Evaluation of the operational conditions in the production and morphology of Chlorella sp / Avaliação das condições operacionais na produção e morfologia de Chlorella sp

Abstract It was evaluated the effect of operational conditions in the production of Chlorella sp. after its selection from genus Chlorella sp., Scenedesmus sp., Nannochloris sp., Tetraselmis sp. and Dunaliella salina. Microalgae were inoculated in drinking water with addition of NPK fertilizer (N 24%, P 24%, K 18%), at a concentration of 0.5 g/L, agitation of 150 rpm, temperature 25 °C, light intensity of 1680 lumens at a color temperature of 6400K, without pH control for 8 days. The cellular concentrations obtained were 3.72x107 (Chlorella sp.), 1.36x107 (Scenedesmus sp.), 3.55x107 (Tetraselmis sp.), 5.74x107 (Nannochloris sp.) and 3.45x106 (Dunaliella salina), where the microalgae Chlorella sp., shows invasive capacity in drinking water cultivations. Applying the 2n-p fractional factorial design concept for the elemental composition of the microalgae and the cellular morphology, it was obtained 44.33% of C, 7.09% of H, 8.53% of N and 0.84% ​​of S for the Chlorella sp.

Resumo Foi avaliado o efeito das condições operacionais na produção de Chlorella sp. após a seleção do gênero Chlorella sp., Scenedesmus sp., Nannochloris sp., Tetraselmis sp. e Dunaliella salina. Microalgas foram inoculadas em água potável com adição de fertilizante NPK (N 24%, P 24% e K 18%), na concentração de 0,5 g/L, agitação de 150 rpm, temperatura de 25 °C, intensidade luminosa de 1.680 lúmens para uma temperatura de cor de 6.400 K, sem controle de pH por 8 dias. As concentrações celulares obtidas foram de 3,72 x 107 (Chlorella sp.), 1,36 x 107 (Scenedesmus sp.), 3,55 x 107 (Tetraselmis sp.), 5,74 x 107 (Nannochloris sp.) e 3,45 x 106 (Dunaliella salina), em que a microalga Chlorella sp. mostrou capacidade invasiva em cultivos de água potável. Aplicando o conceito de projeto fatorial fracionado 2n-p para a composição elementar da microalga e a morfologia celular, foram obtidos 44,33% de C, 7,09% de H, 8,53% de N e 0,84% de S para a Chlorella sp.

Uso de parches protectores faciales no reduce la presión facial en un modelo simulado de ventilación mecánica no invasiva / Face protective patches do not reduce facial pressure ulcers in a simulated model of non-invasive ventilation

La ventilación mecánica no invasiva (VMNI) tiene como complicación frecuente el desarrollo de úlceras faciales por presión (UPP). Su prevención considera el uso empírico de parches protectores entre piel y mascarilla, para disminuir la presión ejercida por ésta. Objetivos: Evaluar el efecto de los parches protectores sobre la presión ejercida por la mascarilla facial, y su impacto en los parámetros ventilatorios programados. Método: Modelo simulado de VMNI binivelada usando mascarilla facial total en fantoma con vía aérea fisiológica (ALS PRO+) en posición supina. Se midió la presión en frente, mentón y pómulos, usando 3 tipos de parches protectores de uso habitual versus un grupo control, utilizando sensores de presión (Interlinks Electronics®). Se evaluaron los valores obtenidos con el modelo de mascarilla-parches protectores en las variables programadas flujo máximo inspiratorio (FMI), volumen corriente espirado (Vte) y presión positiva inspiratoria (IPAP), con ventilador Trilogy 100, Respironics®. La programación y registro de las variables fue efectuada en 8 oportunidades en cada grupo por operadores independientes. Resultados: No se observó disminución de la presión facial con ninguno de los parches protectores respecto al grupo control. Moltoprén aumentó la presión facial en todos los puntos de apoyo (p < 0,001), aumentó fuga, disminuyó FMI, Vte e IPAP (p < 0,001). Parches de hidrocoloide aumentaron la presión facial sólo en pómulo izquierdo, aumentaron la fuga y disminuyeron FMI. Parches de poliuretano no generaron cambios en la presión facial ni en variables ventilatorias. Conclusión: El uso de parches protectores de moltoprén, hidrocoloide y poliuretano transparente no contribuyó a la disminución de la presión facial. Se observó un efecto deletéreo de los parches de moltoprén e hidrocoloide sobre la administración de variables ventilatorias, concluyendo que el no uso de los parches protectores permitió una mejor administración de los parámetros programados.

