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
  • 1
    Electronic Resource
    Electronic Resource
    Subcortical rotation in Xenopus eggs: A preliminary study of its mechanochemical basis (1987)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 8 (1987), S. 143-154 
    Details
    ISSN: 0886-1544
    Keywords: amphibian egg ; Nile blue stain ; microtubules ; subcortial rotation ; cytoplasmic movement ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The amphibian egg undergoes a 30° rotation of its subcortical contents relative to its surface during the first cell cycle, a displacement of 350 μm in 50 min. This is directly visualized by following the movement of an array of Nile blue (a subcortical stain) spots applied to the egg periphery (Vincent, Oster, and Gerhart: Dev Bio 113:484-500, '86). We have investigated the mechanochemical basis of this unusual cell motility. Subcortical rotation depends on microtubule integrity during its entire course and is insensitive to inhibitors of microfilament assembly. It does not depend on newly synthesized proteins for its operation or timing, and it does not involve calcium-dependent processes. Finally, we show that vegetal fragments of the egg can complete rotation on their own, indicating that mechanochemical components can operate locally in this hemisphere.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970080206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Localization of p35 (annexin I, lipocortin I) in normal adult rat kidney and during recovery from ischemia (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 153 (1992), S. 467-476 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The 35-kDa protein (p35, lipocortin I, annexin I), originally discovered as a Ca++-dependent substrate for the EGF receptor tyrosine kinase, binds Ca++ and phospholipids, is developmentally regulated in embryos and has restricted expression in adults. Immunohistochemistry of normal rat kidney shows that p35 is enriched in epithelia of Bowman's capsule, the macula densa, and medullary/papillary collecting ducts, suggesting that p35 is related to specialized renal functions. Light staining is observed in the thick ascending limb; elsewhere, immunoreactivity is nil. Since renal recovery from ischemia involves both hyperplasia and hypertrophy and reportedly is accelerated by EGF, we examined p35 distribution during this process. After 48 hours of recovery, both the distribution and amount of renal p35 are altered. Immunoblots show p35 levels increased at least threefold in whole-kidney homogenates. The expression of p35 is still highly restricted in recovering kidneys; however, the thick ascending limb now stains heavily. This is the first documentation of alterations in annexin levels during a pathophysiologic response. However, our attempts to discern effects of exogenous EGF on the recovery from ischemia were negative for both mitotic index and renal function assays. © 1992 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041530305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Procedures for obtaining high percentages of viable in vitro capacitated hamster sperm (1979)
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 207-211 
    Details
    ISSN: 0148-7280
    Keywords: sperm ; capacitation ; acrosome ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Suspensions of nearly 100% viable golden hamster sperm were prepared by passing washed cauda epididymal sperm through a column of 0.25-0.3 mm glass beads. Incubations of these viable sperm under in vitro capacitation conditions in volumes of 0.1 or 1 ml (2-2.5 × 106/ml) resulted in 85-92% viable sperm after four hours and 45 minutes of incubation. More than 70% of these sperm were judged to have been capacitated after four hours and 45 minutes of incubation on the basis of their having undergone acrosome reactions and the presence of high numbers of sperm exhibiting the activated motility characteristic of capacitated hamster sperm.Thus, for the first time, procedures are available that will yield large numbers of viable capacitated sperm for biochemical analysis and that will also allow other studies of hamster sperm capacitation with minimum interference from molecules released from dead sperm.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120020304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Stimulation of hamster sperm capacitation and acrosome reaction in vitro by glucose and lactate and inhibition by the glycolytic inhibitor α-chlorohydrin (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 515-523 
    Details
    ISSN: 0148-7280
    Keywords: glucose ; glycolysis ; lactate ; sperm ; capacitation ; acrosome reactions ; α-chlorohydrin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Studies were made of the effects of D(+)-glucose, L-lactate and pyruvate on in vitro capacitation and acrosome reactions (AR) of hamster sperm using a more “defined” medium that that used in previous similar studies. In the absence of glucose or lactate, sperm underwent very few AR and activation (whiplash-like motility characteristic of capacitated hamster sperm) was reduced compared to those events in sperm preincubated in the presence of glucose plus lactate plus pyruvate. Glucose and pyruvate supported more AR than glucose alone, but less than glucose, lactate, and pyruvate. The glycolytic inhibitor α-chlorohydrin (10 μm) inhibited AR by 50% and reduced activation by less. When glucose was added to sperm incubated 2 hr with pyruvate and lactate, the number of AR observed after 4 hr was the same as that obtained when glucose was present throughout the incubation. When glucose was added after 3.5 hr, AR were delayed for 1 hr and lower numbers of sperm underwent AR. In the presence of lactate and pyruvate, 0.38 mM glucose was able to support activation and AR as well as 3.24 mM glucose. These results indicate that exogenous glucose and lactate are necessary for in vitro capacitation and AR of hamster sperm; only low levels of exogenous glucose are required; exogenous glucose is not required during the first 2 hr of capacitation; and glycolytic activity is necessary for capacitation and the AR.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040605
