Infection with Burkholderia cepacia complex (Bcc) bacteria is a threat to cystic fibrosis (CF) pa... more Infection with Burkholderia cepacia complex (Bcc) bacteria is a threat to cystic fibrosis (CF) patients, commonly leading to a fatal pneumonia, the cepacia syndrome. It causes a massive production of pro-inflammatory cytokines and leucocyte recruitment to airway epithelium without resolving infection and contributing to tissue lesion. To dissect how Bcc bacteria subvert the immune response, we developed a co-culture model with human dendritic cells (DCs) and B. cenocepacia clonal variants isolated from a chronically infected CF patient, who died with cepacia syndrome. We demonstrated that the two late variants were sevenfold and 17-fold (respectively) more internalized by DCs than the variant that initiated infection. The late variants showed improved survival within DCs (60.29 and 52.82 CFU/DC) compared to the initial variant (0.38 CFU/DC). All clonal isolates induced high expression of inflammatory cytokines IL-8, IL-6, IL-1β, IL-12, IL-23, TNF-α and IL-1β. This pro-inflammatory t...
<strong>Introduction:</strong> The urinary tract infe... more <strong>Introduction:</strong> The urinary tract infections, after respiratory infections, are the most common in the community. The knowledge about the prevalence of microbial strains and their antibiotic susceptibility is crucial to establish an effective empirical therapy. The aim of this study was to determine the antibiotic susceptibility patterns of bacterial strains isolated from positive urine cultures performed in patients from the central region of Portugal.<br /><strong>Material and Methods:</strong> We carried out a documental analysis of 6008 urine bacteriological exams, to be made available to physicians, most of which run through the automated system VITEK 2, bioMérieux. The majority (80%) of the urine bacteriological exams were from female. Escherichia coli was the most prevalent bacterial pathogen (65.9%), followed by Klebsiella spp (12%).<br /><strong>Results:</strong> Nitrofurantoin showed high levels of activity (96%) for Escherichia coli, as well as Fosfomycin (96.6%). Amoxicillin-clavulanic acid presents an activity level of only 81.1% for the same germ. Quinolones exhibit efficacy to only 78% of the strains of Escherichia coli, below the Fosfomycin and Nitrofurantoin. Nitrofurantoin showed high levels of activity (96%) for E. coli as well as Fosfomycin (96.6%). Amoxicillin-Clavulanic Acid presents a level of activity of only 81.1% for the same germ. The quinolones have a efficacy for only 78% of strains of E. coli, lower than Fosfomycin.<br /><strong>Discussion:</strong> Escherichia Coli was the most prevalent uropathogen (65.9%). High efficacy against this pathogenic agent was found for Fosfomycin (96.6%) and Nitrofurantoin (96%).<br /><strong>Conclusion:</strong> Further antimicrobial surveillance studies should be developed, in order to formulate local empirical therapy<br />recommendations for optimized therapeutical choices.<br /><strong>Keywords:</strong> Urinary Tract Infections; Drug Resistance, Bacterial; Anti-Bacterial Agents; Community-Acquired Infections.<br />
The International Journal of Biochemistry & Cell Biology, 2015
Around 60-80% of all breast tumors are estrogen receptor-positive. One of the several therapeutic... more Around 60-80% of all breast tumors are estrogen receptor-positive. One of the several therapeutic approaches used for this type of cancers is the use of aromatase inhibitors. Exemestane is a third-generation steroidal aromatase inhibitor that undergoes a complex and extensive metabolism, being catalytically converted into chemically active metabolites. Recently, our group showed that the major exemestane metabolites, 17β-hydroxy-6-methylenandrosta-1,4-dien-3-one and 6-(hydroxymethyl)androsta-1,4,6-triene-3,17-dione, as well as, the intermediary metabolite 6β-Spirooxiranandrosta-1,4-diene-3,17-dione, are potent aromatase inhibitors in breast cancer cells. In this work, in order to better understand the biological mechanisms of exemestane in breast cancer and the effectiveness of its metabolites, it was investigated their effects in sensitive and acquired-resistant estrogen receptor-positive breast cancer cells. Our results indicate that metabolites induced, in sensitive breast cancer cells, cell cycle arrest and apoptosis via mitochondrial pathway, involving caspase-8 activation. Moreover, metabolites also induced autophagy as a promoter mechanism of apoptosis. In addition, it was demonstrated that metabolites can sensitize aromatase inhibitors-resistant cancer cells, by inducing apoptosis. Therefore, this study indicates that exemestane after metabolization originates active metabolites that suppress the growth of sensitive and resistant breast cancer cells. It was also concluded that, in both cell lines, the biological effects of metabolites are different from the ones of exemestane, which suggests that exemestane efficacy in breast cancer treatment may also be dependent on its metabolites.