Noninvasive ventilation (NIV) frequently involves the development of facial pressure ulcers (FPU). Its prevention considers the empirical use of protective patches between skin and mask, in order to reduce the pressure exerted by it. Objectives: To evaluate the effect of protective patches on the pressure exerted by the facial mask, and its impact on the programmed ventilatory parameters. Method: Bilevel NIV simulated model using full face mask in phantom with a physiological airway (ALS PRO +) in supine position. Forehead, chin and cheekbones pressure were measured using 3 types of standard protective patches versus a control group using pressure sensors (Interlinks Electronics®). The values obtained with the protective patches-mask model were evaluated in the programmed variables maximum inspiratory flow (MIF)), expired tidal volume (Vte) and positive inspiratory pressure (IPAP), with Trilogy 100 ventilator, Respironics®. The programming and recording of the variables was carried out in 8 opportunities in each group by independent operators. Results: There was no decrease in facial pressure with any of the protective patches compared to the control group. Moltopren increased facial pressure at all support points (p < 0.001), increased leakage, it decreased MIF, Vte and IPAP (p < 0.001). Hydrocolloid patches increased facial pressure only in the left cheekbone, increased leakage and decreased MIF. Polyurethane patches did not produce changes in facial pressure or ventilatory variables. Conclusion: The use of protective patches of moltopren, hydrocolloid and polyurethane transparent did not contribute to the decrease of the facial pressure. A deleterious effect of the moltopren and hydrocolloid patches was observed on the administration of ventilatory variables, concluding that the non-use of the protective patches allowed a better administration of the programmed parameters.

Evaluation of the operational conditions in the production and morphology of Chlorella sp

Abstract It was evaluated the effect of operational conditions in the production of Chlorella sp. after its selection from genus Chlorella sp., Scenedesmus sp., Nannochloris sp., Tetraselmis sp. and Dunaliella salina. Microalgae were inoculated in drinking water with addition of NPK fertilizer (N 24%, P 24%, K 18%), at a concentration of 0.5 g/L, agitation of 150 rpm, temperature 25 °C, light intensity of 1680 lumens at a color temperature of 6400K, without pH control for 8 days. The cellular concentrations obtained were 3.72x107 (Chlorella sp.), 1.36x107 (Scenedesmus sp.), 3.55x107 (Tetraselmis sp.), 5.74x107 (Nannochloris sp.) and 3.45x106 (Dunaliella salina), where the microalgae Chlorella sp., shows invasive capacity in drinking water cultivations. Applying the 2n-p fractional factorial design concept for the elemental composition of the microalgae and the cellular morphology, it was obtained 44.33% of C, 7.09% of H, 8.53% of N and 0.84% of S for the Chlorella sp.

