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1.
Ecotoxicol Environ Saf ; 169: 418-424, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30469027

RESUMO

Toxic metal content were measured in samples of mollusc Concholepas concholepas obtained from the Chilean coast. Samples were collected during two periods, one before and one after the earthquake-tsunami which occurred in the Maule Region, Chile, February 27th, 2010 as a result of an earthquake with a magnitude of 8.8. Quantification of toxic metals in samples of hepatopancreas and muscle tissue was performed using flame atomic absorption spectroscopy. The analytical methodology was validated with certified reference material. The content means measured in muscle tissue for January 2010 were Cu: 10.3; Cr: 0.7; Cd: < 0.1; Mn: 3.6 and Zn: 38.6 µg g-1 (dry weight). For October 2014, the means were Cu: 8; Cr: 2.4; Cd: < 0.1; Mn: 5.6 and Zn: 45.4 µg g-1 (dry weight). In hepatopancreas tissue, the content means were Cu: 14.8; Cr: 2.4; Cd: 246.2; Mn: 4.4 and Zn: 1552.9 µg g-1 (dry weight). For October 2014, the means were Cu: 53.7; Cr: 3.5; Cd: 118; Mn: 13.4 and Zn: 1352.3 µg g-1 (dry weight). Cd, Cr, Cu, Mn and Zn content in the samples of hepatopancreas were generally higher than those recorded in muscle tissue however they were not always statistically significant. Statistical analysis showed that Cu and Mn content in the post-tsunami period increased in the hepatopancreas tissue. The concentrations of Cd, Cr, Cu, Mn, and Zn measured in the muscular tissue (edible part) of the species Conchalepas concholepas, were lower than the maximum contents allowed by the current legislation (FAO/WHO, 2004; EU, 2001) and its consumption is not a risk to human health.


Assuntos
Terremotos , Monitoramento Ambiental/métodos , Gastrópodes/efeitos dos fármacos , Metais Pesados/análise , Músculos/efeitos dos fármacos , Tsunamis , Animais , Chile , Gastrópodes/química , Humanos , Músculos/química , Espectrofotometria Atômica
2.
Phys Rev E ; 106(1): L012201, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35974581

RESUMO

The interaction of light beams with helical defects in optical materials generates optical vortices. Understanding and manipulating the dynamics of helical defects allows for the creation of versatile sources of optical vortex beams. Using a magnetic ring on a nematic liquid crystal cell, we trapped helical defects identified as matter vortices. We observe oscillatory rotating and beating matter vortices by applying a low-frequency voltage. Experimentally, we determine the region of parameters where these vortices are observed. The amplitude of oscillatory rotating vortices decays with the inverse of the voltage frequency. We propose an adequate amplitude equation, which allows us to describe the vortex dynamics; theoretical findings have a qualitative agreement with the experimental observations.

3.
Waste Manag ; 126: 643-651, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33872973

RESUMO

Conventional municipal waste management systems based on collecting and storing waste for future management are cost-effective and flexible. These systems present significant problems such as odours, plagues and hygiene problems caused by their storage and greenhouse gas emissions from garbage trucks used for the transport of waste. The Automated Waste Collection System (AWCS) and Automated Vacuum Waste Collection (AVWC) systems, in which waste is transported directly underground to the processing plants, are efficient collection systems and respectful of the environment as alternatives to traditional systems. The pneumatic system reduces the value of the per capita generation of general waste. The present study explains the origin of pipe failure in two different AWCS factories, as well as the identification of the failure phenomena. To carry out the study, a classification of 90 failure cases by primary cause was performed, followed by recommendations to avoid these failures in the future. Moreover, a computational fluid dynamics (CFD) simulation was performed in order to help in the failure determination and the key recommendations to avoid the most common and frequent failures.


