Increased S100B serum levels in diffuse dermatitis.
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Biomedical subjects
Publications and source records attributed to B Zappacosta.
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Tobacco smoke is involved in the pathogenesis of several diseases regarding different body systems, mainly cardiovascular and respiratory in addition to its local toxic effect in the oral cavity. The noxious effects of smoke compounds justify the high incidence of periodontal diseases, caries, and neoplastic diseases of oral tissues in smokers. Some toxic components of tobacco smoke, unsaturated and saturated aldehydes, could interact with thiol rich compounds, leading to structural and functional modification of these molecules. Previous papers have demonstrated an in vitro significant decrease of some enzymatic activities, both in plasma and in saliva, following external addition of aldehydes or exposure to cigarette smoke (CS). Furthermore, the same studies underlined the protective effect exerted by the addition of glutathione (GSH) against the damaging role of smoke aldehydes. In this study some salivary enzymes (lactic dehydrogenase [LDH], aspartate aminotransferase [AST] and amylase), and total GSH were measured in 20 volunteers smokers, before and just after smoking a single cigarette. All enzymatic activities showed a significant inhibition following a single cigarette, probably due to the interaction between smoke aldehydes and -SH groups of the enzyme molecules. Moreover, the percentage of the enzymatic inhibition showed a negative correlation with the basal level of salivary GSH. Our results emphasize that not only one cigarette is sufficient to impair the salivary enzymatic activities but also strengthen the proposed protective role of GSH against the noxious biochemical effects of CS.
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.
Ninety-nine patients bearing recurrent malignant glioma sequentially selected according to strict eligibility criteria (72 GBL and 27 AA) entered the study. All patients were previously managed with radiotherapy 60 Gy total dose and chemotherapy with nitrosoureas and platinum compounds. At recurrence they were subdivided in homogeneous groups, all treated with the same systemic chemotherapy protocol: 27 GBL (group A) only systemically treated, 20 GBL (group B) treated also locally by delivering 4mg of mitoxantrone every 20 days through the Ommaya reservoire, and 25 GBL (group C) treated with a second surgery and locally as group B. Of the AA group, 13/27 were treated locally trough the Ommaya reservoir after repeat surgery. A trend to different demographic features among subgroups (with locoregionally treated patients and patients undergoing repeat surgery being younger than the others) was seen in this non-randomized study, but this was not statistically significant. Median overall survival was 27, 26 and 15.5 months respectively for groups c, b and a (log-rank = 0.1). After tumor recurrence median survival was 16.8, 12 and 6.6 months respectively for groups c, b and a (log-rank = 0.001) For the 29 AA, overall survival was 48.5 and 100 months (log-rank = 0.03) if treated locally with second tumor debulking. Our results stress the opinion that a second operation could be indicated only if it is a part of a therapeutic protocol to allow a locoregional treatment. Moreover we can finally assume that local delivery of chemotherapy after tumor recurrence, possibly extends patients survival but certainly improves the number of long-survivors.
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.
OBJECTIVES: Patients with inflammatory bowel disease (IBD) have an increased risk of thrombotic complications. Moreover, a hypercoagulable state has been hypothesized as a contributing factor in the pathogenesis of IBD. Recently, a growing amount of interest has focused on mild-to-moderate hyperhomocysteinemia as a risk factor for thromboembolic disease. We aimed to evaluate the prevalence of hyperhomocysteinemia in patients with IBD and to investigate the contribution of genetic defects in the enzymes involved in homocysteine (Hcy) metabolism and vitamin status in determining increased levels of plasma total Hcy (tHcy). METHODS: The concentrations of tHcy, folate, and vitamin B12 as well as the prevalence of methylenetetrahydrofolate reductase (MTHFR) 677C to T mutation and the 68-bp insertion at exon 8 of cystathionine beta-synthase (CBS) were measured in patients with IBD and healthy controls. RESULTS: In all, 17 out of 64 IBD patients (26.5%) and four out of 121 (3.3%) controls had hyperhomocysteinemia with a statistically significant difference (p < 0.0001). No significant difference was found between IBD patients and controls with regard to the prevalence of homozygotes for the C677T variant (TT) of MTHFR or the prevalence of heterozygotes for the CBS-gene mutation (IN). Among the IBD patients the only independent factor significantly associated with hyperhomocysteinemia was folate deficiency (p = 0.0002), regardless of the MTHFR or the CBS genotype. CONCLUSIONS: IBD patients have a higher prevalence of hyperhomocysteinemia than do healthy controls. Folate deficiency is the only independent risk factor in developing hyperhomocysteinemia.
