Recommendations of the Society of Thoracic Surgery and the Section of Cardiothoracic and Vascular Surgery of the Spanish Society of Anesthesia, Resuscitation and Pain Therapy, for patients undergoing lung surgery included in an intensified recovery program.

In recent years, multidisciplinary programs have been implemented that include different actions during the pre, intra and postoperative period, aimed at reducing perioperative stress and therefore improving the results of patients undergoing surgical interventions. Initially, these programs were developed for colorectal surgery and from there they have been extended to other surgeries. Thoracic surgery, considered highly complex, like other surgeries with a high postoperative morbidity and mortality rate, may be one of the specialties that most benefit from the implementation of these programs. This review presents the recommendations made by different specialties involved in the perioperative care of patients who require resection of a lung tumor. Meta-analyzes, systematic reviews, randomized and non-randomized controlled studies, and retrospective studies conducted in patients undergoing this type of intervention have been taken into account in preparing the recommendations presented in this guide. The GRADE scale has been used to classify the recommendations, assessing on the one hand the level of evidence published on each specific aspect and, on the other hand, the strength of the recommendation with which the authors propose its application. The recommendations considered most important for this type of surgery are those that refer to pre-habilitation, minimization of surgical aggression, excellence in the management of perioperative pain and postoperative care aimed at providing rapid postoperative rehabilitation.

Recommendations of the Society of Thoracic Surgery and the Section of Cardiothoracic and Vascular Surgery of the Spanish Society of Anesthesia, Resuscitation and Pain Therapy, for patients undergoing lung surgery included in an intensified recovery program. / Recomendaciones de la Sociedad Española de Cirugía Torácica y de la Sección de Cardiotorácica y Cirugía Vascular de la Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor, para los pacientes sometidos a cirugía pulmonar incluidos en un programa de recuperación intensificada.

In recent years, multidisciplinary programs have been implemented that include different actions during the pre, intra and postoperative period, aimed at reducing perioperative stress and therefore improving the results of patients undergoing surgical interventions. Initially, these programs were developed for colorectal surgery and from there they have been extended to other surgeries. Thoracic surgery, considered highly complex, like other surgeries with a high postoperative morbidity and mortality rate, may be one of the specialties that most benefit from the implementation of these programs. This review presents the recommendations made by different specialties involved in the perioperative care of patients who require resection of a lung tumor. Meta-analyses, systematic reviews, randomized and non-randomized controlled studies, and retrospective studies conducted in patients undergoing this type of intervention have been taken into account in preparing the recommendations presented in this guide. The GRADE scale has been used to classify the recommendations, assessing on the one hand the level of evidence published on each specific aspect and, on the other hand, the strength of the recommendation with which the authors propose its application. The recommendations considered most important for this type of surgery are those that refer to pre-habilitation, minimization of surgical aggression, excellence in the management of perioperative pain and postoperative care aimed at providing rapid postoperative rehabilitation.

Effect of voltage and oxygen on inactivation of E. coli and S. typhi using pulsed dielectric barrier discharge.

This work presents the study of the voltage and oxygen effect on bacterial inactivation in water using a pulsed dielectric barrier discharge (DBD) under atmospheric pressure, where Escherichia coli (E. coli) and Salmonella typhi (S. typhi) bacteria were used as model microorganisms. A cylindrical DBD reactor was developed and tested in applications to assay the efficiency of bacterial inactivation in water on a volume of 500 mL flowing continuously throughout the system assisted with a peristaltic pump at 4.4 ± 0.1 mL/s. The efficiency of the treatment reached a 6-log10 reduction for both E. coli and S. typhi bacteria at 106 CFU/mL of concentration at the end of the first cycle of treatment at a minimum voltage of 12 kV with oxygen bubbling gas, concluding that there was a minimum voltage to produce inactivation of E. coli and S. typhi samples. Bacterial inactivation without the oxygen condition contrasted with the high rate of inactivation with oxygen at relatively low voltage discharges.

Microbial mortality behavior promoted by silver (Ag+/Ago)-modified zeolite-rich tuffs for water disinfection.

