Influence of salt and temperature in the growth of pathogenic free-living amoebae.

Introduction: Free-living amoebae are an extensive group of protistans that can be found in a wide variety of environments. Among them, the Acanthamoeba genus and Naegleria fowleri stand out as two of the most pathogenic amoebae and with a higher number of reported cases. N. fowleri is mainly found in warm freshwater water bodies whereas amoebae of the Acanthamoeba genus are broadly distributed through natural and anthropogenic environments. In this regard, the management and the control of the amoebic populations in swimming pools has become a major public health challenge for institutions. Methods: The aim of this work was to evaluate the growth pattern of trophozoites of A. griffini and N. fowleri at different temperatures and salt concentrations. Results and discussion: Our results showed that A. griffini resisted a higher concentration of salt than N. fowleri. Moreover, no trophozoites could withstand the salt levels of the sea in in vitro conditions. This work supports the contention that salinity could represent an important and useful tool for the control of the most pathogenic amoebic populations in recreational water bodies.

Effects of food deprivation on conditioned orthonasal olfactory preferences with caloric and non-caloric reinforcers.

Three experiments were conducted to investigate Conditioned Olfactory Preferences using orthonasal inhalation, which is a less explored perceptual pathway compared to retronasal inhalation. In these experiments, odors were impregnated onto plastic disks to prevent the subjects from consuming or tasting them. The reinforcers used were a sucrose solution (Caloric groups) and a saccharin solution (Non-Caloric groups). The influence of nutritional deprivation was analyzed, with unrestricted access to food throughout the procedure in Experiment 1, food restriction during the conditioning phase in Experiment 2, and limited access to food during the test phase in Experiment 3. The results revealed conditioned preferences using both sucrose and saccharin as reinforcers. Furthermore, dietary restriction reduced the conditioned preference induced by saccharin, but not the preference induced by sucrose. These findings are discussed in light of the potential differences between orthonasal and retronasal presentation of odors during conditioning.

Ultraviolet - Chlorine combined treatment efficiency to eliminate Naegleria fowleri in artificial surf lagoons.

Naegleria. fowleri, a protozoa belonging to the free-living amoeba group, is the causative agent of a central nervous system affecting disease that is fatal in more than the 95% of the reported cases. This parasite can be found in warm water bodies such as lakes, rivers or inadequately disinfected swimming pools. On the other hand, chlorination and UV light treatment are two of the most extensively used disinfection methods in recreational water facilities. In this study the effect of chlorination and UV light on N. fowleri trophozoites was studied in a close water circuit with the aim to assess the efficacy of this disinfection methods in large pools. The obtained results showed that the chlorination was able to decrease the number of viable cells despite the elimination was not totally achieved. Nonetheless, the combination of the UV light with the chlorination allowed the complete removal of the N. fowleri trophozoites from the water in experimental testing conditions.

Model-based methodology for the design of optimal control strategies in MBR plants.

This paper proposes a model-based methodology that allows synthesising the most appropriate strategies for optimising the operation of wastewater treatment plants (WWTPs). The methodology is applied with the aim of maximising the nitrogen removal in membrane bioreactors (MBRs). The proposed procedure is based on a systematic approach composed of four steps. First, a sensitivity analysis of the input variables is carried out in order to obtain a first assessment of the potential for operational improvements. Then, the optimum input variable values are calculated by a model-based optimisation algorithm that minimises a cost function associated with the effluent total nitrogen at different temperatures. Then, the optimum operational strategies are identified. Finally, these operational strategies form the conceptual knowledge base for designing automatic control laws. The obtained optimal control strategies have shown a significant improvement in performance in comparison with fixed operation for the studied case, reducing the total nitrogen by 40%.

Brief Biofeedback Intervention on Anxious Freshman University Students.

The increasing number of mental health disorders on university students represents a growing problem with negative impact on this population. Stress and anxiety issues are two of most predominant problems in this population and most campus health services have limited resources to face them. Research has provided evidence about biofeedback effectiveness. This study aims to verify the impact of a short duration biofeedback programme on freshmen university students with high levels of anxiety. A sample of 50 first-year students, with scores above percentile of 75 on STAI Y-2 were randomly selected and divided into two groups. Biofeedback Group took a 15 min session per week, over 8 weeks. No intervention was made on Control Group. Both groups were assessed before and after the biofeedback programme, and the results of the Trait Anxiety Scale and the Inventory of Stress for College Students were compared. The Biofeedback Group presented significant decreases in anxiety and stress values. Control Group presented slight and non-significant changes in scores. These results are consistent with previous studies and reinforce the evidence of biofeedback's programmes as a valid solution to help students to manage their anxiety and stress.

Assessment of the level of sedation in children after cardiac surgery.

