Library

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
    ISSN: 1432-2307
    Keywords: Mouse teratoma ; Centrifugal elutriation ; Neuroepithelial enrichment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Dissociation and centrifugal elutriation procedures were applied to subcutaneous transplants of the OTT-6050 mouse teratoma line in order to enrich the neuroepithelial cells. One of the resultant cell fractions, designated IB-21, was then implanted beneath the renal capsule of syngeneic mice and rebanked every 3 to 6 weeks for a total of 58 passages over 5 years. Sequential passages resulted in a tumor restricted to stem cells and neural cells (neuroblasts and glial cells). The primitive neural cells lost the ability to form rosettes after the early transplants. Subcutaneous or intracerebral transplantation of these tumors evinced their capacity for further neuroepithelial differentiation, with the demonstration of astrocytes and occasional mature synapse-forming neurons. Conversion of the tumor to the ascitic form resulted in unorganized clusters of neoplastic cells in contrast to the highly structured embryoid bodies that are characteristic of the parent OTT-6050 line. The absence of non-neural cells in the IB-21 tumor fraction and its ability to demonstrate divergent neural differentiation suggest that a transplantable neural-determined cell population exists in the OTT-6050 mouse teratoma.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2307
    Keywords: Mouse teratoma ; Centrifugal elutriation ; Melanotic neuroepithelium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Dissociation and elutriation procedures were applied to the OTT-6050 mouse teratoma line carried in subcutaneous implants in 129/J mice in order to enrich the differentiating neuroepithelial cells. Subsequent renal subcapsular implantation of one of the resultant cell fractions (IB-9) in syngeneic mice led to the constant production of macroscopically pigmented tumors which, in addition to undifferentiated stem cells, contained primitive neuroepithelial populations composed of medullary epithelium, neuroblasts, and numerous ependymoblastic rosettes. Melanin pigment, confirmed by the presence of melanosomes and premelanosomes, was found in medullary epithelium and other primitive neural cells. The tumors preserved their characteristics through 65 sequential transplants over a period of 5 1/3 years. The pigment was maintained in vitro for up to 3 months in an organ culture system. Subcutaneous or intracerebral transplantation of the renal tumors of the IB-9 fraction accentuated the capacity of these primitive cells towards further neuroepithelial differentiation into mature synapse-forming neurons, and was associated with a decrease in primitive neuroepithelium and an absence or a marked decrease of melanin. Return of the tumor to the kidney resulted in the reappearance of melanin after one to three passages, again associated with the presence of primitive neuroepithelium. The recognition of melanin pigment in the OTT-6050 mouse teratoma transplants could be a useful marker for the successful selection of primitive neuroepithelial cell populations in this experimental tumor system. These populations may help to study the relationship between melanin production and certain types of primitive neuroectodermal tumors in man.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-2307
    Keywords: Mouse teratoma ; Embryoid bodies ; Cerebral transplantion ; Neural differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Small embryoid bodies (EB's) from the OTT-6050 transplantable mouse teratoma, obtained by gravity filtration through a 74 μ mesh, were injected into the right cerebral hemisphere of syngeneic newborn or adult mice of both sexes in order to produce differentiating teratomas after a single passage. In subsequent experiments, two solid tumors resulting from two different EB-implants into the brains of adult hosts were used to initiate sequential tumors and were carried intracerebrally in adult mice for 12 and 18 passages respectively. The animals were sacrificed when signs of increased intracranial pressure developed. Survival times were as follows: single passages in adult mice: mean, 35 days; single passages in neonatal mice: mean, 19 days; sequential passages in adult mice: mean, 25 days. Multipotential stem cells accounted for l/2 to 3/4 of the cens in all tumors. Primitive neural cells, ependymoblastic rosettes, neuroblasts and glia were present in all; stem cells, primitive neural cells and rosettes decreased proportionately as the more differentiated neural populations became prominent. Mature ganglion cells were found only in the sequentially passaged tumors and in tumors maintained for more than one month after a single passage in adult mice. Synapses were noted in the most differentiated areas. Neuroblasts were infrequent in tumors developing in neonatal hosts, and mature ganglion cells were absent. Glial fibrillary acidic protein was present by the 24th day in tumors obtained in adult hosts after single passage and in sequential passages. Both in the OTT-6050-derived tumor fractions IB-9 and IB-21, previously reported, and in the EB-derived tumors described in the present study the cerebral microenvironment did not appear to have unique properties favoring neural differentiation and maturation, since similar neural features were found in their subcutaneous counterparts. The findings reported suggest that any accentuation of neuroepithelial differentiation elicited by injecting EB's either intracerebrally or subcutaneously is apparently directly related to the total time of in vivo maintenance of the tumor and therefore presumably to the length of time necessary for such maturation to occur.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Urological research 11 (1983), S. 285-290 
    ISSN: 1434-0879
    Keywords: Trace metals ; Cadmium ; Kidney cortex ; Ischaemic heart disease ; Medulla