Assuntos
Resíduos de Alimentos , Gases de Efeito Estufa , Eliminação de Resíduos , Gerenciamento de Resíduos , Vácuo
4.
Transplant Proc ; 50(5): 1489-1495, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29880376

RESUMO

BACKGROUND: Heart transplantation (HT) is regarded as the treatment of choice for end-stage heart failure (ESHF) patients. Severe acute kidney injury (AKI) after HT is a frequent clinical problem with devastating consequences for HT recipients. METHODS: Data from 112 ESHF patients undergoing HT in 2010-2015 were retrospectively reviewed. The primary end point was the development of AKI stage III, and secondary outcomes were in-hospital and 1-year mortality according to Kidney Disease Improving Global Outcomes criteria. RESULTS: In total, 81 patients (72.3%) developed AKI, of which 33 (29.4%) developed AKI stage I, 18 (16%) stage II, and 30 (26.7%) stage III; within this group, 27 recipients (24%) required renal replacement therapy (RRT). Overall hospital mortality was 14%. However, when stratifying by AKI stage, hospital mortality increased from 0% to 46% comparing recipients without AKI and those with AKI stage III, respectively (P = .001). In the same way, 1-year mortality increased from 6% to 53% for recipients without AKI compared with those who developed AKI stage III (log-rank test for trend: P = .001). Recipients that required RRT had a 1-year mortality of 59.2% compared with 5.8% in those without RRT requirement. CONCLUSIONS: The findings indicate that AKI stage III is common after HT and adversely affects early and late mortality. Clinical variables together with perioperative hemodynamic assessment could add more powerful prognostic information to predict severe AKI before HT and therefore evaluate potential heart-kidney recipients.


Assuntos
Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Transplante de Coração/efeitos adversos , Transplante de Coração/mortalidade , Adulto , Estudos de Coortes , Feminino , Mortalidade Hospitalar , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos
5.
Dalton Trans ; 47(6): 1808-1818, 2018 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-29322149

RESUMO

Main group element coordination polymers (MGE-CPs) are important compounds for the development of multifunctional materials. However, there has been a shortage of studies regarding their structural, optical, catalytic, mechanical, and antibacterial properties. This work presents an exhaustive study of a set of crystalline MGE-CPs obtained from bismuth and indium metals and iminodiacetate, 1,2,4,5-benzenetetracarboxylate, and 2,2'-bipyridine as building blocks. An in-depth topological analysis of the networks was carried out. Additionally, nanoindentation studies were performed on two representative low-dimensional compounds in order to find the relationships between their structural features and their intrinsic mechanical properties (hardness and elasticity). The solid-state photoluminescence (SSPL) properties were also studied in terms of excitation, emission, lifetimes values, and CIE chromaticites. Moreover, the heterogeneous catalytic activities of the compounds were evaluated with the cyanosilylation reaction using a set of carbonylic substrates under solvent-free conditions. Finally, the inhibitory effect of the Bi-CPs on the growth of microorganisms such as Escherichia coli, Salmonella enterica serovar Typhimurium, and Pseudomonas aeruginosa, which are associated with relevant infectious diseases, is reported.

7.
Circulation ; 100(19): 1958-63, 1999 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-10556221

RESUMO

BACKGROUND: There is growing evidence of the prognostic importance of C-reactive protein (CRP) in unstable angina. However, the independent value of CRP relative to other conventional markers at different stages of treatment has not been established. Therefore, we assessed the in-hospital and 90-day prognostic values of serum CRP in unstable angina. We also compared the relation of CRP at admission and discharge with 90-day outcome. METHODS AND RESULTS: One hundred ninety-four consecutive patients were included in a derivation (n = 105) and a validation set (n = 89). Serum CRP was measured at admission, at 48 hours, and at hospital discharge. A cutoff point of 1.5 mg/dL for CRP provided optimum sensitivity and specificity for adverse outcome, based on the receiver operator curves. No association was found between CRP on admission and in-hospital outcome. CRP at admission, adjusted for age, ECG findings on admission, silent ischemia, left ventricular wall motion score, and high-risk clinical presentation, was related to the combined end point of refractory angina, myocardial infarction, or death at 90 days (hazard ratio [HR] 1.9, 95% CI 1.2 to 8.3, P = 0.002). CRP at hospital discharge was the strongest independent marker of an adverse outcome (HR 3.16, 95% CI 2.0 to 5.2, P = 0.0001). These results were confirmed in the validation set (CRP at discharge: HR 3. 3, 95% CI 2.0 to 7.69, P = 0.0001). CONCLUSIONS: In unstable angina, CRP is a strong independent marker of increased 90-day risk. Compared with CRP at admission, CRP at discharge is better related to later outcome and could be of great utility for risk stratification.


