ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
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  (15)
  • ASTROPHYSICS
  • METEOROLOGY AND CLIMATOLOGY
  • 1980-1984  (15)
  • 1
    Electronic Resource
    Electronic Resource
    The in vitro trypanocidal activity of N-substituted p-benzoquinone imines: Assessment of biochemical structure-activity relationships using the Hansch approach (1984)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 25 (1984), S. 15-29 
    Details
    ISSN: 0730-2312
    Keywords: N-substituted p-benzoquinone imines ; Trypanosoma brucei brucei ; trypanocidal drugs ; Hansch approach ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: It has previously been found that naphthoquinones can potentiate the rate of hydrogen peroxide production by mitochondrial preparations of Trypanosoma brucei brucei and that organisms treated with naphthoquinones are more susceptible to lysis, especially in the presence of compounds such as heme, which promote the homolytic cleavage of hydrogen peroxide. We have evaluated the lytic effect of various N-substituted p-benzoquinone imines both in vitro and in vivo and have attempted to correlate their structure with trypanocidal activity using the Hansch approach. While none of the compounds tested proved to be active in vivo, all caused the lysis of trypanosomes in vitro. The parameters that correlated best with trypanocidal activity were the conditional redox potential, the lipophilicity of the substituent attached to the nitrogen atom and the number of active hydrogens on the quinoncid ring. These findings suggest two possible modes of action, which may in fact be related. Conjugate nucleophilic addition and/or oxidative damage could be responsible for lysis of the parasites. These same compounds were previously found to be active against the ascitic sarcoma 180 in mice. The strong correlation between antineoplastic activity in vivo and trypanocidal activity in vitro suggests a similar mode of action in both cases. Further studies aimed at developing a quinonelike compound that will be active against trypanosomes in vivo are now in progress.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240250103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A spectrin-like protein from mouse brain membranes: Immunological and structural correlations with erythrocyte spectrin (1983)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 3 (1983), S. 635-647 
    Details
    ISSN: 0886-1544
    Keywords: brain spectrin ; actin ; immunofluorescence ; peptide mapping ; protein phosphorylation ; syndeins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Membrane-associated mouse brain spectrin is a 972,000 Mr, 10.5S, (αβ)2 tetramer containing two ∼ 240,000 Mr subunits and two ∼ 235,000 Mr subunits. Two-dimensional [125I]tryptic peptide mapping indicates that these subunits share only limited and equivalent overlap with the α- and β-subunits of red blood cell (RBC) spectrin. Both the 220,000 Mr β-subunit of RBC spectrin and the 235,000 Mr β-subunit of brain spectrin are phosphorylated in the intact mouse. In vitro analysis suggests that both are phosphorylated by a cAMP-independent protein kinase. Antibodies against pure native mouse red blood cell spectrin cross-react with brain spectrin, and antibodies against pure brain spectrin cross-react with both the α-and β-subunits of mouse RBC spectrin. Both antibodies have been utilized to localize brain spectrin within distinct cellular entities of the mouse cerebellum. Granule cell neurons of the internal granule layer and Purkinje cell neurons demonstrated intense fluorscence of the cortical cytoplasm immediately adjacent to the plasma membrane and unstained nuclei, when either RBC or brain spectrin antibodies were utilized for staining. The molecular layer of the cerebellum stained only lightly, and oligodendrocytes and astrocytes appeared to have little fluorescence. Therefore, while brain is a tissue rich in nonerythroid spectrin, the concentration of these immunoreactive analogues is quite variable within distinct cellular entities of the cerebellum.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970030528
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Osteocranial development in the viviparous surfperch Amphistichus argenteus (pisces: Embiotocidae) (1982)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 174 (1982), S. 95-120 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The development of the cranial and branchial skeleton of the surfperch Amphistichus argenteus, a member of the family Embiotocidae, is described, and phylogenetic and functional aspects of the skull development of this species are discussed. The earliest bones to appear are those dermal elements of the branchial skeleton involved with feeding, and the bones, both dermal and endochondral, located in the basicranial region of the neurocranium. These are followed by dermal bones associated with the lateral line system and finally by the remainder of the bones of the branchial skeleton and the cartilaginous bones of the otic capsules. The last bone to develop is the ethmoid.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051740108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Morphometric diffusing capacity and functional anatomy of the book lungs in the spider Tegenaria spp. (Agelenidae) (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 182 (1984), S. 339-354 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The presence of both book lungs and a tracheal system in many spiders raises the question of the functional significance of this double respiratory system. The present physiological and morphometric study of the house spider (Tegenaria spp.) reveals that the diffusing capacity (Dto2) of the lungs alone suffices during rest and following exercise to meet measured rates of oxygen consumption (\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm V}\limits^{\rm.