RESUMO
The incidence of psoriasis in patients with rheumatoid arthritis (RA) is higher than in the general population. In addition, psoriasis may negatively affect the severity of rheumatological diseases in patients with autoinflammatory or autoimmune diseases. In this study, we evaluated the effect of psoriasis or a family history of psoriasis on the characteristics of RA. This is a cross-sectional study. We included 737 RA patients who met the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) RA Classification Criteria, but did not meet the CASPAR psoriatic arthritis criteria. Subsequently, we compared disease activity, the need for biologic therapy, the number of conventional synthetic disease-modifying anti-rheumatic drugs taken, the frequency of erosive disease and extra-articular involvement, glucocorticoid doses and the Stanford Health Assessment Questionnaire scores between patients with and without a history of psoriasis, and patients with and without a family history of psoriasis. Thirteen (1.8%) patients had psoriasis, while 58 (7.9%) had a family history of psoriasis in first- or seconddegree relatives. All outcome parameters were found to be similar between the groups. We show that concomitant psoriasis has no effect on the evaluated disease characteristics of RA.
Assuntos
Antirreumáticos , Artrite Psoriásica , Artrite Reumatoide , Antirreumáticos/uso terapêutico , Artrite Psoriásica/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/epidemiologia , Artrite Reumatoide/genética , Estudos Transversais , Humanos , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Carotid intima-media thickness (CIMT) is a potential indicator of subclinical atherosclerosis in patients with psoriasis. Epicardial fat thickness (EFT) is proposed as a new cardiometabolic risk factor. OBJECTIVE: To evaluate the association between EFT and CIMT in patients with psoriasis. METHODS: This was a cross-sectional and observational study; 65 patients with psoriasis and 50 age- and sex- matched control subjects were included. Data about echocardiographic EFT, CIMT, anthropometric measurements and metabolic profile were obtained. RESULTS: The EFT and CIMT were significantly increased (7.3 ± 0.5 vs. 6.5 ± 0.5 mm, P < 0.01; 0.74 ± 0.11 vs. 0.60 ± 0.07 mm, P < 0.01, respectively) in patients with psoriasis compared with the controls. EFT was significantly correlated with CIMT (r = 0.69, P < 0.01). In a multiple linear regression model in which EFT was independently associated with psoriasis (ß = 0.45, P < 0.01), age (ß = 0.33, P = 0.01), CIMT (ß = 0.50, P < 0.01), body mass index (ß = 0.25, P = 0.01), high-sensitivity C-reactive protein (ß = 0.32, P < 0.01) and duration of disease (ß = 0.34, P = 0.03). CONCLUSIONS: We demonstrated that EFT and CIMT are increased in patients with psoriasis, and that echocardiographic EFT is closely correlated with CIMT in patients with psoriasis. The echocardiographic assessment of EFT may have the potential to be a simple marker of subclinical atherosclerosis and increased cardiovascular risk in patients with psoriasis.
Assuntos
Tecido Adiposo/patologia , Aterosclerose/diagnóstico , Psoríase/complicações , Adulto , Biomarcadores/metabolismo , Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Espessura Intima-Media Carotídea , Estudos de Casos e Controles , Estudos Transversais , Ecocardiografia , Feminino , Humanos , Masculino , Pericárdio/patologia , Fatores de Risco , Circunferência da CinturaRESUMO
We report on the effect of the International Nosocomial Infection Control Consortium's (INICC) multidimensional approach for the reduction of ventilator-associated pneumonia (VAP) in adult patients hospitalized in 21 intensive-care units (ICUs), from 14 hospitals in 10 Indian cities. A quasi-experimental study was conducted, which was divided into baseline and intervention periods. During baseline, prospective surveillance of VAP was performed applying the Centers for Disease Control and Prevention/National Healthcare Safety Network definitions and INICC methods. During intervention, our approach in each ICU included a bundle of interventions, education, outcome and process surveillance, and feedback of VAP rates and performance. Crude stratified rates were calculated, and by using random-effects Poisson regression to allow for clustering by ICU, the incidence rate ratio for each time period compared with the 3-month baseline was determined. The VAP rate was 17.43/1000 mechanical ventilator days during baseline, and 10.81 for intervention, showing a 38% VAP rate reduction (relative risk 0.62, 95% confidence interval 0.5-0.78, P = 0.0001).