It is well known that in the aging process a variety of physiological functions such as cardiac p... more It is well known that in the aging process a variety of physiological functions such as cardiac physiology and energy metabolism decline. Imbalance in production and elimination of reactive oxygen species (ROS) may induce oxidative stress. Research shows that oxidative stress is an important factor in the aging process. Studies suggest that ɷ-3 polyunsaturated fatty acids (PUFAs) and moderate physical exercise modulate the ROS system. Therefore, the present study aimed to investigate whether ɷ-3 present in fish oil supplementation coupled with moderate physical training could improve antioxidant and metabolic enzymes in the hearts of adult and aged rats and, if these effects could be associated to glycemia, plasma lipid profile or murinometric parameters. Adult (weighing 315.1±9.3g) and aged rats (weighing 444.5±11.8g) exercised and receive fish oil supplementation for 4weeks. Then they were used to evaluate murinometric parameters, fasting glucose and lipid profile. After this, their hearts were collected to measure the levels of malondialdehyde (MDA), antioxidant enzyme activity (superoxide dismutase-SOD, catalase-CAT, glutathione peroxidase-GPx) and oxidative metabolism marker (citrate synthase-CS activity). Fish oil supplementation increases HDL concentration and activity of CAT and CS. Moreover, physical training coupled with fish oil supplementation induces additional effects on SOD, GPx and CS activity mainly in aged rats. Our data suggest that combined treatment in aged rat hearts improves the antioxidant capacities and metabolic enzyme that can prevent the deleterious effects of aging.
Seizures are frequent in the neonatal period. They can be idiopathic, be caused by organic brain ... more Seizures are frequent in the neonatal period. They can be idiopathic, be caused by organic brain anomalies or by metabolic disturbances. Evaluation of the etiologic diagnosis and clinical evolution of the newborns with neonatal seizures admitted at one tertiary neonatal intensive care unit. Retrospective review of the clinical files of the newborns with neonatal seizures, during a period of eight years. Neonatal seizures occurred in 91 cases. Seventy nine (86.8%) received anticonvulsant therapy during clinical seizure. Image and/or electrophysiological studies were performed in the majority of newborns (86.8%). Etiology was identified in 51.6% of the 91 cases studied, being the more frequent situations: central nervous system bleeding (11 cases), hypoxic-ischemic encephalopathy (10 cases) and electrolytes disturbances (7 cases). Mortality rate was 16.5%. The newborns followed in our hospital had good neurodevelopment, in 70.2% of cases but in 10.6% was detected important neurodevelo...
The urinary tract infections, after respiratory infections, are the most common in the community.... more The urinary tract infections, after respiratory infections, are the most common in the community. The knowledge about the prevalence of microbial strains and their antibiotic susceptibility is crucial to establish an effective empirical therapy. The aim of this study was to determine the antibiotic susceptibility patterns of bacterial strains isolated from positive urine cultures performed in patients from the central region of Portugal. We carried out a documental analysis of 6008 urine bacteriological exams, to be made available to physicians, most of which run through the automated system VITEK 2, bioMérieux. The majority (80%) of the urine bacteriological exams were from female. Escherichia coli was the most prevalent bacterial pathogen (65.9%), followed by Klebsiella spp (12%). Nitrofurantoin showed high levels of activity (96%) for Escherichia coli, as well as Fosfomycin (96.6%). Amoxicillin-clavulanic acid presents an activity level of only 81.1% for the same germ. Quinolones...