Haemoglobin (Hb) J-Sardegna [alpha50(CE8)His-->Asp] is a haemoglobin variant characteristic of subjects from the island of Sardinia. Here we report a study of the functional properties of both fetal and adult Hb J-Sardegna. The results indicate that adult Hb J-Sardegna displays an oxygen affinity that is higher than that of adult Hb only in the presence of 2,3-diphosphoglycerate (2,3-DPG). On the contrary, at 20 degrees C, the oxygen affinity of fetal Hb J-Sardegna is identical to that of normal fetal haemoglobin, both in the presence and in the absence of 2,3-DPG. A significant difference between these two systems (i.e. a higher oxygen affinity of fetal Hb J-Sardegna) shows up very clearly only when temperature is increased to 37 degrees C. Hence in fetal Hb, the main effect of the amino acid substitution is a decrease in the overall enthalpy change of oxygenation. The results outline the role of the alpha(1)-beta(1) interface in assessing the thermodynamics of oxygen binding. The functional properties of both adult and fetal Hb J-Sardegna have been interpreted at the structural level in light of the results obtained by a computational modelling approach performed in comparison with HbA and Hb Aichi, a variant characterized by a different mutation [alpha50(CE8)His-->Arg] at the same position.
The natural history of neuroectodermal tumors is still debated as far as prognostic factors are concerned; the same uncertainty applies to the optimal radiotherapy schedule and even more to the presumptive additive effect of chemotherapy. The rarity of these tumors and the heterogeneity of management make interpretation of literature data also more difficult. We evaluated clinical course in a cohort of 39 patients, including 31 with medulloblastoma (MB) and 8 with primitive neuroectodermal tumors (PNET). All patients were treated with radiotherapy, a standardized chemotherapy protocol including PCV scheme, and a second-line chemotherapy with cisplatin and etoposide (VP16) at recurrence. In 27 patients, intrathecal chemotherapy was also delivered. Median follow-up was 10.8 years. Overall, PNET had a worse outcome as compared to MB: median survival times were 42.8 vs. 92.6 months, respectively (p = 0.05). At 5 years, 45% of MB patients are alive. No significant difference in disease-free period was found between patients of different age, desmoplastic variant, tumor localization, or extent of surgery. Patients considered to be "high risk" had a significantly shorter disease-free period as compared with low-risk patients (27 vs. 54.7 months, p = 0.04). Systemic or intrathecal chemotherapy did not influence progression-free survival (PFS). However, in the majority of chemotherapy-treated patients, a low-dose craniospinal radiotherapy was also delivered. This combination of treatments may have avoided the expected increased percentage of failure. Moreover, more than half of recurrent patients had a partial response to chemotherapy that extended survival for approximately 3 years. Repeated surgery and chemotherapy at recurrence favorably influenced survival time.
