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Biomedical subjects

G Pagano

Publications and source records attributed to G Pagano.

At least 55 records · Page 3Linked to original sources
PubMed2001

Factors affecting R6 fungicide toxicity on sea urchin fertilization and early development: roles of exposure routes and mixture components.

A technical fungicide mixture, R6 and its components, cymoxanil (CYM) and cupric oxychloride (Cu-OCl), were tested by sea urchin bioassays (Paracentrotus lividus and Sphaerechinus granularis). A set of toxicity endpoints was evaluated including both lethal and sublethal effects with the following endpoints: (a) acute embryotoxicity, (b) developmental defects, (c) changes in sperm fertilization success, (d) transmissible damage from sperm to the offspring, and (e) cytogenetic abnormalities. Acute effects on developing embryos were observed as early (prehatch) mortality at R6 levels > or =25 microg/ml. The pesticide mixture R6 was tested at realistic concentrations, ranging from 25 ng/ ml to 2.5 microg/ml, and the two components, CYM and Cu-OCl, were tested, either alone or in mixture, at concentrations equal to their levels in the corresponding R6 solutions. R6 was either dissolved in filtered seawater (water only, W-O), or spiked in "pristine" silt-clay sediment or soil samples before bioassays. Developmental toxicity of R6, following W-O dissolution, displayed a significant dose-related increase of larval malformations and differentiation arrest at concentrations of 750 ng/ml to 2.5 microg/ml both in P. lividus and in S. granularis larvae. Developmental toxicity was removed in spiked sediment up to R6 nominal levels (25 microg/ml), 10-fold above the embryotoxic R6 levels in W-O exposure. No significant developmental toxicity was exerted by CYM or Cu-OCl (W-O exposure) up to their concentrations equivalent to 2.5 microg/ml R6. The laboratory-prepared mixture of CYM and Cu-OCl, in the same concentration range, only resulted in minor effects, as larval retardation, suggesting the presence of toxic impurities (or additional components) in the R6 formulation. When sperm from either P. lividus or S. granularis were exposed to R6 before fertilization, a W-O exposure resulted in a dose-related decrease in fertilization of P. lividus sperm (up to 250 microg/ml R6), whereas S. granularis sperm underwent a significant increase of fertilization rate at the highest R6 nominal levels (up to 25 microg/ml). Equivalent CYM or Cu-OCl levels were ineffective on sperm fertilization success in both species. The offspring of S. granularis sperm exposed to 25 microg/ml R6 showed a significant increase in larval malformations, which were not detected in the offspring of R6-exposed P. lividus sperm. Again, CYM or Cu-OCl was unable to exert any transmissible damage from sperm to the offspring in either species. The present study raises the case of possible discrepancies between toxicity of a technical mixture and of its analytical-grade components, also providing evidence for a loss of pesticide toxicity following dispersion in an environmental matrix such as sediment or soil.

Acetamides↗
PubMed2001

Diepoxybutane and mitomycin C toxicity is associated with the induction of oxidative DNA damage in sea urchin embryos.

Diepoxybutane (DEB)- and mitomycin C (MMC)-associated toxicity was investigated in embryos from the sea urchin (SU) species Sphaerechinus granularis. DEB- and MMC-induced toxicity resulted in S. granularis embryos and larvae at concentrations ranging 10(-5) to 10(-4) M DEB, and 3 x 10(-6) to 3 x 10(-5) M MMC, in terms of larval malformations, developmental arrest and mortality. The formation of DNA oxidative damage, 8-hydroxy-2'-deoxyguanosine (8-OHdG) was measured in DEB- and in MMC-exposed embryos (at gastrula stage). A dose-dependent increase in 8-OHdG levels was observed that was significantly correlated with DEB- and MMC-induced developmental defects. The results lend further support to the body of evidence associating both DEB and MMC toxicity with oxidative stress, including DNA oxidative damage.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2001

Low HDL-cholesterol: a component of the metabolic syndrome only in the presence of fasting hypertriglyceridemia in type 2 diabetic patients.