Assuntos
Angina Instável/sangue , Proteína C-Reativa/análise , Angina Instável/fisiopatologia , Eletrocardiografia , Feminino , Humanos , Masculino , Análise Multivariada , Prognóstico
8.
Cochrane Database Syst Rev ; (4): CD003614, 2005 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-16235330

RESUMO

BACKGROUND: Patients with stable angina not controlled by monotherapy with nitrates, beta blockers, or calcium channel blockers are often treated with combinations of these drugs. There may be adverse effects from, or contraindications to, the use of combinations. In low risk groups, medical treatment appears to be as good an option as percutaneous transluminal coronary angioplasty in terms of averting myocardial infarction, death, or subsequent revascularization. Revascularization procedures are too costly or inaccessible for many patients in developing countries therefore effective and safe medical treatment is needed. Trimetazidine is a less well known anti-anginal drug that controls myocardial ischaemia through intracellular metabolic changes. Trimetazidine has been reported, in some studies, to be better tolerated than combined anti-anginal therapy; however it is not considered in published guidelines. OBJECTIVES: To determine the efficacy and tolerability of trimetazidine in patients with stable angina. SEARCH STRATEGY: We searched The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, LILACS and SCISEARCH, without language restriction, from inception to October 2003. Experts in the field were contacted to locate unpublished studies. SELECTION CRITERIA: Randomised studies comparing trimetazidine with placebo, or other anti-angina drug in adults with stable angina. DATA COLLECTION AND ANALYSIS: Two reviewers independently applied the inclusion criteria, assessed trial quality and extracted data. MAIN RESULTS: Twenty-three studies (1378 patients) met the inclusion criteria. There was a paucity of information about mortality, cardiovascular events and quality of life. Trimetazidine, compared with placebo, reduced the number of weekly angina attacks ( mean difference -1.44, 95% CI -2.10 to -0.79; P < 0.0001), reduced weekly nitroglycerin tablet consumption (95% CI -1.47 to -2.20, -0.73; P < 0.0001) and improved exercise time to 1 mm segment depression (P=0.0002). Four small trials (263 patients) compared trimetazidine against other anti-anginal agents. One favoured trimetazidine over nitrates. Three tended to favour alternative regimens but with confidence intervals consistent with both major increases and decreases in frequency of angina episodes. In this subgroup, adverse events were considered in 5 trials (448 patients) and totals of 2 versus 12 drop outs due to adverse events were observed in the trimetazidine and alternative regimens respectively, but this was mostly driven by a single trial. AUTHORS' CONCLUSIONS: Trimetazidine is effective in the treatment of stable angina compared with placebo, alone or combined with conventional anti-anginal agents. Trimetazidine may result in fewer dropouts due to adverse events. Large, long term trials comparing trimetazidine with other anti-anginal drugs assessing clinically relevant important outcomes are required to establish its role in clinical management.


Assuntos
Angina Pectoris/tratamento farmacológico , Trimetazidina/uso terapêutico , Vasodilatadores/uso terapêutico , Adulto , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Trimetazidina/efeitos adversos , Vasodilatadores/efeitos adversos
9.
Gastroenterol. latinoam ; 31(2): 98-106, 2020. tab, ilus, graf
Artigo em Espanhol | LILACS | ID: biblio-1292434

RESUMO

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that survives in gastric acidity. Approximately 50% of the world population is a carrier of this infection and the prevalence is higher in African and Latin American populations. The clinical manifestations associated with this infection are gastritis, peptic ulcers, MALT lymphoma, gastric cancer (GC), and other extra-digestive pathologies. Chronic H. pylori infection is the most important risk factor for GC development. There are several diagnostic methods to detect H. pylori infection. The most widely used invasive methods are the rapid urease test and Giemsa staining in gastric biopsies. Culture and molecular techniques are very useful for the study of H. pylori presence and antibiotic resistance, but they are not easily available in health centers. The most widely used non-invasive methods are the urea breath test and bacterial antigens in stools. Serological studies are used for population studies. The use and indication of the diagnostic method for detecting H. pylori infection will depend on the clinical manifestations, risk factors for GC, and the age of the patient.