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Changes in motility that accompany the acrosome reaction in hyperactivated hamster spermatozoa (1984)
    New York, NY : Wiley-Blackwell
    Gamete Research 10 (1984), S. 253-265 
    Details
    ISSN: 0148-7280
    Keywords: sperm motility ; hyperactivation ; acrosome reaction ; spermatozoa ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: High-speed videomicrography was used to compare the movement characteristics of hamster epididymal sperm which completed the acrosome reaction in vitro with those of unreacted sperm in the same sample. More than 90% of the motile sperm incubated for 4.25 hr in a modified Tyrode's medium containing bovine serum albumin, taurine, and epinephrine were hyperactivated and about half were acrosome reacted. The flagella of reacted sperm beat with significantly lower frequency and bent into more acute curves than those of unreacted sperm. Lowered beat frequencies were not attributable to aging, because sperm induced to react synchronously at 3.5 hr using lysophosphatidyl choline beat with similar lowered frequencies. Both acrosome-reacted and unreacted hyperactivated sperm swam in circular trajectories resulting from asymmetrical flagellar beating. The flagellar beating of unreacted sperm was more symmetrical; consequently, they swam in larger circles and had the potential to cover space more rapidly. Some unreacted sperm, perhaps in transition towards hyperactivation, swam in helical trajectories.When preincubated sperm were added to slides containing oocytes in cumulus, some unreacted sperm initiated cumulus penetration. All reacted sperm failed to do so, adhering instead to the cumulus at its boundary. Reacted sperm attached to the zonae pellucidae of cumulus-free oocytes via the region of the inner acrosomal membrane. Unreacted sperm attached via the equatorial region, but pivoted about the point of attachment, thus failing to generate sustained thrust against the zona. In conclusion, unreacted hyperactivated sperm have a different potential than reacted sperm for movement and interaction with egg vestments.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120100305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Experimental determination of whole body average specific absorption rate (SAR) of mice exposed to 200-400 MHz CW (1983)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 4 (1983), S. 267-279 
    Details
    ISSN: 0197-8462
    Keywords: mice ; specific absorption rate ; calorimetry ; TEM chamber ; 200-400 MHz CW ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: A maximum of six live mice, mouse cadavers, prolate spheroids molded from muscle-equivalent tissue, or saline-filled culture flasks, were exposed to continuous wave radiation in a TEM cell at frequencies between 200 and 400 MHz. Whole-body average specific absorption rate (SAR) was determined from power meter measurements of incident, reflected, and transmitted powers. The SARs for both live mice and cadavers were approximately twice that for the prolate spheroid models, and when housed in Plexiglas restraining cages, about 2 1/2 times greater. An error multiplying factor is identified, that quantitatively expresses how SAR data obtained by the three -power-meter method becomes progressively more noisy as the irradiation frequency is lowered or as the TEM cell cross section is increased.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250040307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Magnetic field exposure among utility workers (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 16 (1995), S. 216-226 
    Details
    ISSN: 0197-8462
    Keywords: job classification ; occupational exposure ; personal-exposure monitoring ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The Electric and Magnetic Field Measurement Project for Utilities - the Electric Power Research Institute (EPRI) Electric and Magnetic Field Digital Exposure (EMDEX) Project (the EPRI EMDEX Project) - was a multifaceted project that entailed technology transfer, measurement protocol design, data management, and exposure assessment analyses. This paper addresses one specific objective of the project: the collection, analysis, and documentation of power-frequency magnetic field exposures for a diverse population of utility workers. Field exposure data measured by an EMDEX system were collected by volunteer utility employees at 59 sites in four countries between September, 1988, and September, 1989. Specially designed sampling procedures and data collection protocols were used to ensure uniform implementation across sites. Volunteers within 13 job classifications recorded which of eight work or three nonwork environments they occupied while wearing an EMDEX meter. Approximately 50,000 hours