Library

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
  • Chromosome behaviour  (2)
  • 5-methyltryptophan resistance  (1)
  • Argyrophilic nucleolar organizer regions (AgNORs)  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Invasive meningioma: A tumour with high proliferating and “recurrence” potential (1995)
    Springer
    Acta neurochirurgica 136 (1995), S. 127-131 
    Details
    ISSN: 0942-0940
    Keywords: Argyrophilic nucleolar organizer regions (AgNORs) ; invasiveness ; meningioma ; proliferating cell nuclear antigen (PCNA)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A study was undertaken to investigate the correlation between histological invasiveness and proliferating potential and clinical recurrence in meningioma. In 39 meningiomas, the histological findings at the tumour-brain interface zone were classified into 3 types, consisting of 29 cases of non-invasion (NON), 7 cases of nodular invasion (NOD), and 3 cases of intermingled invasion (INT). Proliferating cell nuclear antigen (PCNA) and argyrophilic nucleolar organizer region (AgNOR) indices were studied. PCNA indices (mean±standard error) of NON, NOD, and INT were 1.7±0.1%, 5.2±0.5%, and 7.5±0.7%, respectively, and the AgNOR indices (dot number/nucleus) were 1.50±0.03, 2.00±0.04, and 2.22±0.07, respectively. Significant differences were found among the three types in both parameters. Clinically, tumour recurrence was observed in 1/29 NON, 4/7 NOD, and 2/2 INT cases, indicating a higher incidence of recurrence in invasive meningiomas (NOD plus INT). Four of 32 patients who underwent gross total removal of the tumours showed recurrence, and all of these four tumours were invasive meningiomas. The results of the present study showed that tumour invasiveness as measured by PCNA + AgNOR indices correlated well with high proliferative potential and clinical recurrence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01410613
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Behaviour of chromosomes in anaphase cells in embryogenic callus cultures of maize (Zea mays L.) (1996)
    Springer
    Theoretical and applied genetics 92 (1996), S. 982-990 
    Details
    ISSN: 1432-2242
    Keywords: Key words Zea mays L. ; Tissue culture ; Aberrations in chromosome structure ; Heterochromatic knobs ; Chromosome behaviour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mitotic anaphase cells of highly friable and embryogenic calluses which had been induced from immature embryos of two inbred lines of maize that have contrasting levels of heterochromatic knobs were analysed for the presence of abnormalities 3, 6, 9 and 12 months after the initiation of culture. A total of 500 typical anaphases was scored at each time point, and various aberrations, such as delay in the separation of sister chromatides, chromosome bridges (single, double and multiple) and chromosome fragments, were revealed to occur extensively in the cultures of both genotypes. Preparations after C-banding revealed that primary breakages often occurred inside knobs or at junction regions between the euchromatin and the heterochromatin of the knobs. Figures characterized by the delayed separation of sister chromatids, which originated preferentially at the knob level and was considered to be an initial event in the development of breakages, were observed at constant frequencies throughout the experiment. Increasing numbers of aberrant cells were detected with time, mainly due to the accumulation of cells with chromosome bridges and fragments. Several mitotic figures suggested the occurrence of breakage-fusion-bridge cycles that were initiated by broken chromosomes. The overall frequencies of aberrant cells were similar for both genotypes, despite the differences in knob composition. However, callus cultures induced from the genotype having the higher level of knobs had more aberrant cells with abnormalities that involved several chromosomes, such as multiple bridges and multiple fragments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220050219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Behaviour of chromosomes in anaphase cells in embryogenic callus cultures of maize (Zea mays L.) (1996)
    Springer
    Theoretical and applied genetics 92 (1996), S. 982-990 
    Details
    ISSN: 1432-2242
    Keywords: Zea mays L. ; Tissue culture ; Aberrations in chromosome structure ; Heterochromatic knobs ; Chromosome behaviour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mitotic anaphase cells of highly friable and embryogenic calluses which had been induced from immature embryos of two inbred lines of maize that have contrasting levels of heterochromatic knobs were analysed for the presence of abnormalities 3, 6, 9 and 12 months after the initiation of culture. A total of 500 typical anaphases was scored at each time point, and various aberrations, such as delay in the separation of sister chromatides, chromosome bridges (single, double and multiple) and chromosome fragments, were revealed to occur extensively in the cultures of both genotypes. Preparations after C-banding revealed that primary breakages often occurred inside knobs or at junction regions between the euchromatin and the heterochromatin of the knobs. Figures characterized by the delayed separation of sister chromatids, which originated preferentially at the knob level and was considered to be an initial event in the development of breakages, were observed at constant frequencies throughout the experiment. Increasing numbers of aberrant cells were detected with time, mainly due to the accumulation of cells with chromosome bridges and fragments. Several mitotic figures suggested the occurrence of breakagefusion-bridge cycles that were initiated by broken chromosomes. The overall frequencies of aberrant cells were similar for both genotypes, despite the differences in knob composition. However, callus cultures induced from the genotype having the higher level of knobs had more aberrant cells with abnormalities that involved several chromosomes, such as multiple bridges and multiple fragments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224038
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Selection and characterization of a rice mutant resistant to 5-methyltryptophan (1991)
    Springer
    Theoretical and applied genetics 82 (1991), S. 405-408 
    Details
    ISSN: 1432-2242
    Keywords: Ethylene imine ; Dominant gene ; Free amino acids ; 5-methyltryptophan resistance ; Rice mutant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A rice plant resistant to 5-methyltryptophan (5MT) was selected from mutagenized M3 seeds (Oryza sativa L. var. Sasanishiki) originating from panicles treated with ethylene imine (0.2%) 2 h after flowering. When germinated on 5MT-containing medium, the seeds (M4) from selfed plants segregated with a 3 resistant:1 sensitive ratio, indicating that the plant was heterozygous for a resistance gene and that the resistance was dominant. The resistance was also expressed in callus derived from seeds. Analysis of the free amino acids in seeds, seedlings, and calli showed that homozygous resistant plants (TR1) contained higher levels of total free amino acids than sensitive plants. In particular the levels of tryptophan, phenylalanine, and histidine were, respectively, 8.5, 5.4, and 4.9 times higher than those in the sensitive plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00588590
    Library Location Call Number Volume/Issue/Year 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...