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  • Cell & Developmental Biology  (1,529)
  • 1
    Electronic Resource
    Electronic Resource
    Preparation of biological tissue sections for correlative ion, electron, and light microscopy (1984)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 1 (1984), S. 299-309 
    Details
    ISSN: 0741-0581
    Keywords: Electron microscopy ; Ion microscopy ; Correlative microscopy ; Electron probe microanalysis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: In order to correctly interpret the chemical images obtained using ion microscopy (IM), it is useful to correlate them with the information provided by conventional light microscopy (LM), secondary electron imaging (SEI), backscattered electron imaging (BEI), and electron probe microanalysis (EPMA). Accordingly, we have devised a technique of specimen preparation which allows for the application of several different microanalytical techniques to a single histologic section mounted on the same substrate. Sections are cut onto polyester plastic coverslips (devoid of peaks for any element with atomic number 〉 9 using EPMA) and studied by LM. After a light rotary coating with carbon (to prevent charging), the section can then be examined by SEI, BEI, and EPMA. Specific areas can be marked for IM study either with an objective-mounted pin tissue microlocater, or by placing small pieces of metal foil, cut in specific geometric shapes, over features of interest. After sputter-coating the sample with platinum, metal-free shadows are visible using a low-power reflected light microscope available on a typical IM sample chamber as a guide for ion beam placement. The conductive coatings also minimize specimen charging during IM. Post-IM light microscopy, SEI, and BEI are used to confirm the location of specific areas probed in the IM experiments and to provide information on differential ion-sputtering artifacts and tissue contaminants. This new correlative technique should permit better understanding of the images obtained with these diverse instruments.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060010309
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  • 2
    Electronic Resource
    Electronic Resource
    Major influence of cell differentiation status on characteristics of proteoglycans synthesized by cultured rabbit renal proximal tubule cells: Role of insulin and dexamethasone (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 154 (1993), S. 175-191 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: To analyze the influence of epithelial cell differentiation and the effects of hormones on the characteristics of cell-associated and secreted proteoglycans (PGs), we studied their distribution, synthesis, and biochemical features in a model of renal proximal tubule cells in primary culture in which cell differentiation could be controlled by medium composition. In cells cultured in serum-free, hormonally defined medium supplemented with insulin and dexamethasone that exhibited a high degree of morphological and functional proximal differentiation (Ronco et al., 1990), cell-associated PGs were similar to those extracted in vivo by their size estimated by Sepharose CL-6B chromatography (Kav = 0.27, vs. 0.26), composition (heparan-sulfate), and localization in a continuous basal layer of extra-cellular matrix (ECM). In contrast, major quantitative and qualitative anomalies of cell-associated PGs were observed in poorly differentiated cells grown in 1% fetal calf serum-supplemented medium (FCS). PGs alterations included: (1) reduced and irregular expression of PGs at the cell basal pole, (2) a 2.8-fold decrease in [35S]-incorporation into cell-associated PGs, (3) a 3.1-fold increase in trypsin-releasable PGs, and (4) the emergence of a high MW PG composed exclusively of chondroitin-sulfate (CS) (Kav = 0.09 on Sepharose CL-6B) as well as of putative free CS-glycosaminoglycan (GAG) chains (Kav = 0.49 on Sepharose CL-6B). The same alterations were identified in the basal defined medium devoid of hormones but were partially or totally abolished by addition of insulin and dexamethasone, respectively. At variance with cell-associated PGs, production and biochemical features of secreted PGs were not influenced by cell differentiation status and medium composition. © 1993 Wiley-Liss, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041540121
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  • 3
    Electronic Resource
    Electronic Resource