BACKGROUND: Human RBC metabolism is modulated by the cell oxygenation state. Among other mechanisms, competition of deoxyhemoglobin and some glycolytic enzymes for the cytoplasmic domain of band 3 is probably involved in modulation. This metabolic modulation is connected to variations in intracellular NADPH and ATP levels as a function of the oxygenation state of the cell, and, consequently, it should have physiologic relevance. The present study investigates the effect of storage on this metabolic modulation and its relationship with the alteration of membrane protein composition. STUDY DESIGN AND METHODS: RBCs stored in CPD-saline-adenine-glucose-mannitol were assayed for glucose uptake and partition between glycolysis and the pentose phosphate pathway at high and low oxygen saturation by nuclear magnetic resonance spectroscopy after 1, 14, 21, 35, and 42 days of storage. Membrane protein composition was determined by SDS-PAGE on Days 1, 14, 35, and 42. Metabolic values and 2,3 DPG concentration were also measured after rejuvenation for 1 hour at 37 degrees C with pyruvate-inosine-phosphate-adenine solution on Day 21. RESULTS: Metabolic differences between RBCs incubated at high and low oxygen saturation decreased during storage, and, on Day 35, the two groups did not have significant differences (p = 0.111). SDS-PAGE showed that membrane protein composition was concurrently modified. The percentage of unmodified band 3 decreased during storage, principally between Days 14 and 35. In rejuvenated RBCs, oxygen-dependent modulation was not restored. CONCLUSIONS: RBCs stored in CPD-saline-adenine-glucose-mannitol do show a progressive loss of oxygen-dependent metabolic modulation, which is not restored after rejuvenation and which seems partly related to modifications in membrane proteins, mainly band 3.
Hyperhomocysteinemia is an established risk factor for deep vein thrombosis. Factor V Leiden has been reported to potentiate the thrombotic risk related with severe hyperhomocysteinemia, being more represented in thrombotic patients with homocystinuria as compared with patients without a history of thrombosis. The results concerning the interaction between moderate hyperhomocysteinemia and inherited thrombophilic factors such as Factor V Leiden or the prothrombin G20210A mutation are contradictory. The relative risk for venous thrombosis has been reported to be increased 10- to 50-fold in patients carrying both hyperhomocysteinemia and inherited thrombophilia in comparison with normal controls, suggesting a synergistic interaction, yet other studies failed to confirm such conclusion. The heterogeneity of these findings is in part due to the small number of individuals with double defects, leading to statistically unreliable results. Genotyping for mutations that are possible causes of moderate hyperhomocysteinemia, such as the thermolabile variant (C677T) of methylenetetrahydrofolate reductase (MTHFR), does not seem useful to identify individuals at higher risk for venous thromboembolism. In fact, in most of the studies the presence of the C677T MTHFR homozygous genotype does not increase the thrombotic risk associated with Factor V Leiden or the prothrombin mutation.
The effect of O2 exposure, expressed by mean daily fractional inspired oxygen concentration (FiO2), was evaluated during the first 6 d of life in the tracheobronchial aspirate fluid of 16 mechanically ventilated preterm infants in terms of both antioxidant response and oxidative damage, by measuring total antioxidant activity, uric acid concentrations and protein carbonyl content. Each day linear regression analysis was performed and a positive correlation was found between total antioxidant activity and FiO2 during the study period, especially on day 2 of life (r = 0.91, p < 0.0001), but uric acid correlated only in the first 3 d, especially on the 2nd day (r = 0.83, p < 0.0001). No correlation was found between carbonyl content and FiO2. The highest values of total antioxidant activity (416 and 790 micromol l(-1)) were found in 2 babies ventilated with highest FiO2: 1 and 0.80, respectively. Total antioxidant activity was not detectable or was very low in the babies not requiring O2 therapy. The highest value of uric acid (270 micromol l(-1)) was found in the baby ventilated with 100% oxygen. Uric acid concentrations obtained in these babies were much higher then those reported in the bronchoalveolar lavage fluid of adults. Preterm babies seem to have an antioxidant response in the tracheobronchial aspirate fluid following an oxidative stress and uric acid may be physiologically important as an antioxidant of the respiratory tract, especially during the first days of life.
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.
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.
