Biosorción de plomo (II) en solución acuosa con biomasa de los cladodios de la tuna (Opuntia ficus indica) / Biosorption of lead (II) in aqueous solution with biomass of prickly pear cladodes (Opuntia ficus indica) / Biossorção de chumbo (II) em solução aquosa com biomassa de cladódios de pera espinhosa (Opuntia ficus indica)

Resumen Se investigó la remoción de plomo de soluciones acuosas por biomasa de los cladodios de la tuna (BCT), una especie abundante en la sierra peruana. Las propiedades físicas y químicas de la BCT se determinaron por técnicas de FTIR y SEM/ EDX. El análisis FTIR confirmó la presencia de grupos -OH, CO-C, C=O y -NH2, los cuales interactuarían con el metal. La micrografía SEM reveló que la morfología superficial de la BCT tiene porosidad adecuada para la biosorción. En un sistema discontinuo se obtuvo la más alta capacidad de biosorción (qe) con una relación masa BCT/volumen de 4 g/L, pH 4,5 y tiempo de contacto de 1 h. La biosorción siguió un modelo cinético de pseudo-segundo orden y el proceso de difusión intraparticular fue el factor principal de control de la velocidad. Los datos en el equilibrio fueron correlacionados con cinco modelos (Langmuir, Freundlich, Temkin, D-R y Redlich-Peterson) y se ajustaron mejor al modelo de Langmuir, lo que indica que el proceso se realiza en centros activos energéticamente homogéneos, el valor de qe máxima fue 50,25 mg/g. Los resultados obtenidos demuestran que la BCT puede ser usada como biosorbente eficiente para el tratamiento de aguas contaminadas con Pb (II).

Abstract The removal of lead from aqueous solutions by the biomass of prickly pear cladodes (BCT), a species found in abundance in the Sierra region in Peru, was investigated. The physical and chemical properties of BCT were determined by FTIR and SEM/EDX techniques. The FTIR analysis confirmed the presence of -OH, C-O-C, C=O and -NH2 groups which would interact with the metal. The SEM micrograph revealed that the surface morphology of the BCT shows adequate porosity for biosorption. In a discontinuous system, the highest biosorption capacity (qe) was obtained with a BCT mass/volume ratio of 4 g/L, pH 4.5 and 1 h of contact time. Biosorption followed a pseudo-second order kinetic model and the intraparticle diffusion process was the main factor controlling speed. Data at equilibrium were correlated using five models (Langmuir, Freundlich, Temkin, DR, and Redlich-Peterson) and were better fitted to the Langmuir model, which would indicate that the process is carried out in energetically homogeneous active centers, the value of qe maximum was 50.25 mg/g. The results obtained demonstrate that BCT can be used as an efficient biosorbent for the treatment of waters contaminated with Pb (II).

Resumo Investigou-se a remoção de chumbo de soluções aquosas pela biomassa de cladódios de pera espinhosa (BCT), espécie encontrada em abundância na região da Sierra, no Peru, e as propriedades físicas e químicas do BCT foram determinadas por técnicas de FTIR y SEM/EDX. A análise por FTIR confirma a presença dos grupos -OH, C-O-C, C=O e -NH2 que interagem com o metal; a micrografia SEM revela que a morfologia da superfície do BCT mostra porosidade adequada para biossorção. Em um sistema descontínuo, a maior capacidade de biossorção (qe) foi obtida com uma relação massa/volume de BCT de 4 g/L, pH 4,5 e tempo de contato 1 h. A biossorção seguiu um modelo cinético de pseudo-segunda ordem e o processo de difusão intrapartículas foi o principal fator de controle da velocidade. Os dados em equilíbrio foram correlