ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Life and Medical Sciences  (157)
  • GEOPHYSICS  (149)
  • 1990-1994  (306)
  • 1985-1989
  • 1915-1919
  • 1992  (306)
  • 1
    ISSN: 1040-452X
    Keywords: Embryonic stem cells ; Cell differentiation ; Pluripotency ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Ten embryonic stem (ES) cell lines from mink blastocysts were isolated and characterized. All the lines had a normal diploid karyotype; of the ten lines studied, five had the XX and five had the XY constitution. Testing of the pluripotency of the ES-like cells demonstrated that (1) among four lines of genotype XX, an X was late-replicating in three; both Xs were active in about one-third of cells of line MES8, and analysis of glucose-6-phosphate dehydrogenase revealed no dosage compensation for the X-linked gene; (2) when cultured in suspension, the majority of lines were capable of forming “simple” embryoid bodies (EB), and two only showed the capacity for forming “cystic” multilayer EBs. However, formation of ectoderm or foci of yolk sac hematopoiesis, a feature of mouse ES ceils, was not observed in the “cystic” EB; (3) when cultured as a monolayer without feeder, the ES cells differentiated into either vimentin-positive fibroblast-like cells or cytokeratin-positive epithelial-like cells (less frequently); neural cells appeared in two lines; (4) when injected into athymic mice, only one of the four tested lines gave rise to tumors. These were fibrosarcomas composed of fibrobalst-like cells, with an admixture of smooth muscular elements and stray islets of epithelial tissue; (5) when the ES cells of line MES1 were injected into 102 blastocyst cavities and subsequently transplanted into foster mathers, we obtained 30 offspring. Analysis of the biochemical markers and coat color did not demonstrate the presence of chimaeras among offspring. Thus the cell lines derived from mink blastocysts are true ES cells. However, their pluripotential capacities are restricted. © 1992 Wiley-Liss, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2011-08-24
    Description: Simultaneous measurements of the stratospheric burdens of CO2, HCN, N2O, CH4, OCS, CF2Cl2, CFCl3, CHF2Cl and HF were made by the Jet propulsion Laboratory MkIV interferometer on board the NASA DC-8 aircraft during January and early February 1989 as part of the Airborne Arctic Stratosphere Experiment. Data were acquired on 11 flights at altitudes of up to 12 km over a geographic region covering the NE Atlantic Ocean, Iceland and Greenland. The results obtained show large variations in the burdens of these tracers due to the effects of transport. The tropospheric source gas burdens were reduced inside the polar vortex, suggesting that the air had subsided with respect to the surrounding midlatitude air. Increased HF burdens inside the vortex support this interpretation. The results obtained from the different tracers are highly consistent with each other and indicate that in the 15- to 20-km altitude range inside the vortex, surfaces of constant volume mixing ratio were located some 5-6 km lower in absolute altitude than outside the vortex. The results also indicate that the magnitude of this subsidence increases with altitude. These conclusions are consistent with other measurements.
    Keywords: GEOPHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 97; D8, M
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2011-08-24
    Description: The interaction between the Space Shuttle exhaust and the ambient atmosphere was studied using spectra in the wavelength region near 630 nm, obtained from the Air Force Maui Optical Station were the temporal, spatial, and spectral distribution of the emission in this region was recorded. The results show that, when the Space Shuttle exhaust gases interact with the atmosphere in the ram direction, an intense long-lasting emission is generated at 630 nm due to O(1D - 3P). A substantial amount of O(1D) is swept back onto the orbiter. Two processes responsible for the formation of O(1D) are proposed.
    Keywords: GEOPHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 97; A12; p. 19,501-19,508.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2019-07-12
    Description: A ULF pulsation event is discussed on the basis of experimental observations of electric and magnetic field measurements as well as particle measurements from the DE 1 spacecraft. The observations were made near the magnetic equator in a space covering a large range of L shells and magnetic latitudes, and comparisons are made to ground observations. Azimuthal oscillations are observed following gradually decaying long-period compressional waves. Weak interaction between magnetic shells indicates that the source is probably weak, and ground data on magnetic pulsations showed strong signals that did not necessarily correspond to the quasisinusoidal pulsations observed in space. Azimuthal pulsations observed by the spacecraft indicate that there was a plasma density gradient beyond the plasmapause. The ULF pulsations were probably affected by changes in the magnetic field and solar-wind dynamic pressure, and their periods are found to be linked to geomagnetic latitude.
