?B and inducible nitric oxide synthase (iNOS) were determined. LPS-treated N2a cells exhibited a significant increase in the expression levels of IL-1?, IL-6, TNF-?, NF-?B and iNOS, while the administration of ketamine eliminated the LPS-induced production of IL-1?, IL-6, TNF-?, NF-?B and iNOS. Based on our data, we hypothesized that the anti-inflammatory effect exerted by ketamine on N2a cells was potentially due to the inhibition of NF-?B and iNOS.

Yang C; Jiang RY; Shen J; Hong T; Liu N; Ding LC; Wang DM; Chen LJ; Xu B; Zhu B

2013-07-01

230

The specificity and genetic background of the rye (Secale cereale L.) tissue culture response.  

UK PubMed Central (United Kingdom)

Rye is one of the most important crops in Eastern and Northern Europe. Despite the numerous beneficial features of rye, its annual production decreases successively which correlates with the lack of progress in its breeding compared with other cereals. Biotechnological methods could effectively improve the breeding of rye. However, their application is highly limited by the absence of an efficient procedure for plant regeneration in vitro, since rye is one of the most recalcitrant cereals with regard to the tissue culture response (TCR), and successful regeneration is highly dependent on genotype. Efforts to understand the genetic mechanisms controlling TCR of rye have elucidated some basic aspects, and several genes and genome regions controlling this trait have been identified. The aim of this review is to summarize the limited current knowledge of this topic.

Targo?ska M; Hromada-Judycka A; Bolibok-Br?goszewska H; Rakoczy-Trojanowska M

2013-01-01

231

Recombinant bromelain production in Escherichia coli: process optimization in shake flask culture by response surface methodology.  

UK PubMed Central (United Kingdom)

Bromelain, a cysteine protease with various therapeutic and industrial applications, was expressed in Escherichia coli, BL21-AI clone, under different cultivation conditions (post-induction temperature, L-arabinose concentration and post-induction period). The optimized conditions by response surface methodology using face centered central composite design were 0.2% (w/v) L-arabinose, 8 hr and 25°C. The analysis of variance coupled with larger value of R2 (0.989) showed that the quadratic model used for the prediction was highly significant (p < 0.05). Under the optimized conditions, the model produced bromelain activity of 9.2 U/mg while validation experiments gave bromelain activity of 9.6 ± 0.02 U/mg at 0.15% (w/v) L-arabinose, 8 hr and 27°C. This study had innovatively developed cultivation conditions for better production of recombinant bromelain in shake flask culture.

Muntari B; Amid A; Mel M; Jami MS; Salleh HM

2012-01-01

232

Recombinant bromelain production in Escherichia coli: process optimization in shake flask culture by response surface methodology.  

Science.gov (United States)

Bromelain, a cysteine protease with various therapeutic and industrial applications, was expressed in Escherichia coli, BL21-AI clone, under different cultivation conditions (post-induction temperature, L-arabinose concentration and post-induction period). The optimized conditions by response surface methodology using face centered central composite design were 0.2% (w/v) L-arabinose, 8 hr and 25°C. The analysis of variance coupled with larger value of R2 (0.989) showed that the quadratic model used for the prediction was highly significant (p bromelain activity of 9.2 U/mg while validation experiments gave bromelain activity of 9.6 ± 0.02 U/mg at 0.15% (w/v) L-arabinose, 8 hr and 27°C. This study had innovatively developed cultivation conditions for better production of recombinant bromelain in shake flask culture. PMID:22336426

Muntari, Bala; Amid, Azura; Mel, Maizirwan; Jami, Mohammed S; Salleh, Hamzah M

2012-02-15

233

The presence of a culturally similar or dissimilar social partner affects neural responses to emotional stimuli  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Emotional responding is sensitive to social context; however, little emphasis has been placed on the mechanisms by which social context effects changes in emotional responding. Objective: We aimed to investigate the effects of social context on neural responses to emotional stimuli to inform on the mechanisms underpinning context-linked changes in emotional responding. Design: We measured event-related potential (ERP) components known to index specific emotion processes and self-reports of explicit emotion regulation strategies and emotional arousal. Female Chinese university students observed positive, negative, and neutral photographs, whilst alone or accompanied by a culturally similar (Chinese) or dissimilar researcher (British). Results: There was a reduction in the positive versus neutral differential N1 amplitude (indexing attentional capture by positive stimuli) in the dissimilar relative to alone context. In this context, there was also a corresponding increase in amplitude of a frontal late positive potential (LPP) component (indexing engagement of cognitive control resources). In the similar relative to alone context, these effects on differential N1 and frontal LPP amplitudes were less pronounced, but there was an additional decrease in the amplitude of a parietal LPP component (indexing motivational relevance) in response to positive stimuli. In response to negative stimuli, the differential N1 component was increased in the similar relative to dissimilar and alone (trend) context. Conclusion: These data suggest that neural processes engaged in response to emotional stimuli are modulated by social context. Possible mechanisms for the social-context-linked changes in attentional capture by emotional stimuli include a context-directed modulation of the focus of attention, or an altered interpretation of the emotional stimuli based on additional information proportioned by the context.

Kate A. Woodcock; Dian Yu; Yi Liu; Shihui Han

2013-01-01

234

Transient responses of nitrogenase to acetylene and oxygen in actinorhizal nodules and cultured Frania  

Energy Technology Data Exchange (ETDEWEB)

Nitrogenase activity in root nodules of four species of actinorhizal plants showed varying declines in response to exposure to acetylene (10% v/v). Gymnostoma papuanum (S.Moore) L. Johnson. and Casuarina equisetifolia L. nodules showed a small decline (5-15%) with little or no recovery over 15 minutes. Myrica gale L. nodules showed a sharp decline followed by a rapid return to peak activity. Alnus incana ssp. rugosa (Du Roi) Clausen. nodules usually showed varying degrees of decline followed by a slower return to peak or near-peak activity. We call these effects acetylene-induced transients. Rapid increases in oxygen tension also caused dramatic transient decreases in nitrogenase activity in all species. The magnitude of the transient decrease was related to the size of the O{sub 2} partial pressure (pO{sub 2}) rise, to the proximity of the starting and ending oxygen tensions to the pO{sub 2} optimum, and to the time for which the plant was exposed to the lower pO{sub 2}. Oxygen-induced transients, induced both by step jumps in pO{sub 2} and by O{sub 2} pulses, were also observed in cultures of Frankia. The effects seen in nodules are purely a response by the bacterium and not a nodule effect per se. Oxygen-induced nitrogenase transients in actinorhizal nodules from the plant genera tested here do not appear to be a result of changes in nodule diffusion resistance.

Silvester, W.B.; Winship, L.J. (Harvard Univ., Petersham, MA (USA))

1990-02-01

235

The Floral Sex-Differentiation of Xanthoceras sorbi folia and the Dynamics of Starch in Anthers  

UK PubMed Central (United Kingdom)

Anatomical and histochemical studies in the floral bud differentiation and development process of Xanthoceras sorbifolia Bunge have been carried out in this paper and the processes of floral sex-differentiation-the development of male and female flowers of Xanthoceras sorbifolia Bunge-have been compared. It has expressed that there is not any difference in morphology and structure between two types of flowers in the early stage of floral sex-differentiation. Distinct changes in the flowers of two types become noticeable only after the first mitosis of microspore. In pistillate flower, the pistil is normal, but the stamen develops slowly; filament is short in length; the tapetum disappears late; the anther is undehiscent; pollen cannot germinate. While, in the male flower, the stamen develops normally, the ovary stops developing in uninucleat stage of embryo sac and degenerates speedily. It is hypothesized that the main factor affecting floral sex-differentiation is closely related to the nutrient situation of tree and floral bud. In the pollen of the pistillate flower, less starch accumulation appears than in the pollen of the male flower during the whole period of microsporogenesis. This could be related to nutritive competition between ovary and stamen. The pollens abortion is due to the shortage of nutrient material and energy.

Wang Jinhua; Li Fenglan; Gao Rongfu

1992-01-01

236

Extensive divergence between mating-type chromosomes of the anther-smut fungus.  

Science.gov (United States)

Genomic regions that determine mating compatibility are subject to distinct evolutionary forces that can lead to a cessation of meiotic recombination and the accumulation of structural changes between members of the homologous chromosome pair. The relatively recent discovery of dimorphic mating-type chromosomes in fungi can aid the understanding of sex chromosome evolution that is common to dioecious plants and animals. For the anther-smut fungus, Microbotryum lychnidis-dioicae (= M. violaceum isolated from Silene latifolia), the extent of recombination cessation on the dimorphic mating-type chromosomes has been conflictingly reported. Comparison of restriction digest optical maps for the two mating-type chromosomes shows that divergence extends over 90% of the chromosome lengths, flanked at either end by two pseudoautosomal regions. Evidence to support the expansion of recombination cessation in stages from the mating-type locus toward the pseudoautosomal regions was not found, but evidence of such expansion could be obscured by ongoing processes that affect genome structure. This study encourages the comparison of forces that may drive large-scale recombination suppression in fungi and other eukaryotes characterized by dimorphic chromosome pairs associated with sexual life cycles. PMID:23150606

Hood, Michael E; Petit, Elsa; Giraud, Tatiana

2012-11-12

237

Extensive divergence between mating-type chromosomes of the anther-smut fungus.  

UK PubMed Central (United Kingdom)

Genomic regions that determine mating compatibility are subject to distinct evolutionary forces that can lead to a cessation of meiotic recombination and the accumulation of structural changes between members of the homologous chromosome pair. The relatively recent discovery of dimorphic mating-type chromosomes in fungi can aid the understanding of sex chromosome evolution that is common to dioecious plants and animals. For the anther-smut fungus, Microbotryum lychnidis-dioicae (= M. violaceum isolated from Silene latifolia), the extent of recombination cessation on the dimorphic mating-type chromosomes has been conflictingly reported. Comparison of restriction digest optical maps for the two mating-type chromosomes shows that divergence extends over 90% of the chromosome lengths, flanked at either end by two pseudoautosomal regions. Evidence to support the expansion of recombination cessation in stages from the mating-type locus toward the pseudoautosomal regions was not found, but evidence of such expansion could be obscured by ongoing processes that affect genome structure. This study encourages the comparison of forces that may drive large-scale recombination suppression in fungi and other eukaryotes characterized by dimorphic chromosome pairs associated with sexual life cycles.

Hood ME; Petit E; Giraud T

2013-01-01

238

History of the invasion of the anther smut pathogen on Silene latifolia in North America.  

Science.gov (United States)

Understanding the routes of pathogen introduction contributes greatly to efforts to protect against future disease emergence. Here, we investigated the history of the invasion in North America by the fungal pathogen Microbotryum lychnidis-dioicae, which causes the anther smut disease on the white campion Silene latifolia. This system is a well-studied model in evolutionary biology and ecology of infectious disease in natural systems. Analyses based on microsatellite markers show that the introduced American M. lychnidis-dioicae probably came from Scotland, from a single population, and thus suffered from a drastic bottleneck compared with genetic diversity in the native European range. The pattern in M. lychnidis-dioicae contrasts with that found by previous studies in its host plant species S. latifolia, also introduced in North America. In the plant, several European lineages have been introduced from across Europe. The smaller number of introductions for M. lychnidis-dioicae probably relates to its life history traits, as it is an obligate, specialized pathogen that is neither transmitted by the seeds nor persistent in the environment. The results show that even a nonagricultural, biotrophic, and insect-vectored pathogen suffering from a very strong bottleneck can successfully establish populations on its introduced host. PMID:23406496

Fontaine, Michael C; Gladieux, Pierre; Hood, Michael E; Giraud, Tatiana

2013-02-13

239

History of the invasion of the anther smut pathogen on Silene latifolia in North America.  

UK PubMed Central (United Kingdom)

Understanding the routes of pathogen introduction contributes greatly to efforts to protect against future disease emergence. Here, we investigated the history of the invasion in North America by the fungal pathogen Microbotryum lychnidis-dioicae, which causes the anther smut disease on the white campion Silene latifolia. This system is a well-studied model in evolutionary biology and ecology of infectious disease in natural systems. Analyses based on microsatellite markers show that the introduced American M. lychnidis-dioicae probably came from Scotland, from a single population, and thus suffered from a drastic bottleneck compared with genetic diversity in the native European range. The pattern in M. lychnidis-dioicae contrasts with that found by previous studies in its host plant species S. latifolia, also introduced in North America. In the plant, several European lineages have been introduced from across Europe. The smaller number of introductions for M. lychnidis-dioicae probably relates to its life history traits, as it is an obligate, specialized pathogen that is neither transmitted by the seeds nor persistent in the environment. The results show that even a nonagricultural, biotrophic, and insect-vectored pathogen suffering from a very strong bottleneck can successfully establish populations on its introduced host.

Fontaine MC; Gladieux P; Hood ME; Giraud T

2013-05-01

240

The unfolded protein response to endoplasmic reticulum stress in cultured astrocytes and rat brain during experimental diabetes.  

UK PubMed Central (United Kingdom)

Oxidative-nitrosative stress and inflammatory responses are associated with endoplasmic reticulum (ER) stress in diabetic retinopathy, raising the possibility that disturbances in ER protein processing may contribute to CNS dysfunction in diabetics. Upregulation of the unfolded protein response (UPR) is a homeostatic response to accumulation of abnormal proteins in the ER, and the present study tested the hypothesis that the UPR is upregulated in two models for diabetes, cultured astrocytes grown in 25mmol/L glucose for up to 4weeks and brain of streptozotocin (STZ)-treated rats with diabetes for 1-7months. Markers associated with translational blockade (phospho-eIF2? and apoptosis (CHOP), inflammatory response (inducible nitric oxide synthase, iNOS), and nitrosative stress (nuclear translocation of glyceraldehyde-3-phosphate dehydrogenase, GAPDH) were not detected in either model. Nrf2 was present in nuclei of low- and high-glucose cultures, consistent with oxidative stress. Astrocytic ATF4 expression was not altered by culture glucose concentration, whereas phospho-IRE and ATF6 levels were higher in low- compared with high-glucose cultures. The glucose-regulated chaperones, GRP78 and GRP94, were also expressed at higher levels in low- than high-glucose cultures, probably due to recurrent glucose depletion between feeding cycles. In STZ-rat cerebral cortex, ATF4 level was transiently reduced at 4months, and p-IRE levels were transiently elevated at 3months. However, GRP78 and GRP94 expression was not upregulated, and iNOS, amyloid-?, and nuclear accumulation of GAPDH were not evident in STZ-diabetic brain. High-glucose cultured astrocytes and STZ-diabetic brain are relatively resistant to diabetes-induced ER stress, in sharp contrast with cultured retinal Müller cells and diabetic rodent retina.

Lind KR; Ball KK; Cruz NF; Dienel GA

2013-04-01

 
 
 
 
241

Dynamic culture substrate that captures a specific extracellular matrix protein in response to light  

Directory of Open Access Journals (Sweden)

Full Text Available The development of methods for the off–on switching of immobilization or presentation of cell-adhesive peptides and proteins during cell culture is important because such surfaces are useful for the analysis of the dynamic processes of cell adhesion and migration. This paper describes a chemically functionalized gold substrate that captures a genetically tagged extracellular matrix protein in response to light. The substrate was composed of mixed self-assembled monolayers (SAMs) of three disulfide compounds containing (i) a photocleavable poly(ethylene glycol) (PEG), (ii) nitrilotriacetic acid (NTA) and (iii) hepta(ethylene glycol) (EG7). Although the NTA group has an intrinsic high affinity for oligohistidine tag (His-tag) sequences in its Ni2+-ion complex, the interaction was suppressed by the steric hindrance of coexisting PEG on the substrate surface. Upon photoirradiation of the substrate to release the PEG chain from the surface, this interaction became possible and hence the protein was captured at the irradiated regions, while keeping the non-specific adsorption of non-His-tagged proteins blocked by the EG7 underbrush. In this way, we selectively immobilized a His-tagged fibronectin fragment (FNIII7–10) to the irradiated regions. In contrast, when bovine serum albumin—a major serum protein—was added as a non-His-tagged protein, the surface did not permit its capture, with or without irradiation. In agreement with these results, cells were selectively attached to the irradiated patterns only when a His-tagged FNIII7-10 was added to the medium. These results indicate that the present method is useful for studying the cellular behavior on the specific extracellular matrix protein in cell-culturing environments.

Jun Nakanishi, Hidekazu Nakayama, Kazuo Yamaguchi, Andres J Garcia and Yasuhiro Horiike

2011-01-01

242

Digestive enzyme response to natural and formulated diets in cultured juvenile spiny lobster, Jasus edwardsii  

UK PubMed Central (United Kingdom)

A better understanding of the nutritional requirements and digestive processes are essential for improving the consumption and growth of spiny lobsters on formulated diets used in commercial culture. Differences in the enzymatic digestive response (i.e., post-prandial changes in digestive enzyme activity, digestive fluid pH and digestive gland structure) of juvenile Jasus edwardsii fed either a natural (mussel flesh) or a formulated diet were investigated. Digestive enzyme activities (total protease, trypsin, ?-amylase and ?-glucosidase) and soluble protein concentration in the foregut after a single feeding event for the two dietary treatments displayed a common peak at 4h, and a second peak at 18h post-prandial for the mussel fed lobsters only. In lobsters fed the formulated diet, the lumen size of the digestive gland tubules was 88% larger, the number of B-cells per tubule at 18h post-feeding was 269% higher, and the pH of the digestive gland was lower (6.20 versus 6.34) than in lobsters fed mussel flesh. These results indicated an intensified intracellular digestion in the digestive gland on the formulated diet that could have played a role in the poor appetite revival (>18h) exhibited on this diet. Rearing of juvenile lobsters on the formulated diet for 6months resulted in a marked decrease in the digestive capacity (i.e., total and specific enzyme activity of the foregut and digestive gland) and nutritional condition of lobsters. Overall, these results suggest that difficulty in the digestive processing of formulated feeds may help to explain the bottlenecks encountered in developing more effective formulated diets for juvenile spiny lobster culture. Improvements in the dissolution of dietary ingredients upon entering the foregut, and in the digestibility of dietary carbohydrate sources, may assist in further improving the performance of formulated diets for lobsters.

Simon CedricJ

2009-09-01

243

Response of peripheral blood mononuclear cells to conditioned medium from cultured oral squamous cell carcinomas  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The current study investigated the capacity for tumor factors secreted by head and neck squamous cell carcinoma (HNSCC) cell lines, KB, KB16, and HEP, to induce the secretion of various cytokines from peripheral blood mononuclear cells (PBMCs). PBMCs were isolated from blood samples collected from six healthy volunteers and these cells were incubated for 6, 24, 48, or 72 hours in the presence of 50% conditioned medium collected from cultured cell lines pretreated with, or (more) without, stimulants such as phytohemagglutinin (PHA) or lipopolysaccharides (LPS). Aliquots of each supernatant were then assayed for levels of IFN-?, vascular endothelial growth factor (VEGF), TNF-?, and IL-4 using enzyme linked immunosorbent assays (ELISAs). Data collected were analyzed using Student's t-test, an ANOVA test followed by Tukey's test, and tests of Pearson's Correlation. PBMCs cultured with KB16-conditioned medium produced the highest levels of IFN-?. VEGF was also detected in conditioned media collected from all of the squamous cell carcinoma (SCC) cell lines used, and a significant difference in VEGF levels between control and KB- or KB16-conditioned media was observed. TNF-? was secreted by all PBMC groups within 6 hours of receiving conditioned media, and these levels increased up to the 24 hour timepoint, after which levels of TNF-? stabilized. In contrast, none of the supernatant samples contained detectable levels of IL-4. In combination, these data suggest that direct contact between fresh human PBMCs and conditioned media from tumor cells induces the secretion of TNF-? and VEGF by PBMCs, and this represents an initial angiogenic response.

França, Cristiane Miranda; Barros, Fabiana Mesquita; Lotufo, Monica Andrade; Fernandes, Kristianne Porta Santos; Borra, Ricardo Carneiro

2011-10-01

244

Effects of short-term culturing on islet phosphoinositide and insulin secretory responses to glucose and carbachol.  

Science.gov (United States)

The ability of glucose and carbachol, alone or in combination, to stimulate islet cell phosphoinositide (PI) hydrolysis and insulin secretory responses in freshly isolated or in 20-24 h cultured rat islets was assessed. In freshly isolated, 3H-inositol-prelabeled islets, 20 mM glucose alone or 1 mM carbachol alone stimulated significant increments in 3H-inositol efflux and inositol phosphate (IP) accumulation. When stimulated with both agonists, a dramatic and synergistic effect on IP accumulation was noted. Carbachol (1 mM) alone had no sustained stimulatory effect on insulin secretion. Glucose (20 mM) alone induced a biphasic insulin secretory response. When compared to prestimulatory secretory rates of 18 +/- 4 pg/islet/min, peak first and second phase responses now averaged 422 +/- 61 and 1016 +/- 156 pg/islet/min, respectively. In contrast to freshly studied islets, culturing islets for 20-24 h in CMRL-1066 medium attenuated all measured responses. The increases in 3H-inositol efflux rates in response to glucose, carbachol, or their combination were significantly less than those observed with fresh islets. The IP responses were also attenuated. Second phase insulin secretory responses to 20 mM glucose alone 68 +/- 9 pg/islet/min) or the combination of 20 mM glucose plus 1 mM carbachol (358 +/- 85 pg/islet/min) were also significantly decreased when compared with fresh islets. We conclude from these studies that the process of culturing islets for one day in CMRL-1066 significantly decreases islet cell PI hydrolysis and insulin secretory responsiveness. These observations may help to explain the discordant conclusions reached concerning the involvement of PI hydrolysis and protein kinase C activation in the regulation of insulin release from freshly isolated versus cultured islets. PMID:8590784

Zawalich, W S; Zawalich, K C; Kelley, G G

1995-10-01

245

Cordysinocan, a polysaccharide isolated from cultured Cordyceps, activates immune responses in cultured T-lymphocytes and macrophages: signaling cascade and induction of cytokines.  