BACKGROUND: There is no reference method for the evaluation of the level of sedation in children after cardiac surgery. The utility of the bispectral index and middle latency auditory evoked potentials has not been evaluated. METHODS: The bispectral index, middle latency auditory evoked potentials, Ramsay scale, and COMFORT scale were used for assessment of the level of sedation in critically ill children after cardiac surgery and other surgical procedures. The measurements with these four methods were recorded simultaneously once a day for five days. The level of sedation was categorized in two levels, moderate or deep, according to the values obtained from each method. Correlations and agreements among the methods and the best bispectral index and middle latency auditory evoked potential values that discriminated between the two levels of sedation were calculated. RESULTS: Thirty-two children after cardiac surgery were included in the study, together with eighteen children after other surgical procedures who formed the control group. In each group, the correlation and agreement between the four methods varied between moderate and good. In the cardiac surgery patients, when the level of sedation was determined by the Ramsay scale, the best values of bispectral index and middle latency auditory evoked potentials that discriminated between the two levels of sedation were 63.5 and 37.5, respectively, and these values predicted the level of sedation correctly in 84.4% of the patients with each method. CONCLUSIONS: Bispectral index and middle latency auditory evoked potentials could be useful to assess the level of sedation in children after cardiac surgery.

Analysis of bispectral index and middle latency auditory-evoked potentials parameters in critically ill children.

To study the parameters of the bispectral index and middle latency auditory-evoked potentials in critically ill children. We performed a prospective, observational study in 81 critically ill children categorized into two levels of sedation (moderate and deep) and three age groups (<1, 1-6, and >6 months). The parameters of the bispectral index and middle latency auditory-evoked potentials studied were the signal quality index, suppression ratio, total power, spectral edge frequency, electromyographic activity, and suppression ratio. Suppression rates were higher in children younger than 1 month than in older children and were also higher in deep sedation. Total power and spectral edge frequency increased with age. Electromyographic activity was higher in moderate sedation. Spectral edge frequency and suppression rates change with age and level of sedation. These variations are a consequence of the electroencephalographic structure at young ages and are secondary to the higher proportion of slow waves in deep states of sedation.

Cardiac output and blood volume parameters using femoral arterial thermodilution.

BACKGROUND: The pulse-induced continuous cardiac output (PiCCO) system is a less invasive method than pulmonary thermodilution for the measurement of cardiac output and estimating blood volume parameters. The normal values in children have not been defined. The purpose of the present paper was therefore to evaluate cardiac output and parameters of blood volume using femoral arterial thermodilution in critically ill children. METHODS: A prospective study was performed in 17 critically ill children aged between 2 months and 14 years. Two measurements were taken for each determination of cardiac output, global end diastolic volume (GEDVI), intrathoracic blood volume index (ITBI), extravascular lung water index (ELWI), systolic volume index (SVI), stroke volume variation (SVV), cardiac function index (CFI), left ventricular contractility (dp/dt max), and the systemic vascular resistance index (SVRI). RESULTS: One hundred and seventeen measurements were performed. The mean cardiac index (CI) was 3.5 +/- 1.3 L/min per m(2). The GEDVI (399.7 +/- 349.1 mL/m(2)), ITBI (574.5 +/- 212.2 mL/m(2)) and dp/dt max (804.6 +/- 372.1 mmHg/s) were lower than reported in adults, whereas ELWI (18.9 +/- 9.3 mL/m2) and CFI (8 +/- 2.5 L/min) where higher. The GEDVI, SVI, dp/dt max and CI increased with the weight of the patients whereas the ELWI values decreased. CONCLUSIONS: Femoral arterial thermodilution is a suitable technique for the measurement of cardiac output in critically ill children. The intrathoracic and intracardiac volumes are lower than in adults, whereas extrapulmonary water is higher; these values are related to the weight of the patient.

Detection of hepatitis C virus in thyroid tissue from patients with chronic HCV infection.

Thyroid dysfunctions are common in chronic hepatitis C virus (HCV) infection. HCV-RNA has been detected by reverse-transcription polymerase chain reaction (PCR) in thyroid from HCV infected patients with acquired immunodeficiency syndrome. However, morphological evidence of HCV replication in thyroid cells from immune competent patients has not been provided. In situ hybridization and real-time-PCR were used to analyze HCV-RNA replication in thyroid tissue from 11 patients (3 anti-HCV, serum HCV-RNA positive; 8 anti-HCV negative). Genomic and antigenomic HCV-RNA was detected in the thyroid of the 3 anti-HCV positive patients at concentrations of 2.6 x 10(4), 1.7 x 10(4), and 8.6 x 10(3) copies/microg of total RNA (genomic) and 3.2 x 10(2), 4.3 x 10(3) and 2.9 x 10(2) HCV-RNA copies/microg of total RNA (antigenomic). No HCV-RNA was detected in the thyroid tissue of the 8 anti-HCV negative patients. Presence of genomic/antigenomic HCV-RNA in the 3 anti-HCV positive cases was confirmed by in situ hybridization. Signals were observed in the cytoplasm of the thyroid cells. In conclusion, the data obtained indicate that HCV may infect cells of the thyroid in immune competent patients with chronic HCV infection. The pathogenic implications of this finding merit further research.