} $\end{document}o2) at driving pressures (ΔPto2) similar to those calculated for vertebrate lungs. During moulting ΔPto2 may rise to more than double the vertebrate values, implying the possible insufficiency of book lungs during this critical life phase. Resting \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm V}\limits^{\rm .} $\end{document}o2 is greatest (92 mm3/h · g) during the early morning and lowest (66 mm3/h · g) near midday: during moulting \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm V}\limits^{\rm .} $\end{document}o2 rises to 278.7 mm3/h · g. In spiders recovering from exercise \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm V}\limits^{\rm .} $\end{document}o2 is consistently greater than during rest: neither value is significantly reduced by blockage of the tracheal stigmas. Regression calculations of morphometric values for a hypothetical 100-mg Tegenaria yield a total lung volume of 0.578 mm3, a pulmonary surface area of 69.8 mm2, and a surface-to-volume ratio of 120.89 mm2/mm3. In spite of the similar thickness of the chitinous and hypodermal components of the air-hemolymph barrier (each ca. 0.2 μm in nonmoulting animals), the low permeability of chitin for oxygen makes this layer the greater barrier to diffusion. For a 100-mg specimen Dto2 is 3.5 mm3/h · torr: similar to that of a turtle (Pseudemys) on a gram-body weight basis.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051820308
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Cystamine augments the stimulation of DNA synthesis by peptide growth factors and microtubule-disrupting agents in cultures of 3T3 mouse fibroblasts (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 303-308 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cystamine together with colchicine markedly enhanced the uptake of [3H]-thymidine into DNA of quiescent cultures of insulin-stimulated Swiss 3T3 mouse fibroblasts. Flow cytofluorometric analyses showed an increased rate of transition of cells from G0/G1 → S + G2 in response to combinations of insulin, colchicine, and cystamine. Cystamine, the most effective of several thiol compounds, gave maximal augmentation at 200 μM and was toxic at 300-500 μM. Amplification of DNA synthesis by cystamine was also obtained with epidermal growth factor, vasopressin, and 0.5% fetal bovine serum. Combinations of cystamine and other microtubule-disrupting agents such as nocodazole, maytansine, and podophyllotoxin enhanced DNA synthesis in insulin-stimulated cells. In experiments involving sequential addition of agents, significant enhancement of DNA synthesis was observed when the addition of colchicine to cystamine-treated cells was delayed or conversely when the addition of cystamine to colchicine-treated cultures was delayed. This reciprocal interaction between cystamine and colchicine suggests that a prereplicative intermediate accumulates in response to the action of these dissimilar compounds. We consider the possibility that cystamine may act by forming mixed disulfides with thiol groups of unknown protein(s) that regulate DNA replication.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Transcription of chick genes by mammalian RNA polymerase II in chick erythrocyte-mammalian cell heterokaryons (1982)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 113 (1982), S. 99-104 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The introduction of chick erythrocyte nuclei into mammalian cell cytoplasms results in their reactivation as evidenced by the de novo transcription of chick genes and the synthesis of both globin and constitutive proteins. In the present study, chick erythrocytes have been fused to L6 rat myoblasts and to alphaamanitin-resistant variants of L6 to determine whether the chick or the mammalian RNA polymerase II was responsible for transcription of chick genes. Heterokaryons formed by fusing chick erythrocytes with alpha-amanitin-resistant L6 myoblasts synthesize both chick globin and chick constitutive proteins in the continued presence of 5 μg/ml alpha amanitin ten days postfusion. Both the synthesis of globin and other chick polypeptides occurs at levels comparable to those observed for untreated heterokaryons. Synthesis occurs under conditions in which insignificant chick RNA polymerase II activity can be detected irv wild-type heterokaryons by autoradiography. These results demonstrate that RNA polymerase II is one of the mammalian proteins that is selectively taken up by the chick nucleus during reactivation in the presence of alpha amanitin. Furthermore, the mammalian RNA polymerase II alone can account for the transcription of both differentiation specific and constitutive genes in the chick nucleus.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041130117
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Epidermal growth factor stimulates fluid phase endocytosis in human fibroblasts through a signal generated at the cell surface (1982)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 19 (1982), S. 383-394 
    Details
    ISSN: 0730-2312
    Keywords: epidermal growth factor ; receptors ; endocytosis ; cell surface ; response kinetics ; compartmentation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We have investigated the stimulation of fluid phase endocytosis by epidermal growth factor (EGF) in normal human fibroblasts using 125I-labeled polyvinylpyrrolidone (125I-PVP) as a fluid phase marker. We found that EGF initially induced a thereefold increase in the rate of 125I-PVP uptake. This initial burst of fluid uptake terminated within 10 min. Thereafter, the rate of fluie uptake in EGF-treated cells was approximately 40% higher than in control cells. To identify the cellular site of EGF action in stimulating fluid phase endocytosis, we examined the kinetics of the induction of this response as well as the kinetics of cell surface binding and internalization of 125I-EGF. Although there was no detectable lag between binding of EGF to the cell surface and its internalization, the kinetics of the two processes were quite different. Significantly, the kinetics of induction of 125I-PVP uptake matched the kinetics of binding of 125I-EGF to its cell surface receptors, indicating that the