UK PubMed Central (United Kingdom)

Cordyceps sinensis, a well-known traditional Chinese medicine, possesses activities in anti-tumor, anti-oxidation and stimulating the immune response; however, the identity of active component(s) is not determined. A strain of Cordyceps sinensis, namely UST 2000, has been isolated. By using activity-guided purification, a novel polysaccharide of molecular weight approximately 82 kDa was isolated from the conditioned medium of cultured Cordyceps. The isolated exo-polysaccharide, namely cordysinocan, contains glucose, mannose, galactose in a ratio of 2.4:2:1. In cultured T-lymphocytes, application of cordysinocan induced the cell proliferation and the secretion of interleukin-2, interleukin-6 and interleukin-8. In addition, the phosphorylation of extracellular signal-regulated kinases (ERK) was induced transiently by the treatment of cordysinocan. Moreover, application of cordysinocan in cultured macrophages increased the phagocytosis activity and the enzymatic activity of acid phosphatase. These results therefore verify the important role of Cordyceps polysaccharide in triggering such immune responses.

Cheung JK; Li J; Cheung AW; Zhu Y; Zheng KY; Bi CW; Duan R; Choi RC; Lau DT; Dong TT; Lau BW; Tsim KW

2009-07-01

246

Evaluation of Rice (Oryza sativa L.) Cultivars Response to Salinity Stress Through Greenhouse Experiment and Tissue Culture Technique  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The response to salinity stress of 4 rice cultivars was evaluated through a greenhouse experiment and a tissue culture technique at Agricultural College, Mazandaran University, Sari, Iran, during 2003. In the first experiment, carried out at seedling stage, three salinity levels (0, 75 and 150 mmol ...

Sahab Rahmanzadeh; Kamal Kazemitabar; Shahin Yazdifar; Azarakhsh Torabi Jafroudi

247

Exploring the Relationship between Self-Awareness and Student Commitment and Understanding of Culturally Responsive Social Work Practice  

Science.gov (United States)

This study explores the relationship between self-awareness and social work students' commitment and understanding of culturally responsive social work practice. Data consisted of assigned papers (N = 23), submitted by graduate social work students, which asked them to describe their ethnic/racial background and ancestors' process of assimilation,…

Bender, Kimberly; Negi, Nalini; Fowler, Dawnovise N.

2010-01-01

248

Different responses of Fe transporters in Caco2/HT29-MTX cocultures than in independent Caco-2 cell cultures  

Science.gov (United States)

The human intestinal epithelium is composed of several cell types; mainly enterocytes and globet (mucin-secreting) cells. This study compares the cellular response for Fe transporters in Caco-2, HT29-MTX, and Caco-2/HT29-MTX coculture models for Fe bioavailability studies. Under culture, Caco-2 cell...

249

Theory and Practice of Positive Feminist Therapy: A Culturally Responsive Approach to Divorce Therapy with Chinese Women  

Science.gov (United States)

Positive Feminist Therapy (PFT) is a strength-based culturally responsive therapy model specifically designed for helping Chinese women facing marital conflicts and divorce, integrating Empowerment Feminist Therapy, systems theory, and positive psychology. To help clients become change agents, PFT uses clients' existing strengths to develop…

Tzou, Jean Yuh-Jin; Kim, Eunha; Waldheim, Kim

2012-01-01

250

Exploring the Relationship between Self-Awareness and Student Commitment and Understanding of Culturally Responsive Social Work Practice  

Science.gov (United States)

|This study explores the relationship between self-awareness and social work students' commitment and understanding of culturally responsive social work practice. Data consisted of assigned papers (N = 23), submitted by graduate social work students, which asked them to describe their ethnic/racial background and ancestors' process of…

Bender, Kimberly; Negi, Nalini; Fowler, Dawnovise N.

2010-01-01

251

Cross cultural adaptation of the Achilles tendon Total Rupture Score with reliability, validity and responsiveness evaluation.  

UK PubMed Central (United Kingdom)

PURPOSE: The Achilles tendon Total Rupture Score (ATRS) was developed because of the need for a reliable, valid and sensitive instrument to evaluate symptoms and their effects on physical activity in patients following either conservative or surgical management of an Achilles tendon rupture. Prior to using the score in larger randomized trial in an English-speaking population, we decided to perform reliability, validity and responsiveness evaluations of the English version of the ATRS. Even though the score was published in English, the actual English version has not be validated and compared to the results of the Swedish version. METHODS: From 2009 to 2010, all patients who received treatment for Achilles tendon rupture were followed up using the English version of the ATRS. Patients were asked to complete the score at 3, 6 and 12 months following treatment for Achilles tendon rupture. The ATRS was completed on arrival in the outpatient clinic and again following consultation. RESULTS: The outcomes of 49 (13 female and 36 male) patients were assessed. The mean (SD) age was 49 (12) years, and 27 patients had treatment for a left-sided rupture, 22 the right. All patients received treatment for ruptured Achilles tendons: 38 acute percutaneous repair, 1 open repair, 5 an Achilles tendon reconstruction using a Peroneus Brevis tendon transfer for delayed presentation, 1 gracilis augmented repair for re-rupture and 4 non-operative treatment for mid-portion rupture. The English version of ATRS was shown to have overall excellent reliability (ICC = 0.986). There was no significant difference between the results with the English version and the Swedish version when compared at the 6-month- or 12-month (n.s.) follow-up appointments. The effect size was 0.93. The minimal detectable change was 6.75 points. CONCLUSIONS: The ATRS was culturally adapted to English and shown to be a reliable, valid and responsive method of testing functional outcome following an Achilles tendon rupture.

Carmont MR; Silbernagel KG; Nilsson-Helander K; Mei-Dan O; Karlsson J; Maffulli N

2013-06-01

252

Growth response and survival of Heterobranchus longifilis cultured at different water levels in outdoor concrete tanks  

Directory of Open Access Journals (Sweden)

Full Text Available Thirteen-day-old hatchery-raised fry obtained from hormonally-induced spawns of mature African catfish H. longifilis brood stock were introduced to three different water levels (0.35, 0.50 and 0.65m) in four replicates in 12 units of 2x2x1m3 outdoor concrete tanks. The fry were similarly stocked initially at 50 fry m-2 and later thinned down to 5 fish m-2 and cultured for 6 months. Fish were fed twice daily with commercial pellet feeds (Coppens™) while adjusting the feeding rate from 10 to 4% body weight and pellet size from 0.2 to 4.5 mm. The effects of pond water levels were evaluated in growth responses and survival. Water quality variables were similar (p > 0.05) in all compartments. Temperature, dissolved oxygen and pH were at the optimum level for fish. The results reveal significant (P H. longifilis from fry to sub-adult and from the grow-out/fattening of sub-adult to adult, respectively, in outdoor concrete tanks.

Anthony A. Nlewadim; James P. Udoh; Aniekan J. Otoh

2011-01-01

253

Cultivate in vitro of wheat Anthers (Triticum Aestivum L.) In the ICA-TENZA and PAV -76 varieties  

International Nuclear Information System (INIS)

[en] The objective of the present work consisted, in determining the cultivation conditions under which it was possible to induce through the technique of the cultivation of anthers, the callus formation and possible regeneration of green plants of wheat (Triticum aestivum L.) in the varieties ICA-Tenza and Pav -76. With the purpose of identifying the but appropriate state of development of the grain of pollen for the inoculation of the anthers, a cytologic study was made in which was correlation among the moriolic parameters of the plant; (inter liguler distances, auricle-knot distances and longitude of the edges) and the state of development of the microspore; Of the parameters, it was recommended to keep in mind the longitude from the edges when harvesting the experimental material. The anthers of both genotypes were inoculated in the means bases Pope 4 and N6, with hormonal levels of ELL (naftalen acetic acid) of 0.0, 0.5 and 1.0 mg/I. the answers of the genotypes were evaluated before the means of basal cultivation, in connection with the induction of tripes and the plants regeneration. Of the two used genotypes, the Pav -76 it presented bigger capacity to induce the formation of tripes, while the ICA-Tenza genotype presented a bigger answer capacity in the regeneration of plants so much green as albino. The results obtained allowed to establish that a relationship exists between the means of cultivation and the capacity of the genotypes to regenerate as much tripes as plants. Due to the drop survival of the regenerated plants, it was not possible to settle down with clarity a relationship of the ploidia level

1994-01-01

254

Characterization of a Collection of Brassica carinata Genotypes for in vitro Culture Response and Mode of Shoot Regeneration  

Directory of Open Access Journals (Sweden)

Full Text Available Brassica carinata, a natural alloploid formed between B. oleracea and B. nigra, is a potential oil crop for the Mediterranean area in which genetic transformation could help to breeding. In vitro culture and shoot regeneration are key factors in developing an efficient transformation method in the genus Brassica. However, the studies for in vitro culture and shoot regeneration in B. carinata are limited to only a few genotypes. The aim of this study was to evaluate the in vitro culture response and shoot regeneration in a collection of B. carinata accessions to identify promising genotypes with high shoot regeneration for genetic transformation experiments. Cotyledonary explants from 51 genotypes were cultured in vitro and callus formation and swelling as well as the mode of shoot regeneration evaluated. A highly positive response to in vitro culture, i.e. callus formation or swelling, was observed in all the genotypes tested. Tissue blackening occurred only in eleven genotypes. Parameters like callus formation and swelling, and number of shoots per explant were highly variable among genotypes. Fourteen genotypes regenerated only via callus formation, whereas only one regenerated only via swelling. Most genotypes showed a higher percentage of callus formation than swelling. The average number of shoots regenerating per explant among genotypes was the most variable factor measured. Six genotypes regenerated more than 6 shoots per explant via callus phase. These genotypes have been identified as having a high regeneration potential and can be used in genetic transformation via Agrobacterium.

Javier Gil-Humanes; Antonio Martín; Francisco Barro

2011-01-01

255

Failure of androgenesis in Miscanthus × giganteus in vitro culture of cytologically unbalanced microspores.  

Science.gov (United States)

Miscanthus × giganteus is a popular energy crop, which due to its hybrid origin is only vegetatively reproduced. Asexual embryogenesis in anther and microspore culture leading to double haploids production could allow to regain the ability for sexual reproduction and to increase the biodiversity of the species. Therefore, the goal of this paper was to investigate the requirements of androgenesis in Miscanthus. The standard protocols used for monocotyledonous plants were applied with many modifications regarding the developmental stage of the explants at the time of culture initiation, stress treatment applied to panicles and isolated anthers as well as various chemical and physical parameters of in vitro culture conditions. Our results indicated that the induction of androgenesis in M. × giganteus is possible. However, the very low efficiency of the process and the lack of regeneration ability of the androgenic structures presently prevent the use of this technique. PMID:23824237

?ur, Iwona; Dubas, Ewa; S?omka, Aneta; Dubert, Franciszek; Kuta, El?bieta; P?a?ek, Agnieszka

2013-07-04

256

Cold response of dedifferentiated barley cells at the gene expression, hormone composition, and freezing tolerance levels: studies on callus cultures.  

Science.gov (United States)

In this study, data is presented how dark-grown, embryogenic barley callus cells respond to cold without any light-dependent, chloroplast-related mechanism, independently of the systemic signals. The expression of HvCBF9, HvCBF14, and HvCOR14b genes, members of one of the most important cold-inducible regulatory system, was measured by real-time PCR. Characteristic of the cold response was similar in the crowns of seedlings and in dark-grown callus cultures, however, gene expression levels were lower in calli. Endogenous concentration of auxins, abscisic acid, and salicylic acid did not change, but phaseic acid and neophaseic acid showed robust accumulation after cold acclimation. Freezing tolerance of the cultures was also higher after 7 days of cold-hardening. The results suggest the presence of a basal, light-independent, cold-responsive activation of the CBF-COR14b pathway in barley cultures. The effects of Dicamba, the exogenous auxin analog used for maintaining tissue cultures were also studied. Dicamba seems to be a general enhancer of the gene expression and physiological responses to cold stress, but has no specific effect on the activation. Our data along with previous findings show that this system might be a suitable model for studying certain basic cellular mechanisms involved in the cold acclimation process in cereals. PMID:22669585

Vashegyi, Ildikó; Marozsán-Tóth, Zsuzsa; Galiba, Gábor; Dobrev, Petre I; Vankova, Radomira; Tóth, Balázs

2013-06-01

257

Cold response of dedifferentiated barley cells at the gene expression, hormone composition, and freezing tolerance levels: studies on callus cultures.  

UK PubMed Central (United Kingdom)

In this study, data is presented how dark-grown, embryogenic barley callus cells respond to cold without any light-dependent, chloroplast-related mechanism, independently of the systemic signals. The expression of HvCBF9, HvCBF14, and HvCOR14b genes, members of one of the most important cold-inducible regulatory system, was measured by real-time PCR. Characteristic of the cold response was similar in the crowns of seedlings and in dark-grown callus cultures, however, gene expression levels were lower in calli. Endogenous concentration of auxins, abscisic acid, and salicylic acid did not change, but phaseic acid and neophaseic acid showed robust accumulation after cold acclimation. Freezing tolerance of the cultures was also higher after 7 days of cold-hardening. The results suggest the presence of a basal, light-independent, cold-responsive activation of the CBF-COR14b pathway in barley cultures. The effects of Dicamba, the exogenous auxin analog used for maintaining tissue cultures were also studied. Dicamba seems to be a general enhancer of the gene expression and physiological responses to cold stress, but has no specific effect on the activation. Our data along with previous findings show that this system might be a suitable model for studying certain basic cellular mechanisms involved in the cold acclimation process in cereals.

Vashegyi I; Marozsán-Tóth Z; Galiba G; Dobrev PI; Vankova R; Tóth B

2013-06-01

258

Physiological Responses of Rice Seedling (Oryza sativa L.) to Salt-stress Cultured under in vitro Photomixotrophic and Photoautotrophic Systems  

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Full Text Available Physiological responses of crop species to salt-stress in conventional in vitro culture may be found some errors due to sucrose as a main carbon source, causing to erratic data. Seven-day-old in vitro seedlings were aseptically transferred to culture under photoautotrophic and photomixotrophic systems for 13 days, subsequently adjusted to 0 and 342 mM NaCl. The pigment degradation of seedlings grown in 342 mM NaCl was positively related to NPR reduction in both the photoautotrophic (r=0.84) and the photomixotrophic system (r=0.95). This resulted in low growth, as measured by leaf expansion, shoot height, root length, fresh weight and dry weight. Moreover, the NPR reduction of seedlings cultured with 342 mM NaCl was positively related to the low survival percentage for both the photoautotrophic (r=0.96) and the photomixotrophic system (r=0.98). Moreover, the phenotypic responses of photoautotrophic seedlings to salt-stress expressed a more realistic phenotype than the photomixotrophic system. Besides, the phenotypic expression of seedlings cultured under photoautotrophic system responded more sensitively to salt-stress than those photomixotrophic system. Therefore, study of the phenotypic responses of seedlings to salt-stress would make use of the photoautotrophic system. This system should be a novel process for phenotypic expression of in vitro to salt stress.

Suriyan Cha-um; Kanyaratt Supaibulwatana; Chalermpol Kirdmanee

2005-01-01

259

Changes of defense proteins in the extracellular proteome of grapevine (Vitis vinifera cv. Gamay) cell cultures in response to elicitors.  

UK PubMed Central (United Kingdom)

In plant cells, elicitors induce defense responses that resemble those triggered by pathogen attack, such as the synthesis of phytoalexins and pathogen-related proteins which accumulate in the extracellular space. In the search for the particular proteins involved in defense responses, we investigated the changes in the extracellular proteome of a grapevine (Vitis vinifera cv. Gamay) cell suspension in response to elicitation with methylated cyclodextrins (MBCD) and methyl jasmonate (MeJA). Twenty-five of the 39 spots differentially expressed in 2-D gels were identified and found to be encoded by 10 different genes: three secretory peroxidases, chitinase-III, beta-1,3-glucanase, thaumatin-like, SGNH plant lipase-like, NtPR27-like, xyloglucan endotransglycosylase and subtilisin-like protease. Most of them belong to the pathogenesis-related type proteins. A new class III secretory basic peroxidase and chitinase III were strongly induced in cultures treated with MBCD alone or combined with MeJA, while cultures treated with MeJA alone displayed a general repression of most of the extracellular proteins. Some of the proteins induced in grapevine cell cultures by MBCD are induced in other species by activators of systemic acquired resistance (SAR), a form of plant immunity. Collectively, the results suggest that treatment with MBCD resembles the effect of SAR induction agents in cell cultures.

Martinez-Esteso MJ; Sellés-Marchart S; Vera-Urbina JC; Pedreño MA; Bru-Martinez R

2009-12-01

260

A refined in vitro model to study inflammatory responses in organotypic membrane culture of postnatal rat hippocampal slices  

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Full Text Available Abstract Background Propagated tissue degeneration, especially during aging, has been shown to be enhanced through potentiation of innate immune responses. Neurodegenerative diseases and a wide variety of inflammatory conditions are linked together and several anti-inflammatory compounds considered as having therapeutic potential for example in Alzheimer's disease (AD). In vitro brain slice techniques have been widely used to unravel the complexity of neuroinflammation, but rarely, has the power of the model itself been reported. Our aim was to gain a more detailed insight and understanding of the behaviour of hippocampus tissue slices in serum-free, interface culture per se and after exposure to different pro- and anti-inflammatory compounds. Methods The responses of the slices to pro- and anti-inflammatory stimuli were monitored at various time points by measuring the leakage of lactate dehydrogenase (LDH) and the release of cytokines interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-?) and nitric oxide (NO) from the culture media. Histological methods were applied to reveal the morphological status after exposure to stimuli and during the time course of the culture period. Statistical power analysis were made with nQuery Advisor®, version 5.0, (Statistical Solutions, Saugus, MA) computer program for Wilcoxon (Mann-Whitney) rank-sum test. Results By using the interface membrane culture technique, the hippocampal slices largely recover from the trauma caused by cutting after 4–5 days in vitro. Furthermore, the cultures remain stable and retain their responsiveness to inflammatory stimuli for at least 3 weeks. During this time period, cultures are susceptible to modification by inflammatory stimuli as assessed by quantitative biochemical assays and morphological characterizations. Conclusion The present report outlines the techniques for studying immune responses using a serum-free slice culture model. Statistically powerful data under controlled culture conditions and with ethically justified use of animals can be obtained as soon as after 4–5 DIV. The model is most probably suitable also for studies of chronic inflammation.

Huuskonen Jari; Suuronen Tiina; Miettinen Riitta; van Groen Thomas; Salminen Antero

2005-01-01

 
 
 
 
261

Cell-mediated immune response to products of Actinomyces viscosus cultures.  

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Hartley strain guinea pigs were sensitized with 0.5 ml of concentrated cell-free Actinomyces viscosus culture supernatant fluids mixed with Freund complete adjuvant. Fourteen to 16 days later the animals were challenged by intradermal injection with 0.1 ml of the culture supernatant, and the reactio...

Turner, D W; Roberson, B S; Longton, R W

262

Regenerated extracellular NH4+ affects the motile chemosensory responses of batch-cultured Oxyrrhis marina  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Regenerated extracellular NH4+in laboratory batch-cultures of the heterotrophic marine microzooplankter Oxyrrhis marina affects the strength and consistency of chemotaxes elicited by synthetic and biogenic chemoattractants. The ecological relevance of experiments with batch-cultured O. marina and limitations of the microcapillary assay for the study of chemosensory behaviours are discussed.

Martel, Claire M.

2010-06-01

263

Keeping up the Conversation on Culture: A Response to Robert Courchene and Others  

Science.gov (United States)

Robert Courchene's 1996 article entitled "Teaching Canadian Culture: Teacher Preparation" sparked a conversation in the pages of the "TESL Canada Journal" that continues today. From advocating the teaching of significant historical events and icons to encouraging second-language learners to embrace cultural ambiguity, there is a wide spectrum of…

Walsh-Marr, Jennifer

2011-01-01

264

The identification of QTLs associated with the in vitro response of rye (Secale cereale L.).  

Science.gov (United States)

This study was conducted in order to identify quantitative trait loci (QTLs) for the in vitro culture response of winter rye (Secale cereale L.) immature embryos and immature inflorescences. A genetic linkage map comprising 67 SSRs, 9 ISSRs, 13 SAMPLs, 7 RAPDs, 2 SCARs and one EST marker was created based on the analyses of 102 recombinant inbred lines from the cross between lines L318 (which has a good response in tissue cultures) and L9 (which is unable to regenerate plants from somatic tissues and anthers). The map spans 979.2 cM, and the average distance between markers is 9.9 cM. Two characteristics were evaluated: callus induction (CI) and somatic embryogenesis ability (SE). They were expressed as the percentage of immature embryos/inflorescences producing callus (designated ECI/ICI) and the percentage of explants producing somatic embryos (ESE/ISE). All the analysed traits showed continuous variation in the mapping population but a non-normal frequency distribution. We identified nine putative QTLs controlling the tissue culture response of rye, explaining up to 41.6% of the total phenotypic variation: two QTLs for ECI - eci-1, eci-2; 4 for ESE - ece-1, ese-2, ese-3, ese-4; 2 for ICI - ici-1, ici2; and 1 for ISE - ise-1. They were detected on chromosomes 1R, 4R, 5R, 6R and 7R. PMID:17579815

Bolibok, Hanna; Gruszczy?ska, Anna; Hromada-Judycka, Aneta; Rakoczy-Trojanowska, Monika

2007-06-20

265

The identification of QTLs associated with the in vitro response of rye (Secale cereale L.).  

