PubMed Health⌕ Search

Biomedical subjects

P De Sole

Publications and source records attributed to P De Sole.

At least 19 recordsLinked to original sources
PubMed2006

Alterations of energy metabolism and glutathione levels of HL-60 cells induced by methacrylates present in composite resins.

OBJECTIVES: Methacrylic compounds such as 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA) and bisphenol A glycerolate (1 glycerol/phenol) dimethacrylate (Bis-GMA) are largely present in auto- or photopolymerizable composite resins. Since the polymerization reaction is never complete, these molecules are released into the oral cavity tissues and biological fluids where they could cause local adverse effects. The aim of this work was to verify the hypothesis that the biological effects of HEMA, TEGDMA and Bis-GMA - at a non-cytotoxic concentration - depend on the interaction with mitochondria and exert consequent alterations of energy metabolism, GSH levels and the related pathways in human promyelocytic cell line (HL-60). METHODS: The biological effects of methacrylic monomers were determined by analyzing the following parameters: GSH concentration, glucose-6-phosphate dehydrogenase (G6PDH) and glutathione reductase (GR) activity, oxygen and glucose consumption and lactate production along with cell differentiation and proliferation. RESULTS: All monomers induced both cellular differentiation and decrease in oxygen consumption. Cells treated with TEGDMA and Bis-GMA showed a significant enhancement of glucose consumption and lactate production. TEGDMA and HEMA induced GSH depletion stimulating G6PDH and GR activity. CONCLUSIONS: All the monomers under study affect the metabolism of HL-60 cells and show differentiating activity. Since alterations in cellular metabolism occurred at compound concentrations well below cytotoxic levels, the changes in energy metabolism and glutathione redox balance could be considered as potential mechanisms for inducing clinical and sub-clinical adverse effects and thus providing useful parameters when testing biocompatibility of dental materials.

Bisphenol A-Glycidyl Methacrylate↗
PubMed2006

Decreased chemiluminescence in leukocyte adhesion deficiency presenting with recurrent sepsis, amoebiasis and Candida albicans urinary tract infection.

Leukocyte adhesion deficiency (LAD) is a rare disorder of cellular immunity, generally due to various mutations producing reduced or altered expression of membrane integrins. The authors report a case of LAD due to integrins expression imbalance. LAD was suspected after recurrent sepsis, fungal infection and amoebiasis with persistent leukocytosis. Neutrophils were studied with chemiluminescence showing decreased functional activity: up to now, this seems the first chemiluminescence study of neutrophil function and the first report of amoebiasis at the onset in LAD.

Animals↗
PubMed2003

Bezafibrate induces a mitochondrial derangement in human cell lines: a PPAR-independent mechanism for a peroxisome proliferator.

Bezafibrate is a hypolipidemic drug that belongs to the group of peroxisome proliferators because it binds to peroxisome proliferator-activated receptors type alpha (PPARs). Peroxisome proliferators produce a myriad of extraperoxisomal effects, which are not necessarily dependent on their interaction with PPARs. An investigation on the peculiar activities of bezafibrate could clarify some of the molecular events and the relationship with the biochemical and pharmacological properties of this class of compounds. In this view, the human acute promyelocytic leukemia HL-60 cell line and human rabdomiosarcoma TE-671 cell line were cultured in media containing bezafibrate and a number of observations such as spectrophotometric analysis of mitochondrial respiratory chain enzymes, NMR metabolite determinations, phosphofructokinase enzymatic analysis, and differentiation assays were carried on. Bezafibrate induced a derangement of NADH cytochrome c reductase activity accompanied by metabolic alterations, mainly a shift to anaerobic glycolysis and an increase of fatty acid oxidation, as shown by NMR analysis of culture supernatants where acetate, lactate, and alanine levels increased. On the whole, the present results suggest a biochemical profile and a therapeutic role of this class of PPARs ligands more complex than those previously proposed.

