Hypoxic tumor cells resist most therapies and cause tumor regrowth when their environment improve... more Hypoxic tumor cells resist most therapies and cause tumor regrowth when their environment improves. Identifying the adaptation strategies to hypoxia would help develop better tailored cancer therapies. Ehrlich carcinomas implanted on mice were analyzed histochemically for the following enzyme activities: lactate, succinate and glucose-6-phosphate dehydrogenases, dihydrofolate reductase, purine nucleoside phosphorylase, xanthine oxidoreductase, and acid phosphatase. With the exception of xanthine oxidoreductase, which was not active in tumor cells, and of succinate dehydrogenase the activity of which was not significatively altered, all other activities were much higher in perinecrotic cells with respect to cells close to blood vessels. These data suggest the integration of metabolic paths allowing purine and lipid biosyntheses. Degradation products from the necrosis are presumed to be employed as surrogates of blood-borne nutritive substances by cells distant from the vascularization.
Advances in Experimental Medicine and Biology, 1990
The therapeutical application of heat, in any manner obtained (radiofrequency, microwave, ultraso... more The therapeutical application of heat, in any manner obtained (radiofrequency, microwave, ultrasound hyperthermia) , causes progressive physiopathologic modifications to the tumoral mass.These consist in structural damages sufficiently known(18). The heating of a neoplastic mass usually brings about impairments of enzymatic cellular processes, with an increase of oxygen consumption, interesting anoxic or partially anoxic cells.These enzymatic impairments imbalance the normal homeostatic equilibrium, leading to cell. death(55). The thermal washout mechanisms, which protect the normal cells, for certain temperature limits, are missing for the neoplastic cells placed in different environment.The nutritive supply to the tumor microenvironment largely depends on an inefficient and inelastic vascular system (8). The temperature increase, beyond an optimal shoulder, 42.5°C, creates higher oxygen consumption, increase of microsomal activity and of anaerobic glycolysis, leading to two different processes: (A) increased production of lactic acid with consequently pH decrease, (B) a drastic reduction of ATP formation. The reduced availability of energy, due to high temperatures, impairs the enzymatic repair system of tumor DNA molecules.
Solid tumors are "organoids" consisting of highly heterogeneous populations of malignan... more Solid tumors are "organoids" consisting of highly heterogeneous populations of malignant, stromal and inflammatory cells and dynamic extracellular matrix. In particular, distinct cellular microenvironments are observed. The survival strategies of malignant cells might therefore be highly differentiated, causing the high genotypic and phenotypic instability characteristic of malignant cells in vivo. A constant interplay between the tumor compartments and the host immune and hemostatic systems determines the behavior of the tumor. A description of typical microenvironments and of cellular and matrix interactions is provided. Based on these, it is here postulated that: (a) any cancer treatment, by influencing differently the various tumor compartments, will alter previously established equilibria; (b) the behavior (growth, invasiveness, metastatic potential, resistance to further treatment) of a malignancy after treatment might be altered with respect to what is assumed in te...
The liver of tumor-bearing hosts manifests fetal phenotypes. We investigated the expression of di... more The liver of tumor-bearing hosts manifests fetal phenotypes. We investigated the expression of differentiation markers on the liver in MMTV-neu (ErbB-2) transgenic mice, in the period from incipient neoangiogenesis to lung metastatization. We report AFP expression by hepatocytes in all lobular zones, CD34 cell arrest and subsequent hemopoiesis in periportal and mid-zone areas, oval-like cells (CD34+, CK19+, AFP+) and ductular reaction in portal tracts, portal CK19+ and GGT+ hepatoblast-like cells, and midzonal large dysplastic hepatocytes. We hypothesize that CD34 cells are recruited by the tumor from the marrow for angiogenic purposes and that their differentiation in the liver is influenced by altered liver microenvironment(s). AFP may act as a growth factor and biological response modifier for these cells and for the tumor. Dysplasia might be enhanced by metabolic stress. We conclude that the liver differentiation potential is lobular-zone-dependent and that the risk for eventual...