The relation between isolated low HDL-cholesterol and the components of the metabolic syndrome is poorly known in type 2 diabetes. We evaluated cardiovascular risk parameters in type 2 diabetic patients with low HDL-cholesterol, compared to those with low HDL-cholesterol and hypertriglyceridemia, isolated hypertriglyceridemia and normal lipid parameters. Patients with low HDL-cholesterol/high triglycerides had higher BMI (29.6 +/- 5.7 vs 27.9 +/- 4.4 or vs 28.1 +/- 5.2 kg/m(2) ), prevalence of obesity (69% vs 55% or vs 54%), higher levels of uric acid (339.0 +/- 83.3 vs 303.3 +/- 95.2 or vs 303.3 +/- 89.2 micromol/l) and C-peptide (0.76 +/- 0.40 vs 0.63 +/- 0.33 or vs 0.63 +/- 0.36 nmol/l) and number of components of the metabolic syndrome (27% patients with all the components) compared to patients with isolated low HDL-cholesterol or normal subjects, respectively. A similar pattern of values was evident in patients with isolated hypertriglyceridemia. With logistic regression analysis, BMI and uric acid levels were significantly associated with the presence of hypertriglyceridemia (both isolated or associated with low HDL-cholesterol), while patients with isolated low HDL-cholesterol and those without dyslipidemia displayed a similar more favourable metabolic pattern. These results indicate that low HDL-cholesterol is a component of the metabolic syndrome only in the presence of fasting hypertriglyceridemia in type 2 diabetic patients.

Aged↗
PubMed2001

Preprandial combination of lispro and NPH insulin improves overall blood glucose control in type 1 diabetic patients: a multicenter randomized crossover trial.

BACKGROUND AND AIM: While lispro insulin has been reported to lower postprandial blood glucose concentrations, less consistent effects have been shown for glycosylated hemoglobin (HbA1c) levels. Aim of this study was to determine whether pre-meal association of NPH, an intermediate-acting insulin, with lispro improves overall glycemic control in type 1 diabetic patients. METHODS AND RESULTS: Eighty-five type 1 diabetic patients were studied in a multicenter randomized comparative (human regular vs lispro insulin) crossover (3-month) study in which NPH insulin was given as a dinner or bedtime injection and at breakfast and lunch if necessary. The number of injections was kept constant: 42% and 58% of patients injected insulin 3 and 4 times per day, respectively. Fasting and preprandial blood glucose levels were similar, while postprandial levels improved after lispro compared to human regular insulin (breakfast: 8.28 +/- 2.39 vs 9.28 +/- 2.72 mmol/l; lunch: 8.33 +/- 2.67 vs 9.06 +/- 2.67 mmol/l, dinner: 8.06 +/- 2.72 vs 9.28 +/- 2.44 mmol/l, ANOVA: p = 0.003). HbA1c also improved after lispro: 8.1 +/- 0.9 vs 8.3 +/- 0.8%, p < 0.05. The rate of hypoglycemia was similar. Patients showed better acceptance of lispro treatment (p < 0.001). CONCLUSIONS: Lispro improves overall blood glucose control in type 1 diabetic patients without increasing the incidence of hypoglycemia. This can be achieved by an optimal combination of lispro insulin with NPH whenever the time intervals between meals are too long.

Adolescent↗
PubMed2000

Spectrin changes occur in erythrocytes from patients with Fanconi's anemia and their parents.

Fanconi's anemia (FA) is a clinically and genetically heterogeneous disease which has been hypothesized to be defective in the detoxification of reactive oxygen species. In this work we report the results obtained by morphometric analyses on the red blood cells (RBCs) from FA patients and their parents. We found that a high rate of erythrocytes from both homozygous and heterozygous subjects was significantly altered. RBCs underwent in fact cytoskeleton-dependent modifications, in particular of spectrin molecule, leading to cell shrinking and blebbing. We hypothesize that these changes may be the result of an oxidative imbalance that probably lead to alterations of RBC plasticity- and deformation-associated functions. Moreover, our results also suggest the possibility to identify FA carriers by the existence of RBC abnormalities.