Assuntos
Pesquisa sobre Serviços de Saúde , Controle de Infecções/métodos , Pneumonia Associada à Ventilação Mecânica/prevenção & controle , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Índia , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos ProspectivosRESUMO
OBJECTIVE: Metabolic syndrome (MS) is common among the patients with myocardial infarction. The degree of the left ventricular systolic dysfunction is shown to be associated with poor prognosis after myocardial infarction. The aim of this study was to evaluate the prevalence of MS and its impact on the left ventricular systolic function in non-diabetic patients suffering first ST elevation myocardial infarction (STEMI). MATERIAL AND METHODS: This study was conducted prospectively in three centers. We included patients presenting with non-diabetic first acute STEMI. The systolic functions of the left ventricle were assessed through the ejection fraction, the wall motion score index (WMSI) and tissue Doppler myocardial S wave velocities. The diagnosis of MS was done based on the Adult Treatment Panel III clinical definition of the MS. RESULTS: Among the 240 patients, 90 patients (37.5%) had MS but 150 patients (62.5%) were free of the MS. The patients in the MS group were older and the prevalence was higher among the females. Mean myocardial S wave velocities were significantly lower in the patients with the MS in comparison to the patients without the MS (6.70 +/- 1.68 vs. 7.39 +/- 1.64; p < 0.01). LVEF and WMSI were similar in two groups. CONCLUSIONS: MS was highly common in nondiabetic patients with acute STEMI and left ventricular systolic function were more severely impaired in these patients. Our observations suggest that more severely impaired left ventricular systolic function after acute STEMI may contribute to the higher morbidity and mortality seen in the patients with MS after acute STEMI.
Assuntos
Síndrome Metabólica/epidemiologia , Síndrome Metabólica/fisiopatologia , Infarto do Miocárdio/fisiopatologia , Função Ventricular Esquerda/fisiologia , Idoso , Idoso de 80 Anos ou mais , Eletrocardiografia , Feminino , Humanos , Lipídeos/sangue , Masculino , Síndrome Metabólica/complicações , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico por imagem , Ultrassonografia , Disfunção Ventricular Esquerda/fisiopatologiaRESUMO
Hyperhomocysteinemia is a significant independent, usually heritable, prothrombotic risk factor for atherothrombotic cardiovascular, cerebrovascular, and peripheral vascular disease. We report a 42-year-old woman who had multiple embolic events.
Assuntos
Predisposição Genética para Doença/genética , Hiper-Homocisteinemia/diagnóstico , Hiper-Homocisteinemia/genética , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Trombose/diagnóstico , Trombose/genética , Adulto , Feminino , Humanos , Mutação/genéticaRESUMO
Electrolyte abnormalities are not uncommon in coronavirus disease 2019 (COVID-19). Several studies have suggested that various electrolyte imbalances seem to have an impact on disease prognosis. However, no study has primarily focused on the effect of baseline electrolyte abnormalities on disease outcome. In this study, we assessed the validity of the hypothesis that baseline electrolyte imbalances may be related to unfavourable outcomes in hospitalized COVID-19 patients. Design of the study was retrospective and observational. We included 408 hospitalized individuals with COVID-19 over 18 years old. Baseline levels of sodium, potassium, calcium and chloride were assessed and the effects of abnormalities in these electrolytes on requirement for intensive care unit and mechanical ventilation, hospitalization duration and treatment outcome were evaluated. Patients were clustered based on electrolyte levels and clusters were compared according to outcome variables. Frequency of other severe disease indices was compared between the clusters. Lastly, we evaluated the independent factors related to COVID-19-associated deaths with multivariate analyses. In all, 228 (55.8%) of the patients had at least one electrolyte imbalance at baseline. Hyponatraemia was the most frequent electrolyte abnormality. Patients with hyponatraemia, hypochloraemia or hypocalcaemia had, respectively, more frequent requirement for intensive care unit and mechanical ventilation, higher mortality rate and longer hospitalization. The clusters associated with electrolyte abnormalities had unfavourable outcomes. Also, Clinical and laboratory features associated with severe disease were detected more often in those clusters. Hyponatraemia was an independent factor related to death from COVID-19 (OR 10.33; 95% CI 1.62-65.62; p 0.01). Furthermore, baseline electrolyte imbalances, primarily hyponatraemia, were related to poor prognosis in COVID-19 and baseline electrolyte assessment would be beneficial for evaluating the risk of severe COVID-19.
