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R Kiss

Publications and source records attributed to R Kiss.

At least 19 recordsLinked to original sources

Dynamic characterization of glioblastoma cell motility.

The cell motility dynamic of two glioblastoma cell lines (U373 and U87) was studied by means of an automatic video-cell-tracking-system enabling each cell in a colony to be tracked for several hours. Twenty-five experiments were performed on both models growing on three different supports (glass, plastic and Matrigel). Cell motility was significantly different in each cell line and also for different growth support in a given cell line. We observed that U87 cells are significantly (p < 0.00001) less motile than U373 cells. The most favorable growth supports for cell motility studies were Matrigel and glass. A significant (p < 0.001) correlation between cell colony density and cell motility was highlighted, with isolated cells exhibiting a motility level distinct from the one observed for colonies. The present methodology, which enabled cell motility to be quantified in human glioblastoma cells, represents an original tool for identifying new classes of compounds able to reduce glioblastoma cell motility and cell migration potential into the brain.

Cell Count

In vivo characterization by means of digital cell image analysis of early-induced fractionated radiotherapy effects on the MXT mouse mammary tumor.

PURPOSE: To study the cell kinetics and chromatin modifications occurring in function of the fractionated irradiation administered to the MXT mouse mammary adenocarcinoma. METHODS AND MATERIALS: The MXT tumor cells were submitted to three fractions of a 4.8 Gy dose delivered at 24-h intervals. MXT tumor cells were collected by means of fine needle aspirations (between 5 and 10 samples were obtained after each irradiation) during treatment and submitted to the computer-assisted microscope analysis of Feulgen-stained specimens. Three groups of parameters has been described: i.e., the geometry of the nucleus, the nuclear DNA content, and the chromatin texture. Furthermore, cell cycle parameters were studied in the aim to know the distribution of the cells within the cell cycle. RESULTS: The mean values relating to geometric parameters (i.e., the nuclear area and its standard deviation) decreased during treatment. Variations in the nuclear DNA content appeared as being cyclical and could be explained in terms of the modifications in the distribution of the cells within the cell cycle. The quantitative analysis of the cell cycle parameters revealed that the percentage of S cells increased regularly after each irradiation. In contrast, the percentage of G2 cells decreased between each irradiation. The parameters describing nuclear texture showed regular variations between each irradiation. These variations consisted in two cycles constituted by a decrease in chromatin condensation, followed by an increase. CONCLUSIONS: The development of the geometric parameters indicates that fractionated radiotherapy leads to the emergence of a more homogeneous population. The effects of the radiotherapy on the distribution of the cells within the cell cycle could be explained through the phenomenon of repopulation and by the high degree of radiosensitivity of the G2 cells (decrease in the percentage of G2 cells). Last, the variations observed at chromatin pattern level could be explained through DNA repair processes.

Animals

Coregulatory effects of epidermal growth factor, dihydrotestosterone, and prolactin on benign human prostatic hyperplasia tissue culture proliferation.

BACKGROUND: A variety of hormones have demonstrated effects on prostatic tissue growth dynamics. Our goal was to define the effect of dihydrotestosterone (DHT), epidermal growth factor (EGF), and prolactin (PRL) on prostate cellular proliferation. METHODS: Thirty benign human prostatic hyperplasias (BPH) were maintained 48 hr as in vitro cultures. Culture media were supplemented with EGF, DHT, and PRL alone and in combinations. Proliferation was assessed by labeling with tritiated thymidine. RESULTS: The proliferative response of individual BPH cultures was heterogeneous. DHT and EGF tended to have a greater proliferative effect than PRL, both in terms of the percent cultures responding and the magnitude of the response. PRL antagonized EGF-induced proliferative effects. EGF- and PRL-mediated effects correlated with each other, while DHT-mediated effects did not correlate with either those of PRL or EGF. CONCLUSIONS: The proliferative response of individual BPH to DHT, EGF, and PRL, alone or in combination, is too variable to define a predictable response to their influence. Our methodology represents a technique with the capacity to define therapeutic potential for individual cases.

Aged

Objective measurement of the different collagen types in the corpus cavernosum of potent and impotent men: an immunohistochemical staining with computerized-image analysis.

