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1.
The presence of a multidrug resistance (MDR) related protein, P-170, in normal and pathological lymphoid cells has been described. The present report evaluates the expression of themdr 1 gene by using the reverse Polymerase Chain Reaction (PCR) on cells obtained from the thymus and bursa of chicken embryos starting from day 12 until hatching. Results show that the thymic cells are positive from day 12 to the end of the observation period. In contrast,mdr mRNA was detected in the bursa from day 14 to day 17 of embryonic life. Possible relationships between the expression ofmdr and the development of T and B lymphocytes are discussed.  相似文献   

2.
The DSCR1 (Adapt78) gene1 is transiently induced by stresses to temporarily protect cells against further potentially lethal challenges. However, chronic expression of the DSCR1 (Adapt78) gene has now been implicated in several pathological conditions including Alzheimer’s disease, Down syndrome and cardiac hypertrophy. Calcipressin 1 has been shown to function through direct binding and inhibition of the serine threonine protein phosphatase Calcineurin. Pharmacological inhibition of calcineurin, by the immunosuppressive drugs cyclosporin A and FK506, affects a wide variety of diseases. It is, therefore, likely that this endogenous calcineurin inhibitor, calcipressin 1, may also play a role in a variety of human diseases. 1Please note that the mammalian DSCR1 gene is also called Adapt78 or RCAN1, and its protein products have been named Calcipressin1, MCIP1 and RCAN1. A proposal to adopt a single gene name of RCAN1 and a protein name RCAN1 (for Regulator of Calcineurin) has been endorsed by the HUGO Gene Nomenclature Committee, but final approval must await agreement from a majority of researchers in the field. Received 2 March 2005; received after revision 27 May 2005; accepted 19 July 2005  相似文献   

3.
Summary Using3H-ouabain autoradiography, Na+–K+-ATPase has been localized on the basolateral membranes of ciliated and nonciliated cells in the oviduct (pars recta, p. convoluta I, II, III) of the European fire salamander,Salamandra salamandra. The mucous and seromucous gland cells of the p.convoluta I, II, III, however, do not show any significant labelling. An asymmetrical distribution of ouabain binding sites is a main feature of transporting epithelia.  相似文献   

4.
Summary The morphology of ovarian follicles in the temperature-sensitive female-sterile mutantl(1)su(f) mad-ts has been studied by means of light and electron microscopy. As the follicle cells gradually degenerate at the restrictive temperature (29°C) the follicles become increasingly disorganized with respect to shape and polarity.Acknowledgments. This work was supported by the Deutsche Forschungsgemeinschaft (SFB 46). We wish to thank Mrs R. Koppa for excellent technical assistance and Mrs G. Mahlke for photographic work. We are also indebted to Dr D. Zissler, Dr E. Gateff and Prof. K. Sander for many helpful suggestions.  相似文献   

5.
Summary In the testes ofMyrmica sulcinodis there are not only haploid and some diploid cells to be found, as in the testes ofM. ruginodis, M. sabulsti andM. rubida, but a large mass of cells that have only half the haploid chromosome number. The diploid chromosome number ofM. sulcinodis is 56, those of six otherMyrmica species are between 42 and 48.  相似文献   

6.
To determine if intestinal stromal cells secrete diffusible factors such as insulin-like growth factors (IGFs) capable of regulating epithelial cell growth in vitro, stromal cells were isolated by enzymatic digestion of rat intestine. Incorporation of [3H]thymidine into DNA and [14C]leucine into protein of IEC-6 cells, a model intestinal epithelial cell line, was significantly increased (two- to threefold) when the IEC-6 cells were co-cultured with stromal cells, relative to IEC-6 cells grown alone. Medium conditioned by stromal cells stimulated DNA synthesis of IEC-6 cells in a dose-dependent manner. Analysis of the conditioned medium revealed that intestinal stromal cells secreted IGF-I, but little IGF-II, in addition to an M r 32,000 IGF-binding protein (IGFBP-2) and an IGFBP having M r∼ 24,000. We conclude that rat intestinal stromal cells secrete one or more diffusible factors, which may include IGF-I and IGFBPs, capable of stimulating proliferation of IEC-6 cells in vitro. Received 25 August 1997; received after revision 7 November 1997; accepted 20 November 1997  相似文献   