UK PubMed Central (United Kingdom)

This study was conducted in order to identify quantitative trait loci (QTLs) for the in vitro culture response of winter rye (Secale cereale L.) immature embryos and immature inflorescences. A genetic linkage map comprising 67 SSRs, 9 ISSRs, 13 SAMPLs, 7 RAPDs, 2 SCARs and one EST marker was created based on the analyses of 102 recombinant inbred lines from the cross between lines L318 (which has a good response in tissue cultures) and L9 (which is unable to regenerate plants from somatic tissues and anthers). The map spans 979.2 cM, and the average distance between markers is 9.9 cM. Two characteristics were evaluated: callus induction (CI) and somatic embryogenesis ability (SE). They were expressed as the percentage of immature embryos/inflorescences producing callus (designated ECI/ICI) and the percentage of explants producing somatic embryos (ESE/ISE). All the analysed traits showed continuous variation in the mapping population but a non-normal frequency distribution. We identified nine putative QTLs controlling the tissue culture response of rye, explaining up to 41.6% of the total phenotypic variation: two QTLs for ECI - eci-1, eci-2; 4 for ESE - ece-1, ese-2, ese-3, ese-4; 2 for ICI - ici-1, ici2; and 1 for ISE - ise-1. They were detected on chromosomes 1R, 4R, 5R, 6R and 7R.

Bolibok H; Gruszczy?ska A; Hromada-Judycka A; Rakoczy-Trojanowska M

2007-01-01

266

RESPONSE OF EMBRYOS OF SOME VARIETIES OF RICE FOR THEIR CALLUSING AND DIFFERENTIATION  

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Full Text Available Rice is the main food of most of the countries of the world. To cope with the population explosion, conventional method of rice production seems inadequate. Hense, for this purpose; tissue culture technology has been introduced. Before applying any advanced study, such as anther culture, protoplast culture or genetic engineering etc., it is essential to work on the rice varieties from its embryo level. In this perspective, four varieties of rice had been undertaken for the response of their embryos on different concentrations of 2,4D, for their callusing and upon different concentrations of IAA and KN for differentiation. Out of the four varieties of rice, Tulsi and Kanak embryos showed the best response for their callusing at the strength 6 mg/l of 2,4D - 40% and 22% respectively, which is followed by Pusa-Basmati and Birsa 101 embryos. Almost all the varieties showed their callusing more or less at all the strength of 2,4D taken into investigation. But the strength 6 mg/l was the best strength of 2,4D as upon this strength, all the varieties showed their callusing response. On the other hand, embryo derived callus when transferrred to differentiating medium MS + IAA (2 mg/l) + KN(4mg/l) gave the best result.

R.P.SINGH; H.P.SHARMA; S.K.SINHA

2007-01-01

267

Lay theory of race affects and moderates Asian Americans' responses toward American culture.  

Science.gov (United States)

People may hold different understandings of race that might affect how they respond to the culture of groups deemed to be racially distinct. The present research tests how this process is moderated by the minority individual's lay theory of race. An essentialist lay theory of race (i.e., that race reflects deep-seated, inalterable essence and is indicative of traits and ability) would orient racial minorities to rigidly adhere to their ethnic culture, whereas a social constructionist lay theory of race (i.e., that race is socially constructed, malleable, and arbitrary) would orient racial minorities to identify and cognitively assimilate toward the majority culture. To test these predictions, the authors conducted 4 studies with Asian American participants. The first 2 studies examine the effect of one's lay theory of race on perceived racial differences and identification with American culture. The last 2 studies tested the moderating effect of lay theory of race on identification and assimilation toward the majority American culture after this culture had been primed. The results generally supported the prediction that the social constructionist theory was associated with more perceived similarity between Asians and Americans and more consistent identification and assimilation toward American culture, compared with the essentialist theory. PMID:18808273

No, Sun; Hong, Ying-yi; Liao, Hsin-Ya; Lee, Kyoungmi; Wood, Dustin; Chao, Melody Manchi

2008-10-01

268

Lay theory of race affects and moderates Asian Americans' responses toward American culture.  

UK PubMed Central (United Kingdom)

People may hold different understandings of race that might affect how they respond to the culture of groups deemed to be racially distinct. The present research tests how this process is moderated by the minority individual's lay theory of race. An essentialist lay theory of race (i.e., that race reflects deep-seated, inalterable essence and is indicative of traits and ability) would orient racial minorities to rigidly adhere to their ethnic culture, whereas a social constructionist lay theory of race (i.e., that race is socially constructed, malleable, and arbitrary) would orient racial minorities to identify and cognitively assimilate toward the majority culture. To test these predictions, the authors conducted 4 studies with Asian American participants. The first 2 studies examine the effect of one's lay theory of race on perceived racial differences and identification with American culture. The last 2 studies tested the moderating effect of lay theory of race on identification and assimilation toward the majority American culture after this culture had been primed. The results generally supported the prediction that the social constructionist theory was associated with more perceived similarity between Asians and Americans and more consistent identification and assimilation toward American culture, compared with the essentialist theory.

No S; Hong YY; Liao HY; Lee K; Wood D; Chao MM

2008-10-01

269

The SlFRK4 promoter is active only during late stages of pollen and anther development.  

UK PubMed Central (United Kingdom)

Carbohydrates are essential for male gametophyte development. However, our understanding of the mechanism by which the sugar supply is controlled in the stamen is still in its infancy. We previously reported on the stamen-specific expression of the tomato (Solanum lycopersicum) sugar metabolic gene, fructokinase 4 (SlFRK4). Here, we present the cloning and the characterization of the SlFRK4 promoter and show its differential activation during anther development. We also show that the tissue-specific expression of SlFRK4 promoter is maintained in Arabidopsis thaliana. By histochemical analyses of the GUS reporter gene and DTA toxin driven by the SlFRK4 promoter, we show that the SlFRK4 promoter is gradually activated in pollen grains throughout the later stages of anther development and upon pollen germination. In addition, we analyzed the expression profile of SlFRK4 and other sugar metabolic genes and found that SlFRK4 and the invertase LIN7 are co-expressed in mature and germinated pollen. These findings point to the existence of a specialized mechanism in which carbohydrates are provided to the male gametophyte during the later stages of its development and suggest a valuable tool for manipulating the development of male gametophytes in crop species.

David-Schwartz R; Weintraub L; Vidavski R; Zemach H; Murakhovsky L; Swartzberg D; Granot D

2013-02-01

270

Human corneal endothelial cell sheets for transplantation: thermo-responsive cell culture carriers to meet cell-specific requirements.  

UK PubMed Central (United Kingdom)

Corneal endothelial diseases lead to severe vision impairment, motivating the transplantation of donor corneae or corneal endothelial lamellae, which is, however, impeded by endothelial cell loss during processing. Therefore, one prioritized aim in corneal tissue engineering is the generation of transplantable human corneal endothelial cell (HCEC) layers. Thermo-responsive cell culture carriers are widely used for non-enzymatic harvest of cell sheets. The current study presents a novel thermo-responsive carrier based on simultaneous electron beam immobilization and cross-linking of poly(vinyl methyl ether) (PVME) on polymeric surfaces, which allows one to adjust layer thickness, stiffness, switching amplitude and functionalization with bioactive molecules to meet cell type specific requirements. The efficacy of this approach for HCEC, which require elaborate cell culture conditions and are strongly adherent to the substratum, is demonstrated. The developed method may pave the way to tissue engineering of corneal endothelium and significantly improve therapeutic options.

Teichmann J; Valtink M; Gramm S; Nitschke M; Werner C; Funk RH; Engelmann K

2013-02-01

271

Human corneal endothelial cell sheets for transplantation: thermo-responsive cell culture carriers to meet cell-specific requirements.  

Science.gov (United States)

Corneal endothelial diseases lead to severe vision impairment, motivating the transplantation of donor corneae or corneal endothelial lamellae, which is, however, impeded by endothelial cell loss during processing. Therefore, one prioritized aim in corneal tissue engineering is the generation of transplantable human corneal endothelial cell (HCEC) layers. Thermo-responsive cell culture carriers are widely used for non-enzymatic harvest of cell sheets. The current study presents a novel thermo-responsive carrier based on simultaneous electron beam immobilization and cross-linking of poly(vinyl methyl ether) (PVME) on polymeric surfaces, which allows one to adjust layer thickness, stiffness, switching amplitude and functionalization with bioactive molecules to meet cell type specific requirements. The efficacy of this approach for HCEC, which require elaborate cell culture conditions and are strongly adherent to the substratum, is demonstrated. The developed method may pave the way to tissue engineering of corneal endothelium and significantly improve therapeutic options. PMID:23099299

Teichmann, J; Valtink, M; Gramm, S; Nitschke, M; Werner, C; Funk, R H W; Engelmann, K

2012-10-23

272

Enhanced responsiveness to parathyroid hormone and induction of functional differentiation of cultured rabbit costal chondrocytes by a pulsed electromagnetic field.  

UK PubMed Central (United Kingdom)

Pulsed electromagnetic fields promote healing of delayed united and ununited fractures by triggering a series of events in fibrocartilage. We examined the effects of a pulsed electromagnetic field (recurrent bursts, 15.4 Hz, of shorter pulses of an average of 2 gauss) on rabbit costal chondrocytes in culture. A pulsed electromagnetic field slightly reduced the intracellular cyclic adenosine 3',5'-monophosphate (cAMP) level in the culture. However, it significantly enhanced cAMP accumulation in response to parathyroid hormone (PTH) to 140% of that induced by PTH in its absence, while it did not affect cAMP accumulation in response to prostaglandin E1 or prostaglandin I2. The effect on cAMP accumulation in response to PTH became evident after exposure of the cultures to the pulsed electromagnetic field for 48 h, and was dependent upon the field strength. cAMP accumulation in response to PTH is followed by induction of ornithine decarboxylase, a good marker of differentiated chondrocytes, after PTH treatment for 4 h. Consistent with the enhanced cAMP accumulation, ornithine decarboxylase activity induced by PTH was also increased by the pulsed electromagnetic field to 170% of that in cells not exposed to a pulsed electromagnetic field. Furthermore, stimulation of glycosaminoglycan synthesis, a differentiated phenotype, in response to PTH was significantly enhanced by a pulsed electromagnetic field. Thus, a pulsed electromagnetic field enhanced a series of events in rabbit costal chondrocytes in response to PTH. These findings show that exposure of chondrocytes to a pulsed electromagnetic field resulted in functional differentiation of the cells.

Hiraki Y; Endo N; Takigawa M; Asada A; Takahashi H; Suzuki F

1987-10-01

273

Effects of silver nanoparticles on primary mixed neural cell cultures: uptake, oxidative stress and acute calcium responses.  

UK PubMed Central (United Kingdom)

In the body, nanoparticles can be systemically distributed and then may affect secondary target organs, such as the central nervous system (CNS). Putative adverse effects on the CNS are rarely investigated to date. Here, we used a mixed primary cell model consisting mainly of neurons and astrocytes and a minor proportion of oligodendrocytes to analyze the effects of well-characterized 20 and 40 nm silver nanoparticles (SNP). Similar gold nanoparticles served as control and proved inert for all endpoints tested. SNP induced a strong size-dependent cytotoxicity. Additionally, in the low concentration range (up to 10 ?g/ml of SNP), the further differentiated cultures were more sensitive to SNP treatment. For detailed studies, we used low/medium dose concentrations (up to 20 ?g/ml) and found strong oxidative stress responses. Reactive oxygen species (ROS) were detected along with the formation of protein carbonyls and the induction of heme oxygenase-1. We observed an acute calcium response, which clearly preceded oxidative stress responses. ROS formation was reduced by antioxidants, whereas the calcium response could not be alleviated by antioxidants. Finally, we looked into the responses of neurons and astrocytes separately. Astrocytes were much more vulnerable to SNP treatment compared with neurons. Consistently, SNP were mainly taken up by astrocytes and not by neurons. Immunofluorescence studies of mixed cell cultures indicated stronger effects on astrocyte morphology. Altogether, we can demonstrate strong effects of SNP associated with calcium dysregulation and ROS formation in primary neural cells, which were detectable already at moderate dosages.

Haase A; Rott S; Mantion A; Graf P; Plendl J; Thünemann AF; Meier WP; Taubert A; Luch A; Reiser G

2012-04-01

274

Conserved host response to highly pathogenic avian influenza virus infection in human cell culture, mouse and macaque model systems  

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Full Text Available Abstract Background Understanding host response to influenza virus infection will facilitate development of better diagnoses and therapeutic interventions. Several different experimental models have been used as a proxy for human infection, including cell cultures derived from human cells, mice, and non-human primates. Each of these systems has been studied extensively in isolation, but little effort has been directed toward systematically characterizing the conservation of host response on a global level beyond known immune signaling cascades. Results In the present study, we employed a multivariate modeling approach to characterize and compare the transcriptional regulatory networks between these three model systems after infection with a highly pathogenic avian influenza virus of the H5N1 subtype. Using this approach we identified functions and pathways that display similar behavior and/or regulation including the well-studied impact on the interferon response and the inflammasome. Our results also suggest a primary response role for airway epithelial cells in initiating hypercytokinemia, which is thought to contribute to the pathogenesis of H5N1 viruses. We further demonstrate that we can use a transcriptional regulatory model from the human cell culture data to make highly accurate predictions about the behavior of important components of the innate immune system in tissues from whole organisms. Conclusions This is the first demonstration of a global regulatory network modeling conserved host response between in vitro and in vivo models.

McDermott Jason E; Shankaran Harish; Eisfeld Amie J; Belisle Sarah E; Neuman Gabriele; Li Chengjun; McWeeney Shannon; Sabourin Carol; Kawaoka Yoshihiro; Katze Michael G; Waters Katrina M

2011-01-01

275

Pollen semi-sterility1 encodes a kinesin-1-like protein important for male meiosis, anther dehiscence, and fertility in rice.  

Science.gov (United States)

In flowering plants, male meiosis produces four microspores, which develop into pollen grains and are released by anther dehiscence to pollinate female gametophytes. The molecular and cellular mechanisms regulating male meiosis in rice (Oryza sativa) remain poorly understood. Here, we describe a rice pollen semi-sterility1 (pss1) mutant, which displays reduced spikelet fertility (~40%) primarily caused by reduced pollen viability (~50% viable), and defective anther dehiscence. Map-based molecular cloning revealed that PSS1 encodes a kinesin-1-like protein. PSS1 is broadly expressed in various organs, with highest expression in panicles. Furthermore, PSS1 expression is significantly upregulated during anther development and peaks during male meiosis. The PSS1-green fluorescent protein fusion is predominantly localized in the cytoplasm of rice protoplasts. Substitution of a conserved Arg (Arg-289) to His in the PSS1 motor domain nearly abolishes its microtubule-stimulated ATPase activity. Consistent with this, lagging chromosomes and chromosomal bridges were found at anaphase I and anaphase II of male meiosis in the pss1 mutant. Together, our results suggest that PSS1 defines a novel member of the kinesin-1 family essential for male meiotic chromosomal dynamics, male gametogenesis, and anther dehiscence in rice. PMID:21282525

Zhou, Shirong; Wang, Yang; Li, Wanchang; Zhao, Zhigang; Ren, Yulong; Wang, Yong; Gu, Suhai; Lin, Qibing; Wang, Dan; Jiang, Ling; Su, Ning; Zhang, Xin; Liu, Linglong; Cheng, Zhijun; Lei, Cailin; Wang, Jiulin; Guo, Xiuping; Wu, Fuqing; Ikehashi, Hiroshi; Wang, Haiyang; Wan, Jianmin

2011-01-31

276

Pollen semi-sterility1 encodes a kinesin-1-like protein important for male meiosis, anther dehiscence, and fertility in rice.  

UK PubMed Central (United Kingdom)

In flowering plants, male meiosis produces four microspores, which develop into pollen grains and are released by anther dehiscence to pollinate female gametophytes. The molecular and cellular mechanisms regulating male meiosis in rice (Oryza sativa) remain poorly understood. Here, we describe a rice pollen semi-sterility1 (pss1) mutant, which displays reduced spikelet fertility (~40%) primarily caused by reduced pollen viability (~50% viable), and defective anther dehiscence. Map-based molecular cloning revealed that PSS1 encodes a kinesin-1-like protein. PSS1 is broadly expressed in various organs, with highest expression in panicles. Furthermore, PSS1 expression is significantly upregulated during anther development and peaks during male meiosis. The PSS1-green fluorescent protein fusion is predominantly localized in the cytoplasm of rice protoplasts. Substitution of a conserved Arg (Arg-289) to His in the PSS1 motor domain nearly abolishes its microtubule-stimulated ATPase activity. Consistent with this, lagging chromosomes and chromosomal bridges were found at anaphase I and anaphase II of male meiosis in the pss1 mutant. Together, our results suggest that PSS1 defines a novel member of the kinesin-1 family essential for male meiotic chromosomal dynamics, male gametogenesis, and anther dehiscence in rice.

Zhou S; Wang Y; Li W; Zhao Z; Ren Y; Wang Y; Gu S; Lin Q; Wang D; Jiang L; Su N; Zhang X; Liu L; Cheng Z; Lei C; Wang J; Guo X; Wu F; Ikehashi H; Wang H; Wan J

2011-01-01

277

Transformation and analysis of tobacco plant var Petit havana with T-urf13 gene under anther-specific TA29 promoter.  

UK PubMed Central (United Kingdom)

T-urf13, a well-documented cms-associated gene from maize, has been shown to render methomyl sensitivity to heterologous systems like rice, yeast and bacteria when expressed constitutively. Since these transgenic plants were fertile, it was hypothesized that T-urf13 gene if expressed in anthers may result in male sterility that could be used for hybrid seed production. Hence, this work was aimed at analysing whether T-urf13 gene when expressed in anthers can result in male sterile plants or requires methomyl treatment to cause male sterility (controllable). This is the first report of transformation of tobacco with T-urf13 gene under anther-specific promoter (TA29) with or without mitochondrial targeting sequence. Most of the transgenic plants obtained were fertile; this was surprising as many male sterile plants were expected as T-urf13 gene is a cms associated gene. Our results suggest that it may not be possible to obtain male sterility by expressing URF13 in the anther by itself or by methomyl application.

Arun V; Kuriakose B; Sridhar VV; Thomas G

2011-09-01

278

In vitro response as a reflection of genomic diversity in long-term cultures of Musa.  

UK PubMed Central (United Kingdom)

Ten commercial cultivars of Musa representing five different types of genomic constitutions were studied for in vitro multiplication through meristem culture. In addition, the effects of various genomic constitutions at different ploidy levels on growth and meristem proliferation in long-term cultures were analysed statistically. Plantlets were readily obtained by culturing the excised meristems on MS semisolid medium supplemented with IAA, IBA and BAP at various concentrations. The regenerative potential of all cultivars of Musa, irrespective of their genomes, remained unaffected in long-term culture, even after 28–30 months. The genomic influence on both the nature and rate of proliferative growth was evident. Statistical analysis revealed that the rates of meristem proliferation between different cultivars of the same passage and between different passages of the same cultivar were significantly different. Those cultivars having only an A genome showed a low rate of meristem proliferation, while under the same culture conditions, cultivars having one or two B genomes in addition to the A exhibited a very high rate.

Banerjee N; Sharma AK

1988-01-01

279

PRESERVATION OF RUSSIAN CULTURAL IDENTITY IN SITUATON OF CHALLENGES OF FAUSTIAN POSTHISTORY: SEARCH OF ADEQUATE RESPONSES  

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Full Text Available The purpose of the research is study of conflict between the secular humanism and traditions in modern Russia, and the search of ways of solution to the conflict. Secular humanism is the ideological core of the globalization process. And it is the product of the Faustian civilization of the West, which is extremely desacral and spiritless one. This civilization translates its cultural codes through the forced modernization and breaks the traditional structures of non-Faustian cultures. It is the "managed pseudo-morphs." Post-historical West must to translate its cultural codes to extend the life of civilization. Russia wants to preserve its cultural identity, so it has to overcome the challenges of managed pseudo-morph. The best way is come back to the tradition that best preserved in the Church. Today the patristic heritage requires neo-patristic synthesis. It’s not only phenomenon of the existential theology. Neo-patristic synthesis is the way of understanding by the society its traditional values. It is a cultural inoculation against unification, proposed Faustian civilization.

Balagurov Oleg Andreyevich

2012-01-01

280

Concentration-dependent gene expression responses to flusilazole in embryonic stem cell differentiation cultures  

International Nuclear Information System (INIS)

The murine embryonic stem cell test (EST) is designed to evaluate developmental toxicity based on compound-induced inhibition of embryonic stem cell (ESC) differentiation into cardiomyocytes. The addition of transcriptomic evaluation within the EST may result in enhanced predictability and improved characterization of the applicability domain, therefore improving usage of the EST for regulatory testing strategies. Transcriptomic analyses assessing factors critical for risk assessment (i.e. dose) are needed to determine the value of transcriptomic evaluation in the EST. Here, using the developmentally toxic compound, flusilazole, we investigated the effect of compound concentration on gene expression regulation and toxicity prediction in ESC differentiation cultures. Cultures were exposed for 24 h to multiple concentrations of flusilazole (0.54-54 ?M) and RNA was isolated. In addition, we sampled control cultures 0, 24, and 48 h to evaluate the transcriptomic status of the cultures across differentiation. Transcriptomic profiling identified a higher sensitivity of development-related processes as compared to cell division-related processes in flusilazole-exposed differentiation cultures. Furthermore, the sterol synthesis-related mode of action of flusilazole toxicity was detected. Principal component analysis using gene sets related to normal ESC differentiation was used to describe the dynamics of ESC differentiation, defined as the 'differentiation track'. The concentration-dependent effects on development were reflected in the significance of deviation of flusilazole-exposed cultures from this transcriptomic-based differentiation track. Thus, the detection of developmental toxicity in EST using transcriptomics was shown to be compound concentration-dependent. This study provides further insight into the possible application of transcriptomics in the EST as an improved alternative model system for developmental toxicity testing.