Quantitative measurements of the collagen types (I, II, and IV) in the corpora cavernosa of potent and impotent men were carried out to investigate whether quantitative immunohistochemistry might contribute additional information as to the cause of erectile dysfunction. The study group consisted of 22 men with various etiologies of impotence and 4 normal, potent men. The quantitative immunohistochemistry measurements were performed by means of a cell-image processor. Three variables for each of the three types of collagen were studied, namely, the mean optical density (MOD), which relates to histochemical staining intensity; the labeling index (LI), which is positively related to the percentage of immunostaining; and the quick score (QS) index, which takes into account both LI and MOD values. None of the quantitative parameters taken individually (monovariate statistical analyses) made it possible to obtain any statistically significant difference between the types of collagen of the group under study. The mean QS value recorded for collagen type IV was significantly lower than that noted for collagen type I in the psychogenic (P = 0.019), arteriogenic (P = 0.012), and venogenic (P = 0.001) groups, whereas the MOD value was significantly lower in the normal (P = 0.043), arteriogenic (P = 0.013), and venogenic (P = 0.001) groups but not in the psycogenic group. The mean MOD of collagen type III was intermediate between that of the other types. In contrast, the mean LI value recorded for collagen type IV was significantly lower only in the venogenic (P = 0.032) and psychogenic (P = 0.049) groups as compared with the other groups. No objective qualitative change in the collagen types was observed that could be correlated to the etiology of erectile dysfunction. The significant difference seen in the quantitative parameters with regard to collagen type IV and the observed increase in the type I/III collagen ratio might attest to the notion that the response of the erectile tissue to ischemia is similar to that of other organs. The net effect of these changes is a restricted capacity for corporal expansion and alteration of the veno-occlusive mechanism.

Adult

Determination of the mechanism of action of anticancer drugs by means of the computer-assisted microscope image analysis of Feulgen-stained nuclei.

The antitumoral effects of 30 drugs was monitored in vitro on three neoplastic cell lines. These 30 drugs belonged to various pharmacological classes which included alkylating agents, antimetabolites, Vinca alkaloids, topoisomerase II inhibitors, and intercalating agents. The aim of the present work is to use the same methodology to characterize the drug-induced effects at several biological levels. The drug-induced modifications were, therefore, monitored by means of the digital cell image analysis of Feulgen-stained nuclei. This methodology enabled the cell cycle kinetics to be studied. Furthermore, the numerical data quantitatively describing chromatin patterns were submitted to multivariate (principal-components) analyses, with the canonical transformation of the data. Statistical analysis shows that each pharmacological class of anticancer drugs induces specific modifications to the chromatin patterns. The present study, therefore, shows that it is possible to identify distinct classes of antineoplastic drugs on the basis of their mechanisms of action by means of the quantitative chromatin pattern description of Feulgen-stained nuclei.

Animals

Lectin histochemistry of astrocytic tumors and in vitro characterization of lectin-induced modifications on the proliferation of the SW1088, U373 and U87 human astrocytic cell lines.

The role of lectins as biosignalling molecules or as markers of human astrocytic tumors remains relatively unexplored. The aim of the present work is to investigate (1) whether or not human astrocytic tumors express specific glycans, evidenced experimentally by means of lectin histochemistry, and (2) whether, in turn, these lectins can significantly modulate astrocytic tumor cell proliferation. Using a cell image processor, we therefore began by quantitatively measuring the histochemical binding pattern of 5 lectins (WGA, PNA, PHA-L, GSA-IA4 and Con A) in 5 astrocytomas, 5 anaplastic astrocytomas and 5 glioblastomas. Secondly, we measured the influence of these 5 lectins on the proliferation of 3 astrocytic tumor cell lines (SW1088, U373 and U87) growing in vitro as monolayers. Cell proliferation was assessed by means of the colorimetric MTT assay. The histochemical lectin staining markedly varied intra- and inter-group. However, some constant results were obtained. Indeed, the staining increased markedly from GSA-IA4 and PHA-L through WGA and PNA to ConA in the three histopathological groups. The assessment of cell proliferation demonstrated that WGA, Con A and PHA-L very significantly decreased proliferation in the 3 astrocytic cell lines in a dose-dependent manner. Astrocytic tumor cells in the confluent growth phase were less sensitive to the WGA, Con A and PHA-L lectin-induced effects than cells in the log growth phase. The GSA-IA4 and PNA lectins had globally very weak effects on the proliferation of the astrocytic tumor cell lines. Increasing the fetal calf serum from 1% to 10% in the culture media significantly antagonized the WGA-, Con A- and PHA-L-induced cell proliferation decrease in the 3 astrocytic cell lines. In conclusion, the present data strongly suggest that some lectins (including WGA, Con A and PHA-L) significantly influence the proliferation of astrocytic tumor cells.