Resumo Foi avaliado o efeito das condições operacionais na produção de Chlorella sp. após a seleção do gênero Chlorella sp., Scenedesmus sp., Nannochloris sp., Tetraselmis sp. e Dunaliella salina. Microalgas foram inoculadas em água potável com adição de fertilizante NPK (N 24%, P 24% e K 18%), na concentração de 0,5 g/L, agitação de 150 rpm, temperatura de 25 °C, intensidade luminosa de 1.680 lúmens para uma temperatura de cor de 6.400 K, sem controle de pH por 8 dias. As concentrações celulares obtidas foram de 3,72 x 107 (Chlorella sp.), 1,36 x 107 (Scenedesmus sp.), 3,55 x 107 (Tetraselmis sp.), 5,74 x 107 (Nannochloris sp.) e 3,45 x 106 (Dunaliella salina), em que a microalga Chlorella sp. mostrou capacidade invasiva em cultivos de água potável. Aplicando o conceito de projeto fatorial fracionado 2n-p para a composição elementar da microalga e a morfologia celular, foram obtidos 44,33% de C, 7,09% de H, 8,53% de N e 0,84% de S para a Chlorella sp.

Asociación de la atorvastatina sistémica en las características clínicas inflamatorias de la periodontitis crónica / Association of atorvastatin in systemic inflammatory characteristics of chronic periodontitis

Determinar el efecto de la atorvastatina sistémica en el índice gingival y el índice de carga inflamatoria periodontal (PIBI), en pacientes con periodontitis crónica en una población adulta del sector norte de la ciudad de Antofagasta. Este estudio se realizó en pacientes derivados a la clínica de periodoncia del Centro Asistencial Norte Antofagasta, departamento dependiente del Servicio de Salud Antofagasta. Se seleccionó un grupo de 60 pacientes, mayores 40 años de edad, diagnosticados con periodontitis crónica, con al menos 14 dientes en la cavidad oral y sin tratamiento antibiótico en los últimos 6 meses. Se dividieron estos pacientes en dos grupos; 30 de ellos en tratamiento con atorvastatina por al menos 1 año (Grupo I) y 30 que no estaban en tratamiento con este medicamento (Grupo II). Las variables analizadas fueron el índice de placa bacteriana simplificado, el índice gingival y el PIBI, de la abreviación del inglés Periodontal inflammatory burden index. La atorvastatina sistémica se asocia a una disminución en el índice gingival y el PIBI, en pacientes adultos con periodontitis crónica.

To determine the effect of systemic atorvastatin on gingival index and periodontal inflammatory burden index (PIBI) in patients with chronic periodontitis in an adult population of the northern sector of the city of Antofagasta. This study was conducted in patients referred from the clinic of periodontology of Centro Asistencial Norte under the Department of Health Service of Antofagasta. A group of 60 patients over 40 years old was selected, diagnosed with chronic periodontitis, with at least 14 teeth in the mouth without antibiotic treatment in the last 6 months. These patients were divided into two groups; 30 of them were treated with atorvastatin for at least 1 year (Group I) and 30 who were not treated with this drug (Group II). The variables analyzed were simplified plaque index, gingival index and PIBI. The atorvastatin systemic is associated with adecrease in gingival index and PIBI in adult patients with chronic periodontitis.

Evaluación de Termografía Tisular Diferenciada en Mama como Potencial Técnica para Asistir la Detección de Cáncer / Evaluation of Thermography Differentiated in Breast Tissue as Potential Technique to Assist Cancer Detection

Diversos grupos han propuesto el procesamiento de imágenes termográficas para detección de Cáncer de Mama (CaMa). Angiogénesis y vascularización dependientes del ciclo menstrual, edad e Índice de Masa Corporal (IMC) modifican la temperatura absoluta en la superficie tisular sin estar necesariamente asociadas a malignidad, en éste estudio proponemos la Termografía Tisular Diferenciada (TTD) en mama con respecto a su contralateral en espejo con el fin de observar diferencias térmicas características de malignidad. El presente trabajo evalúa la posibilidad de emplear la TTD como potencial técnica para asistir la detección de CaMa. Se muestrearon 110 mujeres voluntarias entre 40 y 60 años de edad segmentadas en dos grupos experimentales: grupo sanas (n=90) y grupo con CaMa (n=20) previamente diagnosticadas por mastografía e histopatología. Imágenes termográficas de ambas mamas fueron adquiridas con una cámara infrarroja y se estimó la TTD en relación a la mama contralateral de la misma paciente, se realizó un análisis de sensibilidad y especificidad y se comparó con el diagnóstico radiológico a través de curvas ROC tomando como referencia el diagnóstico histopatológico. La TTD en mama mostró rangos dinámicos diferenciables entre condiciones de malignidad respecto a benignidad. El análisis ROC mostró valores de sensibilidad y especificidad para el estimado TTD del 70% y 54% mientras que para el diagnóstico radiológico fue del 70% y 96%, respectivamente. La TTD muestra viabilidad técnica para asistir la detección de CaMa.