of magnetic field exposure records taken at 10 s intervals were obtained, about 70% of which were from work environments. Exposures and time spent in environments were analyzed by primary work environment, by occupied environment, and by job classification. Generally, for utility-specific job classifications related to the generation, transmission, and distribution of electricity, the field and exposure measurements in terms of workday mean field were higher than in more general occupations. The job classifications with the highest (median workday mean) exposure were substation operators (0.7 μT) and electricians (0.5μT). Total variance also tended to be largest for utility-specific job classifications. For these workers, the contributions of between-worker and within-worker variances to total variance were about the same. Measurements in utility-specific environments were higher than in more general environments. Estimates of time-integrated exposure indicated that utility-specific job classifications received about one-half or more of their total exposure on the job. The nonwork field and exposure distributions for workers in all job categories were comparable with median nonworkday means of about 0.09 μT. © 1995 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250160403
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Regulation of enzymes in isolated plant nuclei (1986)
    New York, NY : Wiley-Blackwell
    BioEssays 5 (1986), S. 120-123 
    Details
    ISSN: 0265-9247
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Purified nuclei are being used as a test system to study the regulation of nuclear enzymes in plants. Regulatory agents such as light, hormones and polyamines can stimulate kinases or phosphatases that control nuclear protein phosphorylation and they can modulate the activity of as yet unidentified enzymes required for transcript synthesis and/or stabilization. This essay summarizes current findings and discusses the advantages and pitfalls of using isolated nuclei to investigate how nuclear functions are controlled.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bies.950050307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Effects of 60 Hz electric and magnetic fields on maturation of the rat neopallium (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 14 (1993), S. 449-458 
    Details
    ISSN: 0197-8462
    Keywords: ELF ; brain development ; prenatal exposure ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: This study was undertaken to determine the effects of extremely low frequency (ELF; 60 Hz) electromagnetic (EM) fields on somatic growth and cortical development, as well as biochemical and morphological maturation, of the rat neopallium. On the fifth day of pregnancy, female rats were put in pairs into plastic cages that were housed in a specially constructed apparatus for irradiation under three separate sets of combination and intensity: 1) 1 kV/m and 10 gauss; 2) 100 kV/m and 1 gauss; and 3) 100 kV/m and 10 gauss. The dams were exposed for 23 h daily, from days 5 through 19 postconception after which they were returned to cages outside the exposure apparatus until they littered. The neonates were culled to eight pups per litter. At 0 (birth), 5, 12, and 19 days postnatally, they were killed for biochemical and morphological studies. Another group of pregnant rats was sham-exposed in an identical apparatus, which was not energized, and the pups were used as controls. The irradiated rats exhibited no physical abnormalities, nor did they show brain deformities such as swelling or herniation following exposure to ELF-EM fields. There was no difference in somatic growth between control and exposed rats, but a small reduction in cortical weight was observed in rats exposed at 1 kV/m and 10 gauss, and 100 kV/m and 1 gauss, respectively. Biochemical measurements of DNA. RNA, protein, and cerebroside concentrations indicated that among the three separate exposures, only the neopallium of rats exposed at 1 kV/m and 10 gauss showed a small reduction in DNA level, as well as small reductions in RNA and protein levels. No changes were noticed in cerebroside levels in any exposed animals, and there were no differences in protein/DNA and cerebroside/DNA ratios between control and exposed rats. Morphological observations did not reveal any detectable alterations in the irradiated rats. These results indicate that exposure to ELF-EM fields caused minimal or no changes in somatic growth and cerebral development of the rat. © 1993 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250140506
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The Gap junction proteins: Vive la différence! (1988)
    New York, NY : Wiley-Blackwell
    BioEssays 9 (1988), S. 167-168 
    Details
    ISSN: 0265-9247
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The intercellular junctions connecting the cytoplasms of fibre cells in the mammalian lens have until recently been regarded as a class of junction which is fundamentally different from that of the gap junctions in other organs. Recent observations, however, suggest that the lens junctions fit protein topology predictions common for all gap junctions. While the homologous peptide portions are predicted to form the channels, the divergent peptide portions of the gap junction polypeptides may adapt channel activity to the special tissue requirements.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bies.950090507
    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...