BACKGROUND: In developing countries, death due to diseases caused by fecal-oral ingestion can be avoided by taking action on drinking water issues. Adequate access to water treatment systems to reduce infections is a critical cause. Silver has been used as an antibacterial product, including biomedical applications. Therefore, in this paper, the effect of the chemical speciation of silver from silver-modified zeolite-rich tuffs on the mortality of Escherichia coli (E. coli), Streptococcus faecalis (S. faecalis) and Candida albicans (C. albicans) suspended in aqueous solution was investigated for disinfection purposes. METHODS: The following aspects were considered to develop the investigation: a) the technique to prepare the modified zeolitic materials, either with ionic silver or silver nanoparticles, which were obtained in two ways: one, with grapefruit extract and the second, by using non-thermal plasma generated in a dielectric barrier discharge reactor of parallel plates; b) the response of the prokaryotes (bacteria) and eukaryote (yeast) microorganisms to disinfectant agents in batch systems; c) the disinfection processes as a function of time to obtain kinetics parameters; and d) the kinetics of the silver release from the silver-modified zeolite-rich tuffs, considering the models of Higuchi and Korsmeyer. The zeolitic materials were characterized by low-vacuum scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). RESULTS: The non-thermal plasma reduced ionic silver is more efficient at generating silver compounds with several oxidation states, which are essential during the microbial inhibition process. For the bacterial (E. coli and S. faecalis), the materials with nanoparticles were efficient to inactivate them. However, the yeast (C. albicans) reaches the total inactivation when the zeolitic material contains ionic silver in the crystalline network. CONCLUSION: The E. coli, S. faecalis and C. albicans survival behavior suspended in aqueous solutions after contact with Ag-modified natural zeolites depends on the chemical speciation of the silver present in these materials, Ag+1 in the case of OAgiZ or nanoparticles of Ago promoted by the grapefruit extract (OAgnpTZ), as well as by non-thermal plasma generated in a dielectric barrier discharge reactor of parallel plates (OAgnpPZ). In general, the concentration of silver in the aqueous solution after the disinfection process cannot exceed the recommended levels established for international organizations. The OAgnpPZ is a potential microbicide agent against E. coli and C. albicans, and the OAgn pTZ for F. faecalis.Graphical abstractARTWORK.

Niveles elevados de aldosterona sérica en pacientes en diálisis: ¿estamos infrautilizando los bloqueantes del sistema renina angiotensina aldosterona en diálisis? / Elevated serum aldosterone levels in dialysis patients: Are we underusing renin-angiotensin-aldosterone system blockers?

La aldosterona sérica (AS) es un marcador de riesgo cardiovascular (CV) en población general. Objetivo: Analizar los niveles de AS en pacientes en diálisis y su relación con las características de la diálisis, antecedentes CV, tensión arterial y uso de bloqueantes del sistema renina-angiotensina-aldosterona (BSRAA). Métodos: Determinamos la AS en 102 pacientes: 81 en hemodiálisis (HD) y 21 en diálisis peritoneal; con una edad media de 71,4 ± 12 años; el 54,9% eran varones; el 29,4%, diabéticos; con un tiempo en diálisis de 59,3 ± 67 meses. En 44 pacientes en HD se midió la actividad de renina plasmática (ARP). Resultados: La media de AS fue 72,6 ± 114,9 ng/dl (rango normal: 1,17-23,.6ng/dl). El 57,8% de los pacientes tenía niveles por encima de la normalidad que no se relacionaron con características de diálisis ni antecedentes CV. Solo el 21% de los pacientes con insuficiencia cardiaca y el 19,2% con cardiopatía isquémica utilizaban BSRAA. Los 25 pacientes en tratamiento con BSRAA tenían niveles de AS significativamente menores. Existe una correlación inversa entre la AS y la tensión arterial sistólica (TAS), y directa con ARP. En el análisis de regresión logística para ver factores asociados a niveles de AS superiores a la mediana, la TAS fue la única variable de riesgo independiente en la población global (OR 0,97; p = 0,022); en los 44 pacientes en HD en los que se determinó ARP este fue el único factor de riesgo independiente (OR 2,24; p = 0,012). Conclusiones: Un alto porcentaje de pacientes en diálisis tiene niveles elevados de AS que no se relacionan con características de la diálisis y sí con disminución de TAS y activación del SRAA. En pacientes con antecedentes de cardiopatía infrautilizamos los BSRAA