7.
Acetyl-coenzyme A synthetase (AMP forming)   总被引:1,自引:0,他引:1  
Acetyl-coenzyme A synthetase (AMP forming; Acs) is an enzyme whose activity is central to the metabolism of prokaryotic and eukaryotic cells. The physiological role of this enzyme is to activate acetate to acetyl-coenzyme A (Ac-CoA). The importance of Acs has been recognized for decades, since it provides the cell the two-carbon metabolite used in many anabolic and energy generation processes. In the last decade researchers have learned how carefully the cell monitors the synthesis and activity of this enzyme. In eukaryotes and prokaryotes, complex regulatory systems control acs gene expression as a function carbon flux, with a second layer of regulation exerted posttranslationally by the NAD+/sirtuin-dependent protein acetylation/deacetylation system. Recent structural work provides snapshots of the dramatic conformational changes Acs undergoes during catalysis. Future work on the regulation of acs gene expression will expand our understanding of metabolic integration, while structure/function studies will reveal more details of the function of this splendid molecular machine.Received 4 December 2003; received after revision 2 March 2004; accepted 16 March 2004  相似文献   

8.
Résumé Dans les leucoyctes en culture de 7 TenrecsCentetes ecaudatus (4 mâles et 3 femelles) provenant de la République Malgache, l'auteur a compté 38 chromosomes et constaté que les sexes ont un caryocyte distinct. C'est la première étude faite sur les chromosomes d'un représentant de la famille des Tenrecidae (Insectivores).

Skin fibroplast cells were cultured fromCentetes ecaudatus (Animal No. 2). These cells gave a count of 38 chromosomes. Using the same techniques as above, whole blood cultures of the related tenrec,Hemicentetes semispinosus G. Cuvier, were counted. Preliminary studies indicate 38 chromosomes for this speices.  相似文献   

9.
Summary The structure of the transitional epithelium of the common European white-toothed shrew (Crocidura russula) was examined by ultrathin serialsections. The epithelium consists of basal, intermediate and superficial cells. Basal and intermediate cells remain in contact with the basal lamina, whereas superficial cells have no connexion with the basal lamina.

Herrn Prof. P. Vogel, Lausanne, danken wir für die Überlassung von Hausspitzmäusen aus seiner Zucht.  相似文献   

10.
Summary Administration of LH-RH to adult male Skipper frogs resulted in marked hypertrophy and degranulation of basophils-2 (B2) in the pars distalis of the pituitary and a significant increase in their nuclear and cellular area. Concomitantly, there is a significant increase in the relative weight of the testes, in the number of cell nests containing secondary spermatogonia and primary spermatocytes, and in the nuclear diameter of the Leydig cells. There is also an increase in the 5-3-hydroxysteroid dehydrogenase and glucose-6-phosphate dehydrogenase activities in the Leydig cells. The results indicate that the B2 cells are gonadotrops and the hormone(s) secreted by B2 cells regulate the spermatogenetic and steroidogenic activity of the testis inR. cyanophlyctis.The free gift of LH-RH from NIH is gratefully acknowledged. Authors are grateful to CSIR, New Delhi, for the award of a SRF to the first author and to Karnatak University, Dharwad for providing laboratory facilities.  相似文献   

11.
Summary LiveTetrahymena cells bound3H-diazepam specifically, as demonstrated by autoradiographic evidence of displacement of about 25% of labeled diazepam in the presence of a 1000-fold amount of cold diazepam. The3H-diazepam bound to membrane preparations isolated from untreated (control) cells was not displaced by cold diazepam, whereas cells involved in primary interaction (imprinting) with diazepam showed amplification and specificity of diazepam binding in both in vivo (cell suspension) and in vitro (pellicle) systems, as well as displacement of bound label in the presence of 1000-fold cold diazepam. It appears that diazepam induced imprinting and, consequently, also the formation of specific receptors inTetrahymena.  相似文献   