Long-term ethanol intake has been reported to evoke both hypertension and increase of systemic va... more Long-term ethanol intake has been reported to evoke both hypertension and increase of systemic vasopressin levels in rats. In this work, we investigated the involvement of systemic vasopressin in the hypertension evoked in rats by long-term ethanol (20% vol/vol) intake for 2 weeks, by systemic treatment with the V1-vasopressin receptor antagonist dTyr(CH2)5(Me)AVP (50 microg/kg). Moreover, plasma arginine-vasopressin (AVP) content was quantified using an AVP radioimmunoassay and the expression of vasopressin mRNA in the supraoptic (SON) and paraventricular (PVN) nuclei was measured using real-time PCR. Mild hypertension was observed after 2 weeks of ethanol treatment when compared with control animals. Moreover, an increase in both the expression of vasopressin mRNA and the vasopressin blood content was observed in ethanol-treated rats in comparison to the control group. Basal blood pressure levels of ethanol-treated animals were significantly reduced by IV treatment with the V1-vas...
Multiresistant Candida septicaemia is an increasing problem in Neonatal Intensive Care Units worl... more Multiresistant Candida septicaemia is an increasing problem in Neonatal Intensive Care Units worldwide. Caspofungin is a new antifungal drug licensed in Portugal for use in children since September 2008, with limited experience in newborns. Preterm female, 26 weeks gestational age, born by vaginal delivery, with 780g birthweight and Apgar score 8/9. The newborn developed a mucocutaneous candidiasis at day 8 of life which was treated with oral nystatin and topic clotrimazol. Clinical and laboratory deterioration occurred at day 15 of life with Candida albicans sepsis being diagnosed. Therapy with amphotericin B liposome was started but the clinical condition and candidemia persisted. Treatment with caspofungin was initiated at day 28 of life and continued for 28 days. There was an improvement of the clinical condition and the blood cultures became negative. The child was discharged at the 80th of life with no evident clinical problems. The long term follow-up revealed bilateral deafn...
The aim of the present work was to establish a time-course correlation between vascular and auton... more The aim of the present work was to establish a time-course correlation between vascular and autonomic changes that contribute to the development of hypertension during ethanol ingestion in rats. For this, male Wistar rats were subjected to the intake of increasing ethanol concentrations in their drinking water during four weeks. Ethanol effects were investigated at the end of each week. Mild hypertension was already observed at the first week of treatment, and a progressive blood pressure increase was observed along the evaluation period. Increased pressor response to phenylephrine was observed from first to fourth week. α1-Adrenoceptor protein in the mesenteric bed was enhanced at the first week, whereas β2-adrenoceptor protein in the aorta was reduced after the second week. In the third week, ethanol intake facilitated the depressor response to sodium nitroprusside, whereas in the fourth week it reduced nitrate content in aorta and increased it plasma. The bradycardic component of the baroreflex was impaired, whereas baroreflex tachycardia was enhanced at the third and fourth weeks. AT1A receptor and C-type natriuretic peptide (CNP) mRNAs in the nucleus tractus solitarius were increased at the fourth week. These findings suggest that increased vascular responsiveness to vasoconstrictor agents is possibly a link factor in the development and maintenance of the progressive hypertension induced by ethanol consumption. Additionally, baroreflex changes are possibly mediated by alterations in angiotensinergic mechanisms and CNP content within the brainstem, which contribute to maintaining the hypertensive state in later phases of ethanol ingestion. Facilitated vascular responsiveness to nitric oxide seems to counteract ethanol-induced hypertension.
Although ascorbic acid (AA) is an antioxidant, under certain conditions it can facilitate oxidati... more Although ascorbic acid (AA) is an antioxidant, under certain conditions it can facilitate oxidation, which may underlie the opposite actions of AA on brain excitability in distinct seizure models. Here, we investigated whether chronic AA administration during brain development alters cortical excitability as a function of AA dose, as indexed by cortical spreading depression (CSD) and by the levels of lipid peroxidation-induced malondialdehyde. Well-nourished and early-malnourished rats received per gavage 30, 60, or 120 mg/kg/d of AA, saline, or no gavage treatment (naïve group) at postnatal days 7-28. CSD propagation and malondialdehyde levels were analyzed at 30-40 days. Confirming previous observations, CSD velocities were significantly higher in the early-malnourished groups than in the well-nourished groups. AA dose was important: 30 mg/kg/d AA decelerated CSD and reduced malondialdehyde levels, whereas 60 mg/kg/d and 120 mg/kg/d accelerated CSD and augmented malondialdehyde levels compared with the corresponding saline and naïve groups. Our findings reinforce previous suggestion that AA acts as an antioxidant in the brain when administered at low doses, but as a prooxidant at high doses, as indicated by CSD propagation and malondialdehyde levels.