2011-03-01

 
 
 
 
281

A noninvasive transfer system for polarized renal tubule epithelial cell sheets using temperature-responsive culture dishes  

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Full Text Available We used temperature-responsive culture dishes onto which the temperature-responsive polymer, poly(Nisopropylacrylamide), was covalently grafted for tissue engineering. Confluent cells harvested as intact sheets from these surfaces by simple temperature reduction can be transferred to various surfaces including additional culture dishes, other cell sheets, and tissues. In order to examine the maintenance of cell polarity, Madin-Darby canine kidney cells and human primary renal proximal tubule epithelial cells which had developed apical-basal cell polarity in culture, were subjected to cell sheet transfer. This functional and structural cell polarity, which is susceptible to treatment with trypsin, was examined by immunohistochemistry and transmission electron microscopy. Using our cell-sheet method, the noninvasive transfer of these cell sheets retaining typical distributions of Na+/K+-ATPase, GLUT-1, SGLT-1, aquaporin-1, neutral endopeptidase and dipeptidylendopeptidase IV, could be achieved. The transferred cell sheets also developed numerous microvilli and tight junctions at the apical and lateral membranes, respectively. For biochemical analysis, immunoblotting of occludin, a transmembrane protein that composes tight junctions, was conducted and results confirmed that occludin remained intact after cell sheet transfer. This two-dimensional cell sheet manipulation method promises to be useful for tissue engineering as well as in the investigation of epithelial cell polarity.

Kushida A.; Yamato M.; Isoi Y.; Kikuchi A.; Okano T.

2005-01-01

282

In vivo-like drug responses of human tumors growing in three-dimensional gel-supported primary culture  

Energy Technology Data Exchange (ETDEWEB)

An in vitro test of cell sensitivity to drugs that indicates in vivo response is an important need in cancer therapy and cancer drug development. Toward this end, the authors previously developed a collagen gel-supported culture system for growth of human tumors. This three-dimensional culture system is general and grows tumors at high frequency directly from surgery or biopsy that maintain important in vivo properties in vitro, including tissue architecture. They report here that with autoradiographic techniques measuring cellular DNA synthesis the drug responses of individual cells within the tissue structure of in vitro-grown tumors can be determined. Twenty tumor classes, including all the major ones, have been measured in toto at >50% frequency. Quantitative and qualitative results show increasing cell kill with rising cytotoxic drug concentration, differential drug sensitivities of multiple cell types within individual cultured tumors, differential sensitivities of a series of tumors of the same histopathological classification to a single drug, differential sensitivities of individual tumors to a series of drugs, and sensitivity patterns of various tumor types similar to the sensitivities found in vivo. Therefore, the results indicate that potentially important therapeutic data can be obtained from tumor specimens growing in vitro for the individual cancer patient as well as for rational and relevant screening for new agents active against human solid tumors.

Vescio, R.A.; Redfern, C.H.; Nelson, T.J.; Ugoretz, S.; Stern, P.H.; Hoffman, R.M.

1987-07-01

283

In vivo-like drug responses of human tumors growing in three-dimensional gel-supported primary culture.  

Science.gov (United States)

An in vitro test of cell sensitivity to drugs that indicates in vivo response is an important need in cancer therapy and cancer drug development. Toward this end, we previously developed a collagen gel-supported culture system for growth of human tumors. This three-dimensional culture system is general and grows tumors at high frequency directly from surgery or biopsy that maintain important in vivo properties in vitro, including tissue architecture. We report here that with autoradiographic techniques measuring cellular DNA synthesis the drug responses of individual cells within the tissue structure of in vitro-grown tumors can be determined. Twenty tumor classes, including all the major ones, have been measured in toto at greater than 50% frequency. Quantitative and qualitative results show increasing cell kill with rising cytotoxic drug concentration, differential drug sensitivities of multiple cell types within individual cultured tumors, differential sensitivities of a series of tumors of the same histopathological classification to a single drug, differential sensitivities of individual tumors to a series of drugs, and sensitivity patterns of various tumor types similar to the sensitivities found in vivo. Therefore, the results indicate that potentially important therapeutic data can be obtained from tumor specimens growing in vitro for the individual cancer patient as well as for rational and relevant screening for new agents active against human solid tumors. Images

Vescio, R A; Redfern, C H; Nelson, T J; Ugoretz, S; Stern, P H; Hoffman, R M

1987-01-01

284

In vivo-like drug responses of human tumors growing in three-dimensional gel-supported primary culture  

International Nuclear Information System (INIS)

An in vitro test of cell sensitivity to drugs that indicates in vivo response is an important need in cancer therapy and cancer drug development. Toward this end, the authors previously developed a collagen gel-supported culture system for growth of human tumors. This three-dimensional culture system is general and grows tumors at high frequency directly from surgery or biopsy that maintain important in vivo properties in vitro, including tissue architecture. They report here that with autoradiographic techniques measuring cellular DNA synthesis the drug responses of individual cells within the tissue structure of in vitro-grown tumors can be determined. Twenty tumor classes, including all the major ones, have been measured in toto at >50% frequency. Quantitative and qualitative results show increasing cell kill with rising cytotoxic drug concentration, differential drug sensitivities of multiple cell types within individual cultured tumors, differential sensitivities of a series of tumors of the same histopathological classification to a single drug, differential sensitivities of individual tumors to a series of drugs, and sensitivity patterns of various tumor types similar to the sensitivities found in vivo. Therefore, the results indicate that potentially important therapeutic data can be obtained from tumor specimens growing in vitro for the individual cancer patient as well as for rational and relevant screening for new agents active against human solid tumors.

1987-01-01

285

Engineering an integrated cellular interface in three-dimensional hydrogel cultures permits monitoring of reciprocal astrocyte and neuronal responses.  

UK PubMed Central (United Kingdom)

This study reports a new type of three-dimensional (3D) tissue model for studying interactions between cell types in collagen hydrogels. The aim was to create a 3D cell culture model containing separate cell populations in close proximity without the presence of a mechanical barrier, and demonstrate its relevance to modeling the axon growth-inhibitory cellular interfaces that develop in the central nervous system (CNS) in response to damage. This provides a powerful new tool to determine which aspects of the astroglial scar response and subsequent neuronal regeneration inhibition are determined by the presence of the other cell types. Astrocytes (CNS glia) and dissociated dorsal root ganglia (DRG; containing neurons and peripheral nervous system [PNS] glia) were seeded within collagen solution at 4 °C in adjacent chambers of a stainless steel mould, using cells cultured from wild-type or green fluorescent protein expressing rats, to track specific populations. The divider between the chambers was removed using a protocol that allowed the gels to integrate without mixing of the cell populations. Following setting of the gels, they were maintained in culture for up to 15 days. Reciprocal astrocyte and neuronal responses were monitored using confocal microscopy and 3D image analysis. At DRG:astrocyte interfaces, by 5 days there was an increase in the number of astrocytes at the interface followed by hypertrophy and increased glial fibrillary acidic protein expression at 10 and 15 days, indicative of reactive gliosis. Neurons avoided crossing DRG:astrocyte interfaces, and neuronal growth was restricted to the DRG part of the gel. By contrast, neurons were able to grow freely across DRG:DRG interfaces, demonstrating the absence of a mechanical barrier. These results show that in a precisely controlled 3D environment, an interface between DRG and astrocyte cultures is sufficient to trigger reactive gliosis and inhibition of neuronal regeneration across the interface. Different aspects of the astrocyte response could be independently monitored, providing an insight into the formation of a glial scar. This technology has wide potential for researchers wishing to maintain and monitor interactions between adjacent cell populations in 3D culture.

East E; Golding JP; Phillips JB

2012-07-01

286

Effect of diclofenac and antidepressants on the inflammatory response in astrocyte cell culture.  

UK PubMed Central (United Kingdom)

Central nervous system (CNS) has a completely separate immune system that communicates with the neurons by small molecules called cytokines. Cytokines are involved in many crucial processes in neuron including cell metabolism and neurotransmitter synthesis. It has been reported that cytokine imbalance is involved in the progression of many CNS diseases such as neuropsychiatric disorders (depression, schizophrenia, autism, and bipolar disorder) and neurodegenerative disorders (Parkinson's and Alzheimer's disease). Here, the effects of diclofenac, different antidepressants (sertraline, venlafaxine, and fluvoxamine), and vitamin B6 (pyridoxine) on IL-10 and tumor necrosis factor-? (TNF-?) change with and without immune challenges with lipopolysaccharide (LPS) were investigated in in vitro culture of astrocytes from 2-day-old Swiss-Albino mice. Diclofenac and Sertraline significantly (p < 0.05) improves anti-inflammatory cytokine (IL-10) while suppress (p < 0.05) LPS-induced elevated level of pro-inflammatory mediators (TNF-?) in astrocyte culture. Pyridoxine was not able to reduce (p > 0.05) TNF-? in the astrocyte culture. Antidepressant (sertraline) showed positive effects (increased IL-10 and reduced TNF-? level) possibly through the suppression of Th1 lymphocytes and monocytes and stimulation of Th2 lymphocytes and monocytes/macrophages. NSAID (diclofenac) showed positive immune regulation effect possibly through the inhibition of cyclo-oxygenase enzyme. Based on these findings, it may conclude that, diclofenac and antidepressants (sertraline) may positively contribute in the cytokine production in astrocyte cell culture.

Al-Amin MM; Uddin MM; Rahman MM; Reza HM; Rana MS

2013-07-01

287

Bystander responses in three-dimensional cultures containing radiolabelled and unlabelled human cells  

International Nuclear Information System (INIS)

[en] Research on the radiation-induced bystander effect has been carried out mainly in 2-D tissue culture systems. This study uses a 3-D model, wherein apparently normal human diploid fibroblasts (AG1522) are grown in a carbon scaffold, to investigate the induction of a G1 checkpoint in bystander cells present alongside radiolabelled cells. Cultures were simultaneously pulse-labelled with 3H-deoxycytidine (3HdC) to selectively irradiate a minor fraction of cells, and bromodeoxyuridine (BrdU) to identify the radiolabelled cells. After thorough washing of cultures, iododeoxyuridine (IdU) was administered to detect proliferating bystander cells. The cultures were harvested at various times thereafter, and cells were reacted with two monoclonal antibodies specific to IdU/BrdU or BrdU, respectively, stained with propidium iodide, and subjected to multi-parameter flow cytometry. Cell-cycle progression was followed in radiolabelled cells (BrdU+) that were chronically irradiated by low energy beta particles emitted by DNA-incorporated 3H, and in unlabelled bystander cells (BrdU-) by a flow cytometry based cumulative labelling index assay. As expected, radiolabelled cells were delayed, in a dose-dependent manner, in G2 and subsequently G1. No delay occurred in progression of bystander cells through G1, when the labelled cells were irradiated at dose rates up to 0.32 Gy h-1. (authors)

2006-01-01

288

Responses of Cultured Astrocytes, C6 Glioma and 1321NI Astrocytoma Cells to Amyloid ?-Peptide Fragments  

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The effect of amyloid ?-peptide (?AP), which can have both neurotrophic or neurotoxic effects on neurons and has been implicated in the pathogenesis of Alzheimer’s disease (AD), was studied on astrocytes using primary cultures and astrocyte cell lines (rat C6 glioma, human 1321NI astrocytoma cells)....

Pentreath, V. W.; Mead, C.

289

Response of Prochlorococcus ecotypes to co-culture with diverse marine bacteria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Interactions between microorganisms shape microbial ecosystems. Systematic studies of mixed microbes in co-culture have revealed widespread potential for growth inhibition among marine heterotrophic bacteria, but similar synoptic studies have not been done with autotroph/heterotroph pairs, nor have ...

Sher, Daniel; Thompson, Jessie W.; Kashtan, Nadav; Croal, Laura; Chisholm, Sallie (Penny)

290

Assessing autistic traits in a Taiwan preschool population: cross-cultural validation of the Social Responsiveness Scale (SRS).  

Science.gov (United States)

The cross-cultural validity of the Mandarin-adaptation of the social responsiveness scale (SRS) was examined in a sample of N = 307 participants in Taiwan, 140 typically developing and 167 with clinically-diagnosed developmental disorders. This scale is an autism assessment tool that provides a quantitative rather than categorical measure of social impairment in the general population. SRS total and subscale scores distinguished significantly between autism spectrum disorder and other developmental disorders (p < 0.01). Total SRS scores and sensitivity and specificity of the scale for diagnosing developmental disorders in the Taiwan study were similar to those observed in Western studies. These findings support the cross-cultural validity of the SRS scale for detecting autistic traits and for distinguishing between autism and other neuropsychiatric conditions. PMID:22407579

Wang, Jessica; Lee, Li-Ching; Chen, Ying-Sheue; Hsu, Ju-Wei

2012-11-01

291

Assessing autistic traits in a Taiwan preschool population: cross-cultural validation of the Social Responsiveness Scale (SRS).  

UK PubMed Central (United Kingdom)

The cross-cultural validity of the Mandarin-adaptation of the social responsiveness scale (SRS) was examined in a sample of N = 307 participants in Taiwan, 140 typically developing and 167 with clinically-diagnosed developmental disorders. This scale is an autism assessment tool that provides a quantitative rather than categorical measure of social impairment in the general population. SRS total and subscale scores distinguished significantly between autism spectrum disorder and other developmental disorders (p < 0.01). Total SRS scores and sensitivity and specificity of the scale for diagnosing developmental disorders in the Taiwan study were similar to those observed in Western studies. These findings support the cross-cultural validity of the SRS scale for detecting autistic traits and for distinguishing between autism and other neuropsychiatric conditions.

Wang J; Lee LC; Chen YS; Hsu JW

2012-11-01

292

Rice improvement, involving altered flower structure more suitable to cross-pollination, using in vitro culture in combination with mutagenesis  

International Nuclear Information System (INIS)

Anther and somatic tissue culture in combination with mutagenesis were carried out to evaluate the efficiency of different mutagenic treatments of various in vitro culture materials, and to obtain some promising variants for rice improvement. Results indicated that in japonica rice radiation treatment of dry seeds and young panicles influenced the percentage of green plantlets regeneration from anther culture. Both treatments increased significantly the percentage of regenerated green plantlets in comparison with the control. Irradiation with 30 Gy of rice callus increased also the percentage of regenerated green plantlets. For indica rice, the combination of the suitable dose of gamma rays irradiation on seeds and an improved medium, increased the percentage of callus induction. This approach made it possible to use anther culture in indica rice breeding. Somatic tissue cultures combined with radiation-induced mutagenesis led to the development of a number of promising mutants including some new cytoplasm-nucleus interacting male-sterile lines with almost 100% stigma exertion. Their development would be of practical significance for increasing the genetic diversity for production of hybrid rice. (author)

1998-01-01

293

Culture Media Optimization through Response Surface Methodology for in vitro Shoot Bud Development of Solanum melongena L. for Micropropagation  

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Full Text Available Response surface methodology was used for the optimization of shoot bud response and shoot bud induction in leaf explants of Solanum melongena cultivar Arka Shirish. Three independent variables were evaluated for shoot bud response and shoot bud induction. The variables include the concentrations of nitrogen (N2), sucrose and growth regulator thidiazuron (TDZ). The shoot bud response for cultured explant was optimized at 4.34 g/l of total nitrogen, 2.65% of sucrose and 0.67 mg/l of TDZ with 95% response. The optimum medium conditions for shoot bud induction was found to be Murashige and Skoog (MS) basal medium supplemented with 4.02 g/l of total nitrogen, 2.36% of sucrose and 1.0 mg/l of TDZ with 10 number of bud per explant. The shoot buds so formed were elongated in 0.5 mg/l 2,3,5-Triiodobenzoic acid (TIBA) and 0.1 mg/l Gibberellic acid (GA3). The elongated shoots were rooted in MS with 1 mg/l Indole-3-butyric acid (IBA). The rooted plants were transferred to pots with farmyard manure upon hardening. This study has validation value for optimization of micropropagation protocol and is further useful in genetic transformation studies for Solanum melongena variety Arka Shirish to maximize regenerative response for automation.

Padma Mallaya Naveenchandra; Sila Bhattacharya; Gokare Aswathanarayana Ravishankar

2011-01-01

294

Cellular responses in primary epidermal cultures from rainbow trout exposed to zinc chloride.  

UK PubMed Central (United Kingdom)

In this study, we examined the effects of zinc chloride (ZnCl(2)) (0-200mg/L) on primary epidermal cultures from Oncorhynchus mykiss. Increases in the rate and amount of mucus released were detected post-exposure, as was a dose-dependent increase in the synthesis of acidic glycoproteins. The cytotoxicity of ZnCl(2) to the cultures was significantly increased (P< or =0.05) when exposures were conducted in serum-free medium as opposed to medium containing serum. Significant increases in the levels of apoptosis and necrosis were observed with increasing exposure concentration, but these were seen to decrease over time. The in vitro cytological and pathological changes observed in this study were found to be in accordance with previously published in vivo studies on the effects of heavy metals on the integument. This model system may help to further elucidate the effects of ecotoxicants on the external innate immune system of fish.

Ní Shúilleabháin S; Mothersill C; Sheehan D; O'Brien NM; O' Halloran J; van Pelt FN; Kilemade M; Davoren M

2006-11-01

295

Interval Nutrient Pulses Responses of Compatitive Culture Experiment: Chaetoceros Sp. Thallassiosira allenii (Takano), Gomphosphaeria Sp.  

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Full Text Available As phytoplankton are indisputably a major component of many food webs, estimating their abundance, biomass and growth rate has been an essential component of marine studies. The aim of this study is to establish the effects of different nutrient pulses on the cell size and biovolumes in competetive experiments of marine phytoplakton that was cultured from natural seawater. The growth of natural pytoplankton populations taken from Izmir bay (Aegean sea, Turkey) was observed for 6 different nutrient pulse periods (4, 8, 12, 24, 48 and 96 h) and determined Chl a, mean cell sizes and biovolumes. Thallassiosira allenii (Takano), Chaetoceros sp. and Gomphosphaeria sp. were dominated all pulse periods during the batch culture experiment. Nutrient pulses T. allenii and Chaetoceros sp. cells enlarged their biovolumes with the extension of pulse period, Gomphosphaeria sp. cells was not.

Goknur Sisman Aydin

2012-01-01

296

Pressure-Driven Microfluidic Perfusion Culture Device for Integrated Dose-Response Assays.  

UK PubMed Central (United Kingdom)

Cell-based assays are widely used in the various stages of drug discovery. Advances in microfluidic systems over the past two decades have enabled them to become a powerful tool for cell-based assays to achieve both reliability and high throughput. The interface between the micro-world and macro-world is important in industrial assay processes. Therefore, microfluidic cell-based assays using pressure-driven liquid handling are an ideal platform for integrated assays. The aim of this article is to review recent advancements in microfluidic cell-based assays focusing on a pressure-driven perfusion culture device. Here, we review the development of microfluidic cell-based assay devices and discuss the techniques involved in designing a microfluidic network, device fabrication, liquid and cell manipulation, and detection schemes for pressure-driven perfusion culture devices. Finally, we describe recent progress in semiautomatic and reliable pressure-driven microfluidic cell-based assays.

Hattori K; Sugiura S; Kanamori T

2013-09-01

297

[Some biochemical indicators of the cytotoxic response of human fibroblasts cultured with natural and synthetic polycations].  

Science.gov (United States)

Cationic antiseptics--catamine AB, polysept (polymeric derivative of chlorhexidine) as well as cationic protein protamine exhibited a pronounced cytotoxic effect on human skin and lung fibroblasts in cell culture. Their effect was accompanied by augmentation of lipid peroxidation products and by inhibition of DT-diaphorase, LDH, ATPase and glutathione reductase. Introduction of alpha-tocopherol into the cultural medium normalized the rate of lipid peroxidation but did not remove the inhibitory effect on activity of oxidoreductase studied. Blood serum proteins immunoglobulins and albumin diminished significantly the cytotoxic effect of cationic preparations contributing to restoration of all the parameters studied to control values; this phenomenon appears to occur due to nonspecific membrane protective and antioxidation effects of the blood serum proteins. PMID:7793094

Eropkin, M Iu; Afinogenov, G E; Eropkina, E M

298

[Some biochemical indicators of the cytotoxic response of human fibroblasts cultured with natural and synthetic polycations  

UK PubMed Central (United Kingdom)

Cationic antiseptics--catamine AB, polysept (polymeric derivative of chlorhexidine) as well as cationic protein protamine exhibited a pronounced cytotoxic effect on human skin and lung fibroblasts in cell culture. Their effect was accompanied by augmentation of lipid peroxidation products and by inhibition of DT-diaphorase, LDH, ATPase and glutathione reductase. Introduction of alpha-tocopherol into the cultural medium normalized the rate of lipid peroxidation but did not remove the inhibitory effect on activity of oxidoreductase studied. Blood serum proteins immunoglobulins and albumin diminished significantly the cytotoxic effect of cationic preparations contributing to restoration of all the parameters studied to control values; this phenomenon appears to occur due to nonspecific membrane protective and antioxidation effects of the blood serum proteins.

Eropkin MIu; Afinogenov GE; Eropkina EM

1995-03-01

299

Effects of propofol on the anoxic and re-oxygenation responses of primary cultured hippocampal neurons  

UK PubMed Central (United Kingdom)

Hippocampal cell cultured for 12 days were randomly divided into three groups: normal control group (Group Nor), 4 hour anoxia and 24 hour re-oxygneation group (Group Ano), 4 hour anoxia and 24 hour re-oxygenation after joined propofol 500#mu#mol/L group (Group Pro). Cell survival ratio was assayed by MTT, C-fos protein immun-ofleurescence staining and neuron apoptosis were performed by flow cytometry for each group. The C-fos protein expression and apoptosisi ratio in Group Pro was less than those in Group Ano. Cell survival ratio was significantly lower in Group Ano (P<0.01), this reaction in Group Pro was increased compared to Group Ano (P<0.05). Propofol may enhance the tolerance of anoxia in primary cultured hippocampal neurons by increasing cell survival ratio and lowering C-fos protein expression and decreasing apoptosis.