Several groups have proposed thermographic image processing for Breast Cancer (BC) detection. Angiogenesis and vascularization of menstrual cycle dependent, as well as age and Body Mass Index change the absolute temperature in the tissue surface without necessarily being associated with malignancy. We have proposed the Differentiated Tissue Thermography (DTT) in breast regarding its contralateral mirror in order to observe differences in temperature characteristics of malignancy. This study evaluates the possibility of using breast DTT as a potential technique to assist the detection of BC. We sampled 110 female volunteers between 40 and 60 years old segmented into two experimental groups: healthy group (n=90) and BC group (n=20), which were diagnosed by mammography and histopathology. Thermal images of both breasts were acquired with an infrared camera and the DTT was estimated relative to its contralateral breast in the same patient. A sensitivity and specificity analysis was developed and the DTT was compared with the radiological diagnosis by ROC curves with the histopathological report as reference. The DTT values showed distinguishable dynamic ranges between malignant and healthy conditions. ROC analysis showed sensitivity and specificity values for DTT of 70% and 54% while for the radiological diagnosis was 70% and 96% respectively. DTT showed technical viability to assist BC detection.

Computed tomography assessment of lung structure in patients undergoing cardiac surgery with cardiopulmonary bypass

Hypoxemia is a frequent complication after coronary artery bypass graft (CABG) with cardiopulmonary bypass (CPB), usually attributed to atelectasis. Using computed tomography (CT), we investigated postoperative pulmonary alterations and their impact on blood oxygenation. Eighteen non-hypoxemic patients (15 men and 3 women) with normal cardiac function scheduled for CABG under CPB were studied. Hemodynamic measurements and blood samples were obtained before surgery, after intubation, after CPB, at admission to the intensive care unit, and 12, 24, and 48 h after surgery. Pre- and postoperative volumetric thoracic CT scans were acquired under apnea conditions after a spontaneous expiration. Data were analyzed by the paired Student t-test and one-way repeated measures analysis of variance. Mean age was 63 ± 9 years. The PaO2/FiO2 ratio was significantly reduced after anesthesia induction, reaching its nadir after CPB and partially improving 12 h after surgery. Compared to preoperative CT, there was a 31 percent postoperative reduction in pulmonary gas volume (P < 0.001) while tissue volume increased by 19 percent (P < 0.001). Non-aerated lung increased by 253 ± 97 g (P < 0.001), from 3 to 27 percent, after surgery and poorly aerated lung by 72 ± 68 g (P < 0.001), from 24 to 27 percent, while normally aerated lung was reduced by 147 ± 119 g (P < 0.001), from 72 to 46 percent. No correlations (Pearson) were observed between PaO2/FiO2 ratio or shunt fraction at 24 h postoperatively and postoperative lung alterations. The data show that lung structure is profoundly modified after CABG with CPB. Taken together, multiple changes occurring in the lungs contribute to postoperative hypoxemia rather than atelectasis alone.