Serum aldosteronelevels (SA) are a marker of cardiovascular (CV) risk in the general population. Objective: To analyze SA levels in dialysis patients and its relationship with characteristics of dialysis; comorbidity; blood pressure and the use of blocking renin-angiotensin-aldosterone system agents (BSRAA). Methods: We determined SA in 102 patients: 81 on hemodialysis (HD) and 21 on peritoneal dialysis. Mean age 71.4 ± 12 years; 54.9% male; 29.4% diabetics. Mean time on dialysis 59.3 ± 67 months. In 44 HD patients plasma renin activity (PRA) was measured. Results: Mean SA was 72.6 ± 114.9ng/dl (normal range 1.17-23.6ng/dl). A total of 57.8% of patients had above normal levels which were not related to dialysis characteristics or comorbidity. Only 21% of patients with heart failure and 19.2% with ischemic heart disease used BSRAA. A number of 25 patients treated with BSRAA had significantly lower levels of SA. There was an inverse correlation between AS and systolic blood pressure (SBP), and direct with PRA. The logistic regression analysis conducted to find SA levels above the median associated factors showed that SBP was the only independent risk variable in the overall population (OR 0.97; P = .022); in the 44 patients in whom PRA was determined this was the only independent risk factor (OR 2.24; P = .012). Conclusions: A high percentage of dialysis patients have elevated levels of SA that are associated to diminished SBP and activated PRA and not to dialysis characteristics. In patients with a history of heart disease we underuse BSRAA

[Elevated serum aldosterone levels in dialysis patients: Are we underusing renin-angiotensin-aldosterone system blockers?] / Niveles elevados de aldosterona sérica en pacientes en diálisis: ¿estamos infrautilizando los bloqueantes del sistema renina angiotensina aldosterona en diálisis?

Serum aldosteronelevels (SA) are a marker of cardiovascular (CV) risk in the general population. OBJECTIVE: To analyze SA levels in dialysis patients and its relationship with characteristics of dialysis; comorbidity; blood pressure and the use of blocking renin-angiotensin-aldosterone system agents (BSRAA). METHODS: We determined SA in 102 patients: 81 on hemodialysis (HD) and 21 on peritoneal dialysis. Mean age 71.4±12 years; 54.9% male; 29.4% diabetics. Mean time on dialysis 59.3±67 months. In 44 HD patients plasma renin activity (PRA) was measured. RESULTS: Mean SA was 72.6±114.9ng/dl (normal range 1.17-23.6ng/dl). A total of 57.8% of patients had above normal levels which were not related to dialysis characteristics or comorbidity. Only 21% of patients with heart failure and 19.2% with ischemic heart disease used BSRAA. A number of 25 patients treated with BSRAA had significantly lower levels of SA. There was an inverse correlation between AS and systolic blood pressure (SBP), and direct with PRA. The logistic regression analysis conducted to find SA levels above the median associated factors showed that SBP was the only independent risk variable in the overall population (OR 0.97; P=.022); in the 44 patients in whom PRA was determined this was the only independent risk factor (OR 2.24; P=.012). CONCLUSIONS: A high percentage of dialysis patients have elevated levels of SA that are associated to diminished SBP and activated PRA and not to dialysis characteristics. In patients with a history of heart disease we underuse BSRAA.

Modern hydroxyethyl starch and acute kidney injury after cardiac surgery: a prospective multicentre cohort.

BACKGROUND: Recent trials have shown hydroxyethyl starch (HES) solutions increase the risk of acute kidney injury (AKI) in critically ill patients. It is uncertain whether these adverse effects also affect surgical patients. We sought to determine the renal safety of modern tetrastarch (6% HES 130/0.4) use in cardiac surgical patients. METHODS: In this multicentre prospective cohort study, 1058 consecutive patients who underwent cardiac surgery from 15th September 2012 to 15th December 2012 were recruited in 23 Spanish hospitals. RESULTS: We identified 350 patients (33%) administered 6% HES 130/0.4 intraoperatively and postoperatively, and 377 (36%) experienced postoperative AKI (AKI Network criteria). In-hospital death occurred in 45 (4.2%) patients. Patients in the non-HES group had higher Euroscore and more comorbidities including unstable angina, preoperative cardiogenic shock, preoperative intra-aortic balloon pump use, peripheral arterial disease, and pulmonary hypertension. The non-HES group received more intraoperative vasopressors and had longer cardiopulmonary bypass times. After multivariable risk-adjustment, 6% HES 130/0.4 use was not associated with significantly increased risks of AKI (adjusted odds ratio 1.01, 95% CI 0.71-1.46, P=0.91). These results were confirmed by propensity score-matched pairs analyses. CONCLUSIONS: The intraoperative and postoperative use of modern hydroxyethyl starch 6% HES 130/0.4 was not associated with increased risks of AKI and dialysis after cardiac surgery in our multicentre cohort.