Adolescent↗
PubMed2000

Cytoskeleton alterations of erythrocytes from patients with Fanconi's anemia.

Fanconi's anemia (FA) is a very rare genetically heterogeneous disease which has been hypothesized to be defective in the detoxification of reactive oxygen species. In this work we report the results obtained by morphometric and biochemical analyses on the red blood cells (RBCs) from FA patients. With respect to RBCs from healthy donors the following changes have been detected: (i) a variety of ultrastructural alterations, mainly surface blebbing typical of acanthocytes and stomatocytes; (ii) a significant quantitative increase of these altered forms; (iii) modifications of spectrin cytoskeleton network; (iv) an altered redox balance, e.g. a decreased catalase activity and significant variations in the GSSG/GSH ratio. We hypothesize that remodeling of the redox state occurring in FA patients results in cytoskeleton-associated alterations of red blood cell integrity and function.

Adolescent↗
PubMed2000

Comparison of embryonic development and metal contamination in several populations of the sea urchin Sphaerechinus granularis (Lamarck) exposed to anthropogenic pollution.

Over the past years the functional deficiencies observed in the sea urchin Sphaerechinus granularis from the Bay of Brest (France) have led us to select several populations within this species to assess water quality in the Bay of Brest. The present study reports on the comparison of the quality of embryonic development and of the level of metal contamination in sea urchin gonads and gut wall in four populations. Three of them lived in the Bay of Brest, and the last one was considered a reference, being settled in the Glénan Archipelago in southern Brittany (France). The sea urchin population living at the mouth of the River Aulne, at the Armorique Point, seemed to be the most affected, for it displayed the highest rate of blockage and the longest delay in embryonic development along with the highest concentrations in heavy metals, i.e., Fe, Cu, Pb, Cd, and Hg, in the gut wall and in the gonads. A comparison with previous data highlighted a degradation of health conditions in the population living at Marloux in the vicinity of Brest harbor. The comparison of the metal levels detected in individuals from these two populations with the data reported in the literature allowed us to conclude for a local contamination of the bay waters by Fe and Hg. In addition, this study also revealed that Zn and Cd concentrations were sometimes higher than the maximum values reported in the literature and evidenced an increase of contamination by Cu and Pb over the period of study; it should be noted, however, that these values were not excess levels. Our investigations also suggest that Zn, Cd, Pb, and Cu levels should be monitored in the future.

Animals↗
PubMed2000

Relationship of residual beta-cell function, metabolic control and chronic complications in type 2 diabetes mellitus.

As the relationships between C-peptide levels and metabolic control and chronic complications are poorly known in type 2 diabetes, due to the slow decline of beta-cell function, we evaluated these associations in a cohort of type 2 diabetic patients. After excluding insulin-treated subjects, 1,533 patients were divided according to their C-peptide fasting levels in quartiles. Patients within the lowest C-peptide quartile showed significantly higher duration of diabetes, prevalence of retinopathy and values of HDL-cholesterol, albumin excretion rate and HbA1c, while BMI, diastolic blood pressure, percentages of hypertension and metabolic syndrome, and values of triglycerides and uric acid were significantly higher in the highest C-peptide quartile. The associations between C-peptide and duration of diabetes, AER, HbA1c, retinopathy and the components of the metabolic syndrome remained significant, after multiple adjustments. In conclusion, these data support the hypothesis that a reduced insulin secretion is associated with a longer duration of diabetes and a greater prevalence of microvascular complications, while higher insulin levels are associated with the components of the metabolic syndrome.

Aged↗
PubMed2000

Lack of association of fibrinogen, lipoprotein(a), and albumin excretion rate with low birthweight.

