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
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 397 (1982), S. 0 
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2307
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The expression of theS-phase associated, nuclear protein proliferating cell nuclear antigen (PCNA) was investigated in routinely paraffin-embedded surgical specimens from 209 breast cancer patients. Cytometric DNA assessments were performed on fine-needle aspirates, upon which the primary diagnosis of breast cancer had been based. The mean clinical follow-up was 16 years (range 13–20 years). The percentage of PCNA immunoreactive tumour cells ranged between less than 5 to 60% (mean value 13.34%). There was a direct association between PCNA expression, high histological tumour grade (p〈0.01), and DNA aneuploidy (p=0.009). In a subgroup of 22 patients with near-diploid DNA distribution patterns the PCNA expression yielded additional prognostic information. Patients with tumours of near-diploid DNA histograms and more than 20% of PCNA immunoreactive neoplastic cells had a significantly worse clinical course, than patients with neardiploid tumours containing less than 20% PCNA immunoreactive cells (p=0.0001). In contrast, the PCNA immunoreactivity did not yield additional prognostic information for patients with distinctly diploid or highly aneuploid tumour variants. In a multivariate analysis comprising all 209 patients, nodal status (p〈0.01), tumour size (p〈0.01), and DNA ploidy (p〈0.01) were found to have significant prognostic effect. The findings indicate that carcinomas characterised by high proliferative activity and near-diploid DNA distribution patterns can show rapid tumour progression. The combined assessment of the PCNA immunoreactivity and of the nuclear DNA content in routinely processed surgical specimens of breast cancer patients appears to be of prognostic value.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé En plus des caractéristiques tumorales histopathologiques classiques, y compris le contenu en ADN, la cinétique cellulaire et l'étude de l'expression de gènes suppresseurs sont peut-être importantes dans le bilan d'un cancer du sein. Nous avons examiné par des coupes en paraffine la surexpression immunohistologique de la protéine associée avec l'interphase (le proliferating cell nuclear antigen: PCNA) et la mutante p 53 chez 180 femmes atteintes de cancer de sein ayant des caractéristiques d'ADN connus. Le pourcentage de PCNA immunoréactif variait entre 〈5 à 60% (moyenne: 13.59±10.85). Il y avait une corrélation positive entre les niveaux d'expression du PCNA (〉20%) et la surexpression p 53 (p=0.001), le grade histologique élevé (p=0.009), et l'aneuploïdie d'ADN (p=0.019). La mutante p 53 a été retrouvée chez 44 des 180 (24%) femmes et était significativement associée à un grade tumoral élevé (p= 0.004), à l'aneuploïdie (p=0.001) et à des taux élevés d'expression de PCNA (p=0.001). Les patientes ayant un cancer agressif (〉20% d'expression de PCNA) avaient une survie sans métastases plus courte lorsque leur tumeur surexprimait la mutante p53. En revanche, la survie des patientes sans métastase à distance ayant une surexpression de p 53 négative était significativement plus longue (p=0.03). La surexpression p 53 semble correspondre à un potentiel malin élevé chez les femmes ayant un cancer du sein. Les tumeurs hautement prolifératives ayant des cellules à expression p 53 sont cliniquement plus agressives que celles qui ne l'ont pas.
