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MARIA U. DELMONTE CORRADO DONATA LOCATELLI LAURA PALEARI GIOVANNI BOTTIROLI 《The Journal of eukaryotic microbiology》1997,44(6):603-608
ABSTRACT. Mating pair formation in Paramecium primaurelia was shown to be inhibited by incubating mating-competent mating type (mt) I and mt U cells with Limulus polyphemus agglutinin (LPA) or wheat germ agglutinin (WGA). Preincubation of LPA and WGA with their specific binding-monosaccharides, N-acetylneuraminic acid (NeuAc) and N-acetylglucosamine (GlcNAc), respectively, prevented the lectin effect on pair formation. Addition either of NeuAc or GlcNAc resulted in a reversal of cell pairing inhibition by LPA or WGA, respectively. Both NeuAc and GlcNAc monosaccharides inhibited pair formation when their concentration exceeded a threshold value. The pattern of the relative distribution of NeuAc and GlcNAc molecules on the cell surface was analyzed using fluorescence resonance energy transfer techniques combined with imaging systems. Mt I1 cells showed a high lectin-binding site density localized just on the surface region engaged in conjugation. The pattern of mt I cells, consisting of a quite homogeneous lectin-binding site density spread on the cell surface, was also common to nonmating-competent cells and to immature cells. These findings suggest that in P. primaurelia pair formation involves both NeuAc and GlcNAc residues and that the development of mating-competence is related to a modification in NeuAc and GlcNAc relative distribution on the cell surface of mt 11 cells. 相似文献
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PHILIP S WANG MATTHIAS ANGERMEYER GUILHERME BORGES RONNY BRUFFAERTS WAI TAT CHIU GIOVANNI DE GIROLAMO JOHN FAYYAD OYE GUREJE JOSEP MARIA HARO YUEQIN HUANG RONALD C KESSLER VIVIANE KOVESS DAPHNA LEVINSON YOSHIBUMI NAKANE MARK A OAKLEY BROWN JOHAN H ORMEL JOSé POSADA-VILLA SERGIO AGUILAR-GAXIOLA JORDI ALONSO SING LEE STEVEN HEERINGA BETH-ELLEN PENNELL SOMNATH CHATTERJI T. BEDIRHAN üSTüN 《World psychiatry》2007,6(3):177-185
Data are presented on patterns of failure and delay in making initial treatment
contact after first onset of a mental disorder in 15 countries in the World
Health Organization (WHO)''s World Mental Health (WMH) Surveys. Representative
face-to-face household surveys were conducted among 76,012 respondents aged
18 and older in Belgium, Colombia, France, Germany, Israel, Italy, Japan,
Lebanon, Mexico, the Netherlands, New Zealand, Nigeria, People''s Republic
of China (Beijing and Shanghai), Spain, and the United States. The WHO Composite
International Diagnostic Interview (CIDI) was used to assess lifetime DSM-IV
anxiety, mood, and substance use disorders. Ages of onset for individual disorders
and ages of first treatment contact for each disorder were used to calculate
the extent of failure and delay in initial help seeking. The proportion of
lifetime cases making treatment contact in the year of disorder onset ranged
from 0.8 to 36.4% for anxiety disorders, from 6.0 to 52.1% for mood disorders,
and from 0.9 to 18.6% for substance use disorders. By 50 years, the proportion
of lifetime cases making treatment contact ranged from 15.2 to 95.0% for anxiety
disorders, from 7.9 to 98.6% for mood disorders, and from 19.8 to 86.1% for
substance use disorders. Median delays among cases eventually making contact
ranged from 3.0 to 30.0 years for anxiety disorders, from 1.0 to 14.0 years
for mood disorders, and from 6.0 to 18.0 years for substance use disorders.
Failure and delays in treatment seeking were generally greater in developing
countries, older cohorts, men, and cases with earlier ages of onset. These
results show that failure and delays in initial help seeking are pervasive
problems worldwide. Interventions to ensure prompt initial treatment contacts
are needed to reduce the global burdens and hazards of untreated mental disorders. 相似文献
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Multiple shrinkage and subset selection in wavelets 总被引:6,自引:0,他引:6
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RAFAEL G. ALBALADEJO SANTIAGO C. GONZÁLEZ‐MARTÍNEZ MYRIAM HEUERTZ GIOVANNI G. VENDRAMIN ABELARDO APARICIO 《Molecular ecology》2009,18(24):5195-5206
Spatiotemporal variation in mating patterns is poorly known in wind‐pollinated plant species. Here, we analysed mating patterns of the wind‐pollinated dioecious shrub Pistacia lentiscus by genotyping 904 seeds from 30 mother plants with eight microsatellite markers in a high‐density population in two consecutive flowering seasons. We found significant differences in some mating system estimates between years, particularly in the levels of correlated paternity. Overall, within‐mothers correlated paternity was higher in 2007 than in 2006 (rpWM = 0.085 and 0.030), which translated into an effective number of fathers (Nep) of 11.8 and 33.6 respectively. Using a smoothing interpolation technique, we show that the effective pollen cloud was spatially structured in patches of high‐ and low‐genetic diversity, which do not remain constant from year to year. In 2006, the among‐mothers correlated paternity (rpAM) showed no trend with distance, suggesting no restriction of pollen dispersal. However, in 2007, rpAM was greater than zero at short distances, revealing the existence of small‐scale patterns of pollen dispersal. The fact that the studied seasons were climatically homogeneous during the flowering time suggested that the observed differences might be ascribed to between‐year phenological variation of individuals in the studied population or other (unknown) factors. Numerical simulations, based on the real data set, indicated that the clumping of males and decreasing plant density, which is related to different types of pollen limitation, greatly increase correlated mating in this wind‐pollinated species, which is of relevance under the frame of the continuous anthropogenic habitat disturbance suffered by Mediterranean ecosystems. 相似文献
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Inhibition of RNA Polymerase by Streptolydigin 总被引:23,自引:0,他引:23
GIOVANNI CASSANI RICHARD R. BURGESS HOWARD M. GOODMAN LAWRENCE GOLD 《Nature: New biology》1971,230(15):197-200
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EMANUELA BAZZONI GIOVANNI SANNA PASSINO MARIO D L MORETTI ROMOLO PROTA 《The Annals of applied biology》1997,131(3):369-374
We report the effects of anethole on adult Ceratitis capitata Wied. (Diptera, Tephritidae) which cause serious damage to fruit crops. Because of the toxicological and environmental pollution due to the indiscriminate use of organophosphates against the endophagous larvae, the control of this pest is now mainly directed against the adults, by the application of bait sprays. Considerable toxic effects have been obtained by oral administration to adults of nutritive formulations containing 5% anethole with some hydrolised commercial proteins. In this test we observed high values of mortality (85% after 24 h) and a total inhibition of reproductive activity. The toxic effect produced by oral administration of the compound tested appears to be correlated to irreversible damage to the gut of the medfly. These results acquire a particular importance in view of the introduction of alternative methods for the control of the medfly. In particular, our objective is the testing of relevant formulations of this active principle in field. The use of anethole combined with protein baits, which can be used in the open field, is therefore particularly promising. 相似文献
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WHEN the replication of density-inhibited cultures of fibroblasts1,2 is stimulated by a change of medium3–5, the rate of nuclear acidic protein synthesis10–13 is immediately increased. We wanted to determine whether the induction of cellular DNA synthesis by an oncogenic virus6–9 is also preceded by nuclear acidic protein synthesis. We report here the effect of SV40 virus infection of a permissive and a non-permissive cell line on their synthesis of total cellular proteins and nuclear acidic proteins in the first hours after infection. 相似文献