An excess of cardiovascular morbidity has been related to low birthweight. The aim of this study was to evaluate the relationship between low birthweight and levels of fibrinogen, lipoprotein(a), and albumin excretion rate, which are known risk factors for coronary artery disease. Seventy-two twins, with the same within-pair gender and normal glucose tolerance, were analyzed in order to avoid confounding factors, such as gestational age, birth order, or sex. Twins with the highest birthweights within the couple showed no significant difference of fibrinogen, lipoprotein(a), and albumin excretion rates compared with the twins with the lowest birthweights among the two co-twins. Moreover, no relevant correlation was found between birthweight and intra-pair birthweight differences and fibrinogen, lipoprotein(a), and albumin excretion rates. The lack of correlation between fibrinogen, lipoprotein(a), albumin excretion rate and birthweight, suggests that these factors do not contribute to the link between intrauterine malnutrition and increased cardiovascular risk.

Albuminuria↗
PubMed2000

Safety profile and tolerability of amprenavir in the treatment of adult and pediatric patients with HIV infection.

BACKGROUND: Amprenavir (APV) is a new HIV-I protease inhibitor used in combination with other antiretroviral agents for the treatment of HIV-1 infection. OBJECTIVE: The aim of this study was to assess the safety profile and tolerability of APV. METHODS: A review of data from 358 adults enrolled in 2 phase III, randomized, 48-week, controlled studies and from 268 children enrolled in 1 phase II and 1 phase III study was conducted. The adult data were collected between February 25, 1997, and April 1, 1999. Data were collected in children from September 10, 1997, to January 15, 1999; these data were collected before completion of either study. Adults and children who had and had not been treated previously with antiretroviral agents were enrolled. In these studies, APV was used in combination with 2 nucleoside reverse transcriptase inhibitors. RESULTS: The most common drug-related adverse events in patients receiving APV were gastrointestinal events and oral/perioral paresthesia. The majority of adverse events were mild or moderate in intensity, early in onset, and transient. Nausea (27/358 patients, 8%), vomiting (15/358, 4%), rash (11/358, 3%), and diarrhea/loose stools (9/358, 3%) were the most common adverse events associated with treatment discontinuation. Severe laboratory abnormalities possibly related to APV were rare. In children, the nature and frequency of adverse events were similar to those in adults. Metabolic complications were infrequent in APV studies to date; symptoms related to fat redistribution were reported in <3% of patients treated with APV. Lipid or glucose laboratory abnormalities were reported with similar frequency in the APV and control groups in both studies in adults. CONCLUSIONS: In the clinical trials reviewed, APV was generally well tolerated when administered with other antiretroviral agents in adult and pediatric patients with HIV infection.

Adolescent↗
PubMed2000

Prospects for nutritional interventions in the clinical management of Fanconi anemia.

The evidence associating Fanconi anemia (FA) phenotype to in-vitro and ex-vivo oxidative stress is reviewed. A cancer-prone genetic disease, FA is characterized by delayed bone marrow failure with a progression to aplastic anemia. It is diagnosed by excess chromosomal instability induced by two clastogens, either diepoxybutane (DEB) or mitomycin C (MMC). Clinical symptoms vary in a broad range including a life-threatening hematological impairment, and an extended set of developmental abnormalities, growth retardation and skin pigmentation. Cancer-proneness in FA results in excess incidence of non-lymphoblastic leukemias, and of some defined solid tumors. The relationships of oxidative stress with FA phenotype rely on a consistent body of evidence that includes: (1) excess formation of DNA oxidative damage (both in vitro and in vivo); (2) cellular protection by hypoxia, low molecular-weight antioxidants, antioxidant enzymes, and thioredoxin overexpression; (3) impaired expression and/or activity of antioxidant enzymes, and (4) the redox-dependent action mechanisms of MMC and DEB. This evidence points to a re-appraisal of FA phenotype, suggesting a causative role for oxidative stress in disease progression towards malignancies and/or bone marrow depletion. A well-established literature reporting epidemiological and experimental data provides the nutritional bases for cancer control. Thus, the present state-of-the-art in the related fields of oxidative stress, nutrition, cancer-proneness and FA phenotype, altogether implies the need to undertake the most appropriate efforts to counteract oxidative stress in the clinical management of FA patients.

Anemia, Aplastic↗
PubMed2000

Microvascular angina (cardiological syndrome X) per se is not associated with hyperinsulinaemia or insulin resistance.

