RESUMO
BACKGROUND: Shared Decision Making (SDM) is an approach where clinicians and patients share the best available evidence to make decision and where patients opinions are considered. This approach provides benefits for patients, clinicians and health care system. The aim of the present study is to investigate the patients' perception of their participation in treatment choices and to identify the possible influences of variables in decision aids and therapeutic choices. Furthermore the present study evaluates the impact of SDM on the length of hospital stay and the health expenditure in Piemonte, an Italian region. METHODS: A cross-sectional study was performed in 2016. The patients were selected after hospitalization to clinical and surgical units at the Rivoli and Susa Hospital. Data were collected through the questionnaire and the Hospital Discharge Registers. STROBE guidelines for observational studies were used. A descriptive analysis was conducted. Frequencies and percentages of the categorical variables were reported. Statistical analyses were performed using t-test, chi-square test and Mann-Whitney test. RESULTS: The final sample was made of 174 subjects. More than half of the sample reported a SDM approach. Female gender (p = 0.027) and lower age (p = 0.047) are associated with an increased possibility to report SDM. Receiving "good" or "excellent" information, having their own request fulfilled and their opinions took into account by healthcare professionals, were all found to be predictors for an approach recognized as SDM (p ≤ 0.05). The perception that healthcare professionals spent a proper amount of time with the patients and used an understendable language are factors increase the chance of a "shared" decision process (p ≤ 0.05). The patients trust in the information given by the healthcare professional is not affecting their perception about the decision making process (P = 0.195). No significant difference where recorded in length of stay and hospital expenditure. CONCLUSIONS: The data show the role played by different dimension of the patients-clinician relationship and that the strongest determinant of a perceived shared decision making approach are healthcare professional-depending.
Assuntos
Tomada de Decisões , Tempo de Internação , Participação do Paciente , Adulto , Idoso , Idoso de 80 Anos ou mais , Atitude do Pessoal de Saúde , Atitude Frente a Saúde , Estudos Transversais , Técnicas de Apoio para a Decisão , Feminino , Pessoal de Saúde , Hospitalização , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto JovemRESUMO
Dentigerous cyst is a developmental odontogenic cyst, which apparently develops by accumulation of fluid between the reduced enamel epithelium and the tooth crown of an unerupted tooth. There is usually no pain or discomfort associated with the cyst unless there is acute inflammatory exacerbation. Management of dentigerous cyst in primary dentition needs special consideration regarding the preservation of the developing permanent tooth buds. Here, we report a case of dentigerous cyst in primary dentition in a 10-year-old male patient and its management.
Assuntos
Cisto Dentígero/diagnóstico , Doenças Mandibulares/diagnóstico , Dente Molar/patologia , Dente Decíduo/patologia , Biópsia por Agulha , Criança , Humanos , Masculino , Radiografia Panorâmica , Retalhos CirúrgicosRESUMO
Numerous changes occur post-mortem in fish, affecting its chemical composition and nutritional quality. In the present paper we describe the effect of storage on ice or at -30 degrees C or -80 degrees C on 10 species of Mediterranean fish. Water and lipid soluble antioxidants, lipid pattern and products of oxidative attack on lipids, proteins and DNA were quantified for 7 consecutive days on homogenates of fish light muscle. The earliest events were oxidation of ubiquinol and vitamin C, which disappeared almost completely within 48 hours. Ubiquinol oxidation gave rise to an initial increase of ubiquinone, which peaked at the second day: thereafter ubiquinone itslef decreased, more rapidly and to a greater extent than vitamin E. The decrease in antioxidants was accompanied by significant oxidative damage to lipids, proteins and DNA. TBARS significantly increased beginning from the third day of storage in all species and were linked to a significant reduction in the n-3 PUFA of triglycerides (TG) and phospholipid fractions (PL). A remarkable elevation of protein carbonyls and 8OHdG occurred approximately 24 hours later than PUFA oxidation. For SOD, GPX and GSH significant depletions occurred for all species only at 6th or 7th day, but the final values were always higher than 50% compared to the initial ones. Deep-freezing of the same species at -30 degrees C and -80 degrees C for up to 12 months did not significantly affect the levels of enzymatic antioxidants, the redox couple GSH/GS-SG, n-3 and n-6 PUFA of TG and PL fractions of the light muscle. The only antioxidants, which at -30 degrees C and -80 degrees C appeared to be degraded after 6 and 12 months were ubiquinol and vitamin C. As expected their degradation was higher at -30 degrees C than at -80 degrees C. In fact the average decrease for ubiquinol at -80 degrees C was 42% at 6 and 12 months respectively, whereas at -30 degrees C the decrease was 61% and 87% For vitamin C the average decrease at -80 degrees C was 36% and 67% at 6 and 12 months respectively, and at -30 degrees C it was 61% and 82%. Vitamin E was considerably more stable than ubiquinol and vitamin C. The relative stability of the antioxidants, with the exceptions of ubiquionols, vitamin C and, to a certain extent, vitamin E, was accompanied by a very limited increase in oxidation products. In addition no significant hydrolysis of TG and PL fractions were observed throughout the storage time. The dynamics of lipid, protein and DNA oxidation is discussed in the light of depletion of the various antioxidant systems.