Studies assessing the effects of partial-hepatic ischemia/reperfusion (I/R) injury focused on the... more Studies assessing the effects of partial-hepatic ischemia/reperfusion (I/R) injury focused on the damage to the ischemic-lobe, whereas few data are available on non-ischemic lobe. This study investigated whether acute liver I/R does affect non-ischemic lobe function via modulation of extracellular matrix remodeling. Male Sprague-Dawley rats underwent left lateral- and median-lobe ischemia for 30 min and reperfusion for 60 min or sham operation. After reperfusion, blood samples and hepatic biopsies from both the ischemic (left-lobe, LL) and the non-ischemic lobe (right-lobe, RL) were collected. Serum hepatic enzymes and TNF-alpha, tissue matrix metalloproteinases (MMP-2, MMP-9), liver morphology, malondialdehyde (MDA), and myeloperoxidase (MPO) were evaluated. Liver I/R injury was confirmed by altered increased hepatic enzymes and TNF-alpha. I/R induced an altered morphology and an increase in MMP-2 and MMP-9 activity not only in left-ischemic lobe (LL) but also in the right-non-isch...
Fluorescence microscopy (microfluorimetry) is an established technique that provides useful infor... more Fluorescence microscopy (microfluorimetry) is an established technique that provides useful information about the biomolecules in a cellular environment[1,2]. The technique consists in exciting the samples (cells or part of them) with a light source of suitable wavelength, and in detecting and processing the fluorescence emission.
The tumor interstitial fluid (TIF) is a fluid phase present in the extracellular space of all tum... more The tumor interstitial fluid (TIF) is a fluid phase present in the extracellular space of all tumors whose importance in oncology is seldom recognized. In order to stimulate other researchers to give it the due importance, a review of the available data (including our own) is provided. An hypothesis is presented for the genesis, fate and role of the TIF in the processes of invasion, growth and metastatization. Open questions regarding the TIF's role in tumor response to therapy are raised.
The effects of Celsior solution were compared with those of the University of Wisconsin solution ... more The effects of Celsior solution were compared with those of the University of Wisconsin solution (UW) after 18 or 48 hours of cold storage in a perfused rat liver model. Lactate dehydrogenase (LDH), hyaluronic acid (HA) uptake, thiobarbituric acid-reactive substances (TBARS), tissue reduced (GSH) and oxidized glutathione (GSSG) and ATP were evaluated. Histochemical in situ evaluation ofLDH and reactive oxygen species (ROS) were also performed. No significant difference in LDH release, HA uptake, TBARS, ATP levels and GSH/GSSG ratio were observed between UW and Celsior solution when the livers were preserved for 18 hours. By contrast, when preservation was performed for 48 hours, LDH release, TBARS and ROS formation were higher and the ATP levels, GSH/GSSG ratio and HA uptake were lower in the liver preserved by Celsior as compared with UW. Celsior solution was as effective as UW in liver preservation up to 18 hours but the superiority of UW over Celsior solution was obtained when li...
ABSTRACT In this paper we discuss the technique of laser fluorescence microscopy. First, we prese... more ABSTRACT In this paper we discuss the technique of laser fluorescence microscopy. First, we present the latest version of a laser microfluorometer, characterized by high spatial and temporal resolution, and by a high degree of versatility and automation due to microprocessor control. We also present our latest results in the application of this technique to the study of the interaction properties of the photosensitizing antitumor drug Hematoporphyrin Derivative (HpD) at cellular level.
This work reports on studies of spectral properties and fluorescence decay times of HpD. The depe... more This work reports on studies of spectral properties and fluorescence decay times of HpD. The dependence of these parameters on physicochemical and biological conditions has been studied in solution, cells, and a culture medium. Particular attention was devoted to the presence of a HpD emission band in the 570-590-nm range. This band does not naturally occur in fresh HpD solution and seems more likely in tumor than in normal HpD-treated cells.