Analysis of Variance

The combined determination of proliferative activity and cell density in the prognosis of adult patients with supratentorial high-grade astrocytic tumors.

Tumor growth represents the ratio between cell gain (number of mitoses per unit of time, i.e., proliferative activity) and cell loss (number of cell deaths during the same unit of time). While in adults, proliferative activity parallels the level of malignancy in astrocytic tumors and therefore represents a useful diagnostic marker, cell loss has never been concomitantly assessed in tumors of this type. We hypothesize that cell density assessable on histologic slides represents the ratio between cell gain and cell loss. This hypothesis concerns only the diffuse type of astrocytic tumors. Proliferative activity (assessed by MIB1 antigen immunostain) and cell density were thus quantitatively assessed by means of a cell image processor in a series of 54 supratentorial astrocytic tumors of adult patients, which included 15 astrocytomas (ASTs), 18 anaplastic astrocytomas (ANAs), and 21 glioblastomas (GBMs). The results show that proliferative activity and cell density were highly correlated (P = .003) and that both correlated with histopathologic grade. The patients with a high-grade astrocytic tumor (i.e., ANA or GBM) that exhibited a low level of proliferative activity but high cell density survived for significantly shorter periods than did patients with a tumor that exhibited low proliferative activity and low cell density (P = .002). The patients with a high-grade astrocytic tumor that exhibited high proliferative activity and high cell density survived for significantly less time than did the patients with a tumor that exhibited high proliferative activity but low cell density (P < .05). A marked difference in survival periods was observed between the patients with a high-grade astrocytic tumor that exhibited a low level of proliferative activity and low cell density and the patients with a tumor that exhibited a high level of proliferative activity and high cell density (P < .001). The concomitant determination of proliferative activity and cell density seems likely to enable determination of the few adult patients who have high-grade astrocytic tumors and who will survive for a considerable period (several years).

Adolescent

Quantitative chromatin pattern description in Feulgen-stained nuclei as a diagnostic tool to characterize the oligodendroglial and astroglial components in mixed oligo-astrocytomas.

The oligoastrocytoma, as a mixed glioma, represents a nosologic dilemma with respect to precisely defining the oligodendroglial and astroglial phenotypes that constitute the neoplastic cell lineages of these tumors. In this study, cell image analysis with Feulgen-stained nuclei was used to distinguish between oligodendroglial and astrocytic phenotypes in oligodendrogliomas and astrocytomas and then applied to mixed oligoastrocytomas. Quantitative features with respect to chromatin pattern (30 variables) and DNA ploidy (8 variables) were evaluated on Feulgen-stained nuclei in a series of 71 gliomas using computer-assisted microscopy. These included 32 oligodendrogliomas (OLG group: 24 grade II and 8 grade III tumors according to the WHO classification), 32 astrocytomas (AST group: 13 grade II and 19 grade III tumors), and 7 oligoastrocytomas (OLGAST group). Initially, image analysis with multivariate statistical analyses (Discriminant Analysis) could identify each glial tumor group. Highly significant statistical differences were obtained distinguishing the morphonuclear features of oligodendrogliomas from those of astrocytomas, regardless of their histological grade. When compared with the 7 mixed oligoastrocytomas under study, 5 exhibited DNA ploidy and chromatin pattern characteristics similar to grade II oligodendrogliomas, I to grade III oligodendrogliomas, and I to grade II astrocytomas. Using multifactorial statistical analyses (Discriminant Analysis combined with Principal Component Analysis). It was possible to quantify the proportion of "typical" glial cell phenotypes that compose grade II and III oligodendrogliomas and grade II and III astrocytomas in each mixed glioma. Cytometric image analysis may be an important adjunct to routine histopathology for the reproducible identification of neoplasms containing a mixture of oligodendroglial and astrocytic phenotypes.