Assuntos
Antioxidantes/metabolismo , Peixes/metabolismo , Conservação de Alimentos/métodos , Mudanças Depois da Morte , Animais , Ácido Ascórbico/metabolismo , Alimentos Congelados/análise , Metabolismo dos Lipídeos , Músculos/metabolismo , Oxirredução , Ubiquinona/análogos & derivados , Ubiquinona/metabolismo , Vitamina E/metabolismoRESUMO
BACKGROUND: Seroepidemiological and clinical studies suggest that Helicobacter pylori may cause iron deficiency anaemia (IDA) in the absence of peptic lesions by undefined mechanisms, which still remain to be fully elucidated. Gastric acidity and ascorbic acid (AA) promote iron absorption. AA is lowered in the presence of H pylori infection. H pylori can cause atrophic body gastritis with achlorhydria, decreased iron absorption, and consequent IDA. Whether alterations in intragastric acidity and AA concentrations play a role in IDA developing in patients with H pylori gastritis remains to be determined. AIM: To evaluate gastric juice pH and gastric juice and plasma AA in patients with H pylori infection and unexplained IDA, compared with controls with IDA and a healthy stomach or with controls with H pylori infection and no IDA. RESULTS: Patients with IDA and H pylori gastritis were characterised by concomitant increased intragastric pH (median value 7) and decreased intragastric AA (median value 4.4 micro g/ml) compared with controls with a healthy stomach (median pH 2; median intragastric AA 17.5 micro g/ml) and with H pylori positive controls without IDA (median pH 2.1; median intragastric AA 7.06 micro g/ml). Intragastric AA was inversely related to pH (r=-0.40, p=0.0059) and corporal degree of gastritis (r=-0.53, p=0.0039). Plasma AA concentrations were lower in all infected groups than in healthy controls. CONCLUSIONS: Patients with unexplained IDA and H pylori gastritis present concomitant changes in intragastric pH and AA that may justify impaired alimentary iron absorption and consequent IDA.