Assessing cellular DNA damage from a helium plasma needle.

The aim of the present study is to determine the deoxyribonucleic acid (DNA) damage by cells exposed to atmospheric pressure non-thermal plasma (APNTP). Mouse leukocytes embedded in agarose were exposed to the plasma at two different distances from a helium plasma needle outlet and during three different exposure periods. Damage was assessed by the single cell gel electrophoresis assay. The results indicate that, at 0.1 cm from the plasma needle, the exposure caused complete DNA fragmentation determined by the presence of so called "clouds". Samples exposed at 0.5 cm from the slide sample surface presented damage proportional to the exposure periods in terms of tail intensity, tail moment and "clouds" frequency. Studies performed with alkaline single cell gel electrophoresis assay to determine DNA breaks and alkali-labile sites, indicates that DNA damage produced by exposure to APNTP was caused mainly by oxidative radicals, rather than by UV light which causes cyclobutane pyrimidine dimers. These results allow us to conclude that plasma needle induced DNA breaks in mice leukocytes proportionally to exposure time.

Inactivation of Escherichia coli in water by pulsed dielectric barrier discharge in coaxial reactor.

An experimental study of ATCC (American Type Culture Collection) 8739 Escherichia coli bacteria inactivation in water by means of pulsed dielectric barrier discharge (PDBD) atmospheric pressure plasmas is presented. Plasma is generated by an adjustable power source capable of supplying high voltage 25 kV pulses, ∼30 µs long and at a 500 Hz frequency. The process was conducted in a ∼152 cm(3) cylindrical stainless steel coaxial reactor, endowed with a straight central electrode and a gas inlet. The bacterial concentration in water was varied from 10(3) up to 10(8) E. coli cells per millilitre. The inactivation was achieved without gas flow in the order of 82% at 10(8) colony-forming units per millilitre (CFU mL(-1)) concentrations in 600 s. In addition, oxygen was added to the gas supply in order to increase the ozone content in the process, raising the inactivation percentage to the order of 90% in the same treatment time. In order to reach a higher efficiency however, oxygen injection modulation is applied, leading to inactivation percentages above 99.99%. These results are similarly valid for lower bacterial concentrations.

[Clinical and biochemical characteristics of predialysis patients in terms of 25 hydroxy vitamin D levels]. / Características clínicas y bioquímicas de pacientes en prediálisis con respecto a los niveles de 25 hidroxivitamina D.

INTRODUCTION: Decreased levels of 25 hydroxyvitamin D (25[OH]D) have been reported in patients with chronic kidney disease (CKD). The pleiotropic effects of vitamin D are known to go beyond mineral metabolism. OBJECTIVES: The aims of this study were to: 1) Determine the 25(OH)D levels in predialysis outpatients. 2) Find out the clinical and biochemical characteristics of patients with 25(OH)D deficiency, and predictive factors for the deficiency. PATIENTS AND METHODS: An observational study in 79 predialysis outpatients was performed. Clinical and biochemical parameters were analysed in terms of nutrition, inflammation and mineral metabolism in relation to serum levels of 25(OH)D. Levels of 25(OH)D lower than 15ng/ml were considered to be deficient. RESULTS: Serum levels of 25(OH)D were deficient in 41 patients (52%). The comparative study regarding levels of vitamin 25(OH)D showed the group of patients with a deficiency, i.e. those with less than 15ng/ml, were older (70 ± 11.97 vs. 61 ± 14.5; p = 0.005), had a greater body mass index, BMI, (30±4.06 vs. 27.1 ± 5.08; p = 0.003) and increased proteinuria (1.42g/24h (0.53-2.96) vs. 0.51 (0.20-1.48), p = 0.009). This group included a greater number of diabetic patients: 20 (76.9%) vs. 6 (23%), p = 0.002. They had a higher level of parathyroid hormone (PTH): 359 (239-658) vs. 233 (129-323), p = 0.000; and more patients were under treatment with Calcitriol: 28 (62.2%) vs. 17 (37.8%), p = 0.024. In the multivariate analysis, high levels of PTH (OR 13.38; CI 95% [2.94-60.89]; p=0.001), increased proteinuria (OR 4.41; CI 95% [1.12-17.25]; p = 0.033); and being diabetic (OR 5.713; CI 95% [1.43-22.77]; p = 0.014) were independent predictor factors for patients with 25(OH)D deficiency. CONCLUSIONS: In our study, we observed a high prevalence of 25(OH)D deficiency among patients with CKD. The increased levels of PTH, the increase of proteinuria and the presence of diabetes were independent predictors for 25(OH)D deficiency.