12.
A population of uterine natural killer (NK) cells, commonly called granulated metrial gland (GMG) cells, differentiates in the mouse uterus during normal pregnancy. Little is known regarding the process of differentiation of GMG cells or of other NK cell subsets. It has been suggested that macrophage precursors, under the combined influences of the cytokine growth factors colony stimulating factor-1 (CSF-1) and interleukin-2, become NK-cell like in morphology, pattern of target cell lysis and surface antigen phenotype. Mice expressing the mutation osteopetrosis (op/op) are unable to produce the cytokine CSF-1. To determine whether CSF-1 is required for the successful differentiation of uterine NK cells, implantation sites in pregnant,op/op mice were studied histologically. GMG cell differentiation appeared to progress normally inop/op mice studied between days 7 and 14 of gestation. Thus, the growth factor CSF-1 is not required for differentiation of the uterine NK cell subset known as GMG cells and probably GMG cells do not differentiate from macrophage precursor cells which are deficient inop/op mice.  相似文献   

13.
Summary Sylvaticin (I), a new tetrahydroxy annonaceous acetogenin with nonadjacent tetrahydrofuran rings, has been isolated from the dried fruits ofRollinia sylvatica St. Hil. (Annonaceae). This compound is extremely cytotoxic to human tumor cells and shows promising insect control properties.  相似文献   

14.
Summary The release calls of male European toads (B. bufo L.,B. calamita Laur.,B. viridis Laur.) have been described and recorded in the form of spectrograms and oscillograms. While only 1 type of release call is uttered byB. bufo, inB. viridis andB. calamita 2 and 3 types respectively were found. The latter 2 species show a close relationship,B. calamita being the most highly developed toad in Europe.  相似文献   

15.
Summary The bugDysdercus intermedius has gustatory receptors on the terminal segments of its antennae. Thirsty bugs discriminate between dry and wet cellulose swabs: only if they are stimulated with moist swabs, do they extend the proboscis. The stimulating effectiveness of different mono-, oligosaccharides and glycosides was studied by touching the antennae of hungry bugs and observing the extension of the proboscis. The result, that fructose is completely ineffective, entitles one to the assumption that the sugar receptor cells ofDysdercus possess neither a 1C site nor a furanose site.  相似文献   

16.
Summary A method is presented for the large scale cultivation of the free-living nematodeCaenorhabditis elegans, using continuous aeration and agitation in glass ware (stirrer flasks) developed for the continuous culture of suspended cells. With this technique, populations up to 109 nematodes may be obtained in a 10 l culture in less than 6 weeks with an inoculum of some 50 worms. Costs can be reduced by using an inexpensive yeast extract, available from the food industry.  相似文献   

17.
Summary In cell juice of aerobic fermenting and of only respiring yeast cells, a thermostable respiratory energy reserve is found which under rigorous anoxybiotic conditions effects a generative reactivation in contact with anabiotic fermenting yeast cells, butnot with only respiring ones. Also in cell juice of Jensen sarcoma and other carcinoma tissues, an adequate energy substance is recognized as being able to replace oxygen biologically.  相似文献   

18.
Summary It has been demonstrated by cytophotometric measurements of the DNA-content in glial- and nerve cells of the snailsHelix pomatia (Stylommatophora) andPlanorbarius corneus (Basommatophora) that the giant nuclei of nerve cells in the central ganglia contain more than tens of thousands of DNA compared with sperm nuclei. According to the DNA-content of sperms (=n), the values for glial cells are between 2n and 4n for both species.

Herrn Prof. Dr. W.Dittrich, Institut für Strahlenbiologie der Universität Münster, danke ich für die Möglichkeit, am UMSP I arbeiten zu dürfen; Frl. A.Stipproweit danke ich für sorgfältige technische Assistenz.  相似文献   

19.
Summary Somatic chromosome complements of the Indian burrowing toad,Uperodon globulosum, have been described for the first time. The 2n number is 26 (NF=52) in both the sexes. No heteromorphism in relation to sex chromosome pair has been recorded. Deviations from 2n number (2n=10–28) have been noticed in the cells of different specimens. The result has been compared withU. systoma.Acknowledgment. Sincere thanks are due to Prof. P. K. Ghosh, Hooghly Mohsin College and to Dr A. K. Roy of the same college for encouragement. Thanks are due to Mr Bipul Kumar Das for his help during collection of specimen.  相似文献   

20.
Summary The epidermis ofGalaxias attenuatus (Galaxiidae, Salmoniformes) was found to contain club cells that are like the alarm substance cells of the Gonorhynchiformes and Cypriniformes. Whether they are alarm substance cells, can be decided only by experiments on the fright reaction. The existence of club cells in the Galaxiidae confirms the opinion that both the Gonorhynchiformes and the Ostariophysi derived from salmonoid-like fish.  相似文献   

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