BACKGROUND: Microvascular angina has been found to be associated with insulin resistance. However, many factors known to affect insulin sensitivity were not excluded in patient selection. We aimed to evaluate whether microvascular angina is per se associated with insulin resistance. MATERIALS AND METHODS: We performed a Frequently Sampled Intravenous Glucose Tolerance Test (0.33 g kg(-1) b.w.) in 10 normal weight and normotensive patients with microvascular angina, with normal glucose tolerance and normal plasma lipids. Ten healthy subjects, comparable for age, sex, body mass index, blood pressure and plasma lipids, were used as control group. RESULTS: Fasting serum glucose (4.49+/-0.2 SEM vs. 4.52+/-0.13 mmol L(-1), P = 0.9), insulin (39.46 +/-3.68 SEM vs. 47.12+/-4.6 pmol L(-1), P = 0.21) and C-peptide (0.56 +/-0.05 SEM vs. 0.53+/-0.05 nmol L(-1), P = 0. 68) values, as well as estimated parameters of insulin secretion and hepatic insulin extraction were similar in the two groups. Insulin sensitivity values (median, range) were also similar in the patients and control subjects (5.76 (3.39-12.30) vs. 7.54 (3.68-13.89. 10(-4) x min(-1)/(microU/mL), P = 0.97). CONCLUSION: Microvascular angina per se is not associated with hyperinsulinaemia or insulin resistance when other confounding factors are excluded in patient selection.

Adult↗
PubMed2000

Low birthweight and metabolic abnormalities in twins with increased susceptibility to Type 2 diabetes mellitus.

AIMS: To evaluate the role of environmental intra-uterine factors in determining the birthweights of twins with increased susceptibility to diabetes and discordant for abnormal responses to the oral glucose tolerance test (OGTT) and verify the possible association of within-pair birthweight differences and metabolic abnormalities in adult life. METHODS: Forty-six monozygotic (MZ) and 32 dizygotic (DZ) twins were enrolled; 13 MZ twins were discordant for impaired glucose tolerance (IGT) and/or hyperinsulinaemia compared to their co-twins. RESULTS: The 13 MZ discordant twins showed significantly lower birthweights than their normal co-twins (P < 0.001). When dividing all twins in those with the highest birthweights within the couple and those with the lowest, all subjects with abnormal OGTT were found in the latter group (P < 0.0001). Within-pair birthweight difference was significantly higher in MZ twins with abnormal OGTT and the metabolic syndrome compared to normal MZ twins. The relative risk of developing the metabolic syndrome was 8.7 (1.6-46.9) when comparing the higher tertile of within-pair birthweight differences (> or = 0.450 kg) to the two lower tertiles (< 0.450 kg). Logistic regression analysis confirmed within-pair birthweight difference as a significant predictor of abnormal responses to the OGTT and the metabolic syndrome. CONCLUSIONS: These data suggest a causative role for environmental intrauterine factors on the determination of birthweight and support the hypothesis that within-pair birthweight difference, rather than an absolute low birthweight, is responsible for the metabolic abnormalities in the adult life.

Adult↗
PubMed2000

Influence of a familial history of diabetes on the clinical characteristics of patients with Type 2 diabetes mellitus.

AIMS: To evaluate the roles of maternal and paternal diabetes and diabetes in relatives other than parents on the clinical characteristics in Type 2 diabetes mellitus. METHODS: A total of 2,113 Type 2 diabetic patients were recruited, and those with diabetic mothers, diabetic fathers, diabetic relatives other than parents and no known diabetic relatives, were considered separately. RESULTS: The prevalence of diabetes in the mother, father and other relatives was 25.5, 6.5 and 21.2%, respectively. No difference in the clinical characteristics was found in patients with diabetes in the mother or father. Patients with parental diabetes were significantly younger, with higher LDL-cholesterol, prevalence of retinopathy and lower age at diabetes diagnosis than those without familial diabetes; on multiple logistic regression, only age (P = 0.0003), age at diabetes diagnosis (P = 0.0014) (inverse association), and LDL-cholesterol (P = 0.030) remained significantly associated with parental diabetes. Patients with diabetic relatives other than parents displayed significantly higher total and LDL-cholesterol, prevalence of retinopathy and lower age at diabetes diagnosis that those with no known diabetic relatives; on multiple logistic regression, only age at diabetes diagnosis was inversely associated with diabetes in relatives other than parents (P = 0.013). CONCLUSIONS: The data do not indicate a different influence of maternal and paternal diabetes on the clinical characteristics of Type 2 diabetic patients, while there is evidence that parental diabetes brings to an earlier onset of the disease and higher LDL-cholesterol values; the presence of diabetes in relatives other than parents constituted a small risk for earlier manifestation of the disease.