Page 1. Influence of the Electrical and Structural Properties of Tin Oxide on the Performances of... more Page 1. Influence of the Electrical and Structural Properties of Tin Oxide on the Performances of Combustible Gas Sensors ♣ Andreia M. Lopes, ♣ Patrícia Nunes, ♠ Paula Vilarinho, ♣ Regina Monteiro, ♣ Elvira Fortunato, ♣ Rodrigo ...
Our aim was to validate a strategy for assessing the risk of significant hyperbilirubinemia in ne... more Our aim was to validate a strategy for assessing the risk of significant hyperbilirubinemia in newborns with gestational ages of ≥35 weeks by combining predischarge bilirubin percentile data with gestational age data, for a European, predominantly white population. We conducted a prospective cohort study with 463 newborns with gestational ages of ≥35 weeks who were admitted to the well-infant nursery. Total bilirubin levels were measured daily until discharge and once after discharge, between the third and eighth days of life, by using a Bilicheck device (Respironics, Murrysville, PA). The values obtained (<52 hours) were plotted on an hour-specific bilirubin nomogram to determine the…
The results of differential scanning calorimetry (DSC) under non-isothermal conditions of the cha... more The results of differential scanning calorimetry (DSC) under non-isothermal conditions of the chalcogenide Inx(Se0.75Te0.25)100−x (where 0≤x≤10at.%) glasses are reported and discussed. The dependence of the characteristic temperatures “glass transition temperature (Tg), the crystallization onset temperature (Tc) and the crystallization peak temperature (Tp) on the heating rate (α) utilized in the determination of the activation energy for the glass transition (Eg),
Infection with Burkholderia cepacia complex (Bcc) bacteria is a threat to cystic fibrosis (CF) pa... more Infection with Burkholderia cepacia complex (Bcc) bacteria is a threat to cystic fibrosis (CF) patients, commonly leading to a fatal pneumonia, the cepacia syndrome. It causes a massive production of pro-inflammatory cytokines and leucocyte recruitment to airway epithelium without resolving infection and contributing to tissue lesion. To dissect how Bcc bacteria subvert the immune response, we developed a co-culture model with human dendritic cells (DCs) and B. cenocepacia clonal variants isolated from a chronically infected CF patient, who died with cepacia syndrome. We demonstrated that the two late variants were sevenfold and 17-fold (respectively) more internalized by DCs than the variant that initiated infection. The late variants showed improved survival within DCs (60.29 and 52.82 CFU/DC) compared to the initial variant (0.38 CFU/DC). All clonal isolates induced high expression of inflammatory cytokines IL-8, IL-6, IL-1β, IL-12, IL-23, TNF-α and IL-1β. This pro-inflammatory t...