Acetates↗
PubMed2001

A fast chemiluminescent method for H(2)O(2) measurement in exhaled breath condensate.

BACKGROUND: Breath condensate can give useful information on volatile compounds produced at alveolar level. Actual concentration of H(2)O(2) in breath condensate is dependent on its production at alveolar level and on the efficacy of the detoxifying systems, catalase, glutathione peroxidase, etc. METHODS: In the present paper, a simple chemiluminescent method for the determination of the H(2)O(2) collected in exhaled breath is shown and data of both smokers and nonsmokers volunteers are presented. RESULTS: The chemiluminescent response is linear up to 100 micromol/l H(2)O(2). The analytical sensitivity is about 0.01 micromol/l. Most of the nonsmokers have a H(2)O(2) content lower than 0.05 micromol/l, while smokers have a content ranging from 0.1 to 0.6 micromol/l.

Adult↗
PubMed2001

Helicobacter pylori CagA-positive strains affect oxygen free radicals generation by gastric mucosa.

BACKGROUND: Helicobacter pylori plays a key role in production of reactive oxygen metabolites (ROMs). However, the importance of virulent CagA-positive H. pylori strains remains to be determined. The aim of this study was to assess ROMs production in gastric biopsies of patients infected by H. pylori. Results were correlated to CagA status and acute inflammatory infiltration. METHODS: Patients undergoing gastroscopy were enrolled. H. pylori infection was assessed by histology and 13C urea breath test. CagA status was assessed through serology. ROMs were assayed in gastric biopsies by luminol-enhanced chemiluminescence (CLS). Gastric mucosal inflammation was histologically graded and neutrophils were individually counted. Macroscopical damage was scored according to a modified Lanza score. RESULTS: 40 out of 60 patients evaluated were H. pylori (HP) positive. Of the 40 infected patients, 24 were CagA-positive. CLS emission was significantly higher in HP-CagA-positive patients than in HP-CagA-negatives and uninfected. ROMs production showed a significant correlation to neutrophil infiltrate in all groups. CONCLUSIONS: Gastric mucosa of patients infected by HP-CagA-positive strains is characterized by a higher generation of ROMs and by greater neutrophil counts than that observed in HP-CagA-negative subjects. Since ROMs production is associated with DNA oxidative damage, a long-term stimulation by these strains might be relevant in the pathogenesis of gastric malignancies. Assessment of CagA status might be useful to discriminate patients in which H. pylori eradication is advisable.

Antigens, Bacterial↗
PubMed2001

Is homocysteine a pro-oxidant?

High plasma homocysteine concentrations have been found to be associated with atherosclerosis and thrombosis of arteries and deep veins. The oxidative damage mediated by hydrogen peroxide production during the metal-catalyzed oxidation of homocysteine is to date considered to be one of the major pathophysiological mechanisms for this association. In this work, a very sensitive and accurate method was employed to measure the effective production of H2O2 during homocysteine oxidation. Furthermore, the interaction of homocysteine with powerful oxidizing species (hypochlorite, peroxynitrite, ferrylmyoglobin) was evaluated in order to ascertain the putative pro-oxidant role of homocysteine. Our findings indicate that homocysteine does not produce H2O2 in a significant amount (1/4000 mole/mole ratio of H2O2 to homocysteine). Moreover, homocysteine strongly inhibits the oxidation of luminol and dihydrorhodamine by hypochlorite or peroxynitrite and rapidly reduces back ferrylmyoglobin, the oxidizing species, to metmyoglobin. All these results should, in our opinion, lead to a rethinking of the commonly held view that homocysteine oxidation is one of the main causative mechanisms of cardiovascular damage.

Animals↗
PubMed2000

Antimicrobial and antioxidant activities of Feijoa sellowiana fruit.