Características clínicas y bioquímicas de pacientes en prediálisis con respecto a los niveles de 25 hidroxivitamina D / Clinical and biochemical characteristics of predialysis patients in terms of 25 hydroxy vitamin D levels

Introducción: Se ha descrito una disminución de los niveles de 25 hidroxivitamina D (25[OH]D) en los pacientes con enfermedad renal crónica (ERC). Conocemos que el efecto pleiotrópico de la vitamina D va más allá del metabolismo mineral. Objetivos: Los objetivos del estudio fueron: 1) determinar los niveles de 25(OH) D en pacientes con ERC seguidos en consulta de prediálisis, y 2) analizar características clínicas y bioquímicas de los pacientes con respecto a los niveles de 25(OH)D y los posibles factores predictivos de la deficiencia en 25(OH)D. Pacientes y métodos: Realizamos un estudio observacional en 79 pacientes con ERC. Analizamos datos clínicos y parámetros bioquímicos en cuanto a nutrición, inflamación y metabolismo mineral en relación con los niveles de 25(..) (AU)

Introduction: Decreased levels of 25 hydroxyvitamin D (25[OH]D) have been reported in patients with chronic kidney disease (CKD). The pleiotropic effects of vitamin D are known to go beyond mineral metabolism. Objetives: The aims of this study were to: 1) Determine the 25(OH)D levels in predialysis outpatients. 2) Find out the clinical and biochemical characteristics of patients with 25(OH)D deficiency, and predictive factors for the deficiency. Patients and methods: An observational study in 79 predialysis outpatients was performed. Clinical and biochemical parameters were analysed in terms of nutrition, inflammation and mineral metabolism in relation to serum levels of 25(OH)D. Levels of 25(OH)D lower than 15ng/ml were considered to be deficient. Results: Serum levels of 25(OH)D were deficient in 41 patients (52%). The comparative study regarding levels of vitamin 25(OH)D showed the group of patients with a deficiency, i.e. those with less than 15ng/ml, were older (70 ± 11.97 vs. 61 ± 14.5; p = 0.005), had a greater body mass index, BMI, (30±4.06 vs. 27.1 ± 5.08; p = 0.003) and increased proteinuria (1.42g/24h (..) (AU)

Resultados clínicos inmediatos y alejados del implante de stents metálicos no recubiertos: ¿Se justifica un reemplazo total por los stents liberadores de drogas? / Acute and long-term clinical results of bare metal coronary stenting