Helicobacter pylori (H. pylori) es una bacteria Gram negativa que sobrevive a la acidez gástrica. Se estima que aproximadamente el 50% de la población mundial es portadora de esta infección, siendo mayor la prevalencia en poblaciones africanas y latinoamericanas. Entre las manifestaciones clínicas asociadas a esta infección se encuentra gastritis, úlceras pépticas, linfoma MALT, cáncer gástrico y otras patologías extradigestivas. La infección crónica por H. pylori es el factor de riesgo más importante para el desarrollo de CG. Existen diversos métodos diagnósticos para detectar la infección por H. pylori, los métodos invasivos más utilizados son la prueba rápida de ureasa y tinción de Giemsa en biopsias gástricas. El cultivo y las técnicas moleculares son de gran utilidad para el estudio de presencia de H. pylori y estudios de resistencia antibiótica, pero suelen estar poco disponibles en los centros de atención en salud. Los métodos no invasivos más utilizados son la prueba de aire espirado con urea marcada y antígeno bacteriano en deposiciones. Los estudios serológicos son utilizados para estudios poblacionales. El uso e indicación de cada uno de los métodos de diagnóstico para la detección de infección por H. pylori, dependerá de las manifestaciones clínicas, los factores de riesgo de CG y la edad del paciente.


Assuntos
Humanos , Helicobacter pylori , Infecções por Helicobacter/diagnóstico , Medicina Baseada em Evidências
10.
Am J Cardiol ; 87(11): 1235-9, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11377346

RESUMO

We assessed the 90-day prognostic value of stress tests and C-reactive protein (CRP) after medical stabilization of unstable angina. We included 139 consecutive patients with unstable angina who were free of complications or did not undergo revascularization during hospitalization. Blinded CRP assays and a stress test (95 exercise electrocardiograms, 44 dobutamine echocardiograms) were performed within the first week after discharge. Of 139 participants, 44 (31.6%) had an ischemic stress test response. CRP was elevated (> 1.5 mg/dl) in 40 patients (28.7%). CRP >1.5 mg/dl was more frequently observed among patients who experienced death or myocardial infarction at 90 days (88.2% vs 20.5%, p <0.0001). Compared with the stress tests, CRP showed greater sensitivity (88% vs 47%) and specificity (81% vs 70%) for increased risk, and higher positive (37.5% vs 18.2%) and negative (98% vs 90%) predictive values. The area under the receiver operating curve of the relation with the 90-day outcome increased from 0.58 +/- 0.07 to 0.83 +/- 0.05 when the CRP data were added to the stress tests results (p <0.001). Elevation of CRP differentiated stress tests negative patients with increased risk of major events during follow-up. In patients who respond to medical treatment for unstable angina, CRP elevation may be a better parameter than the stress test in identifying the presence of persistent plaque instability.


Assuntos
Angina Instável/diagnóstico , Proteína C-Reativa/metabolismo , Teste de Esforço , Idoso , Angina Instável/sangue , Angina Instável/mortalidade , Dobutamina , Ecocardiografia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/mortalidade , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Medição de Risco , Taxa de Sobrevida
11.
Photochem Photobiol ; 64(2): 334-9, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8760573

RESUMO

Ultraviolet-A (365 nm, 120 kJ/m2/h) exposure caused cell death in Pseudomonas aeruginosa at doses at which Escherichia coli cell viability was not affected. We have not found that UVA induced growth delay or any other sublethal effect. Irradiated suspensions of P. aeruginosa showed a marked reduction in membrane-bound succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) activities. Succinate-driven respiration and several nutrient transport systems were also inhibited. Whereas SDH and LDH activities were independent of the irradiation conditions, cell viability, respiration and transport systems were protected when irradiation was performed in an N2 atmosphere. A similar protective effect was observed when cells were grown in media containing glycerol or when preirradiation bacterial growth was carried out at 30 degrees C (instead of 37 degrees C). Results suggest that UVA induces a differential damaging effect on several biochemical functions of P. aeruginosa. The UVA- induced photodamage may fall into two categories: indirect damage mediated by oxygen (cell killing and inhibition of respiration and transport systems) and direct damage to SDH and LDH (apparently not oxygen dependent). These enzymes and leucine transport appear not to be involved in the lethal effect described herein because they were altered despite viability-preserving conditions


Assuntos
Pseudomonas aeruginosa/efeitos da radiação , Raios Ultravioleta , Relação Dose-Resposta à Radiação
12.
Int J Radiat Biol ; 68(3): 293-9, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7561389