Yang Jing; Zhang Bingxi; Li Tianzuo; Wang Fuzhuang

2004-01-01

300

A rapid, novel model of culturing cranial nerve X-derived motoneurons for screening trophic factor outgrowth response.  

UK PubMed Central (United Kingdom)

OBJECTIVES: After cranial nerve X (CN X) injury, vocal fold paralysis treatments currently face a myriad of obstacles in achieving non-synkinetic, functional reinnervation. Of particular therapeutic interest is the targeted administration of locally expressed biological neurotrophic factors (NFs). To date, a method to culture mature CN X motoneurons for NF responsiveness screening has not been described. METHODS: We herein present a novel method for establishing mature murine CN X motoneuron cultures, and use the model to test CN X motoneuron outgrowth response to individual and paired ascending concentrations of selected neurotrophic factors [glial cell-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), and ciliary neurotrophic factor (CNTF)]. RESULTS: Findings demonstrated low concentration (5 ng/ml) CNTF to have the greatest positive effect on motoneuron outgrowth, beyond that of both indivual NF and paired NF combinations, based on total neurite outgrowth [mean total neurite outgrowth = 445.7±84.45 ?m in the (5 ng/ml) CNTF group versus 179.7±13.63 ?m in saline controls (P<0.01)]. Paired treatments with CNTF/GDNF, and CNTF/BDNF promoted motoneuron branching at a variety of concentrations beyond saline controls, and paired GDNF/BDNF had inhibitory effects on motoneuron branching. DISCUSSION: Our described in vitro model of establishing mature CN X cultures allowed rapid screening for responsiveness to therapeutic NFs at a variety of concentrations and combinations. While the model ultimately may be used to investigate the molecular mechanisms of CN X motoneuron regeneration, the current study identified CNTF as a promising therapeutic candidate for the promotion of CN X outgrowth.

McRae BR; Shew M; Aaron GP; Bijangi-Vishehsaraei K; Halum SL

2012-07-01

 
 
 
 
301

Identification and expression analysis of methyl jasmonate responsive ESTs in paclitaxel producing Taxus cuspidata suspension culture cells  

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Full Text Available Abstract Background Taxol® (paclitaxel) promotes microtubule assembly and stabilization and therefore is a potent chemotherapeutic agent against wide range of cancers. Methyl jasmonate (MJ) elicited Taxus cell cultures provide a sustainable option to meet the growing market demand for paclitaxel. Despite its increasing pharmaceutical importance, the molecular genetics of paclitaxel biosynthesis is not fully elucidated. This study focuses on identification of MJ responsive transcripts in cultured Taxus cells using PCR-based suppression subtractive hybridization (SSH) to identify genes involved in global pathway control. Results Six separate SSH cDNA libraries of paclitaxel-accumulating Taxus cuspidata P991 cell lines were constructed at three different post-elicitation time points (6h, 18h and 5 day) to identify genes that are either induced or suppressed in response to MJ. Sequencing of 576 differentially screened clones from the SSH libraries resulted in 331 unigenes. Functional annotation and Gene Ontology (GO) analysis of up-regulated EST libraries showed enrichment of several known paclitaxel biosynthetic genes and novel transcripts that may be involved in MJ-signaling, taxane transport, or taxane degradation. Macroarray analysis of these identified genes unravelled global regulatory expression of these transcripts. Semi-quantitative RT-PCR analysis of a set of 12 candidate genes further confirmed the MJ-induced gene expression in a high paclitaxel accumulating Taxus cuspidata P93AF cell line. Conclusions This study elucidates the global temporal expression kinetics of MJ responsive genes in Taxus suspension cell culture. Functional characterization of the novel genes identified in this study will further enhance the understanding of paclitaxel biosynthesis, taxane transport and degradation.

Lenka Sangram K; Boutaoui Nadia; Paulose Bibin; Vongpaseuth Kham; Normanly Jennifer; Roberts Susan C; Walker Elsbeth L

2012-01-01

302

Protein phosphorylation in intact cultured sycamore (Acer pseudoplatanus) cells and its response to fusicoccin.  

UK PubMed Central (United Kingdom)

Fusicoccin (FC), a natural diterpene glucoside able to stimulate electrogenic H+ extrusion in higher plants, has been shown to stimulate the phosphorylation of a polypeptide of molecular mass approx. 33 kDa in intact cultured cells of sycamore (Acer pseudoplatanus). The effect is specific, rapid and insensitive to cycloheximide. The presence of the 33 kDa polypeptide and the stimulation by FC have been observed in SDS-containing cell homogenates and in the microsomal and soluble fractions after cell fractionation.

Tognoli L; Colombo R

1986-04-01

303

Enhanced triterpene production in Tabernaemontana catharinensis cell suspension cultures in response to biotic elicitors  

Directory of Open Access Journals (Sweden)

Full Text Available Cell suspension cultures of Tabernaemontana catharinensis were treated with autoclaved homogenates of Candida albicans, Fusarium oxysporum, Penicillium avelanium and Saccharomyces cerevisiae. The effects caused by the concentration, exposure time and the type of elicitor on the accumulation of pentacyclic triterpenes were monitored. When exposed to biotic elicitors for longer periods, some cell lines redoubled the production of those triterpenes. Saccharomyces cerevisiae homogenate was the best elicitor of triterpenes in all cell lines investigated.

Paulo Sérgio Pereira; Fábio Kiss Ticli; Suzelei de Castro França; Camila Moniz de Souza Breves; Miriam Verginia Lourenço

2007-01-01

304

Enhanced triterpene production in Tabernaemontana catharinensis cell suspension cultures in response to biotic elicitors  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Cell suspension cultures of Tabernaemontana catharinensis were treated with autoclaved homogenates of Candida albicans, Fusarium oxysporum, Penicillium avelanium and Saccharomyces cerevisiae. The effects caused by the concentration, exposure time and the type of elicitor on the accumulation of pentacyclic triterpenes were monitored. When exposed to biotic elicitors for longer periods, some cell lines redoubled the production of those triterpenes. Saccharomyces cerevisiae homogenate was the best elicitor of triterpenes in all cell lines investigated.

Pereira, Paulo Sérgio; Ticli, Fábio Kiss; França, Suzelei de Castro; Breves, Camila Moniz de Souza; Lourenço, Miriam Verginia

2007-01-01

305

Comparative Tissue Culture Response of Wheat Cultivars and Evaluation of Regenerated Plants  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Three wheat genotypes i.e. Bakhtawar-92, Punjab-96 and Inqilab-91 were tested for their response to callus induction frequency and their subsequent regeneration on a variety of media combinations. Bakhtawar-92 appeared to be the most responsive genotype to callus induction followed by Inqilab-91 and...

Muhammad Farooq; Hamid Rashid; Ihsanullah; Zubeda Chaudhry; Khan Bahadar Marwat

306

Proteomic and metabolomic responses to connexin43 silencing in primary hepatocyte cultures.  

UK PubMed Central (United Kingdom)

Freshly established cultures of primary hepatocytes progressively adopt a foetal-like phenotype and display increased production of connexin43. The latter is a multifaceted cellular entity with variable subcellular locations, including the mitochondrial compartment. Cx43 forms hemichannels and gap junctions that are involved in a plethora of physiological and pathological processes, such as apoptosis. The present study was conducted with the goal of shedding more light onto the role of connexin43 in primary hepatocyte cultures. Connexin43 expression was suppressed by means of RNA interference technology, and the overall outcome of this treatment on the hepatocellular proteome and metabolome was investigated using tandem mass tag-based differential protein profiling and (1)H NMR spectroscopy, respectively. Global protein profiling revealed a number of targets of the connexin43 knock-down procedure, including mitochondrial proteins (heat shock protein 60, glucose-regulated protein 75, thiosulphate sulphurtransferase and adenosine triphosphate synthase) and detoxifying enzymes (glutathione S-transferase ? 2 and cytochrome P450 2C70). At the metabolomic level, connexin43 silencing caused no overt changes, though there was some evidence for a subtle increase in intracellular glycine quantities. Collectively, these data could further substantiate the established existence of a mitochondrial connexin pool and could be reconciled with the previously reported involvement of connexin43 signalling in spontaneously occurring apoptosis in primary hepatocyte cultures.

Vinken M; Maes M; Cavill R; Valkenborg D; Ellis JK; Decrock E; Leybaert L; Staes A; Gevaert K; Oliveira AG; Menezes GB; Cogliati B; Dagli ML; Ebbels TM; Witters E; Keun HC; Vanhaecke T; Rogiers V

2013-05-01

307

Induced cytokine response of human PMBC-cultures: correlation of gene expression and secretion profiling and the effect of cryopreservation.  

UK PubMed Central (United Kingdom)

The immune system is regulated by the complex interaction of multiple cytokines, which are secreted signaling molecules affecting other cells. In this work, we studied the cytokine response to several well-known stimulants, such as OKT-3, Con A, PWM, and SEB. Healthy donor cells (PBMCs) were cultivated for up to 72 h and the mRNA levels and cytokine release of four key cytokines (IL-2, IL-4, IFN-?, and TNF-?) were analyzed by RT-PCR and bead-based multiplex analyses. The generated cytokine profiles showed characteristic expression patterns and secretion kinetics for each cytokine and substance. PWM/SEB and OKT-3 led to a very fast and long-lasting immune response, whereas Con A induced the slowest cytokine production. Cytokine concentrations also differed greatly. The highest IFN-? concentration was 1000 times higher than the respective IL-4 concentration. Gene expression and cytokine concentration profiles were strongly correlated during the time course. The chronological response of the donors' cytokine profiles coincided, but showed individual characteristics regarding the strength of the cytokine release. The comparison of stimulation experiments using freshly isolated and cryopreserved PBMCs showed that, for the observation of an immunological response at early points in time, gene expression experiments are more reliable than the measurement of cytokines in the cell culture supernatant. However, the freezing of cells influences the response significantly. The measurement of secreted proteins is the superior method at later points in time.

Radke L; López Hemmerling DA; Lubitz A; Giese C; Frohme M

2012-01-01

308

Evaluation of Rice (Oryza sativa L.) Cultivars Response to Salinity Stress Through Greenhouse Experiment and Tissue Culture Technique  

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Full Text Available The response to salinity stress of 4 rice cultivars was evaluated through a greenhouse experiment and a tissue culture technique at Agricultural College, Mazandaran University, Sari, Iran, during 2003. In the first experiment, carried out at seedling stage, three salinity levels (0, 75 and 150 mmol NaCl) were used, pots arranged as a split plot based on completely randomized design with four replications and traits including seedling dry weight, wet weight, shoot length and root length were measured. In the second experiment, cultivars were callus induced trough the seed culture and calli placed in LS mediums containing four salinity levels (0, 75, 112.5 and 150 mmol NaCl). The experimental lay-out was factorial based on completely randomized design with 6 replications and callus volume of cultivars was measured according to Hooker and Nabors scale. The results indicated that all cultivars were influenced by increasing salinity level from 0 to 150 mmol NaCl in all traits. Tichung-65 distinguished the most salt-tolerant cultivar, showed the lowest reduction in evaluated traits by increasing salinity stress, whereas Tarom chaloosi was the salt-sensitive one. Moreover, cultivars including Tarom chaloosi and Binam chaloosi, exhibiting low salt tolerance characteristic in seedling stage generated tolerant calli through tissue culture technique as the salinity level increased from 0 to 150 mmol NaCl.

Sahab Rahmanzadeh; Kamal Kazemitabar; Shahin Yazdifar; Azarakhsh Torabi Jafroudi

2008-01-01

309

[Culturing and characterization of human periodontal ligament stem cells and investigating their chemotactic responses to bone morphogenetic protein-2].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To investigate the chemotactic response of human periodontal ligament stem cells (PDLSCs) to bone morphogenetic protein-2 (BMP-2). METHODS: Human PDLSCs were obtained from clinically healthy premolars extracted for orthodontic reasons and used to isolate PDLSCs by limited dilution method. The expression of Vimentin and stem cell marker STRO-1 on PDLSCs were demonstrated with immunocytochemical staining. Differentiation assay was used to detect the differentiation potential of PDLSCs. Cloning formation experiment and 5-bromo-2-deoxyuridine (BrdU) incorporation assay were used to determine the stem cell characteristics of PDLSCs. The chemotactic effect of BMP-2 on PDLSCs was detected by using a 24-multiwell Transwell cell culture chamber. The number of net migrated cells was counted in different microscope fields. RESULTS: Human PDLSCs displayed positive staining for Vimentin and expressed the stem cell marker STRO-1. These cells differentiated into osteoblasts and adipocytes under defined culture conditions, possessed high self-renewal potential and formed single-cell colonies in vitro. The number of cells migrating at concentrations of 100, 200 ng mL(-1) of BMP-2 in Transwell cell culture chamber was significantly higher than that of negative control (P<0.01). CONCLUSION: BMP-2 may participate in regulating chemotaxis of human PDLSCs.

Du L; Yang P; Zhao N; Ge S

2012-02-01

310

Inflammatory cytokine and microRNA responses of primary human dendritic cells cultured with Helicobacter pylori strains  

Science.gov (United States)

Primary human dendritic cells (DC) were used to explore the inflammatory effectors, including cytokines and microRNAs, regulated by Helicobacter pylori. In a 48 h ex-vivo co-culture system, both H. pylori B38 and B45 strains activated human DCs and promoted a strong inflammatory response characterized by the early production of pro-inflammatory TNF? and IL-6 cytokines, followed by IL-10, IL-1?, and IL-23 secretion. IL-23 was the only cytokine dependent on the cag pathogenicity island status of the bacterial strains. DC activation and cytokine production were accompanied by an early miR-146a upregulation followed by a strong miR-155 induction, which mainly controlled TNF? production. These results pave the way for further investigations into the nature of H. pylori antigens and the subsequently activated signaling pathways involved in the inflammatory response to H. pylori infection, the deregulation of which may likely contribute to gastric lymphomagenesis.

Hoces de la Guardia, Anais; Staedel, Cathy; Kaafarany, Itidal; Clement, Aurelien; Roubaud Baudron, Claire; Megraud, Francis; Lehours, Philippe

2013-01-01

311

Linear density gradient separation of human lymphocyte subsets. I. Analysis by mixed leukocyte culture and cell-mediated lympholysis responses.  

UK PubMed Central (United Kingdom)

Linear density gradients were used to separate either unsensitized human peripheral blood lymphocytes or cells sensitized in mixed leukocyte culture (MLC), at different time points in the immune response. Testing of cells from the various density fractions for their ability to respond in MLC and cell-mediated lympholysis (CML) revealed that (a) activity between individual fractions differed, as well as activity between individual fractions and a suspension of unfractionated cells, (b) although precursor cells of MLC and CML were maximally enriched in closely associated light density regions, their respective distribution profiles were strikingly different, and (c) the density of cells responding in MLC and CML differed depending upon the point of the immune response at which the cells were separated. Whereas effector cells were of light density relative to the precursor cells, putative memory cells for CML exhibited a high density.

Zier KS; Huber C; Braunsteiner H

1977-06-01

312

Modulation of cultured porcine granulosa cell responsiveness to follicle stimulating hormone and epidermal growth factor  

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Ovarian follicular development is dependent upon the coordinated growth and differentiation of the granulosa cells which line the follicle. Follicle stimulating hormone (FSH) induces granulosa cell differentiation both in vivo and in vitro. Epidermal growth factor (EGF) stimulates granulosa cell proliferation in vitro. The interaction of these two effectors upon selected parameters of growth and differentiation was examined in monolayer cultures of porcine granulose cells. Analysis of the EGF receptor by /sup 125/I-EGF binding revealed that the receptor was of high affinity with an apparent dissociation constant of 4-6 x 10/sup -10/ M. The average number of receptors per cell varied with the state of differentiation both in vivo and in vitro; highly differentiated cells bound two-fold less /sup 125/I-EGF and this effect was at least partially induced by FSH in vitro. EGF receptor function was examined by assessing EGF effects on cell number and /sup 3/H-thymidine incorporation. EGF stimulated thymidine incorporation in both serum-free and serum-supplemented culture, but only in serum-supplemented conditions was cell number increased. EGF receptor function was inversely related to the state of differentiation and was attenuated by FSH. The FSH receptor was examined by /sup 125/I-FSH binding. EGF increased FSH receptor number, and lowered the affinity of the receptor. The function of these receptors was assessed by /sup 125/I-hCG binding and progesterone radioimmunoassay. If EGF was present continuously in the cultures. FSH receptor function was attenuated regardless of FSH receptor number. A preliminary effort to examine the mechanism of this interaction was performed by analyzing hormonally controlled protein synthesis with /sup 35/S-methionine labeling, SDS polyacrylamide gel electrophoresis and fluorography. FSH promoted the expression of a 27,000 dalton protein. This effect was attenuated by EGF.

Buck, P.A.

1986-01-01

313

Modulation of cultured porcine granulosa cell responsiveness to follicle stimulating hormone and epidermal growth factor  

International Nuclear Information System (INIS)

Ovarian follicular development is dependent upon the coordinated growth and differentiation of the granulosa cells which line the follicle. Follicle stimulating hormone (FSH) induces granulosa cell differentiation both in vivo and in vitro. Epidermal growth factor (EGF) stimulates granulosa cell proliferation in vitro. The interaction of these two effectors upon selected parameters of growth and differentiation was examined in monolayer cultures of porcine granulose cells. Analysis of the EGF receptor by 125I-EGF binding revealed that the receptor was of high affinity with an apparent dissociation constant of 4-6 x 10-10 M. The average number of receptors per cell varied with the state of differentiation both in vivo and in vitro; highly differentiated cells bound two-fold less 125I-EGF and this effect was at least partially induced by FSH in vitro. EGF receptor function was examined by assessing EGF effects on cell number and 3H-thymidine incorporation. EGF stimulated thymidine incorporation in both serum-free and serum-supplemented culture, but only in serum-supplemented conditions was cell number increased. EGF receptor function was inversely related to the state of differentiation and was attenuated by FSH. The FSH receptor was examined by 125I-FSH binding. EGF increased FSH receptor number, and lowered the affinity of the receptor. The function of these receptors was assessed by 125I-hCG binding and progesterone radioimmunoassay. If EGF was present continuously in the cultures. FSH receptor function was attenuated regardless of FSH receptor number. A preliminary effort to examine the mechanism of this interaction was performed by analyzing hormonally controlled protein synthesis with 35S-methionine labeling, SDS polyacrylamide gel electrophoresis and fluorography. FSH promoted the expression of a 27,000 dalton protein. This effect was attenuated by EGF.

1986-01-01

314

Characterization of [Ca2+]i responses in primary cultures of mouse cardiomyocytes induced by Trypanosoma cruzi trypomastigotes  

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Full Text Available Trypanosoma cruzi, the protozoan responsible for Chagas disease, employs distinct strategies to invade mammalian host cells. In the present work we investigated the participation of calcium ions on the invasion process using primary cultures of embryonic mice cardiomyocytes which exhibit spontaneous contraction in vitro. Using Fura 2-AM we found that T. cruzi was able to induce a sustained increase in basal intracellular Ca2+ level in heart muscle cells (HMC), the response being associated or not with Ca2+ transient peaks. Assays performed with both Y and CL strains indicated that the changes in intracellular Ca2+ started after parasites contacted with the cardiomyocytes and the evoked response was higher than the Ca2+ signal associated to the spontaneous contractions. The possible role of the extracellular and intracellular Ca2+ levels on T. cruzi invasion process was evaluated using the extracellular Ca2+ chelator EGTA alone or in association with the calcium ionophore A23187. Significant dose dependent inhibition of the invasion levels were found when intracellular calcium release was prevented by the association of EGTA +A23187 in calcium free medium. Dose response experiments indicated that EGTA 2.5 mM to 5 mM decreased the invasion level by 15.2 to 35.1% while A23187 (0.5 µM) alone did not induce significant effects (17%); treatment of the cultures with the protease inhibitor leupeptin did not affect the endocytic index, thus arguing against the involvement of leupeptin sensitive proteases in the invasion of HMC.

Garzoni Luciana R; Masuda Masako Oya; Capella Márcia M; Lopes Anibal Gil; Meirelles Maria de Nazareth S Leal de

2003-01-01

315

Effects of culture conditions on estrogen-mediated hepatic in vitro gene expression and correlation to in vivo responses  

International Nuclear Information System (INIS)

Refinement of in vitro systems for predictive toxicology is important in order to develop high-throughput early toxicity screening assays and to minimize animal testing studies. This study assesses the ability of mouse Hepa-1c1c7 hepatoma cell model under differing culture conditions to predict in vivo estrogen-induced hepatic gene expression changes. Custom mouse cDNA microarrays were used to compare Hepa-1c1c7 temporal gene expression profiles treated with 10 nM 17?-estradiol (E2) in serum-free and charcoal-stripped serum supplemented media at 1, 2, 4, 8, 12, and 24 h. Stripped serum supplemented media increased the number gene expression changes and overall responsiveness likely due to the presence of serum factors supporting proliferation and mitochondrial activity. Data from both experiments were compared to a gene expression time course study examining the hepatic effects of 100 ?g/kg 17?-ethynyl estradiol (EE) in C57BL/6 mice at 2, 4, 8, 12, 18, and 24 h. Only 18 genes overlapped between the serum-free and in vivo studies, whereas 238 genes were in common between Hepa-1c1c7 cells in stripped serum data and C57BL/6 liver samples. Stripped serum cultured cells exhibited E2-elicited gene expression changes associated with proliferation, cytoskeletal re-organization, cholesterol uptake and synthesis, increased fatty acid ?-oxidation, and oxidative stress, which correlated with in vivo hepatic responses. These results demonstrate that E2 treatment of Hepa-1c1c7 cells in serum supplemented media modulate responses in selected pathways which appropriately model estrogen-elicited in vivo hepatic responses.

2006-08-15

316

Investigation of biomass concentration, lipid production, and cellulose content in Chlorella vulgaris cultures using response surface methodology.  