Adult

In vitro influence of Phaseolus vulgaris, Griffonia simplicifolia, concanavalin A, wheat germ, and peanut agglutinins on HCT-15, LoVo, and SW837 human colorectal cancer cell growth.

BACKGROUND/AIMS: Compared with normal colonic mucosa, lectin receptor expression is increased in hyperplastic and neoplastic tissues; some lectins have been shown to influence human colonic epithelial cell proliferation. The aim was to assess further the influence of five lectins (Phaseolus vulgaris (PNA), Griffonia simplicifolia (GSA), concanavalin A (Con A), wheat germ (WGA), and peanut (PHA-L) agglutinins) on cellular growth in three human colorectal cancer cell lines (LoVo, HCT-15 and SW837). METHODS: Cells were cultured in four lectin concentrations (0.1, 1.0, 10, and 100 micrograms/ml) and growth assessed at days 2, 3, 5, and 7. The experiments were performed in media supplemented with either 1% or 10% fetal calf serum (FCS). Growth was assessed using the MTT (3-(4,5)-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) colorimetric assay. RESULTS: Growth in each cell line was greatly affected by at least two of the lectins tested. There was some variation in the effect of a given lectin on different cell lines. Lectin effects showed a dose-response and the greatest effects generally resulted from the highest concentrations at the longest culture time. WGA and Con A induced large effects in all cell lines; the effects of Con A were partly blocked by the higher concentration of FCS. PNA had modest and uniform stimulatory effects overall. The effects of GSA and PHA-L varied between cell lines. CONCLUSIONS: The lectins studied all have the potential to affect colonic cancer growth in vitro. Many dietary lectins are resistant to digestion and may have important effects in vitro but the definition of their role in human colonic cancer biology must take into account the variability in lectin response.

Cell Division

Plasma dehydroepiandrosterone sulfate levels in patients with hyperfunctioning and non-hyperfunctioning adrenal tumors before and after adrenal surgery.

To investigate the clinical significance of plasma dehydroepiandrosterone sulfate (DHEAS) measurements, 175 patients with histologically confirmed adrenal tumors, 10 cortisol-producing adenomas, 59 aldosterone-producing adenomas, 56 non-hyperfunctioning adenomas, 13 adrenocortical carcinomas, 13 adrenal cysts, and 24 adrenomedullary tumors were studied. Plasma DHEAS levels were expressed as percentage of the mean of sex- and age-matched groups of healthy, normal subjects (DHEAS %). We found that before adrenal surgery, DHEAS % values were significantly reduced in patients with cortisol-producing (mean, 15.2% of control; 95% confidence interval (CI), 9.4-24.7%), non-hyperfunctioning (28.4%; 22.4-36.0%) as well as aldosterone-producing adrenocortical adenomas (55.4%; 47.1-65.1%) compared with controls, while values were normal in patients with adrenal cysts and in those with adrenomedullary tumors. Plasma DHEAS % values exhibited a great variability in adrenocortical carcinomas (mean, 84.0%; 95% CI, 33.2-212.5%). Death from adrenocortical carcinoma was more frequent in patients with high plasma DHEAS % values compared with those with low DHEAS %. During long-term postoperative monitoring, we found that plasma DHEAS levels of patients with aldosterone-producing and non-hyperfunctioning adenomas returned to normal in the second and fourth postoperative year respectively. In patients with cortisol-producing adenomas, plasma DHEAS remained suppressed for as long as 8 years after the operation. These findings show that except in adrenocortical carcinomas and cysts, plasma DHEAS levels are significantly decreased in all groups of adrenocortical tumors, including non-hyperfunctioning and aldosterone-producing tumors. The extent of this decrease and the postoperative persistence of suppressed plasma DHEAS levels may be related to the glucocorticoid production of adrenocortical tumors.