RESUMO

The effect of sublethal fluences (50-200 kJ m-2) of UV-A radiation (320-400 nm) in bacterial cells is a transient growth inhibition related to photo-modified tRNA and is associated with changes in membrane structure and function. Higher UV-A fluences result in cell death due to the production of reactive oxygen species, so far undetected at sublethal doses. Oxidative mechanisms of toxicity induced by 120 kJ m-2 UV-A radiation can be recorded by ultra-weak chemiluminescence, useful in quantifying oxidative reactions. When Escherichia coli was exposed to UV-A stress at a fluence rate equivalent to that of the Sun in the biosphere (33 W m-2), chemiluminescence levels were proportional to the photodamage. Chemiluminescence and photo-damage are linearly proportional and dependent on environmental conditions of the cells. It is postulated that in addition to tRNA photo-modification, UV-A alters the membrane structure of E. coli by oxidative damage, since changes in the membrane structure under different environmental conditions play a key role in the cell's response to UV-A injury.


Assuntos
Escherichia coli/efeitos da radiação , Membrana Celular/efeitos dos fármacos , Membrana Celular/enzimologia , Escherichia coli/crescimento & desenvolvimento , Etanol/farmacologia , L-Lactato Desidrogenase/metabolismo , Medições Luminescentes , Nitrogênio/farmacologia , Oxirredução , Peróxidos/química , Succinato Desidrogenase/metabolismo , Temperatura , Raios Ultravioleta
13.
Nutrition ; 7(2): 122-4, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1802193

RESUMO

We measured the temperature of 10 previously refrigerated parenteral-nutrition solutions (PN solutions) at the end of a standard intravenous-infusion set (IIS) (Intrafix, 145 cm long), an IIS with a mechanical device to control the flow of the solution (Dial-a-Flow, 226 cm long), and an IIS to be used with a volumetric infusion pump (Infusomat, 259 cm long). The temperature of the PN solution just after taking it out of the refrigerator was 6.0 +/- 0.8 degrees C (mean +/- SD), and that of the room was 24.2 +/- 0.7 degrees C. We recorded the temperature again at the end of the IIS after draining it freely, i.e., until there was no air inside the set (time 0), after 5, 10, and 15 min of infusion at 100 ml/h. After 15 min, the temperature at the end of the Intrafix set did not statistically differ (P less than 0.05) from room temperature. With Dial-a-Flow, the temperature of the solution was not statistically different from room temperature at any time. Finally, with Infusomat, the temperature was statistically different from that of the room for the first 5 min. We thus conclude that refrigerated PN solution can be administered to patients without having to warm it whenever an IIS is longer than 145 cm and flow not exceeding 100 ml/h is used. Adverse reactions sometimes observed in patients at the beginning of the administration of PN solution cannot, in our opinion, be attributed to the low temperature of the solution.


Assuntos
Temperatura Baixa , Nutrição Parenteral/instrumentação , Soluções , Humanos
14.
JPEN J Parenter Enteral Nutr ; 26(1): 30-41, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11833749

RESUMO

BACKGROUND: Fatty acids from the diet or from IV fat emulsions are incorporated into the plasma and cell membrane phospholipids and act as substrates in the synthesis of eicosanoids. This study reports the effect of 2 parenteral lipid emulsions in plasma phospholipids fatty acids. METHODS: A total of 83 patients aged 18 to 75 years were randomized to receive long-chain triglycerides (LCT) or 50/50 mix of long- and medium-chain triglyceride emulsion (LCT/MCT). Blood samples were collected at baseline and at weekly intervals for 28 days. Plasma phospholipid fatty acids were measured by gas chromatography. RESULTS: Patients receiving LCT versus MCT/LCT emulsion have an increase in 18:2n6 and a decrease in 20:4n6 and 22:4n6 after 7, 14, and 21 days of treatment with parenteral nutrition. Phospholipid fatty acids at 15 days of treatment with parenteral nutrition with LCT versus MCT/LCT for 18:2n6 were 17.30% versus 22,90% (p < .05), for 20:4n6 10.44% versus 8.38% (p < .05), and for 22:4n6 0.51% versus 0.40% (p < .05). The 20:4n6 percentage inversely correlated with the percentage of 18:2n6 on days 7, 14, and 21: regression coefficients: -7.40 (p < .001), -7.39 (p < .001), and 5.70 (p < .001), respectively. CONCLUSIONS: Parenteral lipid emulsions modify fatty acid profiles in plasma phospholipids. MCT/LCT emulsions produce in phospholipids a fatty-acid profile that is closer to normality than that achieved with LCT emulsions. These changes in phospholipid fatty acids are suggestive of an inhibition of A-5-desaturase in patients who received LCT emulsions.