RESUMO
SARS-CoV-2 has a zoonotic origin and was transmitted to humans via an undetermined intermediate host, leading to infections in humans and other mammals. To enter host cells, the viral spike protein (S-protein) binds to its receptor, ACE2, and is then processed by TMPRSS2. Whilst receptor binding contributes to the viral host range, S-protein:ACE2 complexes from other animals have not been investigated widely. To predict infection risks, we modelled S-protein:ACE2 complexes from 215 vertebrate species, calculated changes in the energy of the complex caused by mutations in each species, relative to human ACE2, and correlated these changes with COVID-19 infection data. We also analysed structural interactions to better understand the key residues contributing to affinity. We predict that mutations are more detrimental in ACE2 than TMPRSS2. Finally, we demonstrate phylogenetically that human SARS-CoV-2 strains have been isolated in animals. Our results suggest that SARS-CoV-2 can infect a broad range of mammals, but few fish, birds or reptiles. Susceptible animals could serve as reservoirs of the virus, necessitating careful ongoing animal management and surveillance.
Assuntos
Peptidil Dipeptidase A/química , Filogenia , Glicoproteína da Espícula de Coronavírus/química , Enzima de Conversão de Angiotensina 2 , Animais , Betacoronavirus/classificação , Betacoronavirus/genética , Humanos , Mamíferos , Simulação de Acoplamento Molecular , Mutação , Peptidil Dipeptidase A/classificação , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Ligação Proteica , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/metabolismoRESUMO
N-nitrosodiethanolamine has been found to be present at a concentration of 0.02 to 3 percent in several brands of synthetic cutting fluids. Its identity was confirmed by three independent techniques: (i) by measuring the retention times on two different high-performance liquid-chromatography columns, (ii) by dehydration to N-nitrosomorpholine, and (iii) by preparation of the O-methyl ether derivative.
Assuntos
Poluentes Ambientais , Nitrosaminas/análise , Poluentes Ambientais/efeitos adversos , Etanolaminas/análise , Humanos , Neoplasias/induzido quimicamente , Medicina do TrabalhoRESUMO
Protein kinase C (PKC) is an important constituent of the signaling pathways involved in apoptosis. We report here that like staurosporine, withaferin A is a potent inhibitor of PKC. In Leishmania donovani, the inhibition of PKC by withaferin A causes depolarization of DeltaPsim and generates ROS inside cells. Loss of DeltaPsim leads to the release of cytochrome c into the cytosol and subsequently activates caspase-like proteases and oligonucleosomal DNA cleavage. Moreover, in treated cells, oxidative DNA lesions facilitate the stabilization of topoisomerase I-mediated cleavable complexes, which also contribute to DNA fragmentation. However, withaferin A and staurosporine cannot induce cleavable complex formation in vitro with recombinant topoisomerase I nor with nuclear extracts from control cells. Taken together, our results indicate that inhibition of PKC by withaferin A is a central event for the induction of apoptosis and that the stabilization of topoisomerase I-DNA complex is necessary to amplify apoptotic process.