<strong>Introduction:</strong> The urinary tract infe... more <strong>Introduction:</strong> The urinary tract infections, after respiratory infections, are the most common in the community. The knowledge about the prevalence of microbial strains and their antibiotic susceptibility is crucial to establish an effective empirical therapy. The aim of this study was to determine the antibiotic susceptibility patterns of bacterial strains isolated from positive urine cultures performed in patients from the central region of Portugal.<br /><strong>Material and Methods:</strong> We carried out a documental analysis of 6008 urine bacteriological exams, to be made available to physicians, most of which run through the automated system VITEK 2, bioMérieux. The majority (80%) of the urine bacteriological exams were from female. Escherichia coli was the most prevalent bacterial pathogen (65.9%), followed by Klebsiella spp (12%).<br /><strong>Results:</strong> Nitrofurantoin showed high levels of activity (96%) for Escherichia coli, as well as Fosfomycin (96.6%). Amoxicillin-clavulanic acid presents an activity level of only 81.1% for the same germ. Quinolones exhibit efficacy to only 78% of the strains of Escherichia coli, below the Fosfomycin and Nitrofurantoin. Nitrofurantoin showed high levels of activity (96%) for E. coli as well as Fosfomycin (96.6%). Amoxicillin-Clavulanic Acid presents a level of activity of only 81.1% for the same germ. The quinolones have a efficacy for only 78% of strains of E. coli, lower than Fosfomycin.<br /><strong>Discussion:</strong> Escherichia Coli was the most prevalent uropathogen (65.9%). High efficacy against this pathogenic agent was found for Fosfomycin (96.6%) and Nitrofurantoin (96%).<br /><strong>Conclusion:</strong> Further antimicrobial surveillance studies should be developed, in order to formulate local empirical therapy<br />recommendations for optimized therapeutical choices.<br /><strong>Keywords:</strong> Urinary Tract Infections; Drug Resistance, Bacterial; Anti-Bacterial Agents; Community-Acquired Infections.<br />
The International Journal of Biochemistry & Cell Biology, 2015
Around 60-80% of all breast tumors are estrogen receptor-positive. One of the several therapeutic... more Around 60-80% of all breast tumors are estrogen receptor-positive. One of the several therapeutic approaches used for this type of cancers is the use of aromatase inhibitors. Exemestane is a third-generation steroidal aromatase inhibitor that undergoes a complex and extensive metabolism, being catalytically converted into chemically active metabolites. Recently, our group showed that the major exemestane metabolites, 17β-hydroxy-6-methylenandrosta-1,4-dien-3-one and 6-(hydroxymethyl)androsta-1,4,6-triene-3,17-dione, as well as, the intermediary metabolite 6β-Spirooxiranandrosta-1,4-diene-3,17-dione, are potent aromatase inhibitors in breast cancer cells. In this work, in order to better understand the biological mechanisms of exemestane in breast cancer and the effectiveness of its metabolites, it was investigated their effects in sensitive and acquired-resistant estrogen receptor-positive breast cancer cells. Our results indicate that metabolites induced, in sensitive breast cancer cells, cell cycle arrest and apoptosis via mitochondrial pathway, involving caspase-8 activation. Moreover, metabolites also induced autophagy as a promoter mechanism of apoptosis. In addition, it was demonstrated that metabolites can sensitize aromatase inhibitors-resistant cancer cells, by inducing apoptosis. Therefore, this study indicates that exemestane after metabolization originates active metabolites that suppress the growth of sensitive and resistant breast cancer cells. It was also concluded that, in both cell lines, the biological effects of metabolites are different from the ones of exemestane, which suggests that exemestane efficacy in breast cancer treatment may also be dependent on its metabolites.
It is well known that in the aging process a variety of physiological functions such as cardiac p... more It is well known that in the aging process a variety of physiological functions such as cardiac physiology and energy metabolism decline. Imbalance in production and elimination of reactive oxygen species (ROS) may induce oxidative stress. Research shows that oxidative stress is an important factor in the aging process. Studies suggest that ɷ-3 polyunsaturated fatty acids (PUFAs) and moderate physical exercise modulate the ROS system. Therefore, the present study aimed to investigate whether ɷ-3 present in fish oil supplementation coupled with moderate physical training could improve antioxidant and metabolic enzymes in the hearts of adult and aged rats and, if these effects could be associated to glycemia, plasma lipid profile or murinometric parameters. Adult (weighing 315.1±9.3g) and aged rats (weighing 444.5±11.8g) exercised and receive fish oil supplementation for 4weeks. Then they were used to evaluate murinometric parameters, fasting glucose and lipid profile. After this, their hearts were collected to measure the levels of malondialdehyde (MDA), antioxidant enzyme activity (superoxide dismutase-SOD, catalase-CAT, glutathione peroxidase-GPx) and oxidative metabolism marker (citrate synthase-CS activity). Fish oil supplementation increases HDL concentration and activity of CAT and CS. Moreover, physical training coupled with fish oil supplementation induces additional effects on SOD, GPx and CS activity mainly in aged rats. Our data suggest that combined treatment in aged rat hearts improves the antioxidant capacities and metabolic enzyme that can prevent the deleterious effects of aging.