Assuntos
Emulsões Gordurosas Intravenosas/farmacologia , Ácidos Graxos/farmacologia , Fosfolipídeos/química , Adolescente , Adulto , Idoso , Cromatografia Gasosa , Dessaturase de Ácido Graxo Delta-5 , Método Duplo-Cego , Emulsões Gordurosas Intravenosas/administração & dosagem , Emulsões Gordurosas Intravenosas/química , Ácidos Graxos Dessaturases/antagonistas & inibidores , Ácidos Graxos/administração & dosagem , Ácidos Graxos/química , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Nutrição Parenteral Total , Fosfolipídeos/sangue , Análise de Regressão , Triglicerídeos/administração & dosagem , Triglicerídeos/farmacologia
15.
J Photochem Photobiol B ; 62(3): 158-65, 2001 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11566280

RESUMO

We report the sublethal effects of ultraviolet A (UVA) on Enterobacter cloacae in comparison with those produced in Escherichia coli. UVA-induced sublethal effects were investigated in either bacterial membrane and at tRNA level. Limited dependence on oxygen concentration for photoinduced inhibition of biochemical membrane functions and low levels of oxidative damage during the irradiation period were found in En. cloacae. On the other hand, ultraviolet spectroscopy and reversed-phase HPLC analysis of hydrolysed tRNA showed that radio induced damage to tRNA is similar in En. cloacae and E. coli. Nevertheless, growth delay induced by UVA in En. cloacae was shorter than that found in E. coli submitted to the same experimental conditions. A limited post-irradiation ppGpp accumulation and the absence of any influence of the membrane damage on the growth delay extent seem to be responsible for the shortness of this effect in En. cloacae. Most of the differences between En. cloacae and E. coli could be attributed to an increased ability of En. cloacae to overcome oxidative stress during UVA exposure.


Assuntos
Enterobacter cloacae/efeitos da radiação , Raios Ultravioleta , Membrana Celular/efeitos da radiação , Reagentes de Ligações Cruzadas , Enterobacter cloacae/genética , Enterobacter cloacae/crescimento & desenvolvimento , RNA Bacteriano/metabolismo , RNA de Transferência de Fenilalanina/metabolismo , RNA de Transferência de Prolina/metabolismo
16.
J Photochem Photobiol B ; 54(2-3): 121-5, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10836541

RESUMO

The aim of the present study is to evaluate the occurrence of oxidative stress in the cladoceran Daphnia longispina exposed to UV-A and UV-B radiation. The activity of antioxidant enzymes and lipid peroxidation markers is investigated and the protective action of ascorbic acid determined. Results show differences in the lethality radioinduced by UV-A and UV-B. Both UV-A and UV-B exposure cause an important increase in malonaldehyde (MDA) concentration and catalase activity. Ascorbic acid addition reduces the MDA concentration, indicating that the oxidative stress caused by either UV-A or UV-B radiation can be controlled by antioxidants. The increase of the antioxidant enzymes may be a response mechanism to oxidative stress.


Assuntos
Daphnia/efeitos da radiação , Estresse Oxidativo , Animais , Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Meios de Cultura , Daphnia/efeitos dos fármacos , Água Doce , Peroxidação de Lipídeos , Raios Ultravioleta
17.
J Photochem Photobiol B ; 50(1): 59-65, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10443032

RESUMO

The presence of NaCl in plating media shows an important protection against the Pseudomonas aeruginosa UV-A-induced lethal effect, contrasting with the known sensitizing action of salts on UV-A-irradiated Escherichia coli cells. MgSO4 exhibits a similar protection, but lower concentrations than for NaCl are needed to achieve the same effect. NaCl protection from lethal effects involves an osmotic mechanism, while MgSO4 could act by a different process. On the other hand, when cells grown in a complete medium are then incubated for 20 min in a synthetic medium and irradiated with UV-A, a very marked protection is obtained. This protection is dependent on protein synthesis, since treatment with tetracycline, during the nutritional stress, blocks its induction. These results offer a new example of cross-protection among different stressing agents. In our experimental conditions, natural phenazines of P. aeruginosa are not present in the cells, ruling out the possibility that these pigments act as photosensitizers. Conversely, pyocyanine (the major phenazine produced by this microorganism) prevents the UV-A killing effect in a concentration-dependent way when present in the irradiation media. Finally, UV-A irradiation induces, as in E. coli, the accumulation of guanosine tetraphosphate and guanosine pentaphosphate, although the physiological meaning of this finding has yet to be determined.