    Middle ear cell line that maintains vectorial electrolyte transport (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 154 (1993), S. 615-622 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The middle ear epithelium plays a major role in keeping the temporal bone cavities fluid-free and air-filled, which is a mandatory condition to allow optimum transmission of the sound vibrations from the tympanic membrane to the inner ear. Previous works have recently established the absorptive function of the middle ear epithelium, using primary cultures derived from Mongolian gerbil (Meriones unguiculatus). Because of the paucity of cells as obtained by enzymatic digestion, we developed a middle ear cell line (MESV) using wild-type SV40 infection of primary culture of Mongolian gerbil's middle ear epithelial cells. Transformation was attested by nuclear expression of SV40 large T antigen, prolonged in vitro passages (presently beyond 50 passages), and tumor-inducing ability when subcutaneously injected in athymic mice. Transport properties were evaluated after the fifteenth passage. MESV cells retained most cardinal properties of the original middle ear epithelial cells: cell polarization was evidenced by the presence of mature junctional complexes that separate the cell membrane in two distinct domains, with apical microvilli at the luminal side, and by vectorial sodium transport responsible for the transepithelial lumen-negative potential difference (-9.3 ± 0.14 mV in culture conditions (n=9), -2.1 ± 0.25 mV after overnight growth factors and serum deprivation). Short-circuit current was, like in primary cultures, mainly related to a sodium transport occuring through amiloride-sensitive apical sodium channels, since apical addition of amiloride (10-5 M) reduced Isc from 7.0 = 1.4 to 0.6 ± 0.1 μA/cm2 (P 〈 0.01, n = 6). Cellular cAMP content was increased by isoproterenol and prostaglandin E2 from 40.5 ± 5.6 to 258.5 ± 17.3 and 55.6 ± 6.2 pmol/mg protein per 5 min, respectively (P 〈 0.05, n = 10). Isoproterenol and prostaglandin E2 increased Isc with very similar maximal effects: isoproterenol (10-4 M) increased Isc from 5.73 ± 0.31 to 12.77 ± 0.39 μA/cm2, while prostaglandin E2 increased Isc from 5.47 ± 0.21 to 12.87 ± 0.42 (n = 3). Since amiloride (10-5 M) abolished this stimulation, this may be related to an increase of the electrogenic sodium transepithelial transport. The MESV cell line could provide an interesting tool as a model of middle ear epithelial cells for the study of pathophysiological modulations of ion transport. © 1993 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041540321
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  • 4
    Electronic Resource
    Electronic Resource
    Cytogenetic study of parthenogenetically activated bovine oocytes matured in vivo and in vitro (1988)
    New York, NY : Wiley-Blackwell
    Gamete Research 20 (1988), S. 265-274 
    Details
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Three experiments were performed to evaluate the potential for parthenogenetic activation of bovine oocytes in in vitro fertilization systems and to determine the chromosome complement of the resulting parthenogenotes. In the first experiment, immature oocytes from slaughtered cattles were matured in vitro in Defined Medium (DM) for 24 h to simulate in vitro fertilization conditions. Subsequently, a portion was fixed, and the remainder were transferred to rabbit oviducts. Oocytes were then cultured for 6-8 h or for 24 h with Colcemid present during the last 6 to 8 h and fixed on slides and examined. In the second experiment, mature oocytes were collected from the preovulatory follicles, and the oocytes were subjected to the same culture as in experiment I. In the third experiment, oocytes were treated as in experiment II, except that instead of transfer to rabbit oviducts, they were cultured an additional 48 h in vitro. In experiment I, 131 oocytes were fixed after culture in DM. Of the 79 oocytes analyzed in the pre-rabbit group, 71 (90%) were at the second meiotic metaphase (MII), and 8 (10%) were at pre-MII stage; none were activated. After transfer to rabbits, 291 were fixed. Of these, 80 were analyzed; 37 (46.3%) were MII, 7 (8.6%) were pre-MII, and 36 (45%) were activated. Of the 36 activated oocytes, 26 (72.2%) were haploid, 4 (11.1%) were diploid, 1 (12.8%) was tetraploid, and 5 (13.8%) were in the process of endoreduplication. In experiment II, 51 oocytes were fixed after culture in DM of which 36 (70.6%) could be analyzed; 30 (83.3%) were MII, and 6 (16.7%) were pre-MII. After culture in the rabbit, 68 were fixed of which 27 (39.7%) could be analyzed. Of these 27, 20 (74.1%) were MII, and 7 (25.9%) were activated; 6 were haploid, and 1 was endoreduplicating. In experiment III, 30 oocytes were fixed at the end of the culture period; only 10 could be analyzed of which 8 (80%) were MII and 2 (20%) were pre-MII. In all, 46% of in vitro and 26% of in vivo matured oocytes were activated, based on chromosomal analysis. Of those activated, the majority (74.4%) were haploid, suggesting that activation occurs at or after completion of MII. Endoreduplication appears to be one of the mechanisms leading to the formation of diploid and polyploid parthenogenotes.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120200303
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  • 5
    Electronic Resource
    Electronic Resource
    Evidence for two forms of phospholipase A2 in human semen (1988)
    New York, NY : Wiley-Blackwell
    Gamete Research 19 (1988), S. 305-314 
    Details
    ISSN: 0148-7280