UK PubMed Central (United Kingdom)

The microalgae Chlorella vulgaris produce lipids that after extraction from cells can be converted into biodiesel. However, these lipids cannot be efficiently extracted from cells due to the presence of the microalgae cell wall, which acts as a barrier for lipid removal when traditional extraction methods are employed. Therefore, a microalgae system with high lipid productivity and thinner cell walls could be more suitable for lipid production from microalgae. This study addresses the effect of culture conditions, specifically carbon dioxide and sodium nitrate concentrations, on biomass concentration and the ratio of lipid productivity/cellulose content. Optimization of culture conditions was done by response surface methodology. The empirical model for biomass concentration (R(2) ?=?96.0%) led to a predicted maximum of 1123.2?mg?dw?L(-1) when carbon dioxide and sodium nitrate concentrations were 2.33% (v/v) and 5.77?mM, respectively. For lipid productivity/cellulose content ratio (R(2) ?=?95.2%) the maximum predicted value was 0.46 (mg?lipid?L(-1) ?day(-1) )(mg cellulose mg biomass(-1) )(-1) when carbon dioxide concentration was 4.02% (v/v) and sodium nitrate concentration was 3.21?mM. A common optimum point for both variables (biomass concentration and lipid productivity/cellulose content ratio) was also found, predicting a biomass concentration of 1119.7?mg?dw?L(-1) and lipid productivity/cellulose content ratio of 0.44 (mg?lipid?L(-1) ?day(-1) )(mg cellulose mg biomass(-1) )(-1) for culture conditions of 3.77% (v/v) carbon dioxide and 4.01?mM sodium nitrate. The models were experimentally validated and results supported their accuracy. This study shows that it is possible to improve lipid productivity/cellulose content by manipulation of culture conditions, which may be applicable to any scale of bioreactors.

Aguirre AM; Bassi A

2013-08-01

317

aluminium blunts the proliferative response, and increases apoptosis of cultured human cells: putative relationship to alzheimer’s disease  

Directory of Open Access Journals (Sweden)

Full Text Available Aluminium (Al) has been investigated as a neurotoxic substance. Al ranks among the potential environmental risk factors for Alzheimer’s disease (AD). Epidemiological studies tested the relationship between Al in drinking water and AD, showing a significant correlation between elevated levels of monomeric Al in water and AD, although data to date remain inconclusive with respect to total Al. The aim of this study was to test whether or not Al exacerbates cellular toxicity mediated by the Amyloid-? (A?) peptide. We evaluated the role of Al in modulating programmed cell death (apoptosis) in human cell cultures. We used the osteosarcoma cell line monolayer (SaOs-2) to demonstrate that treatment of SaOs-2 cultures with the A? peptide mid-fragment (25-35) at 10-9M, followed by co-incubation with physiological concentrations of AlCl3, which release monomeric Al in solution, led to marked expression of caspase 3, but not caspase 9, key markers of the apoptotic process. The same experimental conditions were shown to blunt significantly the proliferative response of normal human peripheral blood mononuclear cells (PBMC) to phytohemagglutinin (PHA) stimulation. Our observations support the hypothesis that Al significantly impairs certain cellular immune responses, and confirm that Al-mediated cell toxicity may play an important role in AD.

Paolo Prolo; Francesco Chiappelli; Enzo Grasso; Maria Gabriella Rosso; Negoita Neagos; Andrea Dovio; Maria Luisa Sartori; Paola Perotti; Fausto Fanto; Massimo Civita; Adriano Fiorucci

2007-01-01

318

Oxidative stress response of Blakeslea trispora induced by iron ions during carotene production in shake flask culture.  

UK PubMed Central (United Kingdom)

The adaptive response of the fungus Blakeslea trispora to the oxidative stress induced by iron ions during carotene production in shake flask culture was investigated. The culture response to oxidative stress was studied by measuring the specific activities of catalase (CAT) and superoxide dismutase (SOD). The addition of 1.0 mM of FeCl3 to the medium was associated with a mild oxidative stress as evidenced by remarkable increase of the specific activities of SOD and CAT. On the other hand, the addition 5.0 mM of FeCl3 caused a strong oxidative stress resulting in a drastic decrease in carotene concentration. The oxidative stress in B. trispora changed the composition of the carotenes and caused a significant increase of ?-carotene ratio. The highest concentration of carotenes (115.0 ± 3.5 mg/g dry biomass) was obtained in the basal medium without the addition of FeCl3 after 8 days of fermentation. In this case, the carotenes consisted of ?-carotene (46.3 %), ?-carotene (40.1 %), and lycopene (13.6 %). The addition of 1.0 mM of FeCl3 into the medium did not change the concentration of carotenes. But, the composition of carotenes was changed with a drastic increase of ?-carotene ratio (61.6 %) and a decrease in ?-carotene and lycopene ratio (31.2 and 7.2 %, respectively).

Nanou K; Roukas T

2013-04-01

319

Comparative study of proliferation of suckling and adult rat hepatocytes in primary culture in response to growth-stimulating factors.  

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Full Text Available The replicative responses of suckling and adult rat hepatocytes in primary culture to growth-stimulating factors were compared. By addition of L-proline alone, the [3H]-thymidine labeling of suckling rat hepatocytes was dramatically enhanced, but that of adult ones was not. Epidermal growth factor (EGF), insulin, triiodothyronine (T3) and glucagon also enhanced the labeling of suckling rat hepatocytes regardless of the presence or the absence of L-proline. On the other hand, in the absence of L-proline, only EGF enhanced the labeling of adult rat hepatocytes, and, in the presence of L-proline, insulin as well as EGF enhanced the labeling. In the presence of growth factors and L-proline, the number of suckling rat hepatocytes increased up to about 143%, whereas that of adult rat hepatocytes hardly increased. Thus, a remarkable difference in replicative responses to growth factors and L-proline was observed between suckling and adult rat hepatocytes in primary culture.

Handa,Yoshihiko; Miyazaki,Masahiro; Sato,Jiro

1986-01-01

320

Aberrant response to commensal Bacteroides thetaiotaomicron in Crohn's disease: an ex vivo human organ culture study.  

UK PubMed Central (United Kingdom)

BACKGROUND: Human ex vivo evidence indicating that an inappropriate immune response(s) to nonpathogenic bacteria contributes to disease pathogenesis in pediatric Crohn's disease (CD) is limited. The aim of the present study was to compare and contrast the early innate immune response of pediatric "healthy" versus CD mucosa to pathogenic, probiotic, and commensal bacteria. METHODS: "Healthy control" and CD pediatric mucosal biopsies (terminal ileum and transverse colon) were cocultured for 8 hours with E. coli O42, Lactobacillus GG (LGG), Bacteroidesthetaiotaomicron (B. theta), or stimulated with interleukin (IL)-1? (positive control). Matched nonstimulated biopsies served as experimental controls. IL-8 was the immune marker of choice. IL-8 mRNA and protein levels were quantified by quantitative polymerase chain reaction and sandwich enzyme-linked immunosorbent assay, respectively. RESULTS: IL-8 secretion was observed when control, ileal biopsies were exposed to pathogenic O42 and probiotic LGG, with no response noted to commensal B. theta. In comparison, Crohn's ileal biopsies showed impaired ability to induce IL-8 in response to O42 and LGG. Control colonic tissue showed a limited response to O42 or B. theta and LGG significantly reduced IL-8 secretion. Unlike control tissue, however, Crohn's ileal and colonic tissue did respond to B. theta, with more enhanced expression in the colon. CONCLUSIONS: We provide the first ex vivo data to support the notion that aberrant mucosal recognition of commensal bacteria may contribute to pediatric CD. While IL-8 responses to O42 and LGG varied with disease status and anatomical location, B. theta consistently induced significant IL-8 both in ileal and colonic CD tissue, which was not seen in control, healthy tissue.

Edwards LA; Lucas M; Edwards EA; Torrente F; Heuschkel RB; Klein NJ; Murch SH; Bajaj-Elliott M; Phillips AD

2011-05-01

 
 
 
 
321

Aberrant response to commensal Bacteroides thetaiotaomicron in Crohn's disease: An ex vivo human organ culture study.  

UK PubMed Central (United Kingdom)

BACKGROUND:: Human ex vivo evidence indicating that an inappropriate immune response(s) to nonpathogenic bacteria contributes to disease pathogenesis in pediatric Crohn's disease (CD) is limited. The aim of the present study was to compare and contrast the early innate immune response of pediatric "healthy" versus CD mucosa to pathogenic, probiotic, and commensal bacteria. METHODS:: "Healthy control" and CD pediatric mucosal biopsies (terminal ileum and transverse colon) were cocultured for 8 hours with E. coli O42, Lactobacillus GG (LGG), Bacteroidesthetaiotaomicron (B. theta), or stimulated with interleukin (IL)-1? (positive control). Matched nonstimulated biopsies served as experimental controls. IL-8 was the immune marker of choice. IL-8 mRNA and protein levels were quantified by quantitative polymerase chain reaction and sandwich enzyme-linked immunosorbent assay, respectively. RESULTS:: IL-8 secretion was observed when control, ileal biopsies were exposed to pathogenic O42 and probiotic LGG, with no response noted to commensal B. theta. In comparison, Crohn's ileal biopsies showed impaired ability to induce IL-8 in response to O42 and LGG. Control colonic tissue showed a limited response to O42 or B. theta and LGG significantly reduced IL-8 secretion. Unlike control tissue, however, Crohn's ileal and colonic tissue did respond to B. theta, with more enhanced expression in the colon. CONCLUSIONS:: We provide the first ex vivo data to support the notion that aberrant mucosal recognition of commensal bacteria may contribute to pediatric CD. While IL-8 responses to O42 and LGG varied with disease status and anatomical location, B. theta consistently induced significant IL-8 both in ileal and colonic CD tissue, which was not seen in control, healthy tissue. (Inflamm Bowel Dis 2010;).

Edwards LA; Lucas M; Edwards EA; Torrente F; Heuschkel RB; Klein NJ; Murch SH; Bajaj-Elliott M; Phillips AD

2010-11-01

322

The influence of exogenous eicosanoids on the radiation response of cultured bovine aortic endothelial cells  

International Nuclear Information System (INIS)

The radioprotection by several eicosanoids was investigated in cultures of bovine aortic endothelial cells. One hour before irradiation (0-500 cGy, 137Cs gamma rays) 10 micrograms/ml of PGD2, PGE1, PGI2, misoprostol (PGE1-analog), 16,16-dimethyl PGE2, PGA2, or 1 microgram/ml LTC4 was added. Radiation decreased incorporation of [3H]thymidine at 4 h, cell number/culture at 24 h, and cell survival as measured by colony formation. Under these conditions the eicosanoids were not radioprotective. Two eicosanoids, PGD2 and PGA2, appeared to be toxic. Because receptors might mediate eicosanoid-induced radioprotection, radioligand binding of PGE2 and LTC4 and levels of adenosine 3',5'-cyclic monophosphate (cAMP) were measured. Evidence for a receptor was equivocal; there was nonspecific binding and metabolism of LTC4. The level of cAMP was elevated by 16-16-dimethyl-PGE2 in the presence of isobutyl methylxanthine; however, this combination of the prostaglandin and the methylxanthine was not radioprotective. These investigations suggest that an elevated cAMP level alone does not lead to eicosanoid-induced radioprotection of bovine aortic endothelial cell monolayers in vitro

1991-01-01

323

The influence of exogenous eicosanoids on the radiation response of cultured bovine aortic endothelial cells  

Energy Technology Data Exchange (ETDEWEB)

The radioprotection by several eicosanoids was investigated in cultures of bovine aortic endothelial cells. One hour before irradiation (0-500 cGy, 137Cs gamma rays) 10 micrograms/ml of PGD2, PGE1, PGI2, misoprostol (PGE1-analog), 16,16-dimethyl PGE2, PGA2, or 1 microgram/ml LTC4 was added. Radiation decreased incorporation of (3H)thymidine at 4 h, cell number/culture at 24 h, and cell survival as measured by colony formation. Under these conditions the eicosanoids were not radioprotective. Two eicosanoids, PGD2 and PGA2, appeared to be toxic. Because receptors might mediate eicosanoid-induced radioprotection, radioligand binding of PGE2 and LTC4 and levels of adenosine 3',5'-cyclic monophosphate (cAMP) were measured. Evidence for a receptor was equivocal; there was nonspecific binding and metabolism of LTC4. The level of cAMP was elevated by 16-16-dimethyl-PGE2 in the presence of isobutyl methylxanthine; however, this combination of the prostaglandin and the methylxanthine was not radioprotective. These investigations suggest that an elevated cAMP level alone does not lead to eicosanoid-induced radioprotection of bovine aortic endothelial cell monolayers in vitro.

Rubin, D.B.; Drab, E.A.; Stone, A.M.; Walden, T.L. Jr.; Hanson, W.R. (Rush-Presbyterian-St. Luke' s-Medical Center, Chicago, IL (USA))

1991-01-01

324

Growth and enzymatic responses of phytopathogenic fungi to glucose in culture media and soil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The effect of inoculation of Aspergillus flavus, Fusarium verticillioides, and Penicillium sp. in Dystrophic Red Latosol (DRL) and Eutroferric Red Latosol (ERL) soils with or without glucose on the total carbohydrate content and the dehydrogenase and amylase activities was studied. The fungal growth and spore production in culture medium with and without glucose were also evaluated. A completely randomized design with factorial arrangement was used. The addition of glucos (more) e in the culture medium increased the growth rate of A. flavus and Penicillium sp. but not of F. verticillioides. The number of spores increased 1.2 for F. verticillioides and 8.2 times for A. flavus in the medium with glucose, but was reduced 3.5 times for Penicillium sp. The total carbohydrates contents reduced significantly according to first and second degree equations. The consumption of total carbohydrates by A. flavus and Penicillium sp. was higher than the control or soil inoculated with F. verticillioides. The addition of glucose to soils benefited the use of carbohydrates, probably due to the stimulation of fungal growth. Dehydrogenase activity increased between 1.5 to 1.8 times (p

Costa, Beatriz de Oliveira; Nahas, Ely

2012-03-01

325

Fish cell cultures as in vitro models of inflammatory responses elicited by immunostimulants. Expression of regulatory genes of the innate immune response.  

UK PubMed Central (United Kingdom)

We report the differential expression of various genes related to the regulation of the innate immune responses, including pro-inflammatory (IL-1?1, IL-8, TNF-?1, TNF-?2) and immune-suppressing (IL-10) cytokines, interferon-induced Mx-1 protein, enzymes regulating nitric oxide (inducible nitric oxide synthase, arginase-2) and eicosanoid (COX-2) production, and Toll-like pathogen pattern-recognition receptors TLR-3, TLR-5 and TLR-9, in two lympho-haematopoietic stromal cell lines derived from the spleen (trout splenic stroma, TSS) and the pronephros (trout pronephric stroma-2, TPS-2) of rainbow trout (Oncorhynchus mykiss), as well as in primary cultures of rainbow trout head kidney macrophages, after their exposure to the well-known immunostimulants LPS, levamisole and poly I:C. Although there were differences in the responses between the two stromal cell lines, using reverse transcription followed by real time polymerase chain reaction (RT-qPCR) we demonstrated that exposure to the immunostimulants, particularly poly I:C and LPS, resulted in significant changes in the expression of the immunoregulatory genes in the two stromal cell lines in many cases their responses resembling in fold change magnitudes and in response profiles to those observed in the primary macrophage cultures. Exposure to poly I:C and, with lower fold change values, to LPS produced upregulation of the pro- (IL-1?, IL-8, TNF-?) and anti-inflammatory (IL-10) cytokine genes, as well as of the Mx-1 gene. Furthermore, the immunostimulation elicited the upregulation of COX-2, iNOS and arginase-2 genes in the cell lines. Likewise, the TSS and TPS-2 cell lines significantly upregulated the expression of TLR-3, TLR-5 and TLR-9 genes after exposure to the immunostimulants, thus explaining the ability of the stromal cells to recognise and respond to the immunostimulants. Such results give support to an important role of lympho-haematopoietic stromal cells in the development and control of pro-inflammatory responses in fish. The upregulation of genes of pro-inflammatory cytokines and of mediators of the innate immune responses correlates well with the previously demonstrated functional capacities, including phagocytosis, microbicidal activity and NO production, exhibited by the TSS and TPS-2 stromal cell lines when exposed to the same immunostimulants. On the other hand, the expression of immunosuppressing genes (IL-10, COX-2 and arginase-2) demonstrate that the lympho-haematopoietic stromal cells are also able to contribute to the control of inflammatory responses. This study reinforce the possibility of using histotypic cell cultures, as those formed by the TSS and TPS-2 cell lines, formed by heterogeneous cell populations that partially replicates the cell-cell and cell-extracellular matrix interactions, to develop cost-effective and repetitive in vitro systems for the screening of immunostimulant candidates for aquaculture, as they are able to replicate in vitro immune regulatory networks occurring in vivo.

Fierro-Castro C; Barrioluengo L; López-Fierro P; Razquin BE; Villena AJ

2013-09-01

326

Fish cell cultures as in vitro models of inflammatory responses elicited by immunostimulants. Expression of regulatory genes of the innate immune response.  

Science.gov (United States)

We report the differential expression of various genes related to the regulation of the innate immune responses, including pro-inflammatory (IL-1?1, IL-8, TNF-?1, TNF-?2) and immune-suppressing (IL-10) cytokines, interferon-induced Mx-1 protein, enzymes regulating nitric oxide (inducible nitric oxide synthase, arginase-2) and eicosanoid (COX-2) production, and Toll-like pathogen pattern-recognition receptors TLR-3, TLR-5 and TLR-9, in two lympho-haematopoietic stromal cell lines derived from the spleen (trout splenic stroma, TSS) and the pronephros (trout pronephric stroma-2, TPS-2) of rainbow trout (Oncorhynchus mykiss), as well as in primary cultures of rainbow trout head kidney macrophages, after their exposure to the well-known immunostimulants LPS, levamisole and poly I:C. Although there were differences in the responses between the two stromal cell lines, using reverse transcription followed by real time polymerase chain reaction (RT-qPCR) we demonstrated that exposure to the immunostimulants, particularly poly I:C and LPS, resulted in significant changes in the expression of the immunoregulatory genes in the two stromal cell lines in many cases their responses resembling in fold change magnitudes and in response profiles to those observed in the primary macrophage cultures. Exposure to poly I:C and, with lower fold change values, to LPS produced upregulation of the pro- (IL-1?, IL-8, TNF-?) and anti-inflammatory (IL-10) cytokine genes, as well as of the Mx-1 gene. Furthermore, the immunostimulation elicited the upregulation of COX-2, iNOS and arginase-2 genes in the cell lines. Likewise, the TSS and TPS-2 cell lines significantly upregulated the expression of TLR-3, TLR-5 and TLR-9 genes after exposure to the immunostimulants, thus explaining the ability of the stromal cells to recognise and respond to the immunostimulants. Such results give support to an important role of lympho-haematopoietic stromal cells in the development and control of pro-inflammatory responses in fish. The upregulation of genes of pro-inflammatory cytokines and of mediators of the innate immune responses correlates well with the previously demonstrated functional capacities, including phagocytosis, microbicidal activity and NO production, exhibited by the TSS and TPS-2 stromal cell lines when exposed to the same immunostimulants. On the other hand, the expression of immunosuppressing genes (IL-10, COX-2 and arginase-2) demonstrate that the lympho-haematopoietic stromal cells are also able to contribute to the control of inflammatory responses. This study reinforce the possibility of using histotypic cell cultures, as those formed by the TSS and TPS-2 cell lines, formed by heterogeneous cell populations that partially replicates the cell-cell and cell-extracellular matrix interactions, to develop cost-effective and repetitive in vitro systems for the screening of immunostimulant candidates for aquaculture, as they are able to replicate in vitro immune regulatory networks occurring in vivo. PMID:23872473

Fierro-Castro, C; Barrioluengo, L; López-Fierro, P; Razquin, B E; Villena, A J

2013-07-18

327

BAP, 2,4-D e ácido acetilsalicílico na indução e diferenciação de calos em anteras de Coffea arabica L BAP, 2,4-D and acetyl-salicylic acid on the callus induction and differentiation in Coffea arabica L. anthers  

Directory of Open Access Journals (Sweden)

Full Text Available O melhoramento genético do cafeeiro por meio de métodos convencionais é um processo demorado para se obter uma nova cultivar. A redução desse tempo é possível através da produção de linhagens homozigóticas, oriundas de dihaplóides obtidas através da cultura de anteras. Objetivou-se aplicar a técnica da cultura de anteras em diferentes cvs. de Coffea arabica L. para induzir a formação de calos e regenerar plântulas di-haplóides, com uso de reguladores vegetais. Os experimentos foram conduzidos no laboratório de Biotecnologia Vegetal da Universidade Federal de Uberlândia (UFU). Anteras das cultivares Mundo Novo LCP-379-19 e Catuaí Vermelho H2077-2-5-44 foram inoculadas em meio MS suplementado com 2,0 mg L-1 de 2,4-D e AAS, nas concentrações de 0; 8; 16; 32 e 64 mg L-1. Calos de 'Catuaí Vermelho 44' foram subcultivados em meio MS acrescido de diferentes concentrações de BAP (0; 2; 4 e 8 mg L-1) e 2,4-D (0; 1; 2 e 4 mg L-1). Tanto para as cvs. Mundo Novo quanto para Catuaí Vermelho 44 o aumento das concentrações de AAS diminuiu a formação de próembrióides nos calos e somente o 2,4-D foi capaz de promover a formação de calos friáveis, porém o equilíbrio da auxina e da citocinina utilizadas no trabalho, favoreceram a produção de calos friáveis.Coffee plant breeding through conventional methods demands a long time to obtain new cultivars. The reduction of this period is possible through the production of homozygous lines, from dihaploids obtained via anther culture. The aim of this study was to apply the anther culture technique on different C. arabica L. cultivars to induce calli formation and to regenerate dihaploid seedlings with the use of plant growth regulators. The experiments were accomplished in the Plant Biotechnology laboratory at Uberlândia Federal University (UFU). Anthers of the cultivars Mundo Novo LCP-379-19 and Catuaí Vermelho H2077-2-5-44 were inoculated on MS medium supplemented with 2.0 mg L-1 2,4-D and ASA at 0, 8, 16, 32 or 64 mg L-1. 'Catuaí Vermelho 44' calli were subcultured on MS supplemented with different concentrations of BAP (0, 2, 4 or 8 mg L-1) and 2,4-D (0, 1, 2 or 4 mg L-1). The increase in ASA concentrations decreased the pro-embryoid formation on calli of both cultivars and only 2,4-D promoted the formation of friable calli. However, the balance of auxin and cytokinin used in this study favored the production of friable calli.