Hypoxic tumor cells resist most therapies and cause tumor regrowth when their environment improve... more Hypoxic tumor cells resist most therapies and cause tumor regrowth when their environment improves. Identifying the adaptation strategies to hypoxia would help develop better tailored cancer therapies. Ehrlich carcinomas implanted on mice were analyzed histochemically for the following enzyme activities: lactate, succinate and glucose-6-phosphate dehydrogenases, dihydrofolate reductase, purine nucleoside phosphorylase, xanthine oxidoreductase, and acid phosphatase. With the exception of xanthine oxidoreductase, which was not active in tumor cells, and of succinate dehydrogenase the activity of which was not significatively altered, all other activities were much higher in perinecrotic cells with respect to cells close to blood vessels. These data suggest the integration of metabolic paths allowing purine and lipid biosyntheses. Degradation products from the necrosis are presumed to be employed as surrogates of blood-borne nutritive substances by cells distant from the vascularization.
Advances in Experimental Medicine and Biology, 1990
The therapeutical application of heat, in any manner obtained (radiofrequency, microwave, ultraso... more The therapeutical application of heat, in any manner obtained (radiofrequency, microwave, ultrasound hyperthermia) , causes progressive physiopathologic modifications to the tumoral mass.These consist in structural damages sufficiently known(18). The heating of a neoplastic mass usually brings about impairments of enzymatic cellular processes, with an increase of oxygen consumption, interesting anoxic or partially anoxic cells.These enzymatic impairments imbalance the normal homeostatic equilibrium, leading to cell. death(55). The thermal washout mechanisms, which protect the normal cells, for certain temperature limits, are missing for the neoplastic cells placed in different environment.The nutritive supply to the tumor microenvironment largely depends on an inefficient and inelastic vascular system (8). The temperature increase, beyond an optimal shoulder, 42.5°C, creates higher oxygen consumption, increase of microsomal activity and of anaerobic glycolysis, leading to two different processes: (A) increased production of lactic acid with consequently pH decrease, (B) a drastic reduction of ATP formation. The reduced availability of energy, due to high temperatures, impairs the enzymatic repair system of tumor DNA molecules.
Solid tumors are "organoids" consisting of highly heterogeneous populations of malignan... more Solid tumors are "organoids" consisting of highly heterogeneous populations of malignant, stromal and inflammatory cells and dynamic extracellular matrix. In particular, distinct cellular microenvironments are observed. The survival strategies of malignant cells might therefore be highly differentiated, causing the high genotypic and phenotypic instability characteristic of malignant cells in vivo. A constant interplay between the tumor compartments and the host immune and hemostatic systems determines the behavior of the tumor. A description of typical microenvironments and of cellular and matrix interactions is provided. Based on these, it is here postulated that: (a) any cancer treatment, by influencing differently the various tumor compartments, will alter previously established equilibria; (b) the behavior (growth, invasiveness, metastatic potential, resistance to further treatment) of a malignancy after treatment might be altered with respect to what is assumed in te...
The liver of tumor-bearing hosts manifests fetal phenotypes. We investigated the expression of di... more The liver of tumor-bearing hosts manifests fetal phenotypes. We investigated the expression of differentiation markers on the liver in MMTV-neu (ErbB-2) transgenic mice, in the period from incipient neoangiogenesis to lung metastatization. We report AFP expression by hepatocytes in all lobular zones, CD34 cell arrest and subsequent hemopoiesis in periportal and mid-zone areas, oval-like cells (CD34+, CK19+, AFP+) and ductular reaction in portal tracts, portal CK19+ and GGT+ hepatoblast-like cells, and midzonal large dysplastic hepatocytes. We hypothesize that CD34 cells are recruited by the tumor from the marrow for angiogenic purposes and that their differentiation in the liver is influenced by altered liver microenvironment(s). AFP may act as a growth factor and biological response modifier for these cells and for the tumor. Dysplasia might be enhanced by metabolic stress. We conclude that the liver differentiation potential is lobular-zone-dependent and that the risk for eventual...
