FRACTAL DIMENSION FOR A CANCER INVASION MODEL

Fractals ◽  
2001 ◽  
Vol 09 (01) ◽  
pp. 61-76 ◽  
Author(s):  
H. AHAMMER ◽  
T. T. J. DEVANEY ◽  
H. A. TRITTHART

A long-established investigation method for in vitro cancer invasion using cancer cell spheroid and normal cell spheroid confrontation for the quantitative determination of invasion was expanded to make use of fractal methods. The box-counting method, the sausage method and a local method were used in comparison with image pre-processing steps such as median filtering, closing and opening, or hole filling and scrapping, and artificially added noise images. It was possible to examine the potential role of the fractal capacity dimension for this invasion model. Several aspects such as the absolute value and variance of the different methods were taken into account and compared to well established quantitative parameters. The fractal approach led to very promising results which improved the determination and examination of the invasion process of cancer.

Fractals ◽  
2009 ◽  
Vol 17 (02) ◽  
pp. 171-180
Author(s):  
R. UTHAYAKUMAR ◽  
G. JAYALALITHA

In this paper we study a model of skin cancer (MM) in vitro, using geometry of fractals as the method of analysis. The fractal dimensions of moles (skin cancer cells) growth pattern have been measured by using the methods of Box-counting method (DB) and Sausage method (DS). The cell growth of this cancer can be modeled by Hidden Markov model (HMM) and percolation model which are depending upon the time complexity. From these models we can find the shape of the irregularity border by using the probability distribution of the cells. The variation in the irregular border of the skin cancer has been found out using ANOVA test and cell's compactness. The fractal approach led to very promising results which improved the determination and examination of the stage of skin cancer.


1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.


2021 ◽  
pp. 1-9
Author(s):  
Etsuo Niki

Reactive oxygen and nitrogen species have been implicated in the onset and progression of various diseases and the role of antioxidants in the maintenance of health and prevention of diseases has received much attention. The action and effect of antioxidants have been studied extensively under different reaction conditions in multiple media. The antioxidant effects are determined by many factors. This review aims to discuss several important issues that should be considered for determination of experimental conditions and interpretation of experimental results in order to understand the beneficial effects and limit of antioxidants against detrimental oxidation of biological molecules. Emphasis was laid on cell culture experiments and effects of diversity of multiple oxidants on antioxidant efficacy.


Development ◽  
1993 ◽  
Vol 117 (3) ◽  
pp. 835-845 ◽  
Author(s):  
K. Kawamura ◽  
K. Hara ◽  
S. Fujiwara

We have extracted retinoids from the budding tunicate Polyandrocarpa misakiensis and, using HPLC, identified some major peaks as cis-retinal, all-trans-retinal and all-trans-retinoic acid, of which cis-retinal was most abundant (~2 micromolar). In developing buds, the amount of cis-retinal was about one-fifth that of the adult animals. In those buds, aldehyde dehydrogenase, which could metabolize retinal in vitro, was expressed in epithelial cells and then in mesenchymal cells at the proximal extremity, that is, the future developmental field of the bud. Exogenous retinoic acid comparable to the endogenous level could induce an additional field at the distal end of the bud, resulting in a double monster. The induction always accompanied an ectopic expression of aldehyde dehydrogenase. The results of this work suggest that retinoic acid or related molecule(s) act as an endogenous trigger of morphallactic development of Polyandrocarpa buds.


1957 ◽  
Vol 189 (2) ◽  
pp. 301-306 ◽  
Author(s):  
Nicholas M. Papadopoulos ◽  
Joseph H. Roe

The role of phosphorylation in the absorption of fructose from the intestinal tract of the fasted rat by in vitro and in vivo techniques was studied. The authors' method for the determination of fructose phosphate esters was used and these esters were identified by paper chromatography and copper reduction techniques. Buffered homogenate of intestinal mucosa of a fasted rat, mixed with ATP, MgCl2, KF and fructose, when incubated at 30°, showed the formation of fructose-6-phosphate and fructose-1, 6-diphosphate at a rate that corresponded to the decrease in free fructose. The same homogenate, mixed with fructose-1, 6-diphosphate and incubated at 37°, showed the formation of fructose-6-phosphate and free fructose at a rate that corresponded to the decrease in the concentration of the diphosphate ester. Following intraduodenal injection of fructose solution into anesthetized fasted rats, homogenates of the intestinal mucosa showed the presence of fructose-6-phosphate and fructose-1, 6-diphosphate in average concentrations 14 and 5 times, respectively, those found in control muocsa, also concentrations of free fructose in the blood of the portal vein up to 24.6 mg % were observed. The large increase in fructose phosphate esters in the intestinal mucosa, observed after fructose administration, suggests that phosphorylation of sugars in absorption serves a more extensive function than to initiate glycolysis for the normal metabolism of the mucosal cells. The data obtained suggest that phosphorylation and dephosphorylation are functional steps in the absorption of fructose from the alimentary tract of the rat.


