Hepatotoxicity following systemic therapy for colorectal liver metastases and the impact of chemotherapy-associated liver injury on outcomes after curative liver resection.

Patients with colorectal liver metastases (CLM) have remarkably benefited from the advances in medical multimodal treatment and surgical techniques over the last two decades leading to significant improvements in long-term survival. More patients are currently undergoing liver resection following neoadjuvant chemotherapy, which has been increasingly established within the framework of curative-indented treatment strategies. However, the use of several cytotoxic agents has been linked to specific liver injuries that not only impair the ability of liver tissue to regenerate but also decrease long-term survival. One of the most common agents included in modern chemotherapy regimens is oxaliplatin, which is considered to induce a parenchymal damage of the liver primarily involving the sinusoids defined as sinusoidal obstruction syndrome (SOS). Administration of bevacizumab, an inhibitor of vascular endothelial growth factor (VEGF), has been reported to improve response of CLM to chemotherapy in clinical studies, concomitantly protecting the liver from the development of SOS. In this review, we aim to summarize current data on multimodal treatment concepts for CLM, give an in-depth overview of liver damage caused by cytostatic agents focusing on oxaliplatin-induced SOS, and evaluate the role of bevacizumab to improve clinical outcomes of patients with CLM and to protect the liver from the development of SOS.

Estrogenic activity of natural and synthetic estrogens in human breast cancer cells in culture.

We investigated the estrogenic activity of various environmental pollutants (xenobiotics), in particular the xenoestrogen o,p-DDT, and compared their effects with those of endogenous estrogens, phytoestrogens, and mycoestrogens on estrogen receptor binding capacity, induction of estrogen end products, and activation of cell proliferation in estrogen-sensitive human breast cancer cells in monolayer culture. We also quantified the levels of phytoestrogens in extracts of some common foods, herbs, and spices and in human saliva following consumption of a high phytoestrogen food source (soy milk) to compare phytoestrogen abundance and bioavailability relative to the reported xenoestrogen burden in humans. Results show that natural endogenous estrogens, phytoestrogens, mycoestrogens, and xenoestrogens bind estrogen receptor (ER) in intact cells, but demonstrate marked differences in their ability to induce end products of estrogen action and to regulate cell proliferation. All of the different classes of estrogens stimulated cell proliferation at concentrations that half-saturated ER, but only some classes were able to induce estrogen-regulated end products. Genistein, a common phytoestrogen found in soy foods, differed from the xenoestrogen DDT in its effects on cell proliferation and ability to induce estrogen-regulated end products. Moreover, we found that many of the foods, herbs, and spices commonly consumed by humans contain significant amounts of phytoestrogens, and consumption of soy milk, a phytoestrogen-rich food, markedly increases the levels of phytoestrogens in saliva. In conclusion, our in vitro results predict that a diet high in phytoestrogens would significantly reduce the binding of weak xenoestrogens to ER in target tissues in vivo.

Estrogenic and antiproliferative properties of genistein and other flavonoids in human breast cancer cells in vitro.

Experimental and epidemiologic studies support the view that soyfoods prevent cancer as well as diseases and symptoms associated with estrogen deficiency. Recent research suggests that the isoflavonoid genistein, a phytoestrogen found in abundance in soyfoods, may be one of the principal molecular components responsible for these health benefits. In this study we investigated the effects of a broad physiologically relevant concentration range of genistein on estrogen receptor (ER) binding, induction of the estrogen-regulated antigen pS2, and cell proliferation rate in ER(+) and ER(-) human breast cancer cells grown in vitro. Dose response to genistein was compared with that of estradiol, tamoxifen, and several other structurally similar iso- and bioflavonoids (e.g., equol, kaempferol, and quercetin). Our results revealed that genistein has potent estrogen agonist and cell growth-inhibitory actions over a physiologically achievable concentration range (10 nM-20 microM). Other flavonoids over the same concentration range were good estrogen agonists and poor cell growth inhibitors (equol) or poor estrogen agonists and potent growth inhibitors (kaempferol and quercetin). The growth-inhibitory actions of flavonoids were distinctly different from those of triphenyl antiestrogens like tamoxifen. In summary, our results reveal that genistein is unique among the flavonoids tested, in that it has potent estrogen agonist and cell growth-inhibitory actions over a physiologically relevant concentration range.

Cloned natural suppressor cell lines express the CD3+CD4-CD8- surface phenotype and the alpha, beta heterodimer of the T cell antigen receptor.

Several cloned lines of natural suppressor (NS) cells were studied for their expression of the TCR complex. Almost all bore the CD3+CD4-CD8- surface phenotype with the alpha, beta TCR as judged by immunofluorescent staining. Immunoprecipitation experiments showed a spot on two-dimensional gels which is characteristic of the TCR heterodimer, but neither gamma- nor delta-chains could be precipitated with the appropriate antibodies. NS cells were stimulated to proliferate in vitro with anti-CD3 antibodies and PMA in the presence of irradiated spleen cells. However, anti-CD3 antibodies did not inhibit the suppressive activity of the NS cells. The role of the TCR complex in the suppressive function of these cells remains to be elucidated.

