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2.
I. I. Moraru Mioara Manciulea Anca Călugăru Gr. Ghyka L. M. Popescu 《Bioscience reports》1987,7(9):731-736
A novel approach was used to assess the role of phosphoinositide hydrolysis in the mitogenic action of phytohemagglutinin (PHA) or concanavalin A (ConA). The treatment of human peripheral blood leukocytes (PBL) with monospecific antibodies against phospholipase C (PLC) produced a dose-dependent inhibition (up to 100%) of PHA (10 g/ml) or ConA (25 g/ml) proliferative effects. Thus, the activation of membrane-bound PLC is asine-qua-non condition for lectin-induced proliferation of T lymphocytes. The key-role of PLC versus protein kinase C (PKC) is stressed by the fact that the inhibition of PKC with Hidaka's compound H-7 (40 M) produced only a partial blockade (about 25%) of lectin mitogenic effect.To whom correspondence should be addressed. 相似文献
3.
Gabi Wegmann Regula Huber Else Zanolla Hans M. Eppenberger Theo Wallimann 《Differentiation; research in biological diversity》1991,46(2):77-87
The expression and the cellular- as well as subcellular-distribution of brain-type B-CK and mitochondrial Mi-CK during development of the chicken retina was studied by immunoblotting, immunofluorescence and immunogold methods. B-CK expression and accumulation in retina was high from early stages of embryonic development on, decreased slightly around hatching and remained high again during adulthood. At early stages of development (days 2-5), B-CK was more or less evenly distributed over the entire retina with the exception of ganglion cells, which were stained more strongly for B-CK than other retinal precursor cells. Then, at around day 10, the beginning of stratified immunostaining by anti-B-CK antibody was noted concomitant with progressing differentiation. Finally, a dramatic increase in staining of the differentiating photoreceptor cells was seen before hatching (day 18) with weaker staining of other cell types. At hatching, as in the adult state, most of the B-CK was localized within rods and cones. Thus, during retinal development marked changes in the immunostaining pattern for B-CK were evident. By contrast, Mi-CK expression was low during development in ovo and rose just before hatching with a predominant accumulation of this isoenzyme within the ellipsoid portion of the inner photoreceptor cell segments. Mi-CK accumulation in the retina coincided with functional maturation of photoreceptors and therefore represents a good marker for terminal differentiation of these cells. B-CK, present from early stages of retina development, seems to be relevant for the energetics of retinal cell proliferation, migration and differentiation, whereas the simultaneous expression of both B- and Mi-CK around the time of hatching indicates a coordinated function of the two CK isoforms as constituents of a PCr-circuit involved in the energetics of vision, which, in autophagous birds, has to be operational at this point in time. 相似文献
4.
Gavril Acălugăriţei 《Acta biotheoretica》1986,35(1-2):107-121
The object of this paper is to present an original classification of ontogenetic reproduction. The main general criterion used is the degree and type of phylogenetic differentiation. In relation to this criterion, criteria are given for the classification of the fundamental types of ontogenetic reproduction and for the classification of the types of ontogenetic generation cycles. Between the fundamental types of ontogenetic reproduction and the types of ontogenetic generation cycles there is a hierarchical relationship which shows that the former are components of the latter. Between the well-defined types of ontogenetic reproduction there exist many intermediate types. 相似文献
5.
Evan M. Schlaich John A. Thomas Lakshmi Kandari Gabi Tremml Anurag Khetan 《Biotechnology progress》2023,39(3):e3330
Single-use bioreactors (SUBs, or disposable bioreactors) are extensively used for the clinical and commercial production of biologics. Despite widespread application, minimal results have been reported utilizing the turndown ratio; an operation mode where the working range of the bioreactor can be expanded to include low fluid volumes. In this work, a systematic investigation into free surface mass transfer and cell growth in high turndown single-use bioreactors is presented. This approach, which combines experimental mass transfer measurements with numerical simulation, deconvolutes the combined effects of headspace mixing and the free surface convective mass transfer on cell growth. Under optimized conditions, mass transfer across the interface alone may be sufficient to satisfy oxygen demands of the cell culture. Within the context of high turndown bioreactors, this finding provides a counterpoint to traditional sparge-based bioreactor operational philosophy. Multiple monoclonal antibody-producing cell lines grown using this high turndown approach showed similar viable cell densities to those cells expanded using a traditional cell bag rocker. Furthermore, cells taken directly from the turndown expansion and placed into production showed identical growth characteristics to traditionally expanded cultures. Taken together, these results suggest that the Xcellerex SUB can be run at a 5:1 working volume as a seed to itself, with no need for system modifications, potentially simplifying preculture operations. 相似文献
6.