The present study was designed to evaluate the antibacterial and antioxidant activities of an aqueous extract from the tropical Feijoa sellowiana Berg. fruit which is widely used for human food. The extract was tested against gram-positive and gram-negative bacteria by a broth dilution test and on human whole blood leukocytes, as well as isolated neutrophils using a chemiluminescence (CL) assay. The extract inhibited bacterial growth; Pseudomonas aeruginosa, Enterobacter aerogenes and Enterobacter cloacae were the most sensitive. The fruit extract significantly decreased CL emission from human whole blood phagocytes and isolated polymorphonuclear leukocytes whether they were activated or not by soluble or phagocytic stimuli. F. sellowiana showed both antibacterial and antioxidant properties and therefore its extract might be used as a new multifaceted drug.

Anti-Bacterial Agents↗
PubMed1999

Effect of smoking one cigarette on antioxidant metabolites in the saliva of healthy smokers.

Concentrations of glutathione, uric acid and total antioxidant activity, expressed as Trolox (a water-soluble vitamin E analogue) equivalent, were measured in the saliva of healthy non-smokers and smokers before and just after smoking a single cigarette. There was no statistically significant difference between smokers and non-smokers in uric acid concentrations and total radical-trapping antioxidant capacity, but glutathione concentrations were significantly (p < 0.05) higher in smokers. Smoking of a single cigarette induced a significant reduction in glutathione concentration (p < 0.05). Salivary antioxidant power may affect individual sensitivity toward tobacco stress.

Adult↗
PubMed1999

Purine metabolites and malondialdehyde in platelets of diabetic patients.

The concentration of some of the purine nucleotides and their metabolites together with that of malondialdehyde (MDA) have been measured in resting and stimulated platelets of type 1 and type 2 diabetic patients. While control platelets show a net decrease of guanosine triphosphate (GTP) (3.1 vs. 2.3 nmol per 10(9) platelets) and guanosine diphosphate (GDP) (3.0 vs. 2.0 nmol per 10(9) platelets) and a significant increase of adenosine (0.04 vs. 0.55 nmol per 10(9) platelets) with platelet stimulation, platelets of type 1 and type 2 diabetic patients have a lesser change of these metabolites (GTP, 2.6 vs. 2.4; GDP, 2.3 vs. 2.4; adenosine, 0.04 vs. 0.30 (P < 0.05 vs. control) nmol per 10(9) platelets in type 1 diabetics; GTP, 2.4 vs. 2.7; GDP, 2.4 vs. 2.1; adenosine, 0.08 vs. 0.32 (P < 0.05 vs. control) nmol per 10(9) platelets in type 2 diabetics). These results indicate that the change (stimulated minus resting) of GTP, GDP and adenosine in diabetic platelets is significantly different from that of controls (P < 0.001). Moreover, the amount of MDA produced during platelet activation seems to be lower than controls only in type 2 diabetes (1.81 vs. 2.86 nmol per 10(9) platelets, P < 0.05). These results seem to indicate that a difference in the pattern of platelet nucleotides could be an important feature even in well-controlled diabetes, while MDA is probably modified only in association with the late vascular complications of diabetes.

Adenosine↗
PubMed1998

Antioxidant properties of Lunularia cruciata (Bryophyta) extract.

The effects of Lunularia cruciata (L.) Dum (Bryophyta) acetonic extract was studied in vitro by means of luminol-dependent chemiluminescence (CL) emission from human peripheral whole blood phagocytes and isolated polymorphonuclear leukocytes (PMNs). L. cruciata adult thalli underwent extraction with acetone. CL emission was evaluated in an automated luminometer, measuring the oxygen free-radical production by phagocytes incubated with opsonized zymosan (OZ) or phorbol myristate acetate (PMA), in absence or in presence of various concentrations of L. cruciata extract. The CL results indicated that L. cruciata induced significant changes in light emission from whole blood phagocytes, as well as isolated PMNs. Its inhibitory activity was more evident when resting isolated PMNs were studied. When the cells were activated, the greatest inhibitory effect was observed with PMA. The L. cruciata activity could be caused by several compounds, such as flavonoids and/or sesquiterpenes, present in the acetonic extract.