    Abstract: Resumen Existe evidencia creciente que indica que, además de las características histopatológicas convencionales, incluyendo la determinación de contenido de DNA, los datos de cinética celular y la investigación de la expresión del gen supresor de tumores podrian suministrar información valiosa en pacientes con cáncer mamario. En consecuencia, hemos investigado por métodos inmunohistoquímicos la sobreexpresión de la proteína PCNA (proliferating cell nuclear antigen) asociada con la interfaz y de la proteina mutante p53 en especímenes quirúrgicos fijados rutinariamente en parafina provenientes de 180 pacientes con cáncer mamario con perfiles conocidos de DNA nuclear. El periodo promedio de seguimiento clínico fue 16 años (13–20 años). El porcentaje de núcleos de células tumorales inmunoreactivos a PCNA osciló entre 〈5% a 60% (valor medio 13.59±10.85). Se encontró una relación directa entre los altos niveles de expresión de PCNA (〉 20%) y sobreexpresión de proteína p53 (P=0.001), un alto grado histológico en el tumor (P=0.009) y aneuploidia de DNA (P=0.019). Se encontró sobreexpresión de proteína p53 en 44 de 180 (24%) casos y con relación significativa con el alto grado histológico tumoral (P=0.004), aneuplodia de DNA (P=0.001) y altos niveles de expresión de PCNA (P=0.001). Las pacientes con carcinomas muy proliferativos (expresión de PCNA〉20%) exhibieron una más corta sobrevida libre de metástasis a distancia cuando su tumor presentó sobreexpresión de p53. En contraste, la sobrevida libre de metástasis distantes en pacientes con tumores altamente proliferativos y p53 negativos apareció significativamente prolongada (P=0.03). Por consiguiente, la sobreexpresión de proteína p53 parece ser un indicador de un incrementado potencial de malignidad en pacientes con cáncer mamario. Los tumores altamente proliferativos, compuestos de céluls neoclásicas inmunoreactivas a p53 parecen tener un comportamiento clínico más agresivo en comparación con los tumores altamente proliferativos pero p53 negativos.
    Notes: Abstract An increasing body of evidence suggests that in addition to conventional histopathologic tumor characteristics, DNA content measurements, cell kinetic data, and investigatios of tumor suppressor gene expressions might be of valuable information in breast cancer patients. Against this background we investigated immunohistochemically overexpression of the interphase associated protein proliferating cell nuclear antigen (PCNA) and the mutant p53 protein in routinely paraffin-embedded surgical specimens from 180 breast cancer patients with known nuclear DNA profiles. The mean clinical follow-up was 16 years (range 13–20 years). The percentage of PCNA immunoreactive tumor cell nuclei ranged between 〈5% and 60% (mean 13.59±10.85%). There was a direct association between high levels of PCNA expression (〉20%) and p53 protein overexpression (p=0.019). Mutant p53 protein overexpression was found in 44 of 180 (24%) cases and was significantly related to high histologic tumor grade (p=0.004), DNA aneuploidy (p=0.001), and high levels of PCNA expression (p=0.001). Patients with highly proliferative carcinomas (〉20% PCNA expression) had a shortened distant metastases-free survival when their neoplasms overexpressed p53. In contrast, the distant metastases-free survival of patients with highly proliferative, p53-negative tumors was significantly longer (p=0.03). Immunohistochemical p53 protein overexpression thus appears to be indicative of an increased malignant potential in breast cancer patients. Highly proliferative tumors composed of p53 immunoreactive neoplastic cells clinically seem to behave more aggressively than the highly proliferative p53-negative tumors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé La valeur pronostique de l'ADN (DNA) nucléaire en cas de cancer papillaire de la thyroïde a été étudiée chez 90 malades. Quatre-vingts des opérés ont survécu plus de 10 ans mais 10 moururent entre 6 mois et 12 ans après le diagnostic. Les données cliniques aussi bien que les caractères histologiques des lésions furent étudiés. La mesure de l'ADN (DNA) sur les cellules tumorales fut pratiquée soit après biopsie aspiration à l'aiguille fine, soit sur la coupe histologique. Les tumeurs des malades qui survécurent étaient constituées par des cellules dont le taux d'ADN (DNA) était comparable à celui des cellules normales, alors que les cellules des malades qui mouraient présentaient un taux d'ADN (DNA) significativement plus élevé. Cette étude suggère que la mesure de l'ADN (DNA) en présence d'un cancer papillaire de la thyroïde constitue un appoint utile aux données classiques de la clinique et de l'histologie.
