Francesco Maria Baccino

1. Rats bearing the Yoshida ascites hepatoma AH-130 showed an important decrease in white adipose tissue lipoprotein lipase activity as compared with non-tumour bearing rats. This was associated with a lower adipose tissue mass, as estimated from the weight of the lumbar fat-pads. Conversely, lipoprotein lipase activity was markedly increased in brown adipose tissue and heart. 2. These changes were associated with a distinct hyperlipaemia, essentially manifested as an increase in circulating triacylglycerol levels, whereas no changes were observed in glycaemia. 3. Tumour-bearing rats were treated with a polyclonal anti-murine tumour necrosis factor-α antibody or with a non-immune IgG preparation. Control animals were either untreated or received a nonimmune IgG preparation. Anti-tumour necrosis factor-α treatment resulted in a significant increase in lipoprotein lipase activity in white adipose tissue in animals bearing a tumour growing exponentially (day 4 after inoculation) as com...

Plasma and ascitic fluid of rats bearing the Yoshida ascites hepatoma AH-130 were shown to contain high levels of proteolytic enzymes belonging to different classes active at neutral and acidic pH. Relative to those measured in control rat plasma, in tumor-bearing animals, the activity levels of lysosomal cathepsins B and L, in their latent, acidic-activatable form, were approximately 5-fold higher in plasma and 9-fold higher in ascitic fluid, and cathepsin D activity was about 5-fold higher in both plasma and ascitic fluid. Plasma and ascitic fluid of tumor-bearing rats also contained novel neutral and acidic gelatinolytic activities. The latter, as revealed by zymographic analysis conducted at pH 6.0, in the presence of dithiothreitol and in the absence of divalent metal ions, was sensitive to iodoacetamide inhibition but not to EDTA, showed a molecular mass of approximately 90 kD on SDS-PAGE, and was lost upon limited proteolysis with pepsin. Therefore, this enzyme is not identif...

Cancer has always a negative impact on nutritional status, weight loss being a common feature in patients with neoplastic diseases. If left untreated, weight loss may evolve into cancer cachexia, a complex syndrome characterized by marked depletion of body weight, associated with profound alterations of both nutritional status and metabolic homeostasis. Progressive wasting of skeletal muscle mass and adipose tissue is a typical feature of cancer cachexia. Cachexia has a large impact on morbidity and mortality, and significantly affects patients' response and tolerance to treatments and quality of life. On this line, understanding the pathogenic mechanisms of cachexia is of crucial importance to define targeted therapeutic strategies. Well structured, systematic and timely appropriate nutritional intervention in cancer patients is of pivotal importance. Indeed, it has been shown that malnutrition in cancer patients can be delayed when nutritional supplementation is adopted early ...

The ascites hepatoma Yoshida AH130 causes in the host a rapid and progressive body weight loss, associated with reduced food intake, and protein and lipid hypercatabolism. Because insulin regulates glucose as well as lipid and protein metabolism, we suggest that the observed alterations are at least in part secondary to hypoinsulinemia and/or to the increase of counterregulatory hormones in AH130-bearing rats. To verify this hypothesis, controls with free access to food (n = 4), controls with free access to food plus insulin (107 micromol. kg body wt-1. d-1) (n = 4), controls pair-fed to the tumor-bearing rats (n = 4), pair-fed controls treated with insulin (n= 4), tumor hosts (n = 9), and tumor hosts treated with insulin (n = 6) were used. The Yoshida ascites hepatoma cells ( approximately 10(8) cells/rat) were inoculated intraperitoneally. Daily food intake and body weight were measured; insulin was injected starting the day of tumor implantation for 6 d. The metabolism of both ch...

The weight of the liver and its DNA content definitely increase in rats transplanted with the ascites hepatoma AH-130 (Yoshida). The specific activity of cathepsin B1 decreases progressively in the liver during the first week after transplantation reaching one third of the initial levels, whereas that of cathepsin D shows the opposite behaviour increasing to levels 40% higher than in controls. The activity of the two proteinases in the blood plasma varies in a similar way, though the modifications are even more pronounced than in the liver. The relevance of the changes in tissue proteinase activities to the liver growth in tumour-bearing animals is discussed.

The segregation of human cathepsin D, studied in baby-hamster kidney cells (BHK) transfected with human cathepsin D cDNA and compared with that of hamster cathepsin D in the same cells, showed that, in cells that expressed human cathepsin D at a low rate, most of the enzyme remained intracellular. In contrast, when the enzyme was expressed at a high rate, most was secreted. The segregation was examined with an anti-(human cathepsin D) antibody that reacted with the human enzyme exclusively and an anti-(rat cathepsin D) antibody that reacted with both enzymes. In one protocol the cells were metabolically labelled and the two antibodies were used in sequence to precipitate the enzymes from extracts of cells and medium. High expression of the human enzyme did not interfere with the segregation of hamster cathepsin D. In another protocol the activity of cathepsin D in cells and medium was measured before and after titration with anti-(human cathepsin D) antiserum. Human cathepsin D was ...