Antioxidants↗
PubMed1997

The priming effect of gemfibrozil on reactive oxygen metabolism of phagocytic leucocytes. An intriguing side effect.

Gemfibrozil is an antihyperlipidaemia agent used in therapy to reduce the occurrence of coronary heart disease. Considering the biochemical and pharmacological peculiarities of this class of drugs, we investigated the influence of a single oral therapeutic dose of gemfibrozil on the reactive oxygen metabolism of phagocytic leucocytes. Analysis was carried out adopting a chemiluminescence assay. Results clearly indicate that gemfibrozil, acting as a primer, significantly enhances the induced reactive-oxygen-species (ROS) production by overall blood phagocytes (increment of Stimulation Index (SI) = +52% with respect to time 0 values; P < 0.01), by polymorphonuclear leucocytes (increment of SI = +28% with respect to control values; P < 0.01) and by monocytes (increment of SI = +83% with respect control values; P < 0.001), when these cells are stimulated by phorbol myristate acetate. This iatrogenic derangement of ROS metabolism could explain, at least in part, the occurrence of some side effects that occur in treatment with fibrates.

Adult↗
PubMed1997

Resting and stimulated human polymorphonuclear leucocytes from type-2 diabetic patients: change in purine nucleotide pattern.

It is known that polymorphonuclear leucocytes are deeply involved in the inflammatory complications of diabetes mellitus, showing many functional and biochemical abnormalities. Because adenine and guanine metabolites exert an important role in many metabolic aspects of phagocytic cells, we have investigated the pattern of purine metabolites during the respiratory burst of polymorphonuclear leucocytes in order to characterize any difference that may be significantly correlated with the abnormal neutrophil function of diabetic patients. The results obtained show clearly that polymorphonuclear leucocytes from diabetic patients are characterized by an abnormal pattern of purine nucleotides and their metabolites. In particular, the concentration of adenine and guanine triphosphates and the net amount of adenosine triphosphate hydrolysed during neutrophil stimulation by phorbol ester is higher in diabetic than in control cells. Moreover, higher values of adenosine monophosphate, inosine monophosphate and inosine have been found in diabetic cells. The behaviour of guanosine triphosphate is highly interesting. In fact, in addition to the higher concentration found in diabetic polymorphonuclear leucocytes, stimulation by phorbol ester induces a net decrease in guanosine triphosphate whereas control neutrophils show a slight increase. These findings have been associated with the ease with which diabetic neutrophils undergo metabolic activation and sustain an inflammatory response.

Adenine Nucleotides↗
PubMed1997

Detection of arrhythmogenic cellular magnesium depletion in hip surgery patients.

The use of high-dose magnesium infusions in critically ill and surgical patients is increasing. This practice is associated with considerable risk of toxicity, as no reliable criteria are currently available to detect significant intracellular magnesium depletion. We have evaluated, before and after surgery, 33 elderly patients with hip fracture, by 24-h Holter ECG monitoring, Doppler echocardiography and serum chemistry; lymphocyte magnesium was measured using atomic absorption spectrophotometry. The severity of ventricular arrhythmias increased, and serum and mononuclear magnesium concentrations decreased significantly after surgery. Decreases in either serum magnesium concentrations > 0.125 mmol litre-1 or cellular magnesium > 6 nmol mg-1, but not serum or lymphocyte absolute magnesium concentrations, were associated with postoperative development of repetitive arrhythmias. Variations in serum magnesium concentrations correlated with intracellular decreases, and yielded good accuracy in predicting the postoperative worsening of arrhythmias. Thus perioperative differences in serum magnesium concentrations reflected intracellular variations and allowed us to identify patients with clinically relevant cellular magnesium depletion.

Aged↗
PubMed1995

Effects of gemfibrozil on the oxygen transport properties of erythrocytes.