Mild hyperhomocysteinaemia is an established risk factor for deep vein thrombosis (DVT); few data concerning its potential interaction with thrombophilic genotypes are available at the present time. We investigated 121 thrombosis-free individuals and 111 patients with at least one objectively confirmed episode of DVT. A thrombophilic condition (deficiency in antithrombin, protein C and S, factor V Leiden, prothrombin G20210A) was detected in 25.2% of the patients; mutant factor V or prothrombin genotypes were present in 6.6% of the controls. Hyperhomocysteinaemia was found in 14.4% of patients and 3. 3% of the controls, with a 3.7-fold increase in risk for DVT (95% CI 1.1-12.3). Adoption of different cut-off levels for definition of hyperhomocysteinaemia did not substantially change the magnitude of the risk. Carriership of both hyperhomocysteinaemia and factor V Leiden or prothrombin G20210A was detected in 2.7% of patients for each combination and in none of the controls. An approximate estimate of 30-fold increased risk in carriers of both hyperhomocysteinaemia and factor V Leiden and 50-fold increased risk in carriers of both hyperhomocysteinaemia and prothrombin G20210A was calculated, suggesting a synergistic interaction between hyperhomocysteinaemia and such thrombophilic genotypes. Yet statistical analysis is highly unstable due to the small number of individuals with combined defects. Further investigations on large series of patients are needed.
Vascular endothelial injuries induced by intravascular administration of radiographic contrast agents may be clinically relevant to the development of thrombosis and platelet activation. In this connection, we investigated the in vitro effects induced by iodamide, iopamidol, and ioxaglate on vascular endothelial ADPase activity and tissue plasminogen activator (t-PA) release in bovine aortic endothelium, in order to extend knowledge required to evaluate endothelial compatibility of radiographic contrast media. Undiluted and Tris-diluted contrast agent formulations were employed, and mannitol and sucrose hyperosmolar solutions were used as comparison. Results demonstrated that the high-osmolar ionic contrast agent iodamide, and to a lesser extent, the low-osmolar nonionic agent iopamidol, stimulated endothelial ADPase activity of the aortic endothelium; the low-osmolar ionic agent ioxaglate left endothelial ADPase activity unchanged. Furthermore, the diluted formulations of iodamide and iopamidol, as well as high-osmolar mannitol and sucrose solutions, were devoid of activity in ADPase. This suggests that the endothelial ADPase stimulation induced by both radiographic contrast media was a hyperosmolar-independent pharmacodynamic activity. Iopamidol and ioxaglate reduced endogenous t-PA release from bovine aortic endothelium only in undiluted formulation, while iodamide showed this inhibiting action in both diluted and undiluted formulations. No effect was observed when using mannitol solutions at different osmolarity values. Our in vitro findings agree with published data on the different thrombotic tendency attributed to the contrast agents used, suggesting endothelial enzymatic activities (ADPase and t-PA release) as suitable tools for evaluating endothelial vessel wall compatibility with radiographic contrast media.
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.
Molecular analysis of spinocerebellar ataxias revealed a pathologic GAA expansion in the gene encoding frataxin in six adult patients from three families. These patients, carrying expanded alleles in the low-range size, had an exceptionally late onset and lacked cardiomyopathy, pointing to phenotypic variability of Friedreich's ataxia. Both mitotic and gametic instability of the expanded triplet repeat were present in these families.
The aim of the study was to evaluate the usefulness of ferritin as an early marker in the diagnosis of renal cell carcinoma (RCC). The Authors dosed the pre-operative concentration of ferritin in the sera of 22 patients (16 males and 6 females) affected by stage I-II, according to Robson's classification, RCC. Plasma concentrations of ferritin were matched for the presence of tumor and for the tumor volume. The results did not evidence any relationship between plasma concentration of ferritin and the presence of renal cancer. In the same way a linear correlation did not show any significant relationship between serum concentration of ferritin and tumor diameter. Ferritin does not seem to be a usefull marker in the early diagnosis of renal cell carcinoma.