    Keywords: GEOPHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 97; A10; p. 14,859-14,875.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2019-08-28
    Description: The properties of the core (0-50 eV) and 'energetic' (0-1 keV) ions, plasma waves, and auroral images obtained from Dynamics Explorer 1 (DE-1) and those of electrons, obtained from DE-2, are examined in the context of the polar cap environment. Results indicate the presence of two populations: high-speed (10-30 eV, or higher, streaming energies) polar beams and low-speed (generally less than 10-eV streaming energies) streams. The high-speed polar beams show an auroral connection (i.e., they are observed on or near the field lines threading auroral arcs), while the low-speed streams are on or near the field lines threading the dark polar cap and may be converted from the cleft ion fountain. Compared to the high-speed streams, the low-speed streams are significantly more stable with respect to energy and flux.
    Keywords: GEOPHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 97; A6 J
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 22 (1992), S. 117-126 
    ISSN: 0886-1544
    Keywords: algae ; cell division ; cytokinesis ; mitosis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have used two monoclonal antibodies to demonstrate the presence and localization of actin in interphase and mitotic vegetative cells of the green alga Chlamydomonas reinhardtii. Commercially available monoclonal antibodies raised against smooth muscle actin (Lessard: Cell Motil. Cytoskeleton 10:349-362, 1988; Lin: Proc. Natl. Acad. Sci. USA 78:2335-2339, 1981) identify Chlamydomonasactin as a ∼43,000-Mr protein by Western immunoblot procedures. In an earlier study, Detmers and coworkers (Cell Motil. 5:415-430, 1985) first identified Chlamydomonas actin using NBD-phallacidin and an antibody raised against Dictyostelium actin; they demonstrated that F-actin is localized in the fertilization tubule of mating gametes. Here, we show by immunofluorescence that vegetative Chlamydomonas cells have an array of actin that surrounds the nucleus in interphase cells and undergoes dramatic reorganization during mitosis and cytokinesis. This includes the following: reorganization of actin to the ante- rior of the cell during preprophase; the formation of a cruciate actin band in prophase; reorganization to a single anterior actin band in metaphase; rearrange- ment forming a focus of actin anterior to the metaphase plate; reextension of the actin band in anaphase; presence of actin in the forming cleavage furrow during telophase and cytokinesis; and finally reestablishment of the interphase actin array. The studies presented here do not allow us to discriminate between G and F-actin. None the less, our observations, demonstrating dynamic reorganization of actin during the cell cycle, suggest a role for actin that may include the movement of basal bodies toward the spindle poles in mitosis and the formation of the cleavage furrow during cytokinesis. © 1992 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0730-2312
    Keywords: adipogenesis ; quiescence ; transcription ; mRNA ; nuclear factors ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The aim of this study was to address whether there is a fundamental difference in regulation of histone gene expression in cells that have become quiescent but retain the ability to proliferate, compared with those cells that have differentiated. We compared multiple levels of regulation of histone gene expression during 3T3-L1 pre-adipocyte differentiation. Confluent cells induced to differentiate by treatment with insulin, dexamethasone, and isobutylemethylxanthine initially exhibited an increased proliferative response compared with cells given serum alone. This initial differentiation response was associated with a twofold increase in both histone gene transcription and cellular histone mRNA levels, as well as with enhanced sequence-specific binding of nuclear factors to the proximal cell-cycle-regulatory element of the H4 histone promoter. Transforming growth factor β1, an inhibitor of 3T3-L1 differentiation, increased both the percentage of proliferating cells and the cellular levels of histone mRNA when given in addition to serum stimulation, but no enhancement of these parameters was observed upon addition of TGFβ1 to the differentiation treatment. Interestingly, although TGFβ1 enhanced binding of nuclear factors to the proximal cell cycle regulatory element of the histone promoter, these protein/DNA interactions were not associated with an increase in histone transcription. Our results are consistent with the down-regulation of histone gene expression at confluency being controlled primarily at the post-transcriptional level, in contrast to an increased involvement of transcriptional down-regulation at the onset of differentiation. © 1992 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 50 (1992), S. 201-209 
    ISSN: 0730-2312