1. In the present study we have investigated the effects of the relatively low plasma concentrations of gemfibrozil (GFZ) found in clinical practice on the oxygen dissociation curve (ODC) of erythrocytes. 2. ODCs were measured at 30 degrees C and 37 degrees C and at pH 7.4: a) both on HbA solution and erythrocytes incubated in vitro with gemfibrozil and clofibric acid; b) on erythrocytes from healthy volunteers treated with a single oral dose of gemfibrozil. 3. These experiments showed a significant drug-induced shift of the ODC towards lower O2 affinity values without any significant modification of metabolic parameters of erythrocytes such as intracellular pH and intraerythrocytic levels of ATP and DPG. 4. In our experimental conditions gemfibrozil appears to lower both in vitro and in vivo, the partial pressure of oxygen required to give 50% of the haemes saturated with oxygen (P50) of erythrocytes from the control value of 24 +/- 0.5 mm Hg to 29 +/- 0.5 mm Hg (mean +/- s.d.; P < 0.02 by ANOVA). 5. These data clearly indicate that therapeutic doses of gemfibrozil may influence the oxygen transport properties of red cells. This effect could have relevant pharmacological and toxicological implications.

2,3-Diphosphoglycerate↗
PubMed1995

Platelet lactate dehydrogenase activity in systemic lupus erythematosus: correlation with anticardiolipin antibodies.

OBJECTIVE: To evaluate lactate dehydrogenase (LDH) activity in platelet subpopulations in systemic lupus erythematosus (SLE) and to correlate platelet LDH activity with concentrations of anticardiolipin antibody (aCL). METHODS: Twelve female patients with SLE and 12 age matched female control subjects were studied. Platelets were separated on the Percoll gradient, their density values controlled by density marker beads. LDH activity was measured after platelet lysis, expressed as nU/fl. ELISA were used to measure levels of IgG and IgM aCL. RESULTS: A significant increase of LDH activity with a significant correlation to IgG and IgM aCL were found in small, light platelets with a volume < 5 mu 3 compared to large, dense platelets and to controls. LDH activity did not correlate with immunoglobulin classes, anti-DNA antibodies, and complement fractions in small and large SLE platelets. CONCLUSION: Our data suggest a possible chronic activation of subpopulations of small platelets in patients with SLE independent of thrombotic process. Low levels of aCL can mediate small platelet activation. Quantitative and qualitative analysis of the small, light platelets can serve a clinical diagnostic purpose as an in vivo platelet activation index in SLE.

Adolescent↗
PubMed1995

Lactate dehydrogenase activity of platelets in diabetes mellitus.

Lactate dehydrogenase (L-lactate : NAD+ oxidoreductase, EC 1.1.1.27) activity has been measured on the subpopulations of platelets obtained from blood of diabetic patients. Small, but not large platelets show a lactate dehydrogenase activity higher than that of controls. Moreover, a positive statistically significant correlation was found between the activity of small platelets and the percent of glycated haemoglobin, while no correlation was obtained in the case of large platelets. Since we previously demonstrated that lactate dehydrogenase activity of small platelets is exceedingly high in some clinical and experimental conditions, our results not only confirm the involvement of platelets in diabetes but provide more evidence in support of our previous hypothesis of a relationship between lactate dehydrogenase and in-vivo platelet activation.

Adult↗
PubMed1994

Serum coenzyme Q10 in uremic patients on chronic hemodialysis.

In a group of 48 chronic hemodialysis patients, serum levels of coenzyme Q10 (CoQ) have been measured and appeared abnormally low in 62% of cases. Figures were positively correlated to those of serum vitamin E (vit E), although the latter were within a normal range. The chronic hemodialysis (CHD) patients with normal serum values of CoQ exhibited higher blood triglycerides. Pathologically low levels of serum vit E were found only in uremic subjects on conservative regimen with dietary restrictions and low compliance to protein-caloric intake. The reduced CoQ levels may contribute to the defective serum antioxidant activity and the increased peroxidative damage in uremic patients on CHD.

Aged↗