Assessing sedation in critically ill children by bispectral index, auditory-evoked potentials and clinical scales.

OBJECTIVE: To evaluate the correlation and agreement between the bispectral index (BIS), middle latency auditory-evoked potential index (AEP index), Ramsay scale (RS) and COMFORT scale (CS) for evaluation of the level of sedation in critically ill children. DESIGN: Prospective observational study. SETTING: Pediatric critical care unit. PATIENTS: Seventy-seven critically ill children receiving sedation and mechanical ventilation. MEASUREMENTS AND RESULTS: Simultaneous recording of BIS, AEP index, RS and CS were performed once a day, for a maximum of 5 days. Two levels of sedation were categorized: light-moderate versus deep-very deep. Correlations between methods were determined using Spearman rank correlation test and the agreement using Cohen's Kappa test. The correlation and agreement between the four methods was moderate-to-good. Correlation was not found in paralyzed children. There was no correlation between the four methods and the heart rate or blood pressure, or with the type or dose of sedative medication. Receiver-operating characteristic (ROC) analysis revealed best discrimination between light-moderate and deep-very deep sedation at BIS and AEP index values of 63.5 and 33.5 when the level of sedation was classified by the RS, and at BIS and AEP index values of 67 and 37.5, respectively, when the level of sedation was classified by the CS. CONCLUSION: There is a moderate-to-good correlation and agreement of BIS and AEP index with the clinical scales in critically ill children without neuromuscular blockade. BIS and AEP index could be useful to evaluate the level of sedation in critically ill children with and without neuromuscular blockade.

Herpesvirus saimiri transformation may help disclose inherent functional defects of mucosal T lymphocytes in patients with gastric adenocarcinoma.

To dissect the phenotypic and functional features of mucosal T lymphocytes in patients with gastric adenocarcinoma, we have used the Herpesvirus saimiri transformation procedure to achieve T-cell lines from gastric origin. Once achieved, cell function was assessed by in vitro stimulation with mitogens. CD2-specific monoclonal antibodies (alpha-CD2), alone or in combination with interleukin (IL)-2, rendered fewer counts in patients (34 408+/-3965 and 52 157+/-6473 c.p.m., respectively) than in controls (67 471+/-11 755 c.p.m., P<0.01 and 77 864+/-12 545 c.p.m., P<0.05, respectively). Likewise, CD3-based responses were defective in cancer cell lines: alpha-CD3 (54 794+/-9269 vs 86 104+/-10 341 c.p.m., P<0.01), alpha-CD3+IL-2 (57 789+/-8590 vs 88855+/-8516 c.p.m., P<0.01) and alpha-CD3+alpha-CD2 (52 130+/-7559 vs 120 852+/-16 552 c.p.m., P<0.01). Finally, IL-2 failed to adequately stimulate patient cell lines (39 310+/-4023 vs 60 945+/-9463 c.p.m., P<0.05). These results suggest that mucosal T lymphocytes in cancer patients are inherently impaired in their proliferative ability. This may be crucial in the control of tumour growth.

Bispectral index and middle latency auditory evoked potentials in children younger than two-years-old.

BACKGROUND: We analyzed the values of the bispectral index (BIS) and midlatency auditory evoked potentials (MLAEP) and their correlation with the modified Ramsay score (RS) during wakefulness and natural sleep in healthy children without pharmacological sedation. METHODS: Fifty-three healthy children younger than 2-yr-old were studied. Children were evaluated simultaneously using the modified RS, the BIS, and MLAEPs. Each patient was studied only once. The correlation and agreement were studied. The correlation among the three methods was determined using the Spearman Rank Correlation test and the agreement among the methods was assessed using by Cohen's Kappa test. RESULTS: There was a moderate-to-good correlation (r) among the three methods (P = 0.01): BIS and MLAEP (r = 0.574), BIS and RS (r = -0.504), and MLAEP and RS (r = -0.624). However, the level of agreement (kappa) was only poor to fair: BIS and MLAEP (kappa = 0.392), BIS and RS (kappa = 0.270), and MLAEP and RS (kappa = 0.409). All the correlations were lower in children between 1 and 6 mo-of-age. When the children were asleep (RS: 3-5), the BIS values were higher in children younger than 1 mo-of-age than in children older than 6 mo-of-age (P after Bonferroni correction = 0.028). CONCLUSIONS: The BIS, MLAEP, and RS have a good correlation in children younger than 2 yr not receiving pharmacological sedation, though the level of agreement was poor.