Recently investigators reported ultrastructural modifications of rat liver lysosomes which probably correlate with an increased level of blood plasma glucagon in streptozotocin-diabetes. We are investigating whether biochemical changes occur in this condition. Lysosome fragility is increased in the hepatocytes of streptozotocin-diabetic rats. Moreover the plasma activity of two glycosidases, B-N-acetylglucosaminidase and B-galactosidase, is markedly increased in streptozotocin-treated rats. Both these changes are largely prevented by insulin treatment. These findings support the idea that the morphologic and biochemical modifications of the hepatocytes, which are observed in experimental diabetes, involve the lysosomes showing an increased autophagic activity which is probably connected with enhanced liver protein catabolism.

Overexpression of the proto-oncogene c-ski in mice results in the development of a hypertrophic phenotype, characterized by increases in body and muscle weights. It has been previously shown in our laboratories that down-regulation of muscle protein breakdown associated with reduced expression of genes pertaining to different proteolytic systems likely account for this hypertrophic pattern. The aim of the present study was to evaluate the resistance of c-ski transgenic mice to catabolic stimuli such as those induced by the growth of the Lewis lung carcinoma. The tumor elicited a loss of body weight either in transgenic or in non-transgenic animals, although it was less pronounced in the former. The mass of gastrocnemius, tibialis and extensor digitorum longus (EDL) muscles were significantly reduced in non-transgenic tumor-bearing mice. Despite the anabolic setting displayed by the transgenic animals, the EDL only is completely protected against wasting. Indeed, gastrocnemius, tibialis and soleus show a reduction in weight, the latter two being significantly more depleted when compared to the non-transgenic tumor bearers. Similarly, the perigenital white adipose tissue presented a reduced mass which was more marked in the transgenic group. The quantitation of gene expression for ubiquitin, E2, C8 and calpain in the EDL showed marked differences between the transgenic and the non-transgenic groups of tumor hosts. As expected from previous results, in the latter group most of the transcripts examined increased with respect to controls as a consequence of tumor growth; by contrast, in the transgenic tumor hosts there was a significant reduction of ubiquitin, E2, C8 subunit, and calpain mRNA levels in comparison with the transgenic tumor-free animals. These results show that c-ski hyperexpression prevents tumor-induced muscle wasting in the EDL muscle, likely by impairing the state of activation of different proteolytic systems. However, the lack of effectiveness in the other muscles examined suggests that the achievement of a significant interference with the development of cachexia at the molecular level is not an easy task and probably should be designed taking into consideration more than one target.

Cells have to double their protein mass in order to divide. Whether this is achieved through increased synthesis (PS), decreased degradation (PD), or a combination of both is still debated. Likewise open are other basic questions: whether, beyond differences relating to growth phase (GP) or rate, reduced PD rates are a general characteristic of neoplastic versus normal cells, conferring to them a definite growth advantage; which mechanisms are operating the PD regulation, if any, during GP transitions, and which ones may be defective in neoplastic cells. Growing liver under conditions of regeneration or development is known to achieve a net protein accumulation thanks to increased PS, and particularly, to decreased PD rates, as compared with the adult, steady-state tissue; the level of lysosomal proteinase (LP) activities is reduced; in the regenerating liver this reduction has been located in cycling hepatocytes. AH-130 Yoshida ascites hepatoma cells effect the transition from log ...

Chronic diseases, including cirrhosis, are often accompanied by protein-energy malnutrition and muscle loss, which in turn negatively affect quality of life, morbidity and mortality. Unlike other chronic conditions, few data are available on the molecular mechanisms underlying muscle wasting in this clinical setting. To assess mechanisms of muscle atrophy in patients with cirrhosis. Nutritional [subjective global assessment (SGA) and anthropometry] and metabolic assessment was performed in 30 cirrhotic patients awaiting liver transplantation. Rectus abdominis biopsies were obtained intraoperatively in 22 cirrhotic patients and in 10 well-nourished subjects undergoing elective surgery for non-neoplastic disease, as a control group. Total RNA was extracted and mRNA for atrogenes (MuRF-1, Atrogin-1/MAFbx), myostatin (MSTN), GSK3β and IGF-1 was assayed. A total of 50% of cirrhotic patients were malnourished based on SGA, while 53% were muscle-depleted according to mid-arm muscle area (MAMA<5th percentile). MuRF-1 RNA expression was significantly increased in malnourished cirrhotic patients (SGA-B/C) vs. well-nourished patients (SGA-A) (P = 0.01). The phosphorylation of GSK3β was up-regulated in cirrhotic patients with hepatocellular carcinoma (HCC) vs. patients without tumour (P < 0.05). Muscle loss is frequently found in end-stage liver disease patients. Molecular factors pertaining to signalling pathways known to be involved in the regulation of muscle mass are altered during cirrhosis and HCC.