    Keywords: radiation inactivation ; spermatozoa ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The molecular weight of the active unit of phospholipase A2 (PA2) in human seminal plasma and spermatozoa was determined using the radiation inactivation technique. Fresh spermatozoa possess more than one form of PA2 activity as judged by the biphasic nature of the curve obtained during enzyme inactivation. However, when stored frozen for several months followed by a period of heating for 60 min at 60 °C prior to irradiation, the sperm exhibited PA2 activity, which corresponded to a single low molecular mass form of 12,000 d when radioactive phosphatidylcholine (PC) was used as substrate and 8,000 d when radioactive phosphatidylethanolamine (PE) was used as substrate. In fresh seminal fluid, only one active form of PA2 was detected as judged by the linear nature of the curve obtained during enzyme inactivation by irradiation. Using PC as substrate, the active unit was again estimated to be 12,000 d, whereas it corresponded to 18,000 d when PE was used. The PA2 activity associated with normal spermatozoa exhibited a 60% decrease in activity after storage at -20 °C for 48 hr followed by a heating period of 10 min at 60 °C. Long-term storage of spermatozoa at -20 °C also resulted in a similar decrease in the deacylation of PC. No further loss of activity was observed during subsequent heat treatment at 60 °C. Seminal plasma, however, showed no loss of activity following short (48 hr at 4 °C or -20 °C) or long-term storage and subsequent heat treatment. Thus, the behavior of PA2 when the effect of temperature was studied and in radiation inactivation experiments indicates that the low molecular weight component in the seminal plasma as well as in spermatozoa is temperature resistant. However, in fresh spermatozoa, a second form of PA2 was found and was sensitive to changes in temperature.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120190309
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of follicle size on bovine oocyte quality and developmental competence following maturation, fertilization, and culture in vitro (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 37 (1994), S. 48-53 
    Details
    ISSN: 1040-452X
    Keywords: Cattle ; IVM ; IVC ; IVF ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The aim of the present series of experiments was to investigate the effect of the size of follicle from which the oocytes originate on their subsequent in vitro developmental ability. Ovarian follicles were isolated and grouped according to size (2-6 mm, 〉6 mm). Primary oocytes were carefully liberated and grouped according to morphology into one of five categories: denuded; expanded; with two or three layers of cumulus; with four or five layers; and with many (six or more) layers. Following in vitro maturation (IVM), fertilization (IVF), and culture (IVC), more oocytes with many layers of cumulus (P 〈 0.01, 70.2%, 73/104 vs. 46.8%, 87/186, respectively) and a higher proportion of blastocysts were obtained from follicles 〉 6 mm compared to 2-6 mm follicles (P 〈 0.01, 65.9%, 60/91 from 〉6 mm follicles vs. 34.3%, 34/99 from 2-6 mm follicles, respectively). Use of follicular fluid (BFF) from follicles of different sizes in the IVM medium did not significantly increase the cleavage rate or blastocyst yield compared to controls. Administration of procine folliclestimulating hormone (pFSH) to donors prior to slaughter was investigated as a possible means of increasing the number of larger sized follicles in the ovaries and, thereby, the quality of the recovered oocytes. It was found that administration of six injections of pFSH beginning 3 days prior to slaughter resulted in a significant increase (P 〈 0.001) in the proportion of follicles 〉6 mm in diameter (31.6%) compared to that in nontreated controls (6.6%) and to animals that received only four injection groups (9.4%). The blastocyst yield from oocytes originating from 〉6 mm follicles, whether from unstimulated or from pFSH-treated animals, was approximately double that of oocytes from 2-6 mm follicles (P 〈 0.01; 42.9%, 24/56 for 〉6 mm follicles vs. 22.8%, 21/92 for 2-6 mm follicles, respectively, for the 6 pFSH group; P 〉 0.05; 62.5%, 5/8 for 〉6 mm follicles vs. 32.8%, 22/67 for 2-6 mm follicles, respectively, for the control). © 1994 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080370107
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  • 7
    Electronic Resource
    Electronic Resource
    Flow cytometric detection of bicarbonate-induced changes in lectin binding in boar and ram sperm populations (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 40 (1995), S. 164-176 
    Details
    ISSN: 1040-452X