Assuntos
Pseudomonas aeruginosa/efeitos da radiação , Raios Ultravioleta , Meios de Cultura , Sulfato de Magnésio/farmacologia , Fenazinas/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Piocianina , Cloreto de Sódio/farmacologia
18.
Nutr Hosp ; 5(2): 104-7, 1990.
Artigo em Espanhol | MEDLINE | ID: mdl-2127702

RESUMO

It is common practice to let parenteral nutrition bags that are kept refrigerated stand at room temperature before administration. In this study the temperature of the mixtures administration. In this study the temperature of the mixtures flowing at the end of a conventional system (Intrafix 145 cm long) and at the end of a flow-control system (Dial-a-flow 226 cm long) were measured. Mixture temperatures within the parenteral nutrition bag were recorded upon removal from the refrigerator, at the end of the infusion system after purging the system with the fastest flow rate possible (time 0), and at 5, 10, and 15 minutes, after sustaining continuous flow at 100 cc/hour. The conventional system showed no statistically significant differences (P less than 0.05) between room temperature (23.7 +/- 0.5) and mixture temperature at the end of the infusion line at 15 minutes of infusion (23.0 +/- 0.9). The Dial-a-flow system showed no statistically significant differences between room temperature (24.5 +/- 0.9) and mixture temperatures at the end of the system (time 0: 23.7 +/- 2.2; 5 minutes, 24.1 +/- 0.8; 10 minutes, 24.3 +/- 0.7; 15 minutes, 24.4 +/- 0.7) (p less than 0.05). Therefore, the results indicate that refrigerated parenteral nutrition bags can be administered directly to the patient without waiting for the mixture to warm up, anytime the length of the infusion system is over 145 cm. Occasional reactions observed at the onset of parenteral nutrition therapy cannot be attributed to low mixture temperature, and as such, other reasons must be searched for.


Assuntos
Alimentos Formulados , Infusões Parenterais , Nutrição Parenteral , Temperatura , Temperatura Baixa , Infusões Parenterais/instrumentação , Nutrição Parenteral/instrumentação
19.
Health Serv J ; 109(5682): 32-3, 1999 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-11067480

RESUMO

From this month, 80 per cent of health authorities will have at least one personal medical services pilot scheme in their area. The extension of the schemes raises concerns about equity and management issues for HAs. An HA where schemes will cover almost a third of the population has had to adopt an off-the-peg approach to development.


Assuntos
Medicina de Família e Comunidade/organização & administração , Assistência Individualizada de Saúde/organização & administração , Atenção Primária à Saúde/organização & administração , Regionalização da Saúde/organização & administração , Humanos , Avaliação das Necessidades , Projetos Piloto , Salários e Benefícios , Medicina Estatal/organização & administração , Reino Unido
20.
Med Cutan Ibero Lat Am ; 12(6): 501-8, 1984.
Artigo em Espanhol | MEDLINE | ID: mdl-6397672

RESUMO

A new case of diffuse melanosis with melanuria is reported. Light and electron microscopic technics were employed. Several hypothesis were proposed to explain the pathogenesis of this particular pigmentation: Dermal perivascular histiocitic cells phagocyte organelles originated in lysed circulating melanoma cells. Phagocytosis of the altered circulating melanoma cells by the endothelium. Macrophages containing ingested melanin migrate from the capillary lumen into the dermis. We consider that in this particular pigmentation participate two mechanism: a) The perivascular dermal macrophage phagocyte the pigment originated in the lysis of the circulating melanoma cells. b) Macrophages loaded with pigment granules cross the capillary wall and remain around the blood vessels.


Assuntos
Melaninas/urina , Melanoma/complicações , Melanose/etiologia , Adulto , Humanos , Macrófagos/patologia , Masculino , Melanócitos/patologia , Melanoma/patologia , Melanoma/urina , Metástase Neoplásica , Células Neoplásicas Circulantes , Fagocitose , Pele/patologia , Neoplasias Cutâneas/patologia
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