Age of Onset↗
PubMed2000

Redox-dependent toxicity of diepoxybutane and mitomycin C in sea urchin embryogenesis.

The effects and mechanisms of action of diepoxybutane (DEB) and mitomycin C (MMC) were investigated on sea urchin embryogenesis, (Sphaerechinus granularis and Paracentrotus lividus). DEB- and MMC-induced toxicity was evaluated by means of selected end-points, including developmental defects, cytogenetic abnormalities and alterations in the redox status [oxygen-dependent toxicity, Mn-superoxide dismutase (MnSOD) and catalase activities and glutathione (GSH) levels]. Both DEB and MMC exhibited developmental toxicity (at concentrations ranging from 3 x 10(-5) to 3 x 10(-4) M and 3 x 10(-6) to 3 x 10(-5) M, respectively) expressed as larval abnormalities, developmental arrest and mortality. The developmental effects of both compounds were significantly affected by oxygen at levels ranging from 5 to 40%. These results confirmed previous evidence for oxygen-dependent MMC toxicity and are the first report of oxygen dependence for DEB toxicity. Both DEB and MMC exerted significant cytogenetic abnormalities, including mitotoxicity and mitotic aberrations, but with different trends between the two chemicals, at the same concentrations as exerted developmental toxicity. The formation of reactive oxygen species was evaluated using: (i) luminol-dependent chemiluminescence (LDCL); (ii) reactions of the main antioxidant systems, such as GSH content and MnSOD and catalase activities. The results point to clear-cut differences in the effects induced by DEB and MMC. Thus, DEB suppressed GSH content within the concentration range 10(-7)-3 x 10(-5) M. The activity of catalase was stimulated at lower DEB levels (10(-7)-10(-6) M) and then decreased at higher DEB concentrations (> or =10(-5) M). Increasing MMC concentrations induced LDCL and MnSOD activity (> or =10(-6) M) greatly and modulated catalase activity (10(-7) - 10(-6) M). GSH levels were unaffected by MMC. The results suggest that oxidative stress contributes to the developmental and genotoxic effects of both toxins studied, although through different mechanisms.

Animals↗
PubMed2000

Mitomycin C and diepoxybutane action mechanisms and FANCC protein functions: further insights into the role for oxidative stress in Fanconi's anaemia phenotype.

Evidence for redox-dependent toxicities of mitomycin C (MMC) and diepoxybutane (DEB), through different mechanisms, has been related to the phenotypic defect(s) of Fanconi's anaemia (FA) cells, due to their excess sensitivity to these agents. Recent data have pointed to interactions of the FANCC protein (encoded by the FA complementation group C gene, FA-C) with NADPH cytochrome P450 reductase and glutathione S-transferase (GST), two activities involved in either triggering or detoxifying reactive intermediates, including xenobiotics and reactive oxygen species. A body of evidence points to: (i) oxygen hypersensitivity of FA cells; (ii) oxygen-dependent MMC and DEB toxicity; (iii) excess oxidative DNA damage in FA cells; and (iv) DEB-induced glutathione depletion and GST inhibition. The available evidence corroborates the previously suggested role for oxidative stress in FA phenotype and disease progression, shedding new light on the redox-dependent mechanisms in MMC and DEB toxicities, and suggesting a direct association of oxidative stress with the primary genetic defect in FA.

Cell Cycle Proteins↗