Assuntos
Anemia Ferropriva/microbiologia , Gastrite Atrófica/microbiologia , Infecções por Helicobacter/complicações , Helicobacter pylori , Adulto , Idoso , Anemia Ferropriva/metabolismo , Ácido Ascórbico/análise , Ácido Ascórbico/sangue , Feminino , Determinação da Acidez Gástrica , Suco Gástrico/química , Gastrite Atrófica/metabolismo , Gastrite Atrófica/patologia , Gastroscopia , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: The O-(beta-hydroxyethyl)-rutosides (HRs) are a standard mixture of flavonoid-derivatives that have a clinico-pharmacological activity on peripheral circulation, particularly on the endothelial cells of veins and lymphatics. Flavonoids are believed to prevent the oxidative damage derived from radical oxidative species (ROS), like hydroxyl radicals (HO.) and hypochlorite (-OCl). The aim of the study was to investigate the stability and capability of HRs in toto and of their single components (7-mo-nohydroxy ethyl rutoside; 7,4'-dihydroxyethyl rutoside; 7,3',4'-trihydroxyethyl rutoside and the 7,5,3',4'-tetrahydroxyethyl rutoside) of scavenging ROS and other radicals generated by different oxidative systems, and also their anti-lipoperoxidative activity at mM concentrations (1.0-10.0 mM). METHODS: The following oxidative systems have been employed: Fenton reaction for the hydro-xylation of l-tyrosine to l-DOPA and the peroxidation of arachidonic acid; photo-Fenton type reaction for the oxidation of toluene in the aqueous UV irradiated TiO2 system; the azocompound 2.2'-azobis(2, 4-dimethylvaleronitrile (AMVN) to produce peroxy radicals and the daily autoxidation of arachidonic acid. Analyses were performed by HPLC, HPLC-MS, GC-MS, and spectrophotometry. RESULTS: At 5.0 mM concentration, HRs produced the following inhibitions: 63+/-5% of the overall formation of cresols, benzaldehyde, benzyl alcohol, and biphenyl induced by photo-Fenton reaction; 91.6+/-5% and 59+/-8% of the synthesis of l-DOPA induced by HO. generated by Fenton reaction; 45+/-7% and 52+/-6% of the oxidation of arachidonic acid induced by Fenton reaction and AMVN; 60+/-4% of the autoxidation of arachidonic acid. These effects were strictly concentration dependent. CONCLUSIONS: At mM concentrations, HRs display a significant antilipoperoxidative activity due to their notable scanvenging activity against HO.; moreover these actions are concentration-dependent.
Assuntos
Aldeído Redutase/antagonistas & inibidores , Sequestradores de Radicais Livres/farmacologia , Hidroxietilrutosídeo/análogos & derivados , Hidroxietilrutosídeo/farmacologiaAssuntos
Desferroxamina/farmacologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Quelantes de Ferro/farmacologia , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Piridonas/farmacologia , Talassemia beta/sangue , Talassemia beta/tratamento farmacológico , Antioxidantes/metabolismo , Deferiprona , Desferroxamina/uso terapêutico , Hemoglobinas/metabolismo , Humanos , Quelantes de Ferro/uso terapêutico , Oxirredução , Oxigênio/metabolismo , Piridonas/uso terapêuticoRESUMO
The Authors have conducted a cohort study on a group of subjects HIV positive, asymptomatic, (group A, according to CDC criteria) who presented Seborrhoeic dermatitis (SD), to evaluate if this cutaneous finding could be considered a marker of the HIV disease. Previously the Authors had shown that healthy subjects affected by SD showed at blood level an imbalance in the ratio of PL-PUFA (fundamental components of cell walls) to the antioxidants Vitamin E (Vit E) and gluthathion peroxidase (GSH-Px); furthermore the Authors reported SD as being constantly present in AIDS patients, in which they found more severe biochemical changes. On these bases they enrolled 72 HIV positive individuals that presented at STD-AIDS Unit of the S Gallicano Institute in the years 1994-1995 and followed them, until the 1998. They were all asymptomatic and were divided at the beginning in two subgroups, respectively with and without SD. Records were made regularly of their clinical, laboratory and biochemical data. The results highlighted the fact that SD-HIV positive individuals had severe biochemical alterations and a worse clinical evolution (higher incidence of opportunistic events). These data confirm on the hand the SD as a cutaneous marker of HIV disease not only, but also its presence could indicate the possibility of a worse progression of the disease. Finally the Authors suggest the possibility of a dietary pharmacological treatment, associated, or not, with antiretroviral therapy, to the aim to improve cell membrane defences and thereby cell immunity itself.
Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Dermatite Seborreica/etiologia , Infecções por HIV/diagnóstico , Soropositividade para HIV/complicações , Adulto , Estudos de Coortes , Dermatite Seborreica/epidemiologia , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
It is well known that brain and nervous system cells are prone to oxidative damage because of their relatively low content of antioxidants, especially enzymatic ones, and of the high levels of both membrane polyunsaturated fatty acids (PUFA) and iron easily released from injured cells. We have investigated the oxidative stress in the blood (plasma, erythrocytes and lymphocytes) of 28 patients affected with multiple sclerosis (MS) and of 30 healthy age matched controls, by performing a multiparameter analysis of non-enzymatic and enzymatic antioxidants--Vitamin E (Vit. E), ubiquinone (UBI), reduced and oxidized glutathione (GSH, GS-SG), superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and fatty acid patterns of phospholipids (PL-FA). PL-FA and Vit. E were assayed by GC-MS; UBI and GSH/GS-SG by HPLC; SOD, GPX and CAT by spectrophotometry. In comparison to controls, patients with MS showed significantly reduced levels of plasma UBI (0.21 +/- 0.10 vs. 0.78 +/- 0.08 mg/ml, p < 0.001), plasma Vit. E (7.4 +/- 2.1 vs. 11.4 +/- 1.8 mg/ml, p < 0.01), lymphocyte UBI (8.1 +/- 4.0 vs. 30.3 +/- 7.2 ng/ml blood, p < 0.001) and erythrocyte GPX (22.6 +/- 5.7 vs. 36.3 +/- 6.4 U/g Hb, p < 0.001). This blood antioxidant deficiency was associated with plasma levels of PL-PUFA--especially C20:3 n-6 and C20:4 n-6--significantly higher than controls. In conclusion, the blood of patients with MS shows the signs of a significant oxidative stress. The possibility of counteracting it by antioxidant administration plus an appropriate diet, might represent a promising way of inhibiting the progression of the disease. Antioxidant supplements should include not only GSH repleting agents, but also Vit. E, ubiquinol, and selenium.
Assuntos
Esclerose Múltipla/sangue , Estresse Oxidativo , Adulto , Antioxidantes/metabolismo , Estudos de Casos e Controles , Cromatografia Líquida de Alta Pressão , Ácidos Graxos/sangue , Humanos , Pessoa de Meia-Idade , Fosfolipídeos/sangue , Análise EspectralRESUMO
It has been reported that iron overload in beta-thalassemia leads to an enhanced generation of reactive oxygen species and to oxidative stress. We have studied the oxidant/antioxidant imbalance in the blood of 48 transfusion-dependent beta-thalassemic patients (TLP) (17 males, 31 females, 11-22 year), under chelation therapy, and in 40 sex and age matched healthy controls (CTR). Plasma and lymphocyte levels of vitamin E (Vit E), ubiquinol (CoQ10H2), ubiquinone (CoQ10), plasma concentrations of vitamin A (Vit A), beta-carotene, lycopene, vitamin C (Vit C), total thiols, fatty acid patterns of phospholipids (PL-FA), and plasma and urinary markers of lipoperoxidation (TBA-RM, conjugated dienes, and azelaic acid (AZA), as well as the urinary levels of catecholamine and serotonin metabolites, were evaluated by gas chromatography-mass spectrometry (GC-MS), HPLC and spectrophotometry. Routine laboratory blood analyses were performed on the same samples; 39/48 TLP were HCV positive. Blood samples were collected just before transfusion, the 24 h urine samples the day before. Our results clearly showed that a severe oxidative stress occurs in the plasma of TLP in comparison with CTR. In fact, the levels of lipophilic antioxidants and ascorbate were severely depleted: CoQ10H2 (-62.5%), total CoQ10 (-35.1%), Vit E (-43.8%), beta-carotene (-31.1%), lycopene (-63.7%), Vit A (-35.9%), Vit C (-23.1%). The impairment of the antioxidant status was associated with elevated plasma levels of by-products of lipoperoxidation and urinary concentrations of catecholamine metabolites and of AZA, indicating a high degree of both neurological stress and lipoperoxidation. A significant positive correlation was found between vitamin E and non-transferrin-bound iron (NTBI) (r = -0.81; p < 0.001), while no correlation was found between antioxidant depletion and ferritin serum levels, average blood consumption, or the presence of clinical complications. The administration of selective antioxidants along with an appropriate diet might represent a promising way of counteracting oxidative damage and its deleterious effects on the progression of the disease.