Assuntos
Apoptose/efeitos dos fármacos , DNA Topoisomerases Tipo I/metabolismo , DNA de Protozoário/metabolismo , Ergosterol/análogos & derivados , Leishmania donovani/citologia , Leishmania donovani/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Animais , Caspases/metabolismo , Catálise/efeitos dos fármacos , Citocromos c/metabolismo , Citosol/efeitos dos fármacos , Clivagem do DNA/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Ergosterol/química , Ergosterol/farmacologia , Glutationa/metabolismo , Leishmania donovani/enzimologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Proteína Quinase C/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Espécies Reativas de Oxigênio/metabolismo , Estaurosporina/química , Estaurosporina/farmacologia , VitanolídeosRESUMO
The incidence of tuberculosis (TB) is high in end-stage renal disease (ESRD) patients undergoing dialysis. Diagnosis is difficult and delayed in this patient group owing to extrapulmonary involvement and nonspecific symptoms. Adverse effects of antituberculosis treatment are seen more frequently in these patients. We retrospectively evaluated the frequency and clinical progression of TB in 18 of 343 dialysis patients diagnosed with TB over a 5-year period at a university hospital in Adana, Turkey. Mean time between initiation of dialysis to diagnosis of TB was 19.5 +/- 26.1 months. Extrapulmonary TB was more frequent (77.8%) than pulmonary TB (22.2%). Diagnosis of TB was made based on clinical data in 1 patient, and microbiologically or pathologically in others. Antituberculosis treatment with 3 or 4 drugs was administered to patients for 6 to 12 months; second-line treatment was initiated in 1 patient infected with multidrug-resistant bacilli. One patient died owing to a cause other than TB; another was lost to follow-up. Adverse effects were hepatotoxicity in 3, optic neuritis in 1, and neuropsychiatric in 3 patients. A clinical response to therapy was achieved in all of the 16 patients who completed treatment. In conclusion, the incidence of TB and the frequency of extrapulmonary involvement are high in dialysis patients. Physicians must be alert to unusual presentations and localizations of the disease; TB must be strongly suspected in endemic regions. Owing to the greater frequency of adverse effects of treatment in these patients, they must be carefully observed during treatment.
Assuntos
Falência Renal Crônica/complicações , Diálise Peritoneal Ambulatorial Contínua , Diálise Renal , Tuberculose/epidemiologia , Adulto , Idoso , Antituberculosos/uso terapêutico , Feminino , Humanos , Incidência , Falência Renal Crônica/microbiologia , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis , Fatores de Tempo , Tuberculose/tratamento farmacológico , Turquia/epidemiologiaRESUMO
OBJECTIVE: Although the relationship between obesity-asthma, obesity-atrial fibrillation (AF) and obesity-sudden cardiac death is clearly known, the risk of AF and ventricular arrhythmia has not been clearly determined in asthmatic patients. The aim of this study was to investigate whether AF, ventricular arrhythmia, and sudden cardiac death risk were increased in asthmatic patients using P wave dispersion (PWD) and corrected QT interval dispersion (CQTD). PATIENTS AND METHODS: The study was designed as a cross-sectional study. A total of 164 participants (88 patients with asthma and 76 healthy volunteers) were enrolled into the study. PWD and CQTD were measured and recorded in both groups. The statistical difference between the two groups was examined. RESULTS: PWD was higher in the asthma patients than in control subjects (31.53 ± 3.18 vs. 30.33 ± 3.53, p = 0.023). However, there was no statistically difference between the groups in terms of CQTD measurement (43.9 ± 1.84 vs. 43.63 ± 2.06, p = 0.385). In comparison between control group and asthma subgroups (mild, moderate and severe), there was a statistically significant difference among these four groups in terms of PWD (p = 0.017). Subgroup analyses showed that this difference was mainly due to patients with severe asthma. CONCLUSIONS: PWD value was elevated in asthmatic compared to the control group. The CQTD was not statistically significant between the groups. These results indicate that the risk of developing AF in asthmatic patients might be higher than in the normal population. Ventricular arrhythmia and sudden cardiac death risk may not be high in asthmatic patients.