Lung hyperinflation stimulates the release of inflammatory mediators in spontaneously breathing subjects

Lung hyperinflation up to vital capacity is used to re-expand collapsed lung areas and to improve gas exchange during general anesthesia. However, it may induce inflammation in normal lungs. The objective of this study was to evaluate the effects of a lung hyperinflation maneuver (LHM) on plasma cytokine release in 10 healthy subjects (age: 26.1 ± 1.2 years, BMI: 23.8 ± 3.6 kg/m²). LHM was performed applying continuous positive airway pressure (CPAP) with a face mask, increased by 3-cmH2O steps up to 20 cmH2O every 5 breaths. At CPAP 20 cmH2O, an inspiratory pressure of 20 cmH2O above CPAP was applied, reaching an airway pressure of 40 cmH2O for 10 breaths. CPAP was then decreased stepwise. Blood samples were collected before and 2 and 12 h after LHM. TNF-á, IL-1â, IL-6, IL-8, IL-10, and IL-12 were measured by flow cytometry. Lung hyperinflation significantly increased (P < 0.05) all measured cytokines (TNF-á: 1.2 ± 3.8 vs 6.4 ± 8.6 pg/mL; IL-1â: 4.9 ± 15.6 vs 22.4 ± 28.4 pg/mL; IL-6: 1.4 ± 3.3 vs 6.5 ± 5.6 pg/mL; IL-8: 13.2 ± 8.8 vs 33.4 ± 26.4 pg/mL; IL-10: 3.3 ± 3.3 vs 7.7 ± 6.5 pg/mL, and IL-12: 3.1 ± 7.9 vs 9 ± 11.4 pg/mL), which returned to basal levels 12 h later. A significant correlation was found between changes in pro- (IL-6) and anti-inflammatory (IL-10) cytokines (r = 0.89, P = 0.004). LHM-induced lung stretching was associated with an early inflammatory response in healthy spontaneously breathing subjects.

Effect of cardiopulmonary bypass on the pharmacokinetics of propranolol and atenolol

The pharmacokinetics of some β-blockers are altered by cardiopulmonary bypass (CPB). The objective of this study was to compare the effect of coronary artery bypass graft (CABG) surgery employing CPB on the pharmacokinetics of propranolol and atenolol. We studied patients receiving oral propranolol with doses ranging from 80 to 240 mg (N = 11) or atenolol with doses ranging from 25 to 100 mg (N = 8) in the pre- and postoperative period of CABG with moderately hypothermic CPB (32°C). On the day before and on the first day after surgery, blood samples were collected before β-blocker administration and every 2 h thereafter. Plasma levels were determined using high-performance liquid chromatography and data were treated by pharmacokinetics-modelling. Statistical analysis was performed using ANOVA or the Friedman test, as appropriate, and P < 0.05 was considered to be significant. A prolongation of propranolol biological half-life from 5.41 ± 0.75 to 11.46 ± 1.66 h (P = 0.0028) and an increase in propranolol volume of distribution from 8.70 ± 2.83 to 19.33 ± 6.52 L/kg (P = 0.0032) were observed after CABG with CPB. No significant changes were observed in either atenolol biological half-life (from 11.20 ± 1.60 to 11.44 ± 2.89 h) or atenolol volume of distribution (from 2.90 ± 0.36 to 3.83 ± 0.72 L/kg). Total clearance was not changed by surgery. These CPB-induced alterations in propranolol pharmacokinetics may promote unexpected long-lasting effects in the postoperative period while the effects of atenolol were not modified by CPB surgery.

Expression of the carotenoid biosynthesis genes in Xanthophyllomyces dendrorhous

In the yeast Xanthophyllomyces dendrorhous the genes idi, crtE, crtYB, crtl and ast are involved in the biosynthesis of astaxanthin from isopentenyl pyrophosphate. The carotenoid production and the kinetics of mRNA expression of structural genes controlling the carotenogenesis in a wild-type ATCC 24230 and in carotenoid overproducer deregulated atxS2 strains were studied. The biosynthesis of carotenoid was induced at the late exponential growth phase in both strains. However, the cellular carotenoid concentration was four times higher in atxS2 than in the wild-type strain in the exponential growth phase, suggesting that carotenogenesis was deregulated in atxS2 at the beginning of growth. In addition, the maximum expression of the carotenogenesis genes at the mRNA level was observed during the induction period of carotenoid biosynthesis in the wild-type strain. The mRNA level of the crtYB, crtl, ast genes and to a lesser extent the idi gene, decayed at the end of the exponential growth phase. The mRNA levels of the crtE gene remained high along the whole growth curve of the yeast. In the atxS2 strain the mRNA levels of crtE gene were about two times higher than the wild-type strain in the early phase of the growth cycle.