Seizures are frequent in the neonatal period. They can be idiopathic, be caused by organic brain ... more Seizures are frequent in the neonatal period. They can be idiopathic, be caused by organic brain anomalies or by metabolic disturbances. Evaluation of the etiologic diagnosis and clinical evolution of the newborns with neonatal seizures admitted at one tertiary neonatal intensive care unit. Retrospective review of the clinical files of the newborns with neonatal seizures, during a period of eight years. Neonatal seizures occurred in 91 cases. Seventy nine (86.8%) received anticonvulsant therapy during clinical seizure. Image and/or electrophysiological studies were performed in the majority of newborns (86.8%). Etiology was identified in 51.6% of the 91 cases studied, being the more frequent situations: central nervous system bleeding (11 cases), hypoxic-ischemic encephalopathy (10 cases) and electrolytes disturbances (7 cases). Mortality rate was 16.5%. The newborns followed in our hospital had good neurodevelopment, in 70.2% of cases but in 10.6% was detected important neurodevelo...
The urinary tract infections, after respiratory infections, are the most common in the community.... more The urinary tract infections, after respiratory infections, are the most common in the community. The knowledge about the prevalence of microbial strains and their antibiotic susceptibility is crucial to establish an effective empirical therapy. The aim of this study was to determine the antibiotic susceptibility patterns of bacterial strains isolated from positive urine cultures performed in patients from the central region of Portugal. We carried out a documental analysis of 6008 urine bacteriological exams, to be made available to physicians, most of which run through the automated system VITEK 2, bioMérieux. The majority (80%) of the urine bacteriological exams were from female. Escherichia coli was the most prevalent bacterial pathogen (65.9%), followed by Klebsiella spp (12%). Nitrofurantoin showed high levels of activity (96%) for Escherichia coli, as well as Fosfomycin (96.6%). Amoxicillin-clavulanic acid presents an activity level of only 81.1% for the same germ. Quinolones...
Long-term ethanol intake has been reported to evoke both hypertension and increase of systemic va... more Long-term ethanol intake has been reported to evoke both hypertension and increase of systemic vasopressin levels in rats. In this work, we investigated the involvement of systemic vasopressin in the hypertension evoked in rats by long-term ethanol (20% vol/vol) intake for 2 weeks, by systemic treatment with the V1-vasopressin receptor antagonist dTyr(CH2)5(Me)AVP (50 microg/kg). Moreover, plasma arginine-vasopressin (AVP) content was quantified using an AVP radioimmunoassay and the expression of vasopressin mRNA in the supraoptic (SON) and paraventricular (PVN) nuclei was measured using real-time PCR. Mild hypertension was observed after 2 weeks of ethanol treatment when compared with control animals. Moreover, an increase in both the expression of vasopressin mRNA and the vasopressin blood content was observed in ethanol-treated rats in comparison to the control group. Basal blood pressure levels of ethanol-treated animals were significantly reduced by IV treatment with the V1-vas...
Multiresistant Candida septicaemia is an increasing problem in Neonatal Intensive Care Units worl... more Multiresistant Candida septicaemia is an increasing problem in Neonatal Intensive Care Units worldwide. Caspofungin is a new antifungal drug licensed in Portugal for use in children since September 2008, with limited experience in newborns. Preterm female, 26 weeks gestational age, born by vaginal delivery, with 780g birthweight and Apgar score 8/9. The newborn developed a mucocutaneous candidiasis at day 8 of life which was treated with oral nystatin and topic clotrimazol. Clinical and laboratory deterioration occurred at day 15 of life with Candida albicans sepsis being diagnosed. Therapy with amphotericin B liposome was started but the clinical condition and candidemia persisted. Treatment with caspofungin was initiated at day 28 of life and continued for 28 days. There was an improvement of the clinical condition and the blood cultures became negative. The child was discharged at the 80th of life with no evident clinical problems. The long term follow-up revealed bilateral deafn...