Limited diversity of T-cell receptor gamma-chain expression of murine Thy-1+ dendritic epidermal cells revealed by V gamma 3-specific monoclonal antibody.

To study the origin of and the degree of T-cell antigen receptor (TCR) diversity of Thy-1+ dendritic epidermal cells (Thy-1+ dECs) in mice, we have developed a monoclonal antibody (mAb 536) to the gamma delta TCR. mAb 536 binds to and stimulates interleukin 2 secretion from Thy-1+ dEC but not cells that express TCR composed of alpha and beta chains. mAb 536 precipitates CD3-associated gamma and delta chains from lysates of radioiodinated Thy-1+ dECs. Analysis of a panel of hybridomas that express gamma delta TCR indicated that mAb 536 defines an epitope of the variable region (V gamma 3) gene product. Flow cytometric analysis revealed that expression of V gamma 3 in the adult mouse is restricted to cells in the epidermis, where essentially all Thy-1+ cells are V gamma 3+. The majority of CD3+ cells in the 14-day fetal thymus also express V gamma 3. These results indicate that the T-cell complement in epidermis are cells that express gamma delta TCR and that the diversity of antigens recognized by the cells might be restricted by the use of a single V gamma gene segment. Finally, the data raise the intriguing possibility that Thy-1+ dECs may arise from precursors that are among the first to emerge from the developing thymus. This suggests that V gene usage during thymocyte development is highly regulated and has important consequences on the tissue localization and function of the emerging cells. As in other developing tissues, it appears that programmed and transient gene expression determines the fate of the emerging cells.

The use of cytoskeletal characteristics of tumor cells for the diagnosis of colon and breast adenocarcinomas.

The cytoskeleton of colon (11 cases) and breast adenocarcinomas (9 cases) was characterized with the use of immunohistochemistry on tissue sections and one- and two-dimensional (2-D) gel electrophoresis of cytoskeletal extracts of tumor cells. By immunofluorescence, antibodies to epidermal cytokeratin (CK) and Mallory body CK recognized cytoplasmic filaments +/- desmosomal contacts, respectively, in both colon and breast adenocarcinomas. In addition, cytoskeletal extracts of both tumors showed similar CK polypeptides by 2-D gel electrophoresis. By immunoperoxidase, anti-actin antibody stained the apical margin of tumor cells in eight (73%) colon adenocarcinomas and four of five metastases, while diffuse cytoplasmic staining was seen in only one (9%) breast adenocarcinoma and not in five metastases. With 2-D gel electrophoresis, a cytoskeletal-associated doublet polypeptide was found in seven (64%) colon adenocarcinomas but not in the breast adenocarcinomas. By immunoblotting, the doublet did not consist of CK polypeptides, vimentin, or type IV collagen. These findings may facilitate the differentiation of colon and breast adenocarcinomas.

Intermediate filaments in meningiomas.

The presence of intermediate filaments (IF) (diameter 10 nm) is a characteristic electron microscopic finding in the cytoplasm of meningioma cells. To identify these IF, immunohistochemical staining for cytokeratins and vimentin and two-dimensional (2-D) gel electrophoresis followed by immunoblot analysis were applied to a group of 16 meningiomas. Thirteen meningiomas were obtained directly from surgery and three came from an autopsy in which they were found in close proximity as discrete tumor masses. Except for the angioblastic type, all major histological variants were represented (nine transitional, four syncytial, and three fibroblastic). None of the meningiomas stained for epithelial or internal organ cytokeratins. With monoclonal antibodies, each of the meningiomas stained positively for vimentin. Two-D gels revealed vimentin and vimentin breakdown products as the only IF present; these findings were verified by immunoblots. The study concludes that vimentin is the IF present in fibroblastic, syncytial, and transitional meningiomas.

[Stimulation-induced changes in the ultrastructure of the synapses in the hippocampus by post-tetanic potentiation]. / Stimulations-induzierte Veränderungen der Ultrastruktur von Synapsen im Hippocampus während posttetanischer Potenzierung.