Background: Since the introduction of stents in 1994, improved clinical results have boosted the development of coronary angioplasty in Chile. Drug eluting stents, that have a reduced rate of restenosis, are being increasingly used. Aim: To assess the acute and long-term results of bare metal stent implantation. Patients and Methods: Acute and long-term clinical, procedural and angiographic results were assessed in non acute myocardial infarction patients undergoing coronary stent implantation between August 1996 and December 2003. Results: During the study period, 932 patients aged 30 to 87 years (194 women) had at íeast one stent implanted. Twenty two percent were diabetic, 33 percent had recent myocardial infarction, 53 percent unstable angina and 22 percent stable angina. Angiographic and clinical success were 99.6 percent and 98.2 percent, respectively. In hospital death was 0.5 percent. During a mean follow-up of 19.1 months, all cause mortality was 3.9 percent, cardiac death 1.9 percent and survival free of major cardiac ischemic events was 85.3 percent. Only 6.4 percent of lesions underwent target vessel revascularization (TVR). Independent predictors of TVR were previous surgery, íeft anterior descending artery, small post stent minimum luminal diameter. Ostial location, in-stent restenosis, and younger age were non significant predictors. Conclusions: Acute and long-term results of bare metal stents in this population were excellent. An intriguingly low rate of TVR was seen. Selective bare metal stenting should continue in lesions and patients with a low risk of clinical restenosis.

Resultados tardíos del tratamiento percutáneo de la reestenosis intrastent con el uso de stents con drogas: un estudio colaborativo / Percutaneous treatment of intra stent restenosis using drug eluting stents: late results in a multicenter study

Introducción. La proliferación neointimal es la causa de la reestenosis coronaria intra stent (RIS). Recientemente, el implante de stents liberadores de drogas (DES) ha emergido como una alternativa efectiva de tratamiento endovascular. Material y método. Seleccionamos pacientes con RIS de stents no recubiertos tratados con DES en forma consecutiva en 3 centros chilenos. Luego del alta los pacientes fueron seguidos por al menos 12 meses. Resultados. De 21 pacientes (19 por ciento mujeres) entre 47 y 91 años tratados por al menos una lesión coronaria con RIS, 33,3 por ciento eran diabéticos y 14,3 por ciento tenían cirugía coronaria previa. Se presentaron de preferencia con síndromes coronarios agudos y la mayoría tenía enfermedad de 1 vaso (71,4 por ciento). Se trató sólo 1 lesión con RIS, implantándose en 15 pacientes DES recubierto con Sirolimus y en 6 con Paclitaxel. El largo promedio de stent implantado fue de27,7 mm (13-51 mm). Se obtuvo éxito en todos los casos y no hubo complicaciones isquémicas intrahospitalarias. Durante el seguimiento, sólo 2 pacientes presentaron reestenosis intrastent y uno de ellos, un anciano, falleció en forma súbita en el seguimiento. El 90 por ciento se mantuvo libre de eventos isquémicos en el seguimiento. Conclusión. El implante de DES aparece como una alternativa efectiva en el tratamiento de la RIS.

Background. Neointimal proliferation causes coronary intrastent restenosis (ISR). Recently, drug eluting stents(DES) have emerged as an effective therapeutic approach to treat ISRMethods. Consecutive patients from 3 centers with in stent restenosis after bare metal stent implantation were treated with DES. Patients were followed for 12 months after discharge.Results. Of 21 patients (19 percent females), 47 to 91 years old, with one or more intrastent restenosis, diabetes was present in 33 percent and previous coronary artery surgery in 14 percent. Most patients presented with acute coronary syndromes and 71 percent had single vessel disease. Only one lesion in each patient was treated with DES implantation, 15 with paclitaxel and 6 with sirolimus stents. Mean stent length was 27.7 mm (13-51). The procedure was successful in all patients and no ischemic complications were observed prior to discharge. During follow up 2 patients developed new intra stent restenosis and one of them died suddenly. 90 percent of patients were free from ischemic events at the end of follow up. Conclusion. DES appears to be an effective therapy to treat intra stent restenosis.

Considerations on the measurement of practical peak voltage in diagnostic radiology.

An evaluation of the non-invasive measurement of the practical peak voltage (PPV) in the quality control of X-ray units used in diagnostic radiology was carried out. Two instruments were employed: the PTW Diavolt Universal Tester with readings in PPV and the Waveform Tester for X-rays (WATEX) prototype proposed here, which uses a PIN structure (P-type diffusion, Intrinsic region, N-type diffusion) photodiode as a sensor. The reference for the measurements was the voltage signal obtained in an oscilloscope from an invasive high voltage divider in order to verify the accuracy and precision of the measurements. The readings of the PPV in the Diavolt show a systematic error between 1% and 8%, always being less than the real value. An explanation for this difference is proposed, based on the relation between the effect of the X-rays in the film and the response of the sensor to the product of the applied voltage to the X-ray tube (peak voltage kVp), and the anode current. This explanation was confirmed using the WATEX waveform tester.