Assuntos
Antioxidantes/análise , Catecolaminas/urina , Talassemia beta/metabolismo , Adolescente , Adulto , Bilirrubina/sangue , Carotenoides/sangue , Catecolaminas/metabolismo , Criança , Ácidos Graxos/sangue , Ácidos Graxos/metabolismo , Feminino , Ferritinas/sangue , Humanos , Ferro/sangue , Peroxidação de Lipídeos , Masculino , Estresse Oxidativo , Serotonina/metabolismo , Serotonina/urina , Compostos de Sulfidrila/sangue , Ubiquinona/análogos & derivados , Ubiquinona/sangue , Ácido Úrico/sangue , Vitaminas/sangue , Talassemia beta/sangue , Talassemia beta/urinaRESUMO
Gamma irradiation is a potential technique for sterilisation of liposome suspensions. Unfortunately, gamma irradiation may result in chemical degradation of the phospholipids and the toxicological aspects have to be considered. The effects of liposome composition and gamma irradiation on the interactions of the liposomes with the hemostatic mechanisms (hemolysis, aggregation and coagulation) were studied. Non-irradiated liposome suspensions showed no hemolysis of erythrocytes. After irradiation, up to 3.1% hemolysis was measured. Least hemolysis was observed with irradiated liposomes composed of unsaturated or charged phospholipids. The negatively charged DSPG-liposomes (both non-irradiated and irradiated) induced aggregation of platelets as observed by the spectrophotometric method. However, no aggregates were seen in the microscope or measured by the aggregometer. Negatively charged liposomes also affected the coagulation cascade where prolonged coagulation times were measured. Irradiation of the liposome suspensions resulted in even longer coagulation times. The prolonged coagulation times correlated to some extent with the measured binding and depletion of calcium from plasma by the negatively charged liposomes.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Raios gama/efeitos adversos , Hemólise/efeitos dos fármacos , Lipossomos/toxicidade , Agregação Plaquetária/efeitos dos fármacos , Cálcio/metabolismo , Humanos , Técnicas In Vitro , RadiaçãoRESUMO
Epidermal levels of enzymatic and non-enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), vitamin E (Vit E), ubiquinol (CoQ10H2), and reduced glutathione (GSH), as well as polyunsaturated fatty acids of phospholipids (PL-PUFA), were evaluated in the affected epidermis of 15 patients with active vitiligo (AVP) and in the corresponding epidermis of 15 healthy phototype matched controls. The epidermal levels of CoQ10H2, Vit E, GSH, and CAT activity were significantly reduced in AVP and were associated with a marked increase of oxidized glutathione, whereas SODs and GSH-Px activities and ubiquinone concentration remained similar to control values. Antioxidant deficiency, in particular the decline of lipophilic antioxidants, i.e., CoQ10H2 and Vit E, accounts well for PL-PUFA reduction observed in vitiligo epidermis, mainly affecting C18:3 n-3, C20:3 n-6, C20:4 n-6, and C22:6 n-3 fatty acids and suggesting the occurrence of a lipoperoxidative process. In conclusion, both an imbalance of the intracellular redox status and a significant depletion of enzymatic and non-enzymatic antioxidants feature the epidermis of AVP, and represent a fingerprint of an abnormal oxidative stress leading to epidermal cell injury.
Assuntos
Epiderme/enzimologia , Estresse Oxidativo , Vitiligo/enzimologia , Adulto , Antioxidantes/metabolismo , Feminino , Ácido Homovanílico/urina , Humanos , Masculino , Ácido Vanilmandélico/urina , Vitiligo/urinaRESUMO
To examine the sensitivity of vitiligo melanocytes to external oxidative stress, we studied enzymatic and non-enzymatic anti-oxidants in cultured melanocytes of normal subjects (n = 20) and melanocytes from apparently normal skin of vitiligo patients (n = 10). The activity of superoxide dismutase and catalase and the intracellular concentrations of vitamin E and ubiquinone were evaluated in cultures at the fourth or fifth passage. In addition, cells were exposed to various concentrations of a peroxidizing agent, cumene hydroperoxide (CUH, 0.66-20 microM), for 1 and 24 h. Compared to normal melanocytes, vitiligo melanocytes showed normal superoxide dismutase and significantly lower catalase activities and higher vitamin E and lower ubiquinone levels. At the concentration used, CUH did not significantly affect cell number or viability of melanocytes after either period of culture. On the contrary, vitiligo melanocytes were susceptible to the toxic effect of CUH after 24 h of continuous treatment at concentrations greater than 6.6 microM. The degree of CUH toxicity correlated strictly with the anti-oxidant pattern, defined as the ratio between vitamin E concentration and catalase activity, suggesting that the alteration in the antioxidants was the basis for sensitivity to the external oxidative stress. Our results demonstrate the presence of an imbalance in the anti-oxidant system in vitiligo melanocytes and provide further support for a free radical-mediated damage as an initial pathogenic event in melanocyte degeneration in vitiligo.