Cardiopulmonary bypass alters the pharmacokinetics of propranolol in patients undergoing cardiac surgery

The pharmacokinetics of propranolol may be altered by hypothermic cardiopulmonary bypass (CPB), resulting in unpredictable postoperative hemodynamic responses to usual doses. The objective of the present study was to investigate the pharmacokinetics of propranolol in patients undergoing coronary artery bypass grafting (CABG) by CPB under moderate hypothermia. We evaluated 11 patients, 4 women and 7 men (mean age 57 ± 8 years, mean weight 75.4 ± 11.9 kg and mean body surface area 1.83 ± 0.19 m²), receiving propranolol before surgery (80-240 mg a day) and postoperatively (10 mg a day). Plasma propranolol levels were measured before and after CPB by high-performance liquid chromatography. Pharmacokinetic Solutions 2.0 software was used to estimate the pharmacokinetic parameters after administration of the drug pre- and postoperatively. There was an increase of biological half-life from 4.5 (95 percent CI = 3.9-6.9) to 10.6 h (95 percent CI = 8.2-14.7; P < 0.01) and an increase in volume of distribution from 4.9 (95 percent CI = 3.2-14.3) to 8.3 l/kg (95 percent CI = 6.5-32.1; P < 0.05), while total clearance remained unchanged 9.2 (95 percent CI = 7.7-24.6) vs 10.7 ml min-1 kg-1 (95 percent CI = 7.7-26.6; NS) after surgery. In conclusion, increases in drug distribution could be explained in part by hemodilution during CPB. On the other hand, the increase of biological half-life can be attributed to changes in hepatic metabolism induced by CPB under moderate hypothermia. These alterations in the pharmacokinetics of propranolol after CABG with hypothermic CPB might induce a greater myocardial depression in response to propranolol than would be expected with an equivalent dose during the postoperative period.

A micromethod for quantitation of debrisoquine and 4-hydroxydebrisoquine in urine by liquid chromatography

We describe a new simple, selective and sensitive micromethod based on HPLC and fluorescence detection to measure debrisoquine (D) and 4-hydroxydebrisoquine (4-OHD) in urine for the investigation of xenobiotic metabolism by debrisoquine hydroxylase (CYP2D6). Four hundred µl of urine was required for the analysis of D and 4-OHD. Peaks were eluted at 8.3 min (4-OHD), 14.0 min (D) and 16.6 min for the internal standard, metoprolol (20 µg/ml). The 5-µm CN-reverse-phase column (Shimpack, 250 x 4.6 mm) was eluted with a mobile phase consisting of 0.25 M acetate buffer, pH 5.0, and acetonitrile (9:1, v/v) at 0.7 ml/min with detection at lexcitation = 210 nm and lemission = 290 nm. The method, validated on the basis of measurements of spiked urine, presented 3 ng/ml (D) and 6 ng/ml (4-OHD) sensitivity, 390-6240 ng/ml (D) and 750-12000 ng/ml (4-OHD) linearity, and 5.7/8.2 percent (D) and 5.3/8.2 percent (4-OHD) intra/interassay precision. The method was validated using urine of a healthy Caucasian volunteer who received one 10-mg tablet of Declinax®, po, in the morning after an overnight fast. Urine samples (diuresis of 4 or 6 h) were collected from zero to 24 h. The urinary excretion of D and 4-OHD, Fel (0-24 h), i.e., fraction of dose administered and excreted into urine, was 6.4 percent and 31.9 percent, respectively. The hydroxylation capacity index reported as metabolic ratio was 0.18 (D/4-OHD) for the person investigated and can be compared to reference limits of < 12.5 for poor metabolizers (PM) and < 12.5 for extensive metabolizers (EM). In parallel, the recovery ratio (RR), another hydroxylation capacity index, was 0.85 (4-OHD: SD + 4-OHD) versus reference limits of RR < 0.12 for PM and RR > 0.12 for EM. The healthy volunteer was considered to be an extensive metabolizer on the basis of the debrisoquine test.