The aim of the present work was to establish a time-course correlation between vascular and auton... more The aim of the present work was to establish a time-course correlation between vascular and autonomic changes that contribute to the development of hypertension during ethanol ingestion in rats. For this, male Wistar rats were subjected to the intake of increasing ethanol concentrations in their drinking water during four weeks. Ethanol effects were investigated at the end of each week. Mild hypertension was already observed at the first week of treatment, and a progressive blood pressure increase was observed along the evaluation period. Increased pressor response to phenylephrine was observed from first to fourth week. α1-Adrenoceptor protein in the mesenteric bed was enhanced at the first week, whereas β2-adrenoceptor protein in the aorta was reduced after the second week. In the third week, ethanol intake facilitated the depressor response to sodium nitroprusside, whereas in the fourth week it reduced nitrate content in aorta and increased it plasma. The bradycardic component of the baroreflex was impaired, whereas baroreflex tachycardia was enhanced at the third and fourth weeks. AT1A receptor and C-type natriuretic peptide (CNP) mRNAs in the nucleus tractus solitarius were increased at the fourth week. These findings suggest that increased vascular responsiveness to vasoconstrictor agents is possibly a link factor in the development and maintenance of the progressive hypertension induced by ethanol consumption. Additionally, baroreflex changes are possibly mediated by alterations in angiotensinergic mechanisms and CNP content within the brainstem, which contribute to maintaining the hypertensive state in later phases of ethanol ingestion. Facilitated vascular responsiveness to nitric oxide seems to counteract ethanol-induced hypertension.
Although ascorbic acid (AA) is an antioxidant, under certain conditions it can facilitate oxidati... more Although ascorbic acid (AA) is an antioxidant, under certain conditions it can facilitate oxidation, which may underlie the opposite actions of AA on brain excitability in distinct seizure models. Here, we investigated whether chronic AA administration during brain development alters cortical excitability as a function of AA dose, as indexed by cortical spreading depression (CSD) and by the levels of lipid peroxidation-induced malondialdehyde. Well-nourished and early-malnourished rats received per gavage 30, 60, or 120 mg/kg/d of AA, saline, or no gavage treatment (naïve group) at postnatal days 7-28. CSD propagation and malondialdehyde levels were analyzed at 30-40 days. Confirming previous observations, CSD velocities were significantly higher in the early-malnourished groups than in the well-nourished groups. AA dose was important: 30 mg/kg/d AA decelerated CSD and reduced malondialdehyde levels, whereas 60 mg/kg/d and 120 mg/kg/d accelerated CSD and augmented malondialdehyde levels compared with the corresponding saline and naïve groups. Our findings reinforce previous suggestion that AA acts as an antioxidant in the brain when administered at low doses, but as a prooxidant at high doses, as indicated by CSD propagation and malondialdehyde levels.
Page 1. Influence of the Electrical and Structural Properties of Tin Oxide on the Performances of... more Page 1. Influence of the Electrical and Structural Properties of Tin Oxide on the Performances of Combustible Gas Sensors ♣ Andreia M. Lopes, ♣ Patrícia Nunes, ♠ Paula Vilarinho, ♣ Regina Monteiro, ♣ Elvira Fortunato, ♣ Rodrigo ...
Our aim was to validate a strategy for assessing the risk of significant hyperbilirubinemia in ne... more Our aim was to validate a strategy for assessing the risk of significant hyperbilirubinemia in newborns with gestational ages of ≥35 weeks by combining predischarge bilirubin percentile data with gestational age data, for a European, predominantly white population. We conducted a prospective cohort study with 463 newborns with gestational ages of ≥35 weeks who were admitted to the well-infant nursery. Total bilirubin levels were measured daily until discharge and once after discharge, between the third and eighth days of life, by using a Bilicheck device (Respironics, Murrysville, PA). The values obtained (<52 hours) were plotted on an hour-specific bilirubin nomogram to determine the…
The results of differential scanning calorimetry (DSC) under non-isothermal conditions of the cha... more The results of differential scanning calorimetry (DSC) under non-isothermal conditions of the chalcogenide Inx(Se0.75Te0.25)100−x (where 0≤x≤10at.%) glasses are reported and discussed. The dependence of the characteristic temperatures “glass transition temperature (Tg), the crystallization onset temperature (Tc) and the crystallization peak temperature (Tp) on the heating rate (α) utilized in the determination of the activation energy for the glass transition (Eg),
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