Assuntos
Melanócitos/patologia , Oxidantes/farmacologia , Vitiligo/patologia , Adulto , Antioxidantes/farmacologia , Derivados de Benzeno/farmacologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Humanos , Masculino , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Pessoa de Meia-Idade , Estresse Oxidativo , Sensibilidade e Especificidade , Ubiquinona/farmacologia , Vitamina E/farmacologia , Vitiligo/induzido quimicamenteRESUMO
In order to evaluate the free radical defense systems of melanocytes and their possible correlation with melanoma, we have studied in cultured normal human melanocytes (20), normal melanocytes from melanoma patients (15), and melanoma cells (40) the fatty acid pattern of membrane phospholipids as a target of peroxidative damage and the superoxide dismutase and catalase activities, vitamin E, and ubiquinone levels as intracellular antioxidants. Cells were cultured in the same medium and analyzed at III or IV passage. Compared to the values obtained in normal human melanocytes, melanoma cells showed on average: a) higher levels of polyunsaturated fatty acids, b) increased superoxide dismutase and decreased catalase activities, higher vitamin E, and lower ubiquinone levels. Among the normal melanocytes from melanoma patients studied, two groups were differentiated: a) cultures (7) with enzymatic and non-enzymatic antioxidants level similar to those of normal human melanocytes; b) cultures (8) with antioxidant patterns similar to those observed in melanoma cells. Polyunsaturated fatty acids were also increased in the latter group. The results indicate that in melanoma cells and in a percentage of normal melanocytes from melanoma patients, an imbalance in the antioxidant system can be detected that can lead to endogenous generation of reactive oxygen species and to cellular incapability of coping with exogenous peroxidative attacks. These alterations could be correlated with the malignant transformation of cells and with the progression of the disease.
Assuntos
Antioxidantes/metabolismo , Melanócitos/enzimologia , Melanoma/metabolismo , Neoplasias Cutâneas/metabolismo , Adulto , Catalase/metabolismo , Ácidos Graxos Insaturados/metabolismo , Humanos , Melanoma/patologia , Pessoa de Meia-Idade , Valores de Referência , Neoplasias Cutâneas/patologia , Superóxido Dismutase/metabolismo , Ubiquinona/metabolismo , Vitamina E/metabolismoAssuntos
Antineoplásicos/uso terapêutico , Ácidos Dicarboxílicos/uso terapêutico , Melanoma/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Invasividade NeoplásicaRESUMO
During the course of evaluating the interaction between allergens and keratinocytes in the pre-immunological phase of contact sensitization, we have studied the effects of paraphenylene diamine (pPD) on membrane lipid peroxidation and on intracellular antioxidant levels in cultured human keratinocytes. pPD is an aromatic amine which undergoes spontaneous oxidation in culture medium, generating short-lived free radical species including oxyradicals. Following exposure to non-toxic concentrations of pPD (0.5-10 micrograms/ml), we have evaluated the fatty acid pattern of membrane phospholipids as a target of peroxidative damage, and the intracellular level of reduced glutathione (GSH), the activity of superoxide dismutase (SOD), and that of catalase (CAT) as parameters of the antioxidant system. Depending on pPD concentration and the period of exposure, peroxidative damage with a significant decrease in membrane polyunsaturated fatty acids, was detected. Concentrations between 0.5 and 2 micrograms/ml produced an initial increase and then a decrease in both SOD and CAT activities, and in the oxidation of GSH, up to 12 h. After 24 h, when all the pPD had decomposed, recovery of the initial levels of the antioxidants was detected. Concentrations over 5 micrograms/ml induced a progressive decrease in both the enzymatic activities and the GSH concentrations. These results are consistent with the view that oxidative stress can be an essential event in the pre-immunological phase of contact sensitization.