    Keywords: immunofluorescence staining ; DAPI ; microtubules ; chromatin ; digital image processing ; cell morphometry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Synchronized CHO-K1 cells and their dibutyryl c-AMP treated counterparts have been characterized by means of static and flow fluorescence cytometry at the level of nuclear DNA and cytoplasmic microtubules.In order to confirm earlier findings on synchronized population, Carnoy fixed and hydrolyzed, several new findings are here reported at the level of single intact cell. The fluorescence intensity of DAPI-stained glutaraldehyde fixed 2C cells correlates well with the average absorbance of the corresponding Feulgen-stained cells, thereby appearing also to be a measure of chromatin condensation during the G1 phase.In the early part of G1, the drastic alteration in anti-β tubulin immunostaining is shown to parallel microtubule depolymerization induced by calcium or colcemide.The known 1-2 h lengthening of the G1 period after reverse-transformation appears to correlate with a similar delay in the abrupt chromatin decondensation.The above results are discussed in terms of the role of microtubules and nuclear morphometry (and their coupling) in the control of cell cycle progression of transformed vs. fibroblast-like cells. © 1992 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 48 (1992), S. 43-50 
    ISSN: 0730-2312
    Keywords: insulin/IGF-1 hybrid receptors ; autophosphorylation ; substrate phosphorylation ; protein tyrosine kinase ; in vitro assembly ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Classical insulin and IGF-1 receptors are α2β2 heterotetrameric complexes synthesized from two identical αβ half-receptor precursors [1,2]. Recent data strongly suggests, however, that nonidentical αβ half-receptor precursors can assemble to generate hybrid holoreceptor species both in vivo and in vitro [3-6,41]. This review focuses primarily on two types of hybrid receptors. The first type is an insulin/IGF-1 hybrid receptor generated by the association of an αβ insulin half-receptor with an αβ IGF-1 half-receptor. The second type is one formed from a wildtype (kinase-active) insulin or IGF-1 αβ half-receptor and a mutant (kinase-inactive) insulin αβ half-receptor. Although the functional properties of insulin/IGF-1 hybrid receptors have not yet been completely defined, wildtype/mutant hybrid receptors are essentially substrate kinase inactive [6]. These data indicate that the mutant αβ half-receptor exerts a transdominant inhibition upon the wildtype αβ half-receptor within the α2β2 holoreceptor complex. This defect in substrate kinase activity may contribute to the molecular defect underlying some syndromes of severe insulin resistance and diabetes. Heterozygous individuals expressing both wildtype and mutant tyrosine kinase-defective insulin receptor precursors demonstrate varying degrees of insulin resistance and diabetes [7-11]. In addition, cell lines which express both endogenous wildtype and transfected kinase-defective insulin receptors display markedly decreased insulin and IGF-1 sensitivity and responsiveness [12-14]. Formation of hybrid receptors which results in premature termination of insulin signal transduction may be one mechanism underlying the observation that kinase-inactive receptors inhibit the function of native receptors.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0730-2312
    Keywords: carcinogenesis ; chemoprevention ; intermediate end point ; biomarkers ; differentiation ; growth factors ; lung cancer ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The need for validate intermediate end point markers to facilitate lung cancer chemointervention research is competing. Three major classes of lung markers are relevant for this application. Since lung cancer includes four distinct hitologies, markers that map degrees of histologic differentiation are important. Many of the markers for squamous differentiation overlap with the candidates for application in the study of head and neck cancer. Production of tissue-specific cell product especially for surfactant or CEA is of interest, because the gene structure is known and many differentiation-related polymorphisms exist. This strategy would be useful for adenomatous type of tissue. A second type of marker is the broad group of differentiation markers. The carbohydrates or blood group-like antigens comprise a representative example. Carbohydrate structures are expressed in a specific sequence during fetal processes, and this sequence appears to reverse with the development of a cancer. Retrodifferentiation of specific differentiation markers is the basis of a major effort to effect earlier lung cancer detection using sputum immunocytochemistry. The final class includes markers which affects either positive or negative aspects of growths. Candidates in this area include growth factors or their receptors or genes that regulate growth. If the intermediate end point marker reflects tumor biology and is in that casual path of tumor progression, serial observation of that parameter should indicate the success of the intervention. In all three of these examples the clinical material to be analyzed could be sputum specimens bonrchial biopsies or resected lung tissue. Systematic analysis of these markers in context of intervention trials required to validate their utility. Long term clinical follow up will demonstrate the degree of concordance between biomarkers and more traditional clinical trial end points and will establish if such tools can play a role in catalyzing the rate of prevention research. © 1992 Wiley-Liss, Inc.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...