Adelaide Siqueira Silva; José Magno Queiroz Luz; Tatiana Michlovská Rodrigues; Cecília Alves Bittar; Leandro de Oliveira Lino

2009-01-01

328

A 286 bp upstream regulatory region of a rice anther-specific gene, OSIPP3, confers pollen-specific expression in Arabidopsis.  

UK PubMed Central (United Kingdom)

OSIPP3 gene (coding for pectin methylesterase inhibitor protein) was isolated from a pre-pollinated inflorescence-specific cDNA library by differential screening of stage-specific libraries from Oryza sativa. OSIPP3 is present in the genome of rice as a single copy gene. OSIPP3 gene was expressed exclusively in the pre-pollinated spikelets of rice. Upstream regulatory region (URR) of OSIPP3 was isolated and a series of 5'-deletions were cloned upstream of GUS reporter gene and were used to transform Arabidopsis. OSIPP3_del1 and del2 transgenic plants showed GUS expression in root, anther and silique, while OSIPP3_del3 showed GUS activity only in anthers and siliques. Pollen-specific expression was observed in case of plants harboring OSIPP3_del4 construct. It can, therefore, be concluded that the OSIPP3 URR between -178 and +108 bp is necessary for conferring pollen-specific expression in Arabidopsis.

Khurana R; Kathuria H; Mukhopadhyay A; Kapoor S; Tyagi AK

2013-03-01

329

Profiles in coping: responses to sexual harassment across persons, organizations, and cultures.  

Science.gov (United States)

This study explicates the complexity of sexual harassment coping behavior among 4 diverse samples of working women: (a) working-class Hispanic Americans, (b) working-class Anglo Americans, (c) professional Turks, and (d) professional Anglo Americans. K-means cluster analysis revealed 3 common harassment coping profiles: (a) detached, (b) avoidant negotiating, and (c) support seeking. The authors then tested an integrated framework of coping profile determinants, involving social power, stressor severity, social support, and culture. Analysis of variance, chi-square, and discriminant function results identified significant determinants at each of the 4 levels of this ecological model. These findings underscore the importance of focusing on whole patterns of experience--and considering influences at the level of the individual employee and multiple levels of the surrounding context--when studying how women cope with workplace sexual harassment. PMID:15641899

Cortina, Lilia M; Wasti, S Arzu

2005-01-01

330

Tourism communication: the translator’s responsibility in the translation of cultural difference  

Directory of Open Access Journals (Sweden)

Full Text Available Tourist discourse can be considered as a specialised type of cross-cultural communication. The subject of this work is the degree of intervention translators are asked to exercise in order to achieve successful communication. Their task is not that of demonstrating their knowledge on specifi c subjects, as, rather, their capacity of mediating it, so as to make it available to a type of tourist who is necessarily different from that targeted by the original work. Hence, translators should learn to dose the amount of information tourists will be able to take in. Theoretical assumptions will be illustrated by means of a comparison between a tourist text in Italian and its translation into English. It will be demonstrated that translators’ decisions at linguistic and explanatory level allow a more or less substantial degree of reader involvement, and consequently affect the promotion of tourist destinations.

Mirella Agorni

2012-01-01

331

Response of Grape Explants (cv. Bidaneh Soltani) to Different Culture Media  

Directory of Open Access Journals (Sweden)

Full Text Available To study the effects of different combinations of auxin (IBA, NAA) and cytokinin (BAP, TDZ) regulators, basal salts (MS, WPM, NN) and gelling agents (Gelrite and Plant Agar) on the growth and development of seedless grape explants (cv. Bidaneh Soltani), a factorial experiment was conducted based on a completely randomized design. The number and length of grown shoots were analyzed as two main characteristics. Growth regulators and salts had significant effects (at %1) on the shoot proliferation. The highest number of shoots was observed on MS salts combined with BAP (2.2 mg/l) and IBA (0.5 mg/l) on the 18th days of culture. Compared to Plant Agar, Gelrite had a better effect on the normal growth of the shoots. Based on the new shoots, combinations of MS salts and hormones may be used for micropropagation of seedless grape cultivars in the in vitro condition.

R. Haddad; GH. Garousi; M. Ghannadnia

2008-01-01

332

Dopamine attenuates the contractile response to angiotensin II in isolated rat glomeruli and cultured mesangial cells.  

UK PubMed Central (United Kingdom)

Recent evidence suggests that dopamine may alter kidney function by actions not only in the renal vasculature but also at the glomerular-mesangial level. We studied this phenomenon by examining the ability of dopamine to antagonize the contractile properties of angiotensin II in isolated rat glomeruli and cultured mesangial cells. In isolated rat glomeruli angiotensin II caused a decrease in the planar surface area, indicating glomerular contraction, an effect that was abolished by coincubation with dopamine. Angiotensin II also mediated shape changes in cultured mesangial cells, which resulted in a decline in their planar areas. Simultaneous addition of dopamine prevented these decreases in cell size. In mesangial cells grown on a flexible silicone rubber support, angiotensin II addition enhanced wrinkling of the mobile surface. This indicated that the angiotensin-II-induced decrease in cell size observed in cells grown on conventional substrata represented contraction. Conversely, dopamine caused a rapid reduction in wrinkling of the surfaces from control cells as well as those previously treated with angiotensin II, actions consistent with cell relaxation. The prostaglandin inhibitor indomethacin did not alter the ability of dopamine to attenuate angiotensin-II-associated reductions in mesangial cell surface area. Direct determination of mesangial cell prostaglandin-E2 production showed that dopamine did not change either basal synthesis or angiotensin-II-stimulated synthesis of prostaglandin. The results demonstrate that dopamine antagonizes the constrictor effect of angiotensin II at the glomerular-mesangial level. This action of dopamine is prostaglandin independent. These findings support a role for dopamine in the regulation of glomerular filtration and may provide a rationale for its use during states of renal vasoconstriction.

Barnett R; Singhal PC; Scharschmidt LA; Schlondorff D

1986-11-01

333

Cultural Influences on Responses to Items on the Strong Interest Inventory  

Science.gov (United States)

This study examined racial/ethnic group differences on an interest inventory at the item level using differential bundle functioning (DBF) analyses. Specifically, responses of males and females from five different racial/ethnic groups (N=3750) on the General Occupational Themes of the Strong were examined. Items were grouped together based on…

Fouad, Nadya A.; Walker, Cindy M.

2005-01-01

334

Corporate Social Responsibility and Culture : A Study of European Multinational Corporations’ adaptation of Community Involvement Practices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Corporate social responsibility (CSR), which has emerged as a global trend, has gained increased focus in the everyday media and among practitioners on the political agenda. CSR has also risen as an important research topic in the field of organization. This study investigates European multinational...

Henriksson, Sebastian; Hodjikj, Armin; Ognyanova Dinkova, Evgeniya

335

Recombinant bromelain production in Escherichia coli: process optimization in shake flask culture by response surface methodology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bromelain, a cysteine protease with various therapeutic and industrial applications, was expressed in Escherichia coli, BL21-AI clone, under different cultivation conditions (post-induction temperature, L-arabinose concentration and post-induction period). The optimized conditions by response surfac...

Muntari, Bala; Amid, Azura; Mel, Maizirwan; Jami, Mohammed S; Salleh, Hamzah M

336

Neuroglobin-overexpression alters hypoxic response gene expression in primary neuron culture following oxygen glucose deprivation.  

UK PubMed Central (United Kingdom)

Neuroglobin (Ngb) is a tissue globin specifically expressed in neurons. Our laboratory and others have shown that Ngb overexpression protects neurons against hypoxia/ischemia, but the underlying mechanisms remain poorly understood. Recent studies demonstrate that hypoxia/ischemia induces a multitude of spatially and temporally regulated responses in gene expression, and initial evidence suggested that Ngb might function in altering biological processes of gene expression. In this study, we asked how Ngb may help regulate genes responsive to hypoxia. Expression of hypoxic response genes following oxygen-glucose deprivation (OGD) was examined using mRNA arrays in neuroglobin-overexpressing transgenic (Ngb-Tg) and wild type (WT) mouse neurons. From a total of 113 genes on the microarray, mRNA expression of 65 genes was detected. Under rest condition, 14 genes were downregulated in Ngb-Tg neurons compared to WT. In WT neurons, after 4-h OGD followed by 4-h reoxygenation (O4/R4), 20 genes were significantly downregulated, and only Fos mRNA was significantly increased. However, out of the 20 downregulated genes in WT neurons, 12 of them were no longer significantly changed in Ngb-Tg neurons: Add1, Arnt2, Camk2g, Cstb, Dr1, Epas1, Gna11, Hif1a, Il6st, Khsrp, Mars and Rara. Among these 12 genes, 8 (Add1, Camk2g, Cstb, Dr1, Epas1, Gna11, Hif1a, Khsrp) were already reduced in Ngb-Tg neurons compared to WT under rest conditions. Additionally, three genes that initially showed no changes in WT neurons (Ctgf, Egfr and Pea15) were downregulated after OGD in the Ngb-Tg neurons. These findings suggest that Ngb overexpression modulates mRNA expression of multiple hypoxic response genes in the early phase after OGD/reoxygenation. Further studies on these gene networks and interactions may lead to better understanding of Ngb in signaling pathways that contribute to neuroprotection.

Yu Z; Liu J; Guo S; Xing C; Fan X; Ning M; Yuan JC; Lo EH; Wang X

2009-08-01

337

Neuroglobin-overexpression alters hypoxic response gene expression in primary neuron culture following oxygen glucose deprivation.  

Science.gov (United States)

Neuroglobin (Ngb) is a tissue globin specifically expressed in neurons. Our laboratory and others have shown that Ngb overexpression protects neurons against hypoxia/ischemia, but the underlying mechanisms remain poorly understood. Recent studies demonstrate that hypoxia/ischemia induces a multitude of spatially and temporally regulated responses in gene expression, and initial evidence suggested that Ngb might function in altering biological processes of gene expression. In this study, we asked how Ngb may help regulate genes responsive to hypoxia. Expression of hypoxic response genes following oxygen-glucose deprivation (OGD) was examined using mRNA arrays in neuroglobin-overexpressing transgenic (Ngb-Tg) and wild type (WT) mouse neurons. From a total of 113 genes on the microarray, mRNA expression of 65 genes was detected. Under rest condition, 14 genes were downregulated in Ngb-Tg neurons compared to WT. In WT neurons, after 4-h OGD followed by 4-h reoxygenation (O4/R4), 20 genes were significantly downregulated, and only Fos mRNA was significantly increased. However, out of the 20 downregulated genes in WT neurons, 12 of them were no longer significantly changed in Ngb-Tg neurons: Add1, Arnt2, Camk2g, Cstb, Dr1, Epas1, Gna11, Hif1a, Il6st, Khsrp, Mars and Rara. Among these 12 genes, 8 (Add1, Camk2g, Cstb, Dr1, Epas1, Gna11, Hif1a, Khsrp) were already reduced in Ngb-Tg neurons compared to WT under rest conditions. Additionally, three genes that initially showed no changes in WT neurons (Ctgf, Egfr and Pea15) were downregulated after OGD in the Ngb-Tg neurons. These findings suggest that Ngb overexpression modulates mRNA expression of multiple hypoxic response genes in the early phase after OGD/reoxygenation. Further studies on these gene networks and interactions may lead to better understanding of Ngb in signaling pathways that contribute to neuroprotection. PMID:19401220

Yu, Z; Liu, J; Guo, S; Xing, C; Fan, X; Ning, M; Yuan, J C; Lo, E H; Wang, X

2009-05-03

338

Tissue Culture response of Local Varieties of Rice (Oryza sativa L.) of NWFP  

Directory of Open Access Journals (Sweden)

Full Text Available Four rice genotypes i.e. Swat I, Swat II, Dilrosh 97 and Pakhal were tested for their callus induction frequency and their subsequent regeneration from different explants on a variety of media combinations. Swat I appeared to be the most responsive genotype to callus induction followed by Swat II, Dilrosh 97 and Pakhal respectively. Swat I and Swat II produced high amount of callus compared to other genotypes. Callus induction frequencies ranged from 68.88 to 57.70 percent in Swat I, 60.00 percent in Swat II, 52.20 percent in Dilrosh 97 and 40.00 to 42.20 percent in Pakhal from scutella on two different media. Similar response was also found for root induced calli. However, N6 medium containing 2 mg/l of 2,4-D was found to be optimum for callus induction irrespective of the genotypes and explant studied. All varieties showed significant differences in regeneration from two and three week old calli. RM medium containing MS salts and vitamins, 2 gm casamino acid, 1 mg/l NAA, 2 mg/l BAP and 30 gm sorbitol gave comparatively higher regeneration response than the other two media tested. Plants regenerated were grown in harmone free MS medium for vigorous rooting and subsequent transfer to soil.

Asad Jan; Qazi M. Hassan; Tahira Fatima; Tayyab Hasnain

2001-01-01

339

Response of Bread Wheat Genotypes to Immature Embryo Culture, Callus Induction and Drought Stress  

Directory of Open Access Journals (Sweden)

Full Text Available In order to evaluate the response of twenty genotypes of bread wheat (Triticum aestivum L.) to callus induction and in vitro drought stress. The immature embryos of wheat were used in a Completely Randomized Design (CRD) with six replications for callus induction and a 20×2 factorial experiment based on CRD design with three replications was carried out for response of genotypes to in vitro drought stress at the Agricultural College of Razi University, Kermanshah, Iran during 2010-2011. Significant differences were observed among the genotypes for Callus Growth Rate (CGR), Relative Fresh Weight Growth (RFWG), Relative Growth Rate (RGR) and Percentage of Callus Induction (PCI) indicating the presence of genetic variability, different responses of bread wheat genotypes to callus induction and possible selection of callus induction at in vitro level using immature embryos. Mean comparison of the traits measured in callus induction showed that genotypes 1 and 6 had the highest PCI (100%). Analysis of variance for CGR, RFWG and RGR, Relative Water Content (RWC), Percent of Callus Chlorosis (PCC) and Proline Content (PC) exhibited significant differences among the genotypes for all the characters in the stress condition (15% PEG). Screening drought tolerant genotypes and in vitro indicators of drought tolerance using mean rank, standard deviation of ranks and biplot analysis, discriminated genotypes (6), (19) and (1) as the most drought tolerant.

Parvin Elyasi; Ezatollah Farshadfar; Mostafat Aghaee

2012-01-01

340

Studies of the in vitro selection of novel disease resistant plants and mutagenesis of cultured cells  

International Nuclear Information System (INIS)

Plants of Brassica napus ssp. oleifera cv Primor which had been regenerated from secondary embryoids were found to be more susceptible to Leptosphaeria maculans than those grown from seed, but were generally more resistant to Alternaria brassicicola. In vitro selection of secondary embryoids on medium containing toxic filtrates of A. brassicicola did not result in significantly higher levels of resistance to the pathogen, and in the case of L. maculans, the plants were found to be more susceptible after the selection steps. When tissues were challenged with pycnidiospores of L. maculans it was possible to define growth conditions in which differential reactions correlated with in vivo responses. Studies on in vitro mutagenesis revealed that low doses of gamma rays enhanced the production of anther embryoids, although, whereas both gamma and X-rays reduced the regeneration capacity of treated tissues, irradiation with UV did not. Increased resistance to A. brassicicola was detected in doubled haploid plants following a seed treatment with EMS and from microspore culture following UV irradiation. In vitro studies of Helianthus annuus and Macrophomina phaseolina, and Zea mays and Fusarium moniliforme are also reported. (author). 28 refs, 2 figs, 2 tabs

1993-01-01

 
 
 
 
341

Cultural responses to pain in UK children of primary school age: A mixed-methods study.  

UK PubMed Central (United Kingdom)

Pain-measurement tools are often criticized for not addressing the influence of culture and ethnicity on pain. This study examined how children who speak English as a primary or additional language discuss pain. Two methods were used in six focus group interviews with 34 children aged 4-7 years: (i) use of drawings from the Pediatric Pain Inventory to capture the language used by children to describe pain; and (ii) observation of the children's placing of pain drawings on red/amber/green paper to denote perceived severity of pain. The findings demonstrated that children with English as an additional language used less elaborate language when talking about pain, but tended to talk about the pictures prior to deciding where they should be placed. For these children, there was a positive significant relationship between language, age, and length of stay in the UK. The children's placement of pain drawings varied according to language background, sex, and age. The findings emphasize the need for sufficient time to assess pain adequately in children who do not speak English as a first language.

Azize PM; Endacott R; Cattani A; Humphreys A

2013-08-01

342

Reflexiones sobre la actualidad del relativismo cultural: respuesta a Nicolás Sánchez Durá/ Considerations about the Pertinence of Cultural Relativism: Response to Nicolás Sánchez Durá  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Este ensayo propone entablar una discusión con las tesis contenidas en el artículo de Nicolás Sánchez Durá, "Actualidad del relativismo cultural". En primer lugar, se analizan el etnocentrismo y el relativismo como dos respuestas éticas distintas al fenómeno de la diversidad cultural. En segundo lugar, se desarrollan la formulación del relativismo y el concepto de cultura propuestos por Sánchez Durá para analizarlos a la luz de la epistemología elaborada por el (more) Wittgenstein tardío. En tercer lugar, se agregan argumentos a favor del relativismo cultural. El relativismo cultural, visto como una doctrina, tropieza con dilemas lógicos y conceptuales; considerado como una actitud contextual de índole moral y política, contribuye a combatir la autoridad del etnocentrismo basado en la exclusividad del otro. Abstract in english This essay proposes to develop and to discuss some thesis included in the article by Nicolás Sánchez Durá: "The Pertinence of Cultural Relativism". Firstly, the ethnocentric and relativistic positions are both considered as two different ethical attitudes towards the cultural diversity. Secondly, the concepts of "relativism" and "culture" are developed and analyzed in the light of Ludwig Wittgenstein's later philosophy. Although, the cultural relativism considered as a (more) philosophical doctrine faces logical and conceptual dilemmas, the latter disappear when relativism is treated as contextual, mostly moral and political attitude, which contributes to undermine the legacy of ethno-centrism based on the other's exclusivity.

Jacorzynski, Witold

2013-04-01

343

Seasonal variations in the pattern of RNA metabolism of tuber tissue in response to excision and culture  

International Nuclear Information System (INIS)

[en] Between December 1975 and June 1976 explants excised from Jerusalem artichoke tubers were cultured in the presence and in the absence of 2,4-D, the cells in the tissue dividing only in the presence of 2,4-D, in which the length of the first cell cycle increased nonlinearly from 18 hours to 40 hours as the tubers aged in storage at 4 0C. Simultaneously the amount of RNA in the tissue declined linearly from 8 to 5 ?g RNA per explant. Detailed examination of the RNA metabolism in dividing and in non-dividing cells during February and June 1976 revealed superimposed but independent responses to wounding during excision and to stimulation into growth by 2,4-D. The responses to wounding involved only a very low level of metabolic activity, were complete within a few hours of excision and changed very little with the storage of the tubers. Tissue treated with 2,4-D showed a much higher level of metabolic activity including the periodic accumulation of RNA coupled to its discontinuous synthesis. The features of these growth-related responses changed considerably during the investigation. (author)

1979-01-01

344

Quantifying proliferation of cultured human and rabbit airway smooth muscle cells in response to serum and platelet-derived growth factor.  

UK PubMed Central (United Kingdom)

Development of suitable methods for the quantification of the proliferative response of airway smooth muscle (ASM) cells in culture will assist the investigation of the cellular mechanisms underlying the hyperplasia and hypertrophy of ASM as seen in asthmatic airways. In this study, two rapid and simple colorimetric assays have been modified to enable the growth of human bronchial and rabbit tracheal smooth muscle in culture to be assessed. One method depends upon the reduction by living cells of the tetrazolium salt MTT to form a blue formazan product, whereas the other relies on rapid binding of the dye Coomassie brilliant blue to protein at acidic pH. Experiments demonstrated the validity of both assays in quantifying the proliferative response of cultured human and rabbit ASM cells. The increase in optical density observed for each assay correlated directly, throughout the duration of culture, with the increase in cell number determined by hemocytometry in human and rabbit ASM cells proliferating in response to fetal calf serum (1.25 to 10%). This relationship held also for rabbit tracheal ASM cells proliferating in response to the heterodimer of platelet-derived growth factor (1 to 50 ng/ml). Application of these methods to adherent proliferating cultures of human and rabbit ASM cells demonstrated their adaptability to the generation of growth curves in response to serum and to a defined growth factor. These methods allow both total cellular protein and proliferation to be estimated in human and rabbit ASM cells in culture, using assays that are rapid, reproducible, inexpensive, and easy to perform while negating the use of radioisotopes. It is intended that these additional methods should be useful in delineating some of the mechanisms that might contribute to the proliferative response of these cells--particularly since there has been a resurgence in interest in culturing smooth muscle cells derived from the airways.