Studies assessing the effects of partial-hepatic ischemia/reperfusion (I/R) injury focused on the... more Studies assessing the effects of partial-hepatic ischemia/reperfusion (I/R) injury focused on the damage to the ischemic-lobe, whereas few data are available on non-ischemic lobe. This study investigated whether acute liver I/R does affect non-ischemic lobe function via modulation of extracellular matrix remodeling. Male Sprague-Dawley rats underwent left lateral- and median-lobe ischemia for 30 min and reperfusion for 60 min or sham operation. After reperfusion, blood samples and hepatic biopsies from both the ischemic (left-lobe, LL) and the non-ischemic lobe (right-lobe, RL) were collected. Serum hepatic enzymes and TNF-alpha, tissue matrix metalloproteinases (MMP-2, MMP-9), liver morphology, malondialdehyde (MDA), and myeloperoxidase (MPO) were evaluated. Liver I/R injury was confirmed by altered increased hepatic enzymes and TNF-alpha. I/R induced an altered morphology and an increase in MMP-2 and MMP-9 activity not only in left-ischemic lobe (LL) but also in the right-non-isch...
Fluorescence microscopy (microfluorimetry) is an established technique that provides useful infor... more Fluorescence microscopy (microfluorimetry) is an established technique that provides useful information about the biomolecules in a cellular environment[1,2]. The technique consists in exciting the samples (cells or part of them) with a light source of suitable wavelength, and in detecting and processing the fluorescence emission.
The tumor interstitial fluid (TIF) is a fluid phase present in the extracellular space of all tum... more The tumor interstitial fluid (TIF) is a fluid phase present in the extracellular space of all tumors whose importance in oncology is seldom recognized. In order to stimulate other researchers to give it the due importance, a review of the available data (including our own) is provided. An hypothesis is presented for the genesis, fate and role of the TIF in the processes of invasion, growth and metastatization. Open questions regarding the TIF's role in tumor response to therapy are raised.
The effects of Celsior solution were compared with those of the University of Wisconsin solution ... more The effects of Celsior solution were compared with those of the University of Wisconsin solution (UW) after 18 or 48 hours of cold storage in a perfused rat liver model. Lactate dehydrogenase (LDH), hyaluronic acid (HA) uptake, thiobarbituric acid-reactive substances (TBARS), tissue reduced (GSH) and oxidized glutathione (GSSG) and ATP were evaluated. Histochemical in situ evaluation ofLDH and reactive oxygen species (ROS) were also performed. No significant difference in LDH release, HA uptake, TBARS, ATP levels and GSH/GSSG ratio were observed between UW and Celsior solution when the livers were preserved for 18 hours. By contrast, when preservation was performed for 48 hours, LDH release, TBARS and ROS formation were higher and the ATP levels, GSH/GSSG ratio and HA uptake were lower in the liver preserved by Celsior as compared with UW. Celsior solution was as effective as UW in liver preservation up to 18 hours but the superiority of UW over Celsior solution was obtained when li...
ABSTRACT In this paper we discuss the technique of laser fluorescence microscopy. First, we prese... more ABSTRACT In this paper we discuss the technique of laser fluorescence microscopy. First, we present the latest version of a laser microfluorometer, characterized by high spatial and temporal resolution, and by a high degree of versatility and automation due to microprocessor control. We also present our latest results in the application of this technique to the study of the interaction properties of the photosensitizing antitumor drug Hematoporphyrin Derivative (HpD) at cellular level.
This work reports on studies of spectral properties and fluorescence decay times of HpD. The depe... more This work reports on studies of spectral properties and fluorescence decay times of HpD. The dependence of these parameters on physicochemical and biological conditions has been studied in solution, cells, and a culture medium. Particular attention was devoted to the presence of a HpD emission band in the 570-590-nm range. This band does not naturally occur in fresh HpD solution and seems more likely in tumor than in normal HpD-treated cells.
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