Distribution and characterization of Bacillus thuringiensis on the phylloplane of species of piper (Piperaceae) in three altitudinal levels.

Bacillus thuringiensis is found naturally on the phylloplane. In this study 35 samples from 13 species of the genus Piper (Piperaceae) were collected from three altitudinal levels located between 1800 and 2900 m above sea level in the Colombian Andean forest of Central Cordillera. Two hundred and fifty-six isolates of B. thuringiensis were obtained from 74% of the samples studied. B. thuringiensis index (number of isolates of B. thuringiensis/number of isolates of sporulated bacilli) was 0.2. The isolates were characterized by crystal morphology, the presence of cry genes by PCR, and toxicity against insects. Fifty-five percent of the isolates found presented bipyramidal-crystal morphology, and 42% had round-crystal morphology. Seventy percent of the isolates amplified cry1 [cry one] genes (generally toxic to lepidopterans); 41.4% amplified cry4 and/or cry11 [cry eleven] genes (generally toxic to dipterans), and none of the isolates amplified cry3 genes (generally toxic to coleopterans). The most abundant genotype of cry genes (54.7% of the total) was cry1Aa, cry1Ab, cry1Ac, cry1Ad, and cry1B. From the total isolates found, 7.8% presented both cry1 and cry11 genes, and five isolates (2.0%) harbored cry1, cry4, and cry11 genes; all these isolates were toxic to Culex quinquefasciatus (Diptera) but not to Spodoptera frugiperda (Lepidoptera). To our knowledge, these genotypes have not been previously reported. Overall, almost 60% of the isolates were toxic to S. frugiperda, and a little more than 40% of the isolates were toxic to C. quinquefasciatus. The populations of viable vegetative cells and spores per unit area were estimated and studied statistically. No significant differences in the number of B. thuringiensis isolates per cm2 of leaf among the three altitudinal levels were found, nor were they found among the different Piper species evaluated. This study increases the knowledge of the ecology of B. thuringiensis.

Heavy metal removal with Mexican clinoptilolite: multi-component ionic exchange.

This paper describes the interactions of Pb(II), Cd(II), and Cr(VI) competing for ion-exchange sites in naturally occurring clinoptilolite. Dissolved Pb and Cd were effectively removed within 18 h in batch reactors, with higher removal efficiencies (> 95%) in the acidic pH range. The presence of Cr(VI), which can interact with these metals to form anionic complexes, significantly diminished the Pb and Cd removal efficiencies. A decrease in the efficiency of clinoptilolite to remove Pb was also observed in the high (> or = 10) pH range. This was attributed to the formation of anionic hydroxo-complexes with little affinity for cationic ion exchange sites. Pb outcompeted Cd for ion exchange sites in a flow-through column packed with clinoptilolite (contact time = 10 s). The preferential removal of Pb in column, but not in batch reactors, reflects that competitive retention can be affected by contact time because diffusion kinetics may influence the removal efficiency to a greater extent than equilibrium partitioning. Phenol, which was tested as a representative organic co-contaminant, slightly hindered heavy metal removal in batch reactors. This was attributed to the formation of organometallic complexes that cannot penetrate the zeolite exchange channels. Altogether, these results show that natural zeolites hold great potential to remove cationic heavy metal species from industrial wastewater. Nevertheless, process efficiency can be hindered by the presence of ligands that form complexes with reduced accessibility and/or affinity for ion exchange.

Bacteriology of middle ear fluid specimens obtained by tympanocentesis from 111 Colombian children with acute otitis media.

We cultured middle ear fluid specimens obtained by tympanocentesis from 111 Colombian infants and children, ages 11 days to 11 years, with acute otitis media. Bacteria were isolated in 82 patients (74%). Haemophilus influenzae, the most common isolate, was present in 40 cases (36%); 32 were nontypable strains and 8 were type b. Streptococcus pneumoniae, identified in 26 cases (22%), was the second most common pathogen. All H. influenzae and S. pneumoniae strains were susceptible to ampicillin and penicillin, respectively. We conclude that amoxicillin remains the drug of choice for treatment of acute otitis media in our country.