Assuntos
Alérgenos/farmacologia , Queratinócitos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fenilenodiaminas/farmacologia , Antioxidantes/metabolismo , Técnicas de Cultura de Células , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Relação Dose-Resposta a Droga , Ácidos Graxos/metabolismo , Humanos , Queratinócitos/metabolismoRESUMO
Modification of pigmentation and damage of melanocytes are characteristic features of skin colonisation of Pityrosporum orbiculare hyphae in pityriasis versicolor (PV). The yeast is lipophylic and lipid-dependent, capable of oxidising unsaturated lipid components of skin surface, i.e., unsaturated fatty acids, cholesterol and squalene (SQ). The oxidation of unsaturated fatty acids gives rise to dicarboxylic acids (DA) which behave, in vitro, as competitive inhibitors of tyrosinase. In this work, we further investigate the oxidase activity of Pityrosporum in vitro, by evaluating (a) the generation of lipoperoxides in cultures supplemented with fatty acids at various degrees of unsaturation; (b) the mechanism of SQ oxidation; (c) the chemical characteristics of some by-products of lipoperoxidation; (d) the formation of peroxisomes in fungal cells. In cultures supplemented with the saturated palmitic acid (C16:0) and monounsaturated oleic acid (C18:1 n-9), low amounts of lipoperoxides were detected by a spectrophotometric test, whereas in cultures supplemented with di-unsaturated linoleic acid (C18:2 n-6), significant concentrations were found. Gas chromatography-mass spectrometry analyses showed the generation of linoleic acid hydroperoxides both in Pityrosporum cultures and following incubation of acetone powder of the fungus with the unsaturated fatty acid, indicating the presence of a lipoxygenase activity in the fungus. In cultures supplemented with linoleic acid plus SQ, and increase of lipoperoxide generation was observed and trans-trans farnesal and squalene epoxides have been identified. Electron microscopic examinations have evidenced peroxisomes in cells grown in the presence of linoleic acid, whereas they were not detected in cultures supplemented with oleic acid and palmitic acid. The metabolic activities of peroxisomes, through the formation of hydrogen peroxide and the subsequent generation of hydroxyl radicals, may account for the peroxidation of SQ, which is not a substrate of lipoxygenase. Following these results, we propose a mechanism for DA generation by Pityrosporum metabolism and hypothesize that the lipoperoxidation process induced by lipoxygenase activity of the fungus may be the key to understanding the clinical appearance of skin manifestation of PV.
Assuntos
Proteínas Fúngicas/metabolismo , Malassezia/enzimologia , Melanócitos/metabolismo , Pigmentação da Pele , Tinha Versicolor/patologia , Ácidos Dicarboxílicos/metabolismo , Ácidos Dicarboxílicos/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Radical Hidroxila , Ácido Linoleico , Ácidos Linoleicos/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Lipoxigenase/metabolismo , Melanócitos/patologia , Microcorpos/metabolismo , Monofenol Mono-Oxigenase/antagonistas & inibidores , Esqualeno/farmacologia , Tinha Versicolor/microbiologiaRESUMO
The addition of compounds able to peroxidize cell lipids (carbon tetrachloride (CCl4), cumene hydroperoxide (CUH), or linoleic acid hydroperoxide (LAH)) to 5-day-old Czapek-Dox Medium cultures of Aspergillus parasiticus induces a significant reduction of the tri-unsaturated ergosterol (ERG) levels in fungal microsomes and mitochondria, whereas the concentrations of the di-unsaturated linoleic acid (LA; C18:2 n-6) are unaffected. Aflatoxin (AFT) output follows ERG reduction and is associated with both a renewal of fungal growth and a slow increase of ERG concentration in subcellular membranes. We suggest that, by analogy with the regulatory role played on cell proliferation and metabolism by polyunsaturated fatty acid by-products (eicosanoids) in mammalian membranes, by-products of ERG oxidation may be considered triggers sufficient to induce both further fungal growth and AFT biosynthesis.