Within the frame of experimental brain research at present the phenomenon of potentiation (posttetanic potentiation, long-term potentiation) is considered to provide a possible mechanism of learning processes and memory formation on the synaptic level. Tetanic stimulation of the Nucleus septalis fimbrialis produces the posttetanic potentiation in synapses of the hippocampal CA 3-region, whereafter a long-lasting increase in the amplitude of evoked potentials can be recorded. By quantitative electron microscopical morphometry we investigated the morphological changes in synapses of the Stratum radiatum of the hippocampal CA 3-region of rabbits (1 hour following posttetanic stimulation). Tetanic stimulation of the Nucleus septalis fimbrialis induces an enlargement of the postsynaptic spine area significantly by 28% and a decrease of the mean area of presynaptic terminals by 24%. No changed number of synapses were found in comparison to the controls. Furthermore stimulation of the Nucleus septalis fimbrialis induces a transient decrease of synaptic vesicles in various zones of the presynaptic area, especially near the presynaptic membrane. These results demonstrate morphologically detectable changes as a consequence of synaptic activation. Therefore posttetanic potentiation is characterized by various morphologic changes reflecting probably an early phase of the learning process with transient effects on the ultrastructure of the synapses.

[The effect of conditioning on the ultrastructural distribution of synaptic vesicles in the hippocampus of the rat]. / Der Einfluss der Konditionierung auf die ultrastrukturelle Verteilung der synaptischen Vesikel im Hippocampus der Ratte.

In three months old male Wistar-rats the influence of conditioning (brightness discrimination reaction) on the number and distribution of vesicles of the synapses in the stratum radiatum (CA 3) of the hippocampus were investigated. A total of 15 rats (5 trained rats, 5 passive and 5 active controls) were studied by the aid of electron microscopic and morphometric methods. The number of synaptic vesicles was evaluated for the passive controls by 27 vesicles per synaptic area. In the CA 3-region 70 minutes after training the calculation of the number of synaptic vesicles revealed a significant decrease in comparison with passive and active controls (16 and 32 vesicles per synaptic area, respectively; significant difference at p less than 0.05). The volume of the synaptic vesicles was reduced for the trained rats by 20-25% in comparison with controls. The morphological results after training could be correlated with the changes of the Ach fractions, and seem to be of great significance at the initial stages of memory formation.

[Development of neuron structure of the fascia dentata in the rat. Neurohistologico-morphometric, ultrastructural and experimental study]. / Zur Entwicklung der Neuronenstruktur des Fascia dentata bei der Ratte. Neurohistologisch-morphometrische, ultrastrukturelle und experimentelle Untersuchungen.

In the brains of male white rats some structural parameters of granule neurons in the hippocampal dentate gyrus such as cytoarchitectonical arrangement of these cells, structure of dendrites and dendritic spines were analyzed during ontogenetic development as well as changes in these parameters due to modified external conditions (acoustic stimulation, dark rearing, cerebrolysine administration). Transmission electron microscopy as well as cytologic and morphometric methods were employed. Under normal conditions the adult cytoarchitectonical pattern of the dentate gyrus was reached at postnatal day 20 (P 20). At the ultrastructural level the differentiation of the neuronal perikarya during ontogenesis was determined by the size of the nucleus, occurrence of rough endoplasmic reticulum, ribosoms and polysoms, Golgi apparatus and mitochondria between birth and postnatal day 90 (P 0--P 90). Synaptogenesis starts in the perinatal period in form of immature axo-somatic and axo-dendritic contacts. In adults a pronounced structural variability of synapses and the presence of complex spines was found. The average density of spines increased considerably with age in isolated dendritic segments as well as over the whole length of a dendrite. The density was at P--P 2: 0,03; P 5: 0,04; P 8: 0,09; P 10: 0,1; P 15: 0,17; P 20: 0,23; P 30: 0,48; P 180: 0,62 spines per micrometer dendrite. The postnatal development of the neurons under experimental conditions was characterized by significant augmentations of the spine numbers mainly in the early postnatal phase: Controls at P 15 with 0,17, after dark rearing 0,30, after Cerebrolysine 0,32, after acoustic stimulation 0,33 spines per micrometer dendrite. At P 30 only dark rearing resulted in significant augmentation of the spine number (0,63 spines per micrometer dendrite against 0,48 in controls). The data obtained after acoustic stimulation and dark rearing point to a widespread influence of external stimuli on neuronal development not only confined to the corresponding visual or acoustic pathway. The Cerebrolysine results during early postnatal development can be explained by a stimulation of protein synthesis and, hence, of the neurogenesis.

[Electron microscopy of the neural and synaptic organization of the regio cingularis in the rat]. / Elektronenmikroskopische Untersuchungen zur neuronalen und synaptischen Organisation der Regio cingularis anterior bei der Ratte.