Cerebral thrombosis and vasculitis: an uncommon complication of ulcerative colitis

Cerebral thrombotic disease is a rare and nearly always fatal complication of ulcerative colitis. It is associated with a necrotizing vasculitis. We report a fatal case with a confusing neurologic picture arising from this complication. Autopsy revealed necrosis and hemorrhages affecting both cortical grey and white matter. Microscopic examination showed thrombosis of small and medium size vessels associated with hemorrhages and a necrotizing angiitis. Ulcerations, hemorrhages, pseudopolyps, and cryptic abscesses were found in the rectosigmoid region of the colon compatible with active ulcerative colitis. A sudden neurologic deficit in a patient with ulcerative colitis should direct attention to the consideration of a cerebral thrombotic event and the possibility of an associated cerebral vasculitis. Diagnosis may be strongly suggested by MRI or arteriography, but it may require confirmation by biopsy of the brain parenchyma and leptomeninges. A hypercoagulable state has been associated with the thrombosis. Anticoagulation has yielded successful results in some patients with cerebral thrombosis but the risk of massive intracranial and gastrointestinal bleeding preclude to establish clear indications. Neurologic improvement has been obtained with the use of steroids and cyclophosphamide

The effects of positive end-expiratory pressure on respiratory system mechanics and hemodynamics in postoperative cardiac surgery patients

We prospectively evaluated the effects of positive end-expiratory pressure (PEEP) on the respiratory mechanical properties and hemodynamics of 10 postoperative adult cardiac patients undergoing mechanical ventilation while still anesthetized and paralyzed. The respiratory mechanics was evaluated by the inflation inspiratory occlusion method and hemodynamics by conventional methods. Each patient was randomized to a different level of PEEP (5, 10 and 15 cmH2O), while zero end-expiratory pressure (ZEEP) was established as control. PEEP of 15-min duration was applied at 20-min intervals. The frequency dependence of resistance and the viscoelastic properties and elastance of the respiratory system were evaluated together with hemodynamic and respiratory indexes. We observed a significant decrease in total airway resistance (13.12 + or - 0.79 cmH2O l-1 s-1 at ZEEP, 11.94 + or - 0.55 cmH2O l-1 s-1 (P<0.0197) at 5 cmH2O of PEEP, 11.42 + or - 0.71 cmH2O l-1 s-1 (P<0.0255) at 10 cmH2O of PEEP, and 10.32 + or - 0.57 cmH2O l-1 s-1 (P<0.0002) at 15 cmH2O of PEEP). The elastance (Ers; cmH2O/l) was not significantly modified by PEEP from zero (23.49 + or - 1.21) to 5 cmH2O (21.89 + or - 0.70). However, a significant decrease (P<0.0003) at 10 cmH2O PEEP (18.86 + or - 1.13), as well as (P<0.0001) at 15 cmH2O (18.41 + or - 0.82) was observed after PEEP application. Volume dependence of viscoelastic properties showed a slight but not significant tendency to increase with PEEP. The significant decreases in cardiac index (l min-1 m-2) due to PEEP increments (3.90 + or - 0.22 at ZEEP, 3.43 + or - 0.17 (P<0.0260) at 5 cmH2O of PEEP, 3.31 + or - 0.22 (P<0.0260) at 10 cmH2O of PEEP, and 3.10 + or - 0.22 (P<0.0113) at 15 cmH2O of PEEP) were compensated for by an increase in arterial oxygen content owing to shunt fraction reduction from 22.26 + or - 2.28 at ZEEP to 11.66 + or - 1.24 at PEEP of 15 cmH2O (P<0.0007). We conclude that increments in PEEP resulted in a reduction of both airway resistance and respiratory elastance. These results could reflect improvement in respiratory mechanics. However, due to possible hemodynamic instability, PEEP should be carefully applied to postoperative cardiac patients