Adenoma

Nearest-neighbor classification for identification of aggressive versus nonaggressive low-grade astrocytic tumors by means of image cytometry-generated variables.

The authors investigated whether cytometry-related variables generated by means of computer-assisted microscopic analysis of Feulgen-stained nuclei can contribute significant information toward the characterization of low-grade astrocytic tumor aggressiveness. This investigation was conducted using the nearest-neighbor rule (a traditional classification method used in pattern recognition) to analyze a series of 250 supratentorial astrocytic tumors from adult patients. This series included 39 low-grade astrocytomas and 211 high-grade astrocytic tumors (including 47 anaplastic astrocytomas and 164 glioblastomas multiforme [GBMs]). The results show that the 3-nearest-neighbors rule enabled a subgroup of "atypical" astrocytomas to be distinguished from the "typical" tumors. The atypical astrocytoma species exhibited a DNA content (DNA ploidy level) and morphonuclear characteristics that were statistically more similar to the characteristics of GBMs than to those exhibited by the typical astrocytomas. An analysis of survival data revealed that patients with atypical astrocytomas survived for a significantly shorter period (p < 0.001) than patients with typical lesions of this kind. In fact, patients with atypical astrocytomas had a survival period similar to that of patients with anaplastic astrocytomas, whereas patients with typical astrocytomas had a survival period significantly longer (p < 0.0001) than those associated with anaplastic astrocytomas and GBMs.

Adolescent

Decision tree induction: a useful tool for assisted diagnosis and prognosis in tumor pathology.

The aim of the present work is to show that decision tree induction algorithms are a useful tool for extracting reliable information from data series, with the objective of assisting pathologists in identifying specific diagnostic and prognostic markers in various types of tumor pathologies. In terms of accuracy, we show that the decision tree technique exceeds other more sophisticated techniques, such as multilayer neural networks. Furthermore, because of the case with which decision tree results can be interpreted (logical classification rules), new methodologies can be readily developed to further assist in analyzing complex data that mix heterogeneous features. In this paper, we illustrate such capabilities in the context of different complex diagnostic and/or prognostic problems in tumor pathology relating to bladder, astrocytomas, and adipose tissues.

Adult

Contribution of quantitative lectin histochemistry to characterizing well-differentiated, dedifferentiated and poorly differentiated liposarcomas.

OBJECTIVE: To find new diagnostic markers in the group of lipomatous tumors. STUDY DESIGN: The histochemical lectin staining pattern was characterized in a series of 45 lipomatous lesions, including 10 typical lipomas, 6 atypical lipomas, 8 well-differentiated, 6 myxoid, 5 dedifferentiated and 10 pleomorphic liposarcomas. Three lectins were used-peanut (Arachis hypogaea) agglutinin, which binds to terminal Gal(beta 1,3)GalNAc residues; wheat germ (Triticum vulgare) agglutinin (s-WGA, the succinylated form of WGA), which binds to ((1-4)-D-GlcNAc)n and Neu5NAc residues; and jack bean (Concanavalia ensiformis) agglutinin which binds to alpha-D-Man and alpha-D-Glc residues. Histochemical staining was quantitatively measured by means of a cell image processor. RESULTS: In the case of certain carbohydrate residues, typical lipomas closely resemble atypical lipomas, which in turn closely resemble well-differentiated liposarcomas; typical lipomas differ significantly from well-differentiated liposarcomas. This indicates that atypical lipomas, or at least some of them, could represent a biologic link between typical lipomas and well-differentiated liposarcomas. While well-differentiated and pleomorphic liposarcomas differed significantly from each other, the poorly differentiated component of dedifferentiated liposarcomas included histochemical lectin properties, which were common to both well-differentiated and pleomorphic liposarcomas. CONCLUSION: Some atypical lipomas exhibit glycohistochemical characteristics that are common to those of well-differentiated liposarcoma. The poorly differentiated component of dedifferentiated liposarcomas remains more differentiated in terms of glycohistochemical markers than do poorly differentiated pleomorphic liposarcomas.