A rocket immunoelectrophoretic procedure has been developed for the assay of cathepsin D (EC 3.4.23.5) immunoreactive protein, in a 10-100 ng range, directly on crude soluble liver homogenate extracts. By this method, the drop in activity of rat liver cathepsin D effected by repeated doses of cycloheximide, a protein synthesis inhibitor, reflects a parallel change in total enzyme protein content, the specific activity being stable in the course of the treatment. These observations are compatible with the hypothesis that ongoing enzyme degradation, coupled with impaired synthesis, accounts for such a decline of cathepsin D.

Loss of lean body mass is frequently reported in patients with end-stage renal disease (ES-RD). Inadequate nutrient intake, superimposed illnesses, endocrine disorders, uremia and acidosis are some of the potential causes of muscle depletion. Previous reports on experimental models show that lean body mass depletion results from enhancement of muscle tissue protein catabolism, mainly associated with activation of ATP-ubiquitin-dependent proteolysis. Little is known, however, about the affects on this proteolytic system in ESRD patients on maintenance hemodialysis (HD). The present study was designed to investigate the expression of ubiquitin mRNAs in skeletal muscle of patients with ESRD on maintenance HD. Biopsies from the rectus abdominis muscle were obtained from eight ESRD patients and from six control subjects undergoing surgery for benign disease. Ubiquitin mRNA levels were measured by Northern blotting analysis. Patients with ESRD had mild metabolic acidosis, as a result of c...

ABSTRACT This paper presents a model-based control technique to provide the contribution of wind power generators to primary frequency regulation in electric power systems. Models of individual wind power generators and wind farm (WF) as a whole are presented and the proposed control strategy is detailed. It consists of a central controller, a central Kalman filter (KF), and some local KFs, one for each wind turbine. The central controller is disabled in normal operation conditions and its task is to set the power reference for each wind turbine, overwriting the local reference, when a disturbance occurs. Central KF is in charge of estimating the external load variation, while each local KF estimates wind speed and the wind turbines dynamical state. The key feature of this approach is that each wind turbine can react to grid disturbances in a different way, which depends on wind speed as seen by the wind turbine itself and by its dynamical conditions. Real wind data and a large WF connected to the grid in a dedicated simulation environment have been used to test the effectiveness of the proposed control strategy.

ABSTRACT This paper presents a model-based control technique to provide the contribution of wind power generators to primary frequency regulation in electric power systems. Models of individual wind power generators and wind farm (WF) as a whole are presented and the proposed control strategy is detailed. It consists of a central controller, a central Kalman filter (KF), and some local KFs, one for each wind turbine. The central controller is disabled in normal operation conditions and its task is to set the power reference for each wind turbine, overwriting the local reference, when a disturbance occurs. Central KF is in charge of estimating the external load variation, while each local KF estimates wind speed and the wind turbines dynamical state. The key feature of this approach is that each wind turbine can react to grid disturbances in a different way, which depends on wind speed as seen by the wind turbine itself and by its dynamical conditions. Real wind data and a large WF connected to the grid in a dedicated simulation environment have been used to test the effectiveness of the proposed control strategy.

ABSTRACT This work proposes an innovative control technique for improving the contribution to the grid frequency regulation provided by a set of wind power generators belonging to a wind farm. Models of individual generators and of the conventional grid primary frequency control are developed and used for designing a model predictive controller. A proper estimation algorithm is also introduced in order to provide both the dynamical state of the wind turbines and the actual local wind conditions to the regulator. The availability of this data makes the control algorithm able to improve the participation of the whole wind farm to the frequency regulation by suitably coordinating and differentiating the contribution of the individual generators. The proposed strategy is tested on a large wind farm using a dedicated real-time/real-data simulation environment.

ABSTRACT This work proposes an innovative control technique for improving the contribution to the grid frequency regulation provided by a set of wind power generators belonging to a wind farm. Models of individual generators and of the conventional grid primary frequency control are developed and used for designing a model predictive controller. A proper estimation algorithm is also introduced in order to provide both the dynamical state of the wind turbines and the actual local wind conditions to the regulator. The availability of this data makes the control algorithm able to improve the participation of the whole wind farm to the frequency regulation by suitably coordinating and differentiating the contribution of the individual generators. The proposed strategy is tested on a large wind farm using a dedicated real-time/real-data simulation environment.

ABSTRACT The large scale deployment of distributed generation from renewable energy sources may undermine the network safe operation and may require network reinforcements. In order to avoid or postpone the infrastructural investments it is possible to exploit other resources. In this paper the operation of a load aggregator is simulated on the Swedish island of Gotland in different wind penetration condition to test two different business models, one oriented to the price following and the other oriented to the wind following. The adopted methodology is described and the results presented and commented.