Prostaglandin-E2 and cyclic adenosine 3'-5' monophosphate levels in the hypertrophied rat heart

To assess whether prostaglandin-E2 (PGE2) and cyclic adenosine 3'-5'-monophosphate (cAMP) are involved in the cardiac response to chronic pressure overload, we measured by specific radioimmunoassay method the cardiac tissue and plasma concentrations of PGE2 and cAMP in an animal model of left ventricular hypertrophy. The cardiac hypertrophy was accompanied by a significant increase in PGE2 content, and a significant decrease in cAMP content, in the heart. In addition, we found elevated PGE2 and cAMP levels in arterial plasma samples from the rats with hypertrophied hearts compared to normal rats. These findings suggest a link between cardiac and vascular PGE2 and cAMP generation and the hemodynamic stresses of advanced cardiac overload

Klebsiella pneumonie como agente patógeno primario / Klebsiella pneumoniae as primary pathogenic agent

Se investigó la presencia de algunos factores de patogenicidad en cepas de Klebsiella pneumoniae. La prueba de adhesividad a células epiteliales fue positiva en muchas cepas, especialmente en las aisladas de urocultivo. Muchas cepas produjeron enzimas líticas, y se hicieron pocas pruebas de invasividad, que fueron negativas, pero estos resultados no tienen valor estadístico. El polisacárido capsular de las cepas probadas es capaz de inhibir la fagocitosis tanto de polimorfonucleares como de macrófagos peritoneales de ratón, y a bajas concentraciones induce la formación de anticuerpos y complejos inmunes en conejo. También se encontraron cepas productoras de enterotoxinas. La presencia de estos factores de patogenicidad permite que por lo menos algunas cepas sean capaces de producir enfermedad en huéspedes no comprometidos

Acción del maleato de perhexilina sobre la curva de disociación de la hemoglobina en pacientes coronarios / Action of the perhexiline maleate on the dissociation curve of the hemoglobin in coronary patients

La desviación hacia la derecha de la curva de disociación de la hemoglobina (CDO) aumenta la liberación de O2 a los tejidos y podría ser un mecanismo útil en la cardiopatía isquémica. Algunos fármacos, como el propranotol, son capaces de producir este efecto. Con objeto de comprobar si el maleato de perhexilina tuviera alguna acción sobre la CDO, se estudiaron once enfermos coronarios tratados con 100-200 mg/día (media, 163). Se analizó la P50 y los niveles de 2,3 DPG antes de comenzar el tratamiento, a las cuatro horas y a los ocho días del inicio del mismo. La P50 pasó de 25,65 + ou - 0,97 mmHg (-x + ou - SD) a 25,93 + ou - 0,99 y a 26,07 + ou - 1,004. Por su parte, el 2,3 DPG aumentó de 14,35 + ou - 1,6 micromoles/g Hb a 14,67 + ou - 1,58 y 14,81 + ou - 1,39. Estas variaciones no fueron estadisticamente significativas. Se concluye que el maleato de perhexilina, con las pautas aqui empleadas, no altera de modo significativo la COD; existe sin embargo cierta tendencia al aumento progresivo y paralelo de P50 y 2,3 DPG que, para hacerse más evidentes, podrían requerir mayores dosis de la droga, más tiempo de tratamiento o un número de pacientes superior