Stefan Mihailescu John M. Matsoukas Francis L. Abel Valeriu Nestianu Florin Romanescu Cristina Alecu-Parvu 《Letters in Peptide Science》1996,3(4):181-184
Summary The angiotensin II (ANG II) receptor blocker properties of sarmesin and its influence on the homotropic cooperativity of ANG II receptors were studied in two experimental models: isolated rabbit aorta and isolated rabbit atria. The results show that: (i) sarmesin is a specific competitive antagonist of ANG II receptors, with high affinity (pA2=8.93 in the isolated aorta and 8.66 in the isolated atria); and (ii) the slope of the concentration-response curves to ANG II and the Hill coefficient increased in the presence of sarmesin, the latter suggesting an enhancement of the positive homotropic cooperativity of ANG II receptors. These results may be explained overall by the reciprocal negative modulation of receptor affinity between sarmesin and ANG II, due, possibly, to opposite effects on the binding of G-proteins to ANG II receptors. 相似文献
7.
An electrophoretic study of genetic variation at 11 loci was performedfor a population of European minnows, Phoxinus phoxinus (L.). Ten loci, EST-1
*, EST-2
*
EST-3
*,GPD-1
*,GPD-2
*,GPI-1
*,GPI-2
*,MPI
*,6PGD
* and PGM
* were polymorphic. IDH
*wasmonomorphic. The mean number of heterozygotic loci over all 176 fish was 3.05 ± 0.104(SE). Observed mean heterozygosity was 0.28±0.058(SE) and expected mean heterozygosity was 0.27±0.054(SE). EST-2
*, EST-3
* andPGM
* were not in Hardy-Weinberg equilibrium. Length,condition, parasite numbers or male breeding characters, i.e. red colorationand tubercles, were not influenced by single enzyme loci. 相似文献
8.
Biodiversity is declining worldwide under increasing human pressure. Since the location of and the threats are unevenly distributed and the resources available for conservation are limited, prioritization is essential to reduce the losses. Most conservation efforts until now proved to be ineffective in stopping the present worldwide decline of threatened species. We focus on the European Union (EU) after the repeated enlargements in the last decade, from 15 to 27 countries, by considering the present conservation priorities that have shifted towards a continental scale approach. The situation in the EU indicates that despite the differences in wealth across countries, there are no significant differences in the number and surface of protected areas between them, so re-evaluating conservation priorities at a continental scale and a reallocation of funds is required. A major limitation in priority settings for conservation is data availability. We recommend including in the decision process data provided by phylogeographic studies. This will prevent the decline of populations and species with evolutionary potential from centres of speciation and climate refugia. Recent EU members from central and eastern Europe still retain high biodiversity with a rather good conservation status. A large number of areas with high evolutionary potential identified by phylogeographic studies are located there and should be considered priorities within the context of global changes, as a proactive approach. We recommend a periodic re-evaluation of the status of species and habitats based on current research results, harmonization between the priority species listed in the conventions, directives and Red Lists at both EU and national levels. 相似文献
9.
Feldmane Daina Druva-Lūsīte Ieva Pole Valentīna Butac Mădălina Maria Militaru Mădălina Missa Imants Meiere Diāna Rubauskis Edgars 《Journal of Plant Growth Regulation》2021,40(2):533-540
Journal of Plant Growth Regulation - Sour cherry ‘Latvijas Zemais’ (Prunus cerasus) is a promising dwarfing rootstock for sweet cherries in Latvia, but low growing rate of newly... 相似文献
10.
Ruth A. Houseright Veronika Miskolci Oscar Mulvaney Valeriu Bortnov Deane F. Mosher Julie Rindy David A. Bennin Anna Huttenlocher 《The Journal of cell biology》2021,220(8)
Neutrophil recruitment to tissue damage is essential for host defense but can also impede tissue repair. The cues that differentially regulate neutrophil responses to tissue damage and infection remain unclear. Here, we report that the paracrine factor myeloid-derived growth factor (MYDGF) is induced by tissue damage and regulates neutrophil motility to damaged, but not infected, tissues in zebrafish larvae. Depletion of MYDGF impairs wound healing, and this phenotype is rescued by depleting neutrophils. Live imaging and photoconversion reveal impaired neutrophil reverse migration and inflammation resolution in mydgf mutants. We found that persistent neutrophil inflammation in tissues of mydgf mutants was dependent on the HIF-1α pathway. Taken together, our data suggest that MYDGF is a damage signal that regulates neutrophil interstitial motility and inflammation through a HIF-1α pathway in response to tissue damage. 相似文献