    Abstract: Resumen El análisis del contenido de DNA en carcinoma prostático, carcinoma mamario y condrosarcoma ha sido demostrado como una mejor guía de pronóstico que los exámenes clínicos y microscópicos convencionales. El propósito de este estudio fue el de evaluar si la determinación del contenido de DNA puede significar un parámetro confiable de pronóstico en pacientes con carcinoma papilar de tiroides. El valor pronóstico del contenido nuclear de DNA en el carcinoma papilar fue estudiado retrospectivamente en 90 pacientes. Ochenta sobrevivieron por no menos de 10 años, y 10 fallecieron de carcinoma papilar entre 6 meses y 12 años después de efectuado el diagnóstico. Los datos clínicos y las características morfológicas del tumor fueron analizados. Las determinaciones de DNA en células únicas morfológicamente identificadas fueron hechas sobre material de aspiración con aguja fina o sobre secciones histológicas. Los tumores de los supervivientes aparecieron compuestos por células con un contenido de DNA comparable al de las células normales, en tanto que los tumores de los pacientes que no sobrevivieron presentaron valores de DNA considerablemente más altos. Estos datos sugieren que las determinaciones de DNA en el carcinoma papilar significan un valioso parámetro de pronóstico adyuvante del análisis clínico y microscópico ordinario, puesto que existe una correlación entre la supervivencia y el contenido de DNA de las células tumorales. La hemitiroidectomía puede ser una forma adecuada de tratamiento en pacientes con tumor unilateral y medición de DNA que indique un pronóstico favorable, en tanto que los pacientes, aún aquellos con un tumor muy pequeño, en quienes las determinaciones de DNA indiquen un pronóstico pobre, pueden exigir una forma más agresiva de tratamiento.
    Notes: Abstract The prognostic value of nuclear DNA content in papillary thyroid carcinoma was studied retrospectively in 90 patients. Eighty survived for at least 10 years, and 10 died, of papillary thyroid carcinoma, between 6 months and 12 years after diagnosis. Clinical data as well as morphological tumor characteristics were examined. DNA measurements in morphologically identified single tumor cells were performed either on fine-needle aspiration material or on histologic sections. The tumors of the survivors were composed of cells with a DNA content comparable to that of normal cells, whereas the tumors of the non-survivors had significantly higher DNA values. The data suggest that DNA measurements in papillary thyroid carcinoma offer a valuable adjunct to standard clinical and microscopic analysis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1572-9931
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Rat embryo fibroblasts (REFs) are inefficiently transformed by RAS-oncogenes. Induction of p16 INK4A expression by RAS has been suggested to contribute to this resistance. Glucocorti-coid hormones, (DEX), enhance REF transformation by RAS and facilitates the isolation of transformed and immortal cell lines. We show that DEX induced cell proliferation is paralleled by a decrease in Cdkn2a gene transcripts, suggesting a mechanism for hormone promotion. The mechanisms of progression into hormone independent cell lines were examined. Twenty-two of 30 clones which reached a population size of approximately 10 6 cells could be established as cell lines. All lines studied showed homozygous deletions of the Cdkn2 loci (Cdkn2a and Cdkn2b) on RNO5. LOH was found for all RNO5 genetic markers examined in 7 of 19 cell lines, suggesting non-disjunction events. In the remaining 12 cell lines, both copies of Cdkn2 appeared to be lost by deletions/rearrangements, some of which could by demonstrated by karyotype analysis. We conclude that (i) clonal expansion of RAS-transfected REF by DEX is paralleled by down-regulation of Cdkn2a expression; (ii) homozygous deletion of Cdkn2 were estimated to occur at a frequency of 2 × 10 −8 /cell/generation or higher, and (iii) deletion/rearrangements and non-disjunction appear to be the main mechanisms leading to deletion of Cdkn2.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 108 (1981), S. 365-373 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Several studies indicate that glutamine is a critical requirement for cell growth in vitro. Growing and quiescent (serum-starved) 3T3-fibroblasts were exposed to media (Dulbecco's modified Eagle's minimal essential medium) in which the concentration of the 13 essential amino acids had been lowered to 1/100 or 1/1,000 of that in DMEM - either all together or one by one. The effects on DNA synthesis were measured by autoradiographic determinations of the percentage of labeled cells after 24 hours exposure to 3H-thymidine. A reduction of all 13 essential amino acids to 1/100 or 1/1,000 of the normal concentration in the medium resulted only in a minor growth inhibitory effect during the first cell cycle. A similar growth inhibitory effect was caused by the depletion of one of the 13 essential amino acids (except glutamine) from the medium. However, a depletion of glutamine from the medium resulted in a marked inhibition of growth. Conversely, a relative excess of glutamine, when the other 12 amino acids were lowered to 1/1,000 of the normal concentration, counteracted the growth inhibitory effect of serum starvation. It was even possible to stimulate quiescent cells to undergo DNA synthesis by exposing them to a serum-depleted (0.5% serum) medium with a relative excess of glutamine.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 233-241 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Previous studies indicate that glutamine is a critical requirement for cell proliferation in vitro. We recently showed that depletion of glutamine from the cuture medium supporting growing cells significantly reduced the proportion of cells undergoing DNA synthesis. Similarly glutamine depletion significantly reduced the stimulatory response of quiescent cells to 10% serum. This study shows that the inhibitory effects of depletion of glutamine - in either of these two situations - can be overcome by the addition of adenine or adenosine. Adenine was the only nitrogen base and adenosine was the only nucleoside for which this effect was observed. Such effects could, however, also be achieved by addition of the purine metabolites hypoxantine and inosine. Furthermore, it was found that glutamine (or adenine/adenosine) is only required during a limited interval coinciding with the late part of the G1-phase and the beginning of S-phase. These data suggest the possibility that glutamine exerts its main regulatory effects on cell proliferation by acting as a precursor for adenine and adenosine.