The neuronal structure and synaptology of the regio cingularis of the rat was examined with electron microscopical methods. On the basis of GOLGI-impregnation studies of the cingulate region ultrastructural characteristics of pyramidal and nonpyramidal neurons were investigated concerning the variations in size and content of intracytoplasmatic organelles, morphology of the nucleus and the number, site and kind of synaptic contacts. There are mainly small and medium sized pyramidal cells. The axo-somatic synapses appear as symmetrical contacts (type GRAY II). The number and distribution of small and medium sized nonpyramidal neurons (interneurons) are different in various cortical layers. Both types of synapses, asymmetrical as well as symmetrical contacts (type GRAY I and type GRAY II) were found on the pericarya of these nonpyramidal cells. As has been established for the neocortex, the dendrites of cingulate pyramidal neurons are bundled. The numerous spines along these dendrites are of different size and shape. The asymmetric axo-spinodendritic contacts (type GRAY I) are the most frequent type of synapses compared with axo-dendritic junctions. The dendrites of nonpyramidal neurons are of the spiny type or of the sparsely spined type with dilations of "beads" (varicosities) that are present along them. The ultrastructural investigations and the results following terminal degeneration (electrolytical stereotaxic lesions in the nucleus mediodorsalis and in the nucleus anteromedialis thalami) cause the suggestion that the specific thalamic afferents reach monosynaptically the layer III or V pyramids and specific interneurons. Recurrent axon collaterals of the pyramids and inhibitory interneurons represent the morphological correlates for the recurrent inhibition of the pyramids. These results demonstrate a similarity between the cingulate cortex and the neocortex concerning the synaptic organization made up by excitatory and inhibitory neurons.

Defective regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase in a somatic cell mutant.

A somatic cell mutant of the CHO-K1 cell selected to be resistant to the killing effects of 25-hydroxycholesterol in the absence of cholesterol is shown to be defective in the inhibition of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase activity by 25-hydroxycholesterol, cholesterol, and lipoproteins, thus maintaining the enzyme activity found in cells in the absence of exogenous sterol constitutively. The mutants phenotype is shown to be dominant with respect to the wild type. Actinomycin D and cycloheximide prevent the increase of HMG-CoA reductase activity that occurs in the CHO-K1 cell when cholesterol is removed from medium. Degradation of the enzyme, measured during inhibition of protein synthesis by cycloheximide, occurs at the same rate in the mutant as in the wild type. Kinetic studies indicate that the Km for two substrates, the activation energy, and a break in the Arrhenius plot are the same for HMG-CoA reductase determined in wild type and mutant cells. From these studies it is concluded that the mutant is defective in the regulation of synthesis of HMG-CoA reductase. Of the four processes which determine cellular cholesterol levels: biosynthesis, esterification, efflux, and uptake, only biosynthesis is altered, demonstrating that these processes are not co-ordinately controlled as has been suggested previously.

Cortisol induction of pulmonary maturation in the rabbit foetus. Its effects on enzymes related to phospholipid biosynthesis and on marker enzymes for subcellular organelles.

1. Cortisol treatment of rabbit foetuses in utero at 24 days gestation produced a significant decrease in the lung-weight to body-weight ratio compared with littermate controls by day 26. Histological examination revealed that the alveoli of the treated lungs were more open, the walls were thinner and the osmiophilic bodies were more numerous. 2. Cortisol treatment as described above produced significant increases (P<0.05) in the rates of incorporation of [(14)C]choline into phosphatidylcholine and of [(14)C]ethanolamine into phosphatidylethanolamine in vitro compared with littermate controls. This indicates that glucocorticoids produce an overall increase in phospholipid metabolism rather than a specific increase in phosphatidylcholine production. 3. The addition of 1,2-diacyl-sn-glycerols from egg phosphatidylcholine produced a 10-fold increase in the activity of choline phosphotransferase and a 3-fold increase in the activity of ethanolamine phosphotransferase in rabbit lung homogenates. The addition of 1,2-dipalmitoyl-sn-glycerol did not affect these activities. These results demonstrate that in the presence of exogenous 1,2-dipalmitoyl-sn-glycerol, the activities of these enzymes are dependent on the presence of endogenous 1,2-diacylglycerols. 4. Cortisol administration had no significant effect on the activity of choline phosphotransferase or ethanolamine phosphotransferase with endogenous or exogenously added diacylglycerols. The activities of other endoplasmic-reticulum enzymes (sn-glycerol 3-phosphate phosphatidyltransferase, sn-glycerol 3-phosphate acyltransferase and NADPH-cytochrome c reductase) were not significantly altered by the hormone administration. Oestrone sulphate sulphohydrolase activity was significantly decreased (P<0.05) by cortisol injection, but this effect varied with the foetuses from different does. 5. Cortisol administration had no effect on the activities of mitochondrial (monoamine oxidase, succinate dehydrogenase), plasma-membrane (5'-nucleotidase) or lysosomal (acid phosphatase, N-acetyl-beta-d-glucosaminidase) enzymes. The activity of membrane-associated phosphatidate phosphohydrolase, an enzyme associated with the osmiophilic granules of the type-II alveolar cells, was increased in the lungs of treated foetuses, but the difference was not significant (0.10>P>0.05).