Assuntos
Asma/fisiopatologia , Fibrilação Atrial/fisiopatologia , Eletrocardiografia/métodos , Frequência Cardíaca/fisiologia , Taquicardia Ventricular/fisiopatologia , Adulto , Asma/epidemiologia , Fibrilação Atrial/epidemiologia , Estudos Transversais , Morte Súbita Cardíaca/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Taquicardia Ventricular/epidemiologiaRESUMO
We sought to determine the rate of healthcare-associated infection (HCAI), microbiological profile, bacterial resistance, length of stay (LOS) and excess mortality in 12 ICUs of the seven hospital members of the International Infection Control Consortium (INICC) of seven Indian cities. Prospective surveillance was introduced from July 2004 to March 2007; 10 835 patients hospitalized for 52 518 days acquired 476 HCAIs, an overall rate of 4.4%, and 9.06 HCAIs per 1000 ICU-days. The central venous catheter-related bloodstream infection (CVC-BSI) rate was 7.92 per 1000 catheter-days;the ventilator-associated pneumonia (VAP) rate was 10.46 per 1000 ventilator-days; and the catheter-associated urinary tract infection (CAUTI) rate was 1.41 per 1000 catheter-days. Overall 87.5% of all Staphylococcus aureus HCAIs were caused by meticillin-resistant strains, 71.4% of Enterobacteriaceae were resistant to ceftriaxone and 26.1% to piperacillin-tazobactam; 28.6% of the Pseudomonas aeruginosa strains were resistant to ciprofloxacin, 64.9% to ceftazidime and 42.0% to imipenem. LOS of patients was 4.4 days for those without HCAI, 9.4 days for those with CVC-BSI, 15.3 days for those with VAP and 12.4 days for those with CAUTI. Excess mortality was 19.0% [relative risk (RR) 3.87; P < or = 0.001] for VAP, 4.0% (RR 1.60; P=0.0174) for CVC-BSI, and 11.6% (RR 2.74; P=0.0102) for CAUTI. Data may not accurately reflect the clinical setting of the country and variations regarding surveillance may have affected HCAI rates. HCAI rates, LOS, mortality and bacterial resistance were high. Infection control programmes including surveillance and antibiotic policies are a priority in India.
Assuntos
Infecções Bacterianas/epidemiologia , Infecção Hospitalar/epidemiologia , Equipamentos e Provisões/microbiologia , Adulto , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Infecções Bacterianas/microbiologia , Infecções Bacterianas/mortalidade , Infecção Hospitalar/microbiologia , Infecção Hospitalar/mortalidade , Farmacorresistência Bacteriana , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Feminino , Humanos , Índia/epidemiologia , Unidades de Terapia Intensiva , Tempo de Internação/estatística & dados numéricos , Masculino , Resistência a Meticilina , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Pneumonia Bacteriana/epidemiologia , Pneumonia Bacteriana/microbiologia , Prevalência , Estudos Prospectivos , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Infecções Urinárias/epidemiologia , Infecções Urinárias/microbiologiaRESUMO
A number of studies have utilized the Remember/Know paradigm to determine event-related potential (ERP) correlates of recollection and familiarity. However, no prior work has been specifically directed at examining the processing involved in making the Remember/Know distinction. The following study employed a two-step recognition memory test in which participants first decided whether they recognized a word from a prior study list (Old/New decision); if they did, they then determined whether it was recognized on the basis of recollection ('Remember' responses) or familiarity ('Know' responses). By time-locking ERPs to the initial Old/New decision, processing related to making the introspective Remember/Know judgment was isolated. This methodology revealed a posterior negativity that was largest for 'Remember' responses. Previous work has described a late posterior negativity which appears to be related to the search for and recapitulation of study details. Such processing may be critical in making Remember/Know determinations.