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The trace element content of kidneys has been documented in very few international centres. Significant differences can be demonstrated between the cortical and medullary levels of calcium, zinc and cadmium. For the West of Scotland the values for the latter are similar to those found in Scandinavia. There are significantly higher cadmium contents in subjects who smoke and who have evidence of ischaemic heart disease.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Urological research 7 (1979), S. 285-289 
    ISSN: 1434-0879
    Keywords: Cadmium ; Iron ; Bendrofluazide ; Hypercalciuria Hyperzincuria ; Treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cadmium induces a variety of effects on kidney tubules including hypercalciuria. This is accompanied by hyperzincuria. The present work shows that both of these biochemical abnormalities can be corrected but where a state of cadmium-induced-anaemia exists urine zinc and calcium excretion do not follow the expected parallel course in response to iron therapy as they do with bendrofluazide.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Urological research 5 (1977), S. 15-20 
    ISSN: 1434-0879
    Keywords: Cadmium ; Kidney ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cadmium injection in rats affects the genito-urinary system. The renal effects are generally considered to be mainly tubular. Light microscopy of 29 specimens confirms cellular damage in the glomeruli with changes in glomerular capillaries. Electron microscopic changes in the glomeruli confirm changes in the podocytes, thickening of the basement lamina, the occurrence of electron dense deposits in association with the capillary endothelium with platelet and polymorphonuclear cell accumulations which suggests opening of the endothelial junction of the glomerular vessels.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0887-3585
    Keywords: interleukin-4 ; circular dichroism spectroscopy ; site-directed mutagenesis ; protein structure modeling ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The structure of human interleukin 4 (IL-4) was predicted utilizing a series of experimental and theoretical techniques. Circular Dichroism (CD) spectroscopy indicated that IL-4 belonged to the all α-helix class of protein structures. Secondary structure prediction, site-directed mutagenesis, and CD spectroscopy suggested a predominantly α-helical structure, consistent with a four-helix bundle structural motif. A human/mouse IL-4 chimera was constructed to qualitatively evaluate alternative secondary structure predictions. The four predicted helices were assembled into tertiary structures using established algorithms. The mapping of three disulfide bridges in IL-4 provided additional constraints on possible tertiary structures. Using accessible surface contact area as a criterion, the most suitable structures were right handed all antiparallel four-helix bundles with two overhand loop connections. Successful loop closure and incorporation of the three disulfide constraints were possible while maintaining the expected shape, solvent accessibility, and steric interactions between loops and helices. Lastly, energy minimization was used to regularize the chain.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Bioluminescence and Chemiluminescence 4 (1989), S. 507-511 
    ISSN: 0884-3996
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Advent of the multichannel plate and position sensitive detector has made possible true single photon counting imaging tubes. We have investigated the application of these detectors in studies of the ultraweak light emission of biological materials. Initially, we focussed our efforts on two objectives: (1) obtaining single photon counting images of living tissues using only the light (chemiluminescence) emitted by the specimen and (2) developing means of obtaining well-resolved spectra of weakly emitting sources. We have obtained a variety of images. One striking result of this work is the first observation of tissue specific localization of photon emission in situ. Using this detector we have also obtained the first well-resolved spectra of some important ultraweak emission processes. These results illustrate the potential use of single photon imaging in bioluminescence and chemiluminescence research.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Electrophoresis 19 (1998), S. 3190-3198 
    ISSN: 0173-0835
    Keywords: Wheat ; Proteins ; Buffers ; Gliadins ; Capillary electrophoresis ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Studies were conducted to produce faster, simpler, more rugged protocols for separating wheat proteins by high performance capillary electrophoresis (HPCE). Three areas were targeted for improvement: initial capillary equilibration procedures, buffer composition, and post-separation rinsing procedures. For the initial equilibration of capillaries, a brief rinse with a hydroxypropylmethylcellulose (HPMC) solution was the most critical factor for successful separation of wheat proteins. To reduce separation time and maintain resolution, β-alanine and glycine were each used in place of sodium phosphate as buffer ions. Two isoelectric buffers, aspartic acid and iminodiacetic acid (IDA) were also tested. Each of these four buffer systems generated substantially lower currents, and provided faster separations, than sodium phosphate-based buffers. Finally, post-separation rinsing procedures were re-examined with the goal of reducing the time necessary to rinse the capillary after each separation. A critical factor in achieving this goal was removal of albumins and globulins prior to separation. These proteins bind to the capillary wall and cause rising baselines and excessive peak tailing. Once these proteins were removed, capillaries could be rinsed with buffer for only 2 min between separations. Capillary equilibration procedures were shortened from 90 min to 30 min. Likewise, separation times were reduced by ∼ 40% (25 min to 15 min) by using glycine in place of sodium phosphate in the separation buffer. Finally, post-separation times were reduced by 80% (10 min to 2 min). Overall, these factors resulted in a reduction in total separation time of 50% (35 to 17 min) and maintained high resolution separations and good run-to-run repeatability.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...