Hirst SJ; Barnes PJ; Twort CH

1992-12-01

345

Cellular responses in primary epidermal cultures from oncorhynchus mykiss following the combined exposure of ionising radiation and a heavy metal  

Energy Technology Data Exchange (ETDEWEB)

Mechanisms of toxicant action on biological systems are difficult to identify when more than one contaminant is involved due to potential synergistic and antagonistic effects. There is a general paucity of research into the effect of radiation exposure in tandem with common environmental contaminants due to the inherent difficulties involved. In vitro cell cultures are particularly suited to the study of toxic mechanisms due to their proximity to toxic modes of action and the absence of the multiple defence mechanisms present in intact organisms. Primary cell cultures are particularly beneficial in this area of research as they still maintain many of their tissue specific functions. The objective of this study was to distinguish different mechanisms of cell death (growth arrest, apoptosis, primary and secondary necrosis and proliferation), following combination exposure to ionising radiation and a heavy metal (ZnCl{sub 2}). The model system employed was a primary cell culture of rainbow trout (Oncorhynchus mykiss) epidermal tissue which has been previously used to study the effects of various environmental agents in this laboratory. Apoptosis and necrosis were quantified morphologically while proliferation was assessed immuno-cyto-chemically using an anti PCNA (proliferating cell nuclear antigen) antibody. While radiation doses up to and including 10 Gy had no effect on growth, exposure to ZnCl{sub 2} produced a significant dose dependent reduction in growth (10, 50, 75, 100 and 200 ppm ZnCl{sub 2}). Preliminary results indicate no significant effect on growth following a combined exposure of 5 Gy + 50 ppm ZnCl{sub 2}. These results may have important implications for understanding the mechanisms underlying cellular responses to multiple contaminant exposures. (author)

Lyng, F.M.; Ni Shuilleabhain, S.; Davoren, M. [Dublin Institute of Technology, Radiation and Environmental Science Centre, Kevin Street, Dublin (Ireland)

2004-07-01

346

Modulation of Ca2+ transients in cultured endothelial cells in response to fluid flow through alphav integrin.  

UK PubMed Central (United Kingdom)

In order to determine whether integrin dynamics is associated with intracellular Ca(2+) concentration ([Ca(2+)](i)) mobilization in ECs in response to hemodynamic forces, changes in [Ca(2+)](i) in fluo-4-loaded cultured bovine aortic endothelial cells (BAECs) under fluid flow conditions were visualized employing laser scanning confocal microscopy. Following the onset of flow stimulus, transient increases in [Ca(2+)](i) occurred several times in individual BAECs during the 30-min observation period. The frequency of these [Ca(2+)](i) transients was clearly reduced by the application of an integrin antagonist (GRGDSP peptide). Furthermore, treatment of cells with an integrin activator (Mn(2+)) resulted in reduction of peak [Ca(2+)](i) levels and elevated frequency, which was markedly rescued upon GRGDSP administration. In contrast, an actin de-polymerizing agent (cytochalasin D) exerted no inhibitory effects; rather, cytochalasin D more likely facilitated [Ca(2+)](i) transients. Moreover, [Ca(2+)](i) transients, which were suppressed by short interference RNA-induced silencing of alphav integrin, exhibited greater frequently in cells cultured on vitronectin substratum in comparison with those cultured on fibronectin or collagen substratum. Either removal of extracellular Ca(2+), application of an inhibitor of endoplasmic reticulum Ca(2+)-ATPase (thapsigargin) or non-selective cation channel blocker (La(3+)) inhibited the [Ca(2+)](i) transients. Additionally, [Ca(2+)](i) transients were attenuated by extracellular signal-regulated kinase (ERK) kinase inhibitor (U0126); in contrast, [Ca(2+)](i) transients were unaffected by tyrosine kinase inhibitor (genistein) or phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002). Therefore, our findings revealed that alphav integrin dynamics modulates the frequency of flow-induced [Ca(2+)](i) transients in BAECs in an ERK-dependent fashion.

Miyazaki T; Honda K; Ohata H

2007-10-01

347

Impact of corporate social responsibility claims on consumer food choice : A cross-cultural comparison  

DEFF Research Database (Denmark)

Purpose - The study assesses the impact of two different corporate social responsibility (CSR) claims, relating to social and environmental dimensions, on consumers’ wine choice across international markets. It is analysed how point of purchase CSR claims compete with other food claims and their awareness, penetration and consumers’ trust are examined. Design/methodology/approach - A discrete choice experiment with a visual shelf simulation was used to elicit consumer preferences and to estimate marginal willingness to pay for CSR and other food claims across the UK, France, Germany, the US Eastcoast, the US Midwest, Anglophone and Francophone Canada. Findings - CSR claims relating to social and environmental responsibility have a similar awareness, penetration and consumer trust, but differ in their impact on consumer choice, where environmental corporate responsibility claims benefit from a higher marginal willingness to pay. Consumer valuation of CSR claims significantly differs across international markets, but is consistently lower than for organic claims. Research limitations/implications - The study was limited to wine and future research is required to generalise findings to other food categories and different origins. Practical implications - CSR claims are competing with existing food claims and have a lower awareness, lower purchase penetration and less positive impact on consumer choice than organic claims. Producers are recommended to focus on communicating environmental rather than social CSR activities. The relative value of CSR claims differs across countries and companies need to adapt their strategies to specific market conditions. Originality/value - This is the first cross-national study that analyses the impact of CSR claims on consumer food choice relative to other food claims using large representative consumer samples. The strength of the paper also pertains to the utilisation of innovative choice experiments covering a large range of choice relevant product attributes.

Mueller Loose, Simone; Remaud, Hervé

2013-01-01

348

The Technology Transfer Dilemma. Preserving morally responsible education in a utilitarian entrepreneurial academic culture  

Directory of Open Access Journals (Sweden)

Full Text Available 'Research, teaching, and service' is growing to include business. With unbridled enthusiasm, academicians bring discoveries to market instead of having them sit fallow in the public domain. Dilemmas have emerged. Academic scientists underwrite their work with public funds and employ a utilitarian labor force, namely, students seeking an education. The benefits from a successful business are significantly higher than in academic ventures, so the temptation increases to abrogate professional responsibilities and loyalties in favor of personal gain. Safeguards are needed for the institution and its students while simultaneously permitting the development of scientifically, socially, and economically important discoveries.

Brian P. Coppola

2001-01-01

349

Statistical optimization of culture conditions by response surface methodology for synthesis of lipase with Enterobacter aerogenes  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Optimization of lipase production by Enterobacter aerogenes was carried out using response surface methodology (RSM) where the statistical model was obtained by fractional factorial central composite design. The influence of various physico-chemical parameters, viz. temperature, oil concentration, inoculum volume, pH and incubation period on lipase production was examined. Optimization of physico-chemical parameters resulted 1.4- fold increase in lipase activity. The opti (more) mum levels of parameters were 34°C, oil concentration 3%, inoculum volume 7%, pH 7 and incubation time 60 h for obtaining a maximum lipase activity of 27.25 U/ml.

Kumari, Annapurna; Mahapatra, Paramita; Banerjee, Rintu

2009-12-01

350

Understanding the Way Students Speak: A Guide for Educators on Creating Culturally Responsive Environments for Linguistically Diverse Students  

Directory of Open Access Journals (Sweden)

Full Text Available Dialectal diversity is an area of student diversity that is often overlooked in terms of how educators view students who speak nonstandard forms of English. Moreover, public school educators must explore the issue of dialectal diversity among students and how they are perceived based on their language variation. More importantly, educators must examine their perceptions about those who speak non Standard English and how their perceptions translate into classroom practices. This is a theoretical article that explores students’ language variations and its impact on their educational opportunities. More importantly, it examines the notion of teacher perceptions of students who speak nonstandard variations of Standard English and their classroom practices. The article explores the relationship between dialectal diversity and student achievements as well as the role of educators have in creating culturally responsive educational environments to maximize students’ potential. The article also provides guidelines for educators on how to create an optimum learning environment for students.

Alisa Taliaferro

2012-01-01

351

Comparative Tissue Culture Response of Wheat Cultivars and Evaluation of Regenerated Plants  

Directory of Open Access Journals (Sweden)

Full Text Available Three wheat genotypes i.e. Bakhtawar-92, Punjab-96 and Inqilab-91 were tested for their response to callus induction frequency and their subsequent regeneration on a variety of media combinations. Bakhtawar-92 appeared to be the most responsive genotype to callus induction followed by Inqilab-91 and Punjab-96. It also produced significantly higher amount of callus as compared with other genotypes. However, the medium containing 2 mg l-1 2,4-D (2,4-dicholorophenoxy acetic acid) was found to be optimum for callus induction irrespective of the genotypes studied. Regeneration frequency of Bakhtawar-92 was 40% on the medium containing 0.1 mg l-1 IAA (Indole acetic acid) and 2.5 mg l-1 BAP (6-benzyl amino purine). Punjab-96 and Inqilab-91 showed regeneration of 25 and 33% on the medium supplemented with combination of 0.1 mg l-1 IAA and 0.5 mg l-1 BAP. Regenerated plants were evaluated for plant height, maturity and seed set. They had favourable significant differences from the control plants for the most important agronomic traits; plant height, days to maturity and kernels/spike etc.

Muhammad Farooq; Hamid Rashid; Ihsanullah; Zubeda Chaudhry; Khan Bahadar Marwat

2004-01-01

352

Ad Hoc Conference of European Ministers with Responsibility for Cultural Affairs. Oslo 1976, Report of the Conference.  

Science.gov (United States)

The report contains 39 speeches by cultural affairs ministers at a 1976 Council of Europe conference in Oslo, Norway. The focus is on four themes: (1) the challenge of cultural policy in a changing society, (2) cultural policy as an instrument for improving the quality of life, (3) encouraging artistic creation, and (4) European cultural

Council of Europe, Strasbourg (France).

353

Response surface optimisation for acetone-butanol-ethanol production from cassava starch by co-culture of Clostridium butylicum and Bacillus subtilis  

Directory of Open Access Journals (Sweden)

Full Text Available Acetone-butanol-ethanol (ABE) production from cassava starch was enhanced by a syntrophic co-culture of Clostridium butylicum TISTR 1032 and high amylase producing Bacillus subtilis WD 161 without anaerobic pretreatment. The production of amylase and ABE using this co-culture were respectively 16 and 6 times higher than those using the pure culture of C. butylicum TISTR 1032. The effect of the medium components on the performance of the co-culture was investigated using response surface methodology (RSM). Among the investigated components, cassava starch and ammonium nitrate contributed a significant effect on the production of amylase and ABE, while yeast extract had less effect. Based on the optimum strategy using RSM, the ABE production by the co-culture was improved 2.2-fold compared with that obtained from the initial condition and with a minimum requirement of nitrogen source.

Benjamas Cheirsilp

2011-01-01

354

Changes of biomass, lipid content and fatty acids composition under a light-dark cyclic culture of Chlorella pyrenoidosa in response to different temperature.  

UK PubMed Central (United Kingdom)

For outdoor culture with light-dark cycle, the biomass and lipid losing at night resulted in lowering the biomass and lipid productivity. Previous studies focused on the contents of carbohydrate and protein in response to temperature for production of animal feed and nutritional supplements. In this study, the effects of temperature on the variations of biomass concentration, lipid content and fatty acids composition for production of biofuels were investigated under a light-dark cyclic culture. The results showed that 30 °C was the optimal daytime temperature for achieving high biomass and lipid; raising daytime temperature can lessen night biomass loss and stimulate lipid accumulation. Subsequently, outdoor culture strategy has been improved: keeping culture broth no less than 30 °C during the daytime. Consequently, the net biomass and lipid productivity were increased by 37.8% and 44.9% when compared to the former culture process in the same outdoor climatic conditions.

Han F; Wang W; Li Y; Shen G; Wan M; Wang J

2013-03-01

355

Global transcriptome analysis of two ameiotic1 alleles in maize anthers: defining steps in meiotic entry and progression through prophase I  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Developmental cues to start meiosis occur late in plants. Ameiotic1 (Am1) encodes a plant-specific nuclear protein (AM1) required for meiotic entry and progression through early prophase I. Pollen mother cells (PMCs) remain mitotic in most am1 mutants including am1-489, while am1-praI permits meiotic entry but PMCs arrest at the leptotene/zygotene (L/Z) transition, defining the roles of AM1 protein in two distinct steps of meiosis. To gain more insights into the roles of AM1 in the transcriptional pre-meiotic and meiotic programs, we report here an in depth analysis of gene expression alterations in carefully staged anthers at 1 mm (meiotic entry) and 1.5 mm (L/Z) caused by each of these am1 alleles. Results 1.0 mm and 1.5 mm anthers of am1-489 and am1-praI were profiled in comparison to fertile siblings on Agilent® 4 × 44 K microarrays. Both am1-489 and am1-praI anthers are cytologically normal at 1.0 mm and show moderate transcriptome alterations. At the 1.5-mm stage both mutants are aberrant cytologically, and show more drastic transcriptome changes. There are substantially more absolute On/Off and twice as many differentially expressed genes (sterile versus fertile) in am1-489 than in am1-praI. At 1.5 mm a total of 4,418 genes are up- or down-regulated in either am1-489 or am1-praI anthers. These are predominantly stage-specific transcripts. Many putative meiosis-related genes were found among them including a small subset of allele-specific, mis-regulated genes specific to the PMCs. Nearly 60% of transcriptome changes in the set of transcripts mis-regulated in both mutants (N = 530) are enriched in PMCs, and only 1% are enriched in the tapetal cell transcriptome. All array data reported herein will be deposited and accessible at MaizeGDB http://www.maizegdb.org/. Conclusions Our analysis of anther transcriptome modulations by two distinct am1 alleles, am1-489 and am1-praI, redefines the role of AM1 as a modulator of expression of a subset of meiotic genes, important for meiotic progression and provided stage-specific insights into the genetic networks associated with meiotic entry and early prophase I progression.

Nan Guo-Ling; Ronceret Arnaud; Wang Rachel C; Fernandes John F; Cande W Zacheus; Walbot Virginia

2011-01-01

356

Establishing a liquid-covered culture of polarized human airway epithelial Calu-3 cells to study host cell response to respiratory pathogens in vitro.  

UK PubMed Central (United Kingdom)

The apical and basolateral surfaces of airway epithelial cells demonstrate directional responses to pathogen exposure in vivo. Thus, ideal in vitro models for examining cellular responses to respiratory pathogens polarize, forming apical and basolateral surfaces. One such model is differentiated normal human bronchial epithelial cells (NHBE). However, this system requires lung tissue samples, expertise isolating and culturing epithelial cells from tissue, and time to generate an air-liquid interface culture. Calu-3 cells, derived from a human bronchial adenocarcinoma, are an alternative model for examining the response of proximal airway epithelial cells to respiratory insult, pharmacological compounds, and bacterial and viral pathogens, including influenza virus, rhinovirus and severe acute respiratory syndrome-associated coronavirus. Recently, we demonstrated that Calu-3 cells are susceptible to respiratory syncytial virus (RSV) infection in a manner consistent with NHBE. Here, we detail the establishment of a polarized, liquid-covered culture (LCC) of Calu-3 cells, focusing on the technical details of growing and culturing Calu-3 cells, maintaining cells that have been cultured into LCC, and we present the method for performing respiratory virus infection of polarized Calu-3 cells. To consistently obtain polarized Calu-3 LCC, Calu-3 cells must be carefully subcultured before culturing in Transwell inserts. Calu-3 monolayer cultures should remain below 90% confluence, should be subcultured fewer than 10 times from frozen stock, and should regularly be supplied with fresh medium. Once cultured in Transwells, Calu-3 LCC must be handled with care. Irregular media changes and mechanical or physical disruption of the cell layers or plates negatively impact polarization for several hours or days. Polarization is monitored by evaluating trans-epithelial electrical resistance (TEER) and is verified by evaluating the passive equilibration of sodium fluorescein between the apical and basolateral compartments . Once TEER plateaus at or above 1,000 ?×cm(2), Calu-3 LCC are ready to use to examine cellular responses to respiratory pathogens.

Harcourt JL; Haynes LM

2013-01-01

357

Establishing a liquid-covered culture of polarized human airway epithelial Calu-3 cells to study host cell response to respiratory pathogens in vitro.  

Science.gov (United States)

The apical and basolateral surfaces of airway epithelial cells demonstrate directional responses to pathogen exposure in vivo. Thus, ideal in vitro models for examining cellular responses to respiratory pathogens polarize, forming apical and basolateral surfaces. One such model is differentiated normal human bronchial epithelial cells (NHBE). However, this system requires lung tissue samples, expertise isolating and culturing epithelial cells from tissue, and time to generate an air-liquid interface culture. Calu-3 cells, derived from a human bronchial adenocarcinoma, are an alternative model for examining the response of proximal airway epithelial cells to respiratory insult, pharmacological compounds, and bacterial and viral pathogens, including influenza virus, rhinovirus and severe acute respiratory syndrome-associated coronavirus. Recently, we demonstrated that Calu-3 cells are susceptible to respiratory syncytial virus (RSV) infection in a manner consistent with NHBE. Here, we detail the establishment of a polarized, liquid-covered culture (LCC) of Calu-3 cells, focusing on the technical details of growing and culturing Calu-3 cells, maintaining cells that have been cultured into LCC, and we present the method for performing respiratory virus infection of polarized Calu-3 cells. To consistently obtain polarized Calu-3 LCC, Calu-3 cells must be carefully subcultured before culturing in Transwell inserts. Calu-3 monolayer cultures should remain below 90% confluence, should be subcultured fewer than 10 times from frozen stock, and should regularly be supplied with fresh medium. Once cultured in Transwells, Calu-3 LCC must be handled with care. Irregular media changes and mechanical or physical disruption of the cell layers or plates negatively impact polarization for several hours or days. Polarization is monitored by evaluating trans-epithelial electrical resistance (TEER) and is verified by evaluating the passive equilibration of sodium fluorescein between the apical and basolateral compartments . Once TEER plateaus at or above 1,000 ?×cm(2), Calu-3 LCC are ready to use to examine cellular responses to respiratory pathogens. PMID:23426201

Harcourt, Jennifer L; Haynes, Lia M

2013-02-07

358

Safety culture  

International Nuclear Information System (INIS)

The response to a previous publication by the International Nuclear Safety Advisory Group (INSAG) indicated a broad international interest in expanding the concept of Safety Culture in such a way that its effectiveness in particular cases may be judged. This report responds to that need. In its manifestation, Safety Culture has two major components: the framework determined by organizational policy and by managerial action, and the response of individuals in working within and benefiting by the framework. 1 fig

1992-01-01

359

Particles from wood smoke and traffic induce differential pro-inflammatory response patterns in co-cultures  

International Nuclear Information System (INIS)

The inflammatory potential of particles from wood smoke and traffic has not been well elucidated. In this study, a contact co-culture of monocytes and pneumocytes was exposed to 10-40 ?g/cm2 of particles from wood smoke and traffic for 12, 40 and 64 h to determine their influence on pro-inflammatory cytokine release (TNF-?, IL-1, IL-6, IL-8) and viability. To investigate the role of organic constituents in cytokine release the response to particles, their organic extracts and the washed particles were compared. Antagonists were used to investigate source-dependent differences in intercellular signalling (TNF-?, IL-1). The cytotoxicity was low after exposure to particles from both sources. However, wood smoke, and to a lesser degree traffic-derived particles, induced a reduction in cell number, which was associated with the organic fraction. The release of pro-inflammatory cytokines was similar for both sources after 12 h, but traffic induced a greater release than wood smoke particles with increasing exposure time. The organic fraction accounted for the majority of the cytokine release induced by wood smoke, whereas the washed traffic particles induced a stronger response than the corresponding organic extract. TNF-? and IL-1 antagonists reduced the release of IL-8 induced by particles from both sources. In contrast, the IL-6 release was only reduced by the IL-1 antagonist during exposure to traffic-derived particles. In summary, particles from wood smoke and traffic induced differential pro-inflammatory response patterns with respect to cytokine release and cell number. Moreover, the influence of the organic particle fraction and intercellular signalling on the pro-inflammatory response seemed to be source-dependent.

2008-10-15

360

Arsenite and monomethylarsonous acid generate oxidative stress response in human bladder cell culture  

International Nuclear Information System (INIS)

Arsenicals have commonly been seen to induce reactive oxygen species (ROS) which can lead to DNA damage and oxidative stress. At low levels, arsenicals still induce the formation of ROS, leading to DNA damage and protein alterations. UROtsa cells, an immortalized human urothelial cell line, were used to study the effects of arsenicals on the human bladder, a site of arsenical bioconcentration and carcinogenesis. Biotransformation of As(III) by UROtsa cells has been shown to produce methylated species, namely monomethylarsonous acid [MMA(III)], which has been shown to be 20 times more cytotoxic. Confocal fluorescence images of UROtsa cells treated with arsenicals and the ROS sensing probe, DCFDA, showed an increase of intracellular ROS within five min after 1 ?M and 10 ?M As(III) treatments. In contrast, 50 and 500 nM MMA(III) required pretreatment for 30 min before inducing ROS. The increase in ROS was ameliorated by preincubation with either SOD or catalase. An interesting aspect of these ROS detection studies is the noticeable difference between concentrations of As(III) and MMA(III) used, further supporting the increased cytotoxicity of MMA(III), as well as the increased amount of time required for MMA(III) to cause oxidative stress. These arsenical-induced ROS produced oxidative DNA damage as evidenced by an increase in 8-hydroxyl-2'-deoxyguanosine (8-oxo-dG) with either 50 nM or 5 ?M MMA(III) exposure. These findings provide support that MMA(III) cause a genotoxic response upon generation of ROS. Both As(III) and MMA(III) were also able to induce Hsp70 and MT protein levels above control, showing that the cells recognize the ROS and respond. As(III) rapidly induces the formation of ROS, possibly through it oxidation to As(V) and further metabolism to MMA(III)/(V). These studies provide evidence for a different mechanism of MMA(III) toxicity, one that MMA(III) first interacts with cellular components before an ROS response is generated, taking longer to produce the effect, but with more substantial harm to the cell.

2006-11-15