1987 ◽  
Author(s):  
J M Walenga ◽  
J Fareed ◽  
M Petitou ◽  
J C Lormeau ◽  
M Samama ◽  
...  

We have previously reported on the antithromboticaction of a chemically synthesized heparin pentasaccharide which exhibits high affinity to anti thrombinIII and sole anti-factor Xa activity. In order to investigate the relative importance of the 3-0 sulfo group of this pentasaccharide, we evaluated the in vitro and in vivo antithrombotic activity of a synthetic pentasccharide devoid of the sulfo group at the third position of the glucosamine residue. In amidolytic and clot-based assays the 3-0 de- sulfated pentasaccharide (3-0-DP) failed to exhibit any antifactor Xa actions at concentrations <100 ug/ml in humanor rabbit plasmas, whereas pentasaccharide showed strong factor Xa inhibition at 1.0 ug/ml IK-=3.2x10 M)and at 10.0 ug/ml in rabbit plasma (K.=9.0×10™7 M). Using a rabbit stasis thrombosis model in which thrombosis was induce by human serum or an activated pro-thrombin complex concentrate, 3-0-DP failed to produce any antithrombotic action in acute intravenous regimens at dosages up to 200 ug/kg. In these two models, pentasaccharide produced >80% inhibition of induced thrombosis. These studies demonstrate the critical importance of the 3-0 sulfo group in this heparin pentasaccharide for the determination of antithrombotic activity, and that in this type of oligosaccharide, anti-factor Xa activity is responsible for producing the antithrombotic effect.


1987 ◽  
Vol 114 (2) ◽  
pp. R1-R4 ◽  
Author(s):  
R.G. Forage ◽  
R.W. Brown ◽  
K.J. Oliver ◽  
B.T. Atrache ◽  
P.L. Devine ◽  
...  

ABSTRACT Seven Merino–Border Leicester cross–bred ewes were immunized with a purified fusion protein, produced by recombinant DNA methods, of the a subunit of bovine inhibin. Four animals were immunized with the fusion protein alone and three with a conjugate made by coupling the fusion protein to keyhole limpet haemocyanin (KLH) using glutaraldehyde. Each animal received four injections of the fusion protein over 93 days. The animals were synchronized using progestagen sponges and subjected to laparoscopy for the determination of ovulation rates in two consecutive cycles (days 115 and 135). The immunized animals had overall mean ovulation rates for each cycle of 3.4 and 3.4 which was significantly (P < 0.001) above the rates of 1.1 and 1.4 determined for the controls, which had either received no treatment (n=5) or had been immunized with 300 μg KLH (n=4). Analysis of antisera taken on day 115 showed significant fusion protein antibodies and iodinated inhibin–binding capacity in the test but not control groups. Furthermore, antisera to the fusion protein in four out of seven ewes neutralized the inhibin bioactivity of ovine follicular fluid in an in–vitro bioassay. These data demonstrate that neutralization of inhibin can be effected by immunization with bovine inhibin a subunit and that such immunization results in increased ovulation rates as predicted from the biological role of inhibin as a suppressor of FSH.


2002 ◽  
pp. 1482-1486 ◽  
Author(s):  
ADAM JONES ◽  
CHISATO FUJIYAMA ◽  
KEVIN TURNER ◽  
DAVID CRANSTON ◽  
KAYE WILLIAMS ◽  
...  

Blood ◽  
1971 ◽  
Vol 37 (4) ◽  
pp. 463-472 ◽  
Author(s):  
SEYMOUR WERTHAMER ◽  
LEONARD AMARAL

Abstract Lymphocytes obtained from patients with chronic lymphocytic leukemia (CLL) respond to the in vitro presence of cortisol by depressed incorporation of precursors into RNA and protein. The decreased incorporation of uridine into RNA is the sum of (1) an inhibition in the synthesis of RNA and (2) an enhanced destruction of newly synthesized RNA. Whereas cortisol was not dependent upon plasma for the manifestation of the above effects, the presence of plasma was an absolute requirement in order for cortisol to have an inhibitory effect on the synthesis of protein. A comparison of leukemic and normal lymphocytes demonstrated that the magnitude of inhibition of precursors into RNA and protein was greater in leukemic cells. Because it is believed that the plasma factor required is transcortin, determination of transcortin levels by cortisolbinding gel filtration technics were performed. These indicated that transcortin levels of CLL plasma were about 50 per cent lower than that of the normal. Consequently, further experiments involving type-specific plasma substitutions were performed. The results obtained from these experiments indicated that the magnitude of the effect of cortisol on the synthesis of lymphocyte protein was directly related to the transcortin level of the plasma employed.


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