ABSTRACT The large scale deployment of distributed generation from renewable energy sources may undermine the network safe operation and may require network reinforcements. In order to avoid or postpone the infrastructural investments it is possible to exploit other resources. In this paper the operation of a load aggregator is simulated on the Swedish island of Gotland in different wind penetration condition to test two different business models, one oriented to the price following and the other oriented to the wind following. The adopted methodology is described and the results presented and commented.

ABSTRACT The paper describes the definition and the validation of a methodology, based on an extension of the hosting capacity concept, aimed at assessing the effects of plug-in electric vehicles (PEVs) charging on low voltage distribution networks. An index (called time-dependent hosting capacity) is proposed, which enables to include in its formulation the charging duration, in order to point out the grid constraints. The validation of this index was performed through simulations on the CIGRÉ low voltage European reference grid. The simulations consisted in a series of power flow calculations while varying both the load conditions and the number of charging electric vehicles, assuming a constant daily energy need for all vehicles. Moreover, for some simulations the contribution of distributed generation to improve the quality of supply according to EN 50160 was also investigated.

ABSTRACT The paper describes the definition and the validation of a methodology, based on an extension of the hosting capacity concept, aimed at assessing the effects of plug-in electric vehicles (PEVs) charging on low voltage distribution networks. An index (called time-dependent hosting capacity) is proposed, which enables to include in its formulation the charging duration, in order to point out the grid constraints. The validation of this index was performed through simulations on the CIGRÉ low voltage European reference grid. The simulations consisted in a series of power flow calculations while varying both the load conditions and the number of charging electric vehicles, assuming a constant daily energy need for all vehicles. Moreover, for some simulations the contribution of distributed generation to improve the quality of supply according to EN 50160 was also investigated.

ABSTRACT This work aims to propose a state estimation procedure for electric distribution networks and to implement a simulation architecture in order to test it under several scenarios. Measures, obtained from the simulated field through a communication layer, and pseudo-measures, defined according to load and generation models, are combined in different shares to observe the algorithm performances and the effects on the estimation quality. The work also investigates the necessity of a correct load modeling of Medium Voltage/Low Voltage (MV/LV) substations where distributed generation significantly contributes in altering the net power injection at the LV side. The implemented State Estimation (SE) procedure will be installed in a real MV network located in the North of Italy (Sanremo) within a research project.

ABSTRACT This paper proposes an optimal charging strategy for plug-in electric vehicles (PEVs) to be used in electric distribution networks. The optimization algorithm is made up of two phases: 1) an optimal power flow calculation; and 2) a linear optimization. The former, while taking into account the power system technical constraints, sets the upper bounds to the recharge power for each vehicle and the latter defines the recharge profiles of each PEV. In order to test the effectiveness of the optimization algorithm, a case study was set up. The connection of 300 PEVs to the Conseil International des Grands Réseaux Électriques (CIGRÉ) European low voltage benchmark network has been simulated. The proposed algorithm has been compared with a nonoptimal charging strategy, which assigns a flat charging profile by dividing the energy requested by the desired recharge time. The results show that the optimization algorithm both complies with the energy requests set by the end users and with the technical operation limits of the network. This allows for PEVs to provide a basic—although of paramount importance—service to the grid: the smart charge.

ABSTRACT This work aims to propose a state estimation procedure for electric distribution networks and to implement a simulation architecture in order to test it under several scenarios. Measures, obtained from the simulated field through a communication layer, and pseudo-measures, defined according to load and generation models, are combined in different shares to observe the algorithm performances and the effects on the estimation quality. The work also investigates the necessity of a correct load modeling of Medium Voltage/Low Voltage (MV/LV) substations where distributed generation significantly contributes in altering the net power injection at the LV side. The implemented State Estimation (SE) procedure will be installed in a real MV network located in the North of Italy (Sanremo) within a research project.

An increase in the number of autophagic vacuoles and in the size of the dense and residual bodies was observed in the hepatocytes of rats fasted for 24 hours; moreover, the number of dense bodies was reduced. These data suggest that the previously reported acceleration in cell protein degradation caused by fasting can be accounted for by enhanced autography. The treatment with cycloheximide, which was previously found to prevent this proteolytic response, also prevents the appearance of signs of enhanced autophagic activity.

ABSTRACT This paper investigates the operation of a domestic heat load aggregator on the Swedish island of Gotland. In the considered business case the aim of the aggregator is to minimize the losses on the HVDC connection with the mainland matching local wind generation and load. A network model is implemented and static power flow simulations are performed to evaluate the aggregator profit and the effects of its actions on the network behavior. Various aggregator strategies are simulated in different wind penetration scenarios, several indices are calculated to compare the different cases on a quantitative base.