Assuntos
Aflatoxinas/biossíntese , Aspergillus/fisiologia , Ergosterol/metabolismo , Peróxidos Lipídicos/farmacologia , Aspergillus/efeitos dos fármacos , Aspergillus/crescimento & desenvolvimento , OxirreduçãoRESUMO
A gas chromatographic-mass spectrometric technique is described for the simultaneous determination of sorbates, benzoates and other lipophilic preservatives in foods and beverages. The selected ions monitoring (SIM) technique allowed unambiguous identification of the compounds under study. This methodology eliminated all kinds of interferences from the complex food matrices which affect most routinely-used techniques, HPLC included. A very simple and time-saving extraction procedure was therefore employed, since subsequent purification steps were unnecessary, even for detection of trace levels of preservatives. The detection limits fell within the range of 100-200 pg. With this analytical technique, we have conducted a survey on sorbic acid, benzoic acid, methyl, ethyl, and propyl 4-hydroxybenzoate levels in 249 samples of foods and beverages on sale in markets in the Rome area. Samples were chosen from among those currently preserved by these additives. All compounds were also determined by a routinely-used HPLC technique for method comparison.
Assuntos
Bebidas/análise , Conservantes de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Benzoatos/análise , Ácido Benzoico , Estudos de Avaliação como Assunto , Análise de Alimentos , Parabenos/análise , Cidade de Roma , Ácido Sórbico/análiseRESUMO
Azole antifungals are reported to interfere with fungal growth by selective impairment of the P-450 dependent 14 alpha-demethylase system key to biosynthesis of ergosterol (ERG), thus leading to the depletion of this sterol in fungal membranes and to the accumulation of methylated precursors. We have investigated whether azole antifungals ketoconazole, miconazole, econazole, or itraconazole were able to modify the sterol and fatty acid patterns of a toxigenic strain of Aspergillus parasiticus, inducing the growth of mycelium depleted of ergosterol (ERG) and rich in less oxidizable sterols. It had been demonstrated that oxidation of ERG is correlated to aflatoxin biosynthesis. However, in this study no alteration of sterol or fatty acid patterns was observed after 7, 14, and 21 days of incubation of A. parasiticus in the presence of sublethal doses of azole antifungals. Specific production of aflatoxin was unaffected. Among the four antifungals tested, itraconazole was the strongest inhibitor of fungal growth and aflatoxin production while ketoconazole was the least effective.
Assuntos
Aflatoxinas/biossíntese , Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Ergosterol/antagonistas & inibidores , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Meios de Cultura , Sistema Enzimático do Citocromo P-450/metabolismo , Relação Dose-Resposta a Droga , Econazol/farmacologia , Ergosterol/metabolismo , Ácidos Graxos/metabolismo , Itraconazol/farmacologia , Cetoconazol/farmacologia , Miconazol/farmacologiaRESUMO
We recently introduced reduced glutathione into the therapeutic protocols in some selected cases of dyspermia. This therapy improved semen quality both in a pilot follow-up study and in a double-blind cross-over trial. This improvement was seen in patients with varicocele and germ-free genital tract inflammation, two pathologies in which production of reactive oxygen species or other toxic compounds could have a pathogenic role. Polyunsaturated fatty acids of phospholipids play a major role in membrane constitution and function and are one of the main targets of the lipoperoxidative process. Therefore, to understand the therapeutic action of reduced glutathione, we selected infertile patients and studied the modifications produced by the therapy in seminal parameters, biochemical sperm membrane parameters, and the pattern of fatty acids of phospholipids from blood serum and red blood cell membranes (a model widely accepted as representative of general cell membrane status). The results showed an improvement in both sperm parameters and cell membrane characteristics. This study suggests that biochemical modifications in membrane constitution could explain the seminal results of glutathione therapy. On the other hand, it seems likely that only subjects with systemic membrane disturbances associated with andrological pathologies express this membrane damage in spermatozoa, resulting in dyspermia. This sperm alteration can be partially reversed by glutathione therapy if the structural cell membrane damage is not too severe.