Adult

Methodological aspects of using decision trees to characterise leiomyomatous tumors.

The aim of the present work is to present the potential uses of a classification technique labeled the "decision tree" for tumor characterisation when faced with a large number of features. The decision tree technique enables multifeature logical classification rules to be produced by determining discriminatory values for each feature selected. In this report, we propose a methodology that used decision trees to compare and evaluate the information contributed by different types of features for tumor characterisation. This methodology is able to produce a set of hypotheses related to a diagnosis and or prognosis problem. For example, hypotheses can be producted (on the basis of a set of descriptive features) to explain why tumor cases belong to a given histopathological group. To illustrate our purpose, this methodology was applied to the difficult problem of leiomyomatous tumour diagnosis. The aim was to illustrate what kind of diagnostic information can be extracted from a sample data set including 23 smooth muscle tumors (14 benign leiomyomas and 9 malignant leiomyosarcomas) described by a large set of computer-assisted, microscope-generated features. Three groups of features were used relating to: (1) ploidy level determination (10 features), (2) quantitative chromatin pattern description (15 features), and (3) immunohistochemically related antigen specificities (6 features). All these features were quantified by digital cell image analysis. The results suggest that an objective distinction between leiomyomas and leiomyosarcomas can be established by means of simple logical rules depending on only a few features among which the immunohistochemically revealed antigen expression of desmin plays a preponderant part. One of the combinations of features proposed by the methodology is interesting for pathologists, because it includes two features describing the appearance of a nucleus in terms of chromatin distribution homogeneity and density, two features widely used by pathologists in tumor-grading systems.

Adolescent

Influence of gastrin on human astrocytic tumor cell proliferation.

BACKGROUND: Gastrin and cholecystokinin (CCK) mediate their effects through at least two types of receptors (CCK receptors A and B). While it has been hypothesized that gastrin, a stimulator of gastric acid secretion, is also a neurotransmitter and a stimulator of cell proliferation in various normal and neoplastic tissues, its effect on astrocytic brain tumors has not been actively investigated. PURPOSE: Our goal was to determine the effects of gastrin and gastin and/or CCK antagonists on the proliferation in vitro of astrocytic tumor cells by use of both established cell lines and primary cell cultures of tumor tissue. METHODS: Ten established astrocytic tumor cell lines, SW1088, SW1783, Hs683, H4, U87, U118, U138, U373, T98G, and A172, were studied. The effects of added gastrin (at 0.01, 0.1, and microM) and the gastrin/CCK antagonists L-365,260, CI-988, L-364,718, and JMV 234 (each at 0.01, 0.1, and 1 microM) on the cellular proliferation rates of the 10 cell lines were indirectly measured by use of the colorimetric tetrazolium assay. The influence of gastrin (at 0.01 microM) on the cellular proliferation of primary cultures from nine freshly explanted astrocytic tumors was assessed by means of tritiated thymidine uptake and autoradiography. RESULTS: At specific concentrations, added gastrin increased the cellular proliferation of three established astrocytic cell lines (A172, Hs683, and SW1088), decreased it in two (U373 and T98G), and was without effect on the remaining five. Gastrin decreased cellular proliferation in one primary astrocytic tumor cell culture, stimulated it in five, and had no apparent effect in the remaining three. L-365,260, a CCK receptor B antagonist used at 0.01 microM, increased cellular proliferation in seven cell lines (A172, H4, Hs683, SW1783, T98G, U118, and U138), decreased it in one (U87), and had no effect in the remaining two. CI-988, another CCK receptor B antagonist used at 0.01 microM, inhibited cellular proliferation in five cell lines (A172, H4, SW1783, U373, and U87), stimulated it in two (T98G and U138), and had no effect in three. The CCK receptor A antagonists L-364,718 and JMV 234, both used at 0.01 microM, affected the cellular proliferation of only three of the 10 cell lines. CONCLUSIONS: These results suggest that gastrin (and perhaps CCK that belongs to the same peptide family) may play a role in the growth of a substantial proportion of human astrocytic tumors.