Apolipoprotein AI and apolipoprotein E mRNA expression in peripheral white blood cells from patients with orthotopic liver transplantation.

BACKGROUND: Apolipoprotein AI/apolipoprotein E (apo-AI/apo-E) ratio change and its induction in non-hepatic tissues have been reported during liver development, regeneration, and several pathophysiologic states. The clinical implication of such changes is unclear, but these could reflect recovery and/or severity of liver damage. METHODS AND RESULTS: Using RT-PCR we analysed the mRNA expression of apo-AI and apo-E in peripheral white blood cells (PWBC) of patients with different liver diseases who underwent orthotopic liver transplantation (OLT) and compared its expression with the lipid profile and liver function tests. We found that patients showed higher levels of apo-AI mRNA without detection of apo-E mRNA on PWBC at the preoperative day, compared with healthy volunteers (HV). We found an apo-AI/apo-E mRNA ratio of 2.7 during the anhepatic stage, followed by a decrease to 1.3, 0.95, and 0.55 at days 30, 60, and 90, respectively. At the last time point, the apo-AI/apo-E ratio was similar to HV. At day 3 post-OLT, the lowest levels of high-density lipoprotein (HDL)-cholesterol (17 mg/dl; P<0.05) and the highest levels of aspartate aminotransferase, total bilirubin and alkaline phosphatase (77.5 IU/l, 37.9 g/dl, 177.8 IU/l, respectively; P<0.05) were detected. CONCLUSION: These results indicate that changes of HDL-cholesterol and apo-AI/apo-E mRNA ratio could be a good indicator of liver damage and/or hepatic functional recovery post-OLT.

Clinical education reflective ecological model for health science majors

Os estágios clínicos (ECs) são parte integrante dos planos de estudo dos vários cursos da Escola Superior de Saúde da Universidade de Aveiro (i.e. Enfermagem , Fisioterapia, Radiologia, Radioterapia e Terapia da Fala) e têm como objetivo desenvolver competências clínicas para formar um profissional de saúde por excelência. A sua organização tem como base o Modelo Ecológico de Formação Clínico-Reflexiva. A abordagem de formação caracteriza-se pela inovação, centra-se na ação-reflexão do aluno em contexto profssional, e na multidisciplinaridade dos intervenientes(docentes, supervisores e alunos). Com este artigo, divulgam-se os dois primeiros estágios dos cursos de Enfermagem, Fisioterapia e Radiologia. O Estágio Clínico I contou com 123 estudantes e o objetivo foi porporcionar uma visão global da atividade de cada profissional de saúde. O Estágio Clínico II contou com 119 estudantes e visou o desenvolvimento de competências inerentes a cada profissional de saúde. A avaliação dos ECs foi realizada através de questionários dirigidos aos supervisores e aos estudantes visando a sua percepção sobre a preparação, organização e duração dos mesmos. Os questionários incluíram escalas categoriais de 1-5 e perguntas abertas. Os resultados revelaram médias superiores a 3, em todos os itens avaliados, quer pelos supervisores quer pelos estudantes. Em conclusão, verificou-se uma grande aceitação do Modelo Ecológico de Formação Clínico-Reflexiva pelos supervisores e estudantes, bem como a sua aplicabilidade na área da saúde

Is prophylactic cholecystectomy useful in obese patients undergoing gastric bypass?

BACKGROUND: Obesity constitutes a clear risk factor for cholelithiasis, especially if it is associated with a rapid weight loss, as is the case of patients following bariatric surgery. Prophylactic cholecystectomy is indicated in biliopancreatic diversions due to the high incidence of postoperative cholelithiasis. However, there is no agreement on gastric bypass. This study was conducted to establish the incidence of cholecystopathy demonstrated by histology and to assess the indication for prophylactic cholecystectomy in a systematic way on patients undergoing gastric bypass. METHODS: The evaluation is based on 100 consecutive morbidly obese patients undergoing open gastric bypass surgery with concomitant prophylactic cholecystectomy. Variables studied were: age, gender, body mass index, preoperative ultrasound and the anatomopathologic analysis of the gallbladder that was removed. RESULTS: Of the 100 patients who took part in the trial, 11 had had a previous cholecystectomy. Among the 89 patients remaining, preoperative ultrasound diagnosis of cholelithiasis was 16.8%, and the actual postoperative incidence was 24.7%. Other histologic alterations were: cholesterolosis 46.1%, chronic unspecified cholecystitis 22.5%, and granulomatous cholecystitis 1.1%. The total incidence of cholecystopathy was 93.3%. The morbi-mortality related to cholecystectomy was 0%. CONCLUSIONS: Based on these results and given the absence of morbidity, we believe that prophylactic cholecystectomy is suitable during open gastric bypass.