Assuntos
Córtex Cerebral/fisiologia , Variação Contingente Negativa/fisiologia , Tomada de Decisões/fisiologia , Eletroencefalografia , Rememoração Mental/fisiologia , Retenção Psicológica/fisiologia , Aprendizagem Verbal/fisiologia , Adolescente , Adulto , Mapeamento Encefálico , Dominância Cerebral/fisiologia , Potenciais Evocados/fisiologia , Feminino , Humanos , Julgamento , Masculino , Tempo de Reação/fisiologiaRESUMO
BACKGROUND: Hemodialysis patients are at high risk for tuberculosis, and a tuberculin skin test (TST) is not usually helpful in detecting tuberculosis infection because of anergic reactions. Prophylactic therapy against tuberculosis in dialysis patients is important to enhance transplantation success. Herein we evaluated the value of TST in screening for tuberculosis and analyzed any compounding factors that might affect the results of the test in hemodialysis patients in an endemic area of Turkey. METHODS: A total of 187 (96 female, 91 male) patients were screened using a 2-step TST. Test results were compared with clinical, radiologic, and laboratory data. RESULTS: None of the patients had active tuberculosis during the study and 55% had been vaccinated against tuberculosis. After the first purified protein derivative (PPD) test, 55.1% of the patients showed a positive reaction, ultimately reaching a total of 68.4% following the second test. Cumulative positive TST results were significantly correlated with male gender (P=.001, r=.352), previous tuberculosis history (P=.013, r=.183) positively, whereas with the ferritin level (P=.001, r=-.233) negatively; but there were no significant relationships between TST results and other data. CONCLUSIONS: Impairment of delayed-type hypersensitivity reaction is frequent in dialysis patients, but we observed high rates of positivity with the two-step TST which could be attributed to tuberculosis being endemic in Turkey. Further comparative studies with more specific diagnostic methods will be helpful to evaluate the importance of TST positivity in identifying tuberculosis-infected HD patients.
Assuntos
Diálise Renal , Teste Tuberculínico , Tuberculose/epidemiologia , Adulto , Idoso , Feminino , Humanos , Incidência , Falência Renal Crônica/complicações , Transplante de Rim , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Resultado do Tratamento , Tuberculose/prevenção & controle , Turquia/epidemiologiaRESUMO
Salt in diet is very important to make our life healthy and energetic. Quantity and quality of salt with appropriate ratio or balance in electrolytes which are responsible for volume of body, blood velocity, for functions of receptors and enzymes, to prevent inflammation, proliferation and to make balance in muscles contraction and nerve conduction through to avoid high stimulation of sympathetic nervous system. Hence, scanning and focus with monitoring and supply of healthy salt in limits may prevent volume overload, renal dysfunction & left ventricular hypertrophy, to prevent cardiac functions, to avoid the weaken gut immunity and also to prevent cerebral oedema, cerebral aneurysm and hypertension cause stroke. Control of salt with intake of low quantity and high quality with more frequency of intervals during 24 hours in required amount of salt in balanced electrolytes may help to avoid high salt sensitivity. Balanced salt intake is also important to avoid volume expansion and obesity with reduction of insulin resistance leads to prevent hypertension and diabetes which are leading risk factors for cardio-renal syndrome, cardiovascular morbidity and mortality. Our data suggested a 2.5-fold higher risk for high blood pressure in sea or white salt users versus black salt or Himalayan rock salt which showed more potassium and magnesium with low sodium ions as compared to sea salt.
RESUMO
Within the framework of the dual process model of recognition memory, prior work with event-related potentials (ERPs) has suggested that an early component, the FN400, is a correlate of familiarity while a later component, the Late Positive Complex (LPC), is a correlate of recollection. However, other work has questioned the validity of these correlations, suggesting that the FN400 effect is too short-lived to reflect an explicit memory phenomenon and that the LPC may be influenced by decision-related factors. Using a Remember/Know paradigm we addressed these issues by (1) examining the effect of study-test delay on correctly recognized items associated with familiarity ('Know' responses) and recollection ('Remember' responses) and by (2) examining FN400 and LPC modulation associated with false alarms. Supporting the relationship of the FN400 with familiarity, attenuation of this component was present for 'Know' responses relative to correct rejections after both the short (39 min) and long (24 h) delay conditions. Attenuation of the FN400 also occurred for false alarms (responses largely driven by familiarity) relative to correct rejections. Although an increased LPC amplitude was found associated with 'Remember' responses at both delays, a decreased LPC amplitude was observed with false alarms relative to correct rejections. This latter result is discussed with regard to the possibility of an overlapping posterior negativity.