Amino Acid Sequence

In vitro characterization of prolactin-induced effects on proliferation in the neoplastic LNCaP, DU145, and PC3 models of the human prostate.

BACKGROUND: Proliferation of normal and tumoral prostate tissue is regulated by androgens and various growth factors. We characterized the in vitro proliferative influence of prolactin (PRL) in androgen-sensitive and androgen-insensitive human prostate cancers. METHODS: The biologic models employed included the androgen-sensitive LNCaP and the androgen-insensitive DU145 and PC3 cell lines. PRL-induced influences (0.1-10 mIU/ml of medium) on proliferation were assessed using the colorimetric methylthiotetrazole assay. Androgen sensitivity in the three cell lines was determined by assessing the proliferative influence of dihydrotestosterone (DHT) (0.1-10 nM). PRL-induced modifications in PC3 cell kinetics were assessed using Feulgen-stained nuclear image cytometry. RESULTS: Although DHT markedly stimulated LNCaP proliferation, it had no proliferative effect on the DU145 and PC3 cell lines. By contrast, PRL significantly modulated the proliferation of the DU145 and PC3 lines, but exerted weak, if any, effect on the proliferation of the LNCaP cell line. PRL increased the percentage of PC3 proliferating cells (i.e., cells in the S/G2 phases of the cell cycle) at low doses (0.1 mIU/mL) and decreased this percentage at high doses (10 mIU/ml). CONCLUSIONS: Proliferation of androgen-insensitive human prostate cell lines can be significantly modulated by prolactin.

Androgens

The use of the decision tree technique and image cytometry to characterize aggressiveness in World Health Organization (WHO) grade II superficial transitional cell carcinomas of the bladder.

The aggressiveness of human bladder tumours can be assessed by means of various classification systems, including the one proposed by the World Health Organization (WHO). According to the WHO classification, three levels of malignancy are identified as grades I (low), II (intermediate), and III (high). This classification system operates satisfactorily for two of the three grades in forecasting clinical progression, most grade I tumours being associated with good prognoses and most grade III with bad. In contrast, the grade II group is very heterogeneous in terms of their clinical behaviour. The present study used two computer-assisted methods to investigate whether it is possible to sub-classify grade II tumours: computer-assisted microscope analysis (image cytometry) of Feulgen-stained nuclei and the Decision Tree Technique. This latter technique belongs to the Supervised Learning Algorithm and enables an objective assessment to be made of the diagnostic value associated with a given parameter. The combined use of these two methods in a series of 292 superficial transitional cell carcinomas shows that it is possible to identify one subgroup of grade II tumours which behave clinically like grade I tumours and a second subgroup which behaves clinically like grade III tumours. Of the nine ploidy-related parameters computed by means of image cytometry [the DNA index (DI), DNA histogram type (DHT), and the percentages of diploid, hyperdiploid, triploid, hypertriploid, tetraploid, hypertetraploid, and polyploid cell nuclei], it was the percentage of hyperdiploid and hypertetraploid cell nuclei which enabled identification, rather than conventional parameters such as the DI or the DHT.

Adult

Hepatic morphonuclear alterations following portacaval shunt in the rat.

Portacaval shunt (PCS) induced major biochemical alterations to rat liver. We characterized the chromatin status in the rat hepatocyte at various times after this surgical procedure. The samples studied were from histological imprint smears of liver tissue. Nuclear assessments were computed on Feulgen-stained nuclei by means of a cell-image processor. We described the distribution values of the ploidy, of the percentage of diploid and tetraploid cells per case, of the size of nuclei, and of the chromatin pattern. At the 18th hr post-PCS we observed a complete inversion in the ratio of diploid and tetraploid cells. The size of nuclei increased after PCS and returned progressively to normal values at the 72nd hr post-PCS. The chromatin pattern revealed a mirror image between the small and large dense chromatin clumps (SRL and LRL parameters). Twenty-four hours postsurgery, we observed the minimum value for SRL together with the maximum value for LRL, and these two parameters remained to the normal values within 72 hr post-PCS. Our results show that chromatin organization level is changed during portacaval shunt. They also suggest that the value of SRL and LRL parameters are important in the description of normal or neoplasic cells.

Animals