    Additional Material: 9 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, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 127 (1986), S. 267-273 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Proliferating nonconfluent 3T3 cells become committed to proceed through the cell cycle or to enter G0 during the first post-mitotic part of G1 (G1pm). The decision to proceed through G1pm is dependent on the presence of serum growth factors in the culture medium. Cells that have passed this particular growth-factor-dependent cell cycle stage are independent of serum growth factors and undergo mitosis on schedule. We report here that G1ps, S, and G2 cells cease to increase in size when serum is withdrawn. As a result the mitotic cell size after 8 hours serum starvation is reduced to approximately 60% of the normal mitotic cell. This reduced growth in cell size is due to a rapid decrease in protein synthesis and some increase in protein degradation. This dissociation between growth in size and cell-cycle progression within a single cell cycle provides a new approach to study the two processes separately.
    Additional Material: 5 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
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 129 (1986), S. 94-102 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effect of inhibition of 3-Hydroxy-3-methylglutaryl Coenzyme A reductase (HMG CoA reductase) on cell cycle progression in proliferating 3T3 cells was studied. It was found that short transient exposures to the HMG CoA reductase inhibitor 25-hydroxycholesterol temporarily blocked the cell cycle traverse in the postmitotic half of G1 (G1 pm), whereas cells in the subsequent cell cycle phases were unaffected. The kinetics of the cell cycle delay, induced by 25-hydroxycholesterol, resembled the kinetics of the delay induced by serum depletion, which also inhibited the activity of HMG CoA reductase. In contrast to the case of serum depletion, platelet derived growth factor (PDGF), which efficiently prevented the decrease of HMG CoA reductase in serum-free medium, was not capable of preventing the growth inhibitory effect following treatment by 25-hydroxycholesterol. However, cholesterol and two isoprenoids, dolichol and coenzyme Q, were effective in this respect. In addition, dolichol counteracted the cell cycle delay following short periods of serum starvation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 132 (1987), S. 295-302 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Quiescent serum-starved 3T3 cells can be stimulated to initiate DNA synthesis after addition of conditioned media from spontaneously tumor-transformed 3T3 cells (3T6-cells) or from SV-40-transformed 3T3 cells (SV-3T3 cells). The conditioned media were found to stimulate both the chromosome cycle (i.e, DNA synthesis and cell division) and the growth cycle (i.e., cellular enlargement). Furthermore, addition of conditioned media to quiescent 3T3 cells increased the activity of HMG CoA reductase - an enzyme previously proposed to exercise some control on cell proliferation in 3T3 cells Larsson and Zetterberg: J. Cell. Physiol. 129:99-102, 1986. The increased activity of HMG CoA reductase after treatment with tumor cell conditioned media was correlated to the stimulatory effects on DNA synthesis. By treating 3T3 cells stimulated to resume proliferation by addition of conditioned media with mevinolin (a competitive inhibitor of HMG CoA reductase) the activity of HMG CoA reductase as well as the DNA synthesis and cell division were efficiently inhibited. In contrast, HMG CoA activity was not coupled to the cellular enlargement. Therefore, it is proposed that one set of factors present in tumor cell conditioned media preferentially stimulates the chromosome cycle by increasing the HMG-CoA reductase activity, whereas another set of factors is responsible for growth in cell size. Both types of factors are required for balanced growth.
    Additional Material: 6 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...