Assuntos
Potenciais Evocados/fisiologia , Memória/fisiologia , Reconhecimento Psicológico/fisiologia , Adolescente , Adulto , Eletroencefalografia , Eletrofisiologia , Feminino , Humanos , Masculino , Córtex Pré-Frontal/fisiologia , Fatores de TempoRESUMO
The mutagenicity of five cyclic N-nitrosamines was studied with the use of Salmonella typhimurium TA1535 in vitro with and without microsomal activation. The carcinogens nitrosopiperidine and nitrosopyrrolidine required metabolic activation before manifesting mutagenic activity. Nitrosoproline and nitrosohydroxyproline, noncarcinogens, were not mutagenic. Nitroso-3-pyrrolidinol was mutagenic in the absence of microsomes, thereby suggesting a role of hydroxylation in the metabolic activation of nitrosopyrrolidine to an ultimate carcinogenic species.
Assuntos
Mutagênicos , Nitrosaminas/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Hidroxiprolina/análogos & derivados , Hidroxiprolina/farmacologia , Técnicas In Vitro , Microssomos Hepáticos/metabolismo , Nitrosaminas/metabolismo , Piperidinas/farmacologia , Prolina/análogos & derivados , Prolina/farmacologia , Pirrolidinas/farmacologia , Relação Estrutura-AtividadeRESUMO
The present study was undertaken to assess the toxicity of acid alone and two different sublethal concentrations of aluminium, (25% and 75% dose of 96 hr LC50 value in acidified soft water of pH 5) on red blood cells of a stenohaline catfish, C. batrachus for an acute exposure of 5 days. The scanning electron microscopic studies on all the three treated groups revealed several kinds of erythrocyte alterations and modifications with abnormal morphology. These included abnormal surface-wrinkling accompanied with excessive roughness on the membrane, erythrocytes with surface granulation in higher dose and finally the appearance of morphologically abnormal forms, the codocyte (target cell) and the stomatocyte. The results suggest that abnormality in the shape of erythrocytes could be linked to altered surface membrane area to volume ratio, decrease in cytoplasmic volume owing to reduced Hb content or increase in the amount of water content within the cell resulting from osmotic disequilibrium. In this context, the abnormal surface membrane morphology could be attributed to cytoskeleton fragility and defects in structural proteins. Further, the acid group exhibited a striking behavior of cellular adhesion and bonding to adjoining cell surfaces, culminating in several bunches which thereby reduces the surface area for gaseous exchange and could produce blocking effect while flowing through microcirculation.
Assuntos
Alumínio/toxicidade , Peixes-Gato/sangue , Eritrócitos Anormais/efeitos dos fármacos , Animais , Eritrócitos Anormais/ultraestrutura , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de VarreduraRESUMO
The parasites of the order kinetoplastidae including Leishmania spp. emerge from most ancient phylogenic branches of unicellular eukaryotic lineages. In their life cycle, topoisomerase I plays a significant role in carrying out vital cellular processes. Camptothecin (CPT), an inhibitor of DNA topoisomerase I, induces programmed cell death (PCD) both in the amastigotes and promastigotes form of L. donovani parasites. CPT-induced cellular dysfunction in L. donovani promastigotes is characterized by several cytoplasmic and nuclear features of apoptosis. CPT inhibits cellular respiration that results in mitochondrial hyperpolarization taking place by oligomycin-sensitive F0-F1 ATPase-like protein in leishmanial cells. During the early phase of activation, there is an increase in reactive oxygen species (ROS) inside cells, which causes subsequent elevation in the level of lipid peroxidation and decrease in reducing equivalents like GSH. Endogenous ROS formation and lipid peroxidation cause eventual loss of mitochondrial membrane potential. Furthermore, cytochrome c is released into the cytosol in a manner independent of involvement of CED3/CPP32 group of proteases and unlike mammalian cells it is insensitive to cyclosporin A. These events are followed by activation of both CED3/CPP32 and ICE group of proteases in PCD of Leishmania. Taken together, our study indicates that different biochemical events leading to apoptosis in leishmanial cells provide information that could be exploited to develop newer potential therapeutic targets.