    Keywords: Capacitation ; FITC-lectins ; Spermatozoa ; Cell surface ; Glycoconjugates ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Boar and ram spermatozoa were incubated in Tyrode's medium in the presence or absence of bicarbonate/CO2, a component believed essential for capacitation. At intervals, samples were stained with a range of FITC-lectins to detect changes in surface glycoconjugates, using a rapid staining technique to avoid problems of lectin toxicity. The samples were then analysed directly by flow cytometry, using propidium iodide to distinguish dead cells. In the presence of bicarbonate, a live subpopulation of spermatozoa developed, which in both animal species showed higher binding affinities towards Phaseolus Vulgaris Agglutinin (PHA-E), Sophora Japonica Agglutinin (SJA), and Soybean Agglutinin (SBA), and lower binding affinity towards Erythrina Cristagalli Lectin (ECL). In boar samples, the modified subpopulation reached a maximum after 3 hr incubation, whereas in ram samples it maximized after 1.5 hr. No changes were seen when spermatozoa were incubated in bicarbonate-free medium. The bicarbonate-induced changes in lectin binding were not due to the onset of acrosome reactions, because spermatozoa induced to undergo acrosome reactions with the ionophore A23187 displayed very different lectin-binding patterns. Tested on boar spermatozoa, seminal plasma not only inhibited but reversed the bicarbonate-induced development of the modified subpopulation. EGTA also inhibited development of boar sperm subpopulations; excess Ca2+ was unable to overcome this inhibition, suggesting that multivalent metal ions might be involved in bicarbonate's action. We conclude that bicarbonate causes a loss of surface coating material with affinity for ECL and an unmasking of binding sites for SBA, SJA and PHA-E. A modified subpopulation of live spermatozoa is thereby established, which appears to maximize at a rate in accord with reported capacitation times. © 1995 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080400205
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  • 8
    Electronic Resource
    Electronic Resource
    Microscopy in solid state science (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 24 (1993), S. 299-315 
    Details
    ISSN: 1059-910X
    Keywords: STEM ; PEELS ; HAADFI ; Nanolithography ; Super-resolution ; STM ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The Microstructural Physics group at the Cavendish Laboratory is actively involved in a considerable number of research projects which cover a broad range of materials science. In this paper, we describe briefly several such projects, with particular emphasis given to the application of parallel-detection electron energy loss spectroscopy (PEELS) on a scanning transmission electron microscope (STEM) to the analysis of materials such as stainless steels, catalysts, and high temperature superconductors. In addition, we describe a number of related projects that are currently being carried out in the group, particularly those which utilise and develop novel STEM imaging and analytical techniques. © 1993 Wiley-Liss, Inc.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070240404
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  • 9
    Electronic Resource
    Electronic Resource
    In vitro fertilization, development, and implantation after exposure of mature mouse oocytes to visible light (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 297-302 
    Details
    ISSN: 1040-452X
    Keywords: Light exposure ; Implantation rate ; IVF ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mature mouse oocytes were exposed prior to in vitro fertilization to visible light during 1, 2, or 4 hr at an intensity of 4,000 lux. Compared to controls cultured under identical conditions but protected from light, exposed eggs did not show any significant modification of cleavage speed are rate. After transfer of blastocysts obtained in vitro in uteri of pseudopregnant females, the implantation rate and the proportion of normal fetuses were not found to be different in relation to preliminary light exposure of oocytes fertilized and cultured in vitro. © 1992 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080330310
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  • 10
    Electronic Resource
    Electronic Resource
    Pharmacological profile of the substituted beta-lactam L-659,286: A member of a new class of human PMN elastase inhibitors (1989)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 39 (1989), S. 47-53 
    Details
    ISSN: 0730-2312
    Keywords: elastase inhibitors ; β-lactams ; lung damage ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Human polymorphonuclear leukocyte elastase (PMN elastase) is inhibited by L-659, 286 (7α-methoxy-8-oxo-3-[[(1,2,5,6-tetrahydro-2-methyl-5,6-dioxo-1,2,4-triaz-in-3-yl)thio]methyl]-5-thia-1-aza-6R-bicyclo [4.2.O]oct-2-ene-2-pyrrolidine carboxamide-5,-dioxide) with a Ki of 0.4 μM. This inhibition is time-dependent, rapid, and only slowly reversible, with a t1/2 of 〉 3 days at 25°C. L-659, 286 is also highly selective for PMN elastase, as it does not inhibit thrombin, trypsin, papain, plasmin, chymotrypsin, or cathepsin G. L-659, 286 administered intratracheally inhibits lung damage caused by administration via the same route of human PMN elastase into hamsters. In marmosets, L-659, 286 is cleared from blood very rapidly after an intravenous injection but is recovered in bronchoalveolar lavage fluid for several hours after intratracheal administration.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240390106
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