signal for the increase in fluid phase endocytosis is generated at the cell surface. To determine if EGF-stimulated fluid phase endocytosis was related to EGF-stimulated endocytosis of its own receptor, we compared the EGF dose dependency and time course of the two processes. Although the stimulated endocytosis of the EGF receptor was not saturable with respect to the concentration of EGF used, the stimulation of fluid phase endocytosis was half maximal at an EGF concentration of 1 ng/ml and saturated at a concentration of 5 ng/ml. Also, the stimulation of fluid phase endocytosis was sevenfold greater initially after adding EGF than after a 30-min continuous incubation with the hormone, whereas the enhanced clearance of the EGF receptor did not change during this time period. We conclude that the EGF-stimulated increase in fluid phase endocytosis is not directly coupled to EGF-stimulated endocytosis of its own receptor but instead to a separate signal generated at the cell surface.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240190407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Inhibition by Glucocorticoids of Endocytosis in a Macrophage-Like Cell Line (1982)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 18 (1982), S. 423-431 
    Details
    ISSN: 0730-2312
    Keywords: endocytosis ; macrophage-like cell line ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: A macrophage-like cell line (P388D1) has been used to demonstrate that glucocorticoids inhibit the fluid-phase endocytosis of fluorescein-labeled dextran (FITC-dextran). Initial experiments demonstrated that the interaction of FITC-dextran with cells had all the features of fluid-phase uptake, ie, the amount taken up was proportional to the concentration in the medium, the uptake proceeded continuously with time and was blocked at 4°C. Dexamethasone (10-7M) had no effect on endocytosis until 11 hours after addition of the steroid, when it inhibited the uptake of FITC-dextran by 35%. The amount of inhibition increased with longer exposure times to the hormone up to 50% after 22 hours. Although this effect on endocytosis was Observed prior to any effect on growth of the cells, endocytosis as well as cell proliferation were inhibited in a dose-dependent fashion. A preliminary survey of selected steroids has established that the inhibition of endocytosis was restricted to steroids of the glucocorticoid class. The key experiments were also performed using horseradish peroxidase instead of FITC-dextran with, essentially, identical results.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.1982.240180404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Decreased activity of acetyl-CoA carboxylase during chemically induced neutrophilic differentiation of human promyelocytic leukemia cells (1984)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 26 (1984), S. 75-81 
    Details
    ISSN: 0730-2312
    Keywords: actyl-CoA carboxylase ; HL-60 ; differentiation ; leukemia ; fatty acid ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: In order to better understand the mechanism by which changes in the fatty acid composition of cellular lipids occur in leukemia cell lines induced to differentiate, the activity of the first enzyme of fatty acid biosynthesis, acetyl-CoA carboxylase (EC 6.4.1.2) was measured in HL-60 promyclocytic leukemia cells before, during and after treatment with compounds that induce these cells to mature to neutro-phillike cells. After 24 h of exposure to dimethylsulfoxide, retinoic acid, or butyric acid, no morphological or biochemical (nitroblue tetrazolium reduction) evidence of differentiation occurred, but acetyl-CoA carboxylase activity decreased 44, 44.5, and 49% respectively, compared to untreated cells. After 7 days of culture in the presence of these agents, 79, 83, and 72% of cells acquired the ability to reduce nitroblue tetrazolium (versus 15% of control cells) and enzyme activity decreased 92.7, 99.7, and 98%, compared to control cultures, with the three compounds respectively. Thus, some of the reported changes in fatty acid composition of leukemia cells with differentiation may arise, in part, from the depression of the de novo fatty acid biosynthetic pathway and the loss of acetyl-CoA carboxylase activity may be a useful marker for neutrophilic differentiation in HL-60 cells.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240260203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Comparison of the expression-linked extra copy (ELC) and basic copy (BC) genes of a trypanosome surface antigen (1983)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 23 (1983), S. 1-12 
    Details
    ISSN: 0730-2312
    Keywords: trypanosome ; genes ; rearrangement ; surface antigen ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: A recombinant clone of an expression-linked extra copy (ELC) gene of a trypanosome-variable surface glycoprotein was sequenced. In addition the sequences of the corresponding cDNA and portions of the two basic copy genes were determined. Comparison of these sequences reveals that the 5′ boundary of the ELC-transposed segment (2.2 kb) occurs within a repetitive sequence about 700 bp upstream from the start codon of the coding sequence. This sequence does not contain internal symmetries and is not homologous with the repetitive sequence at the 3′ boundary. The first 35 nucleotides of the cDNA are different than the corresponding ELC sequence and presumably were transcribed from another genomic location. A restriction fragment containing predominantly sequences outside of the 5′ boundary hybridizes to a Pst I fragment whose length is variable in different trypanosome clones. This hybridization pattern is similar to that observed using probes for surface glycoprotein genes that are expressed via the nonduplication-associatcd (NDA) mechanism rather than the ELC mechanism. This indicates that there is a sequence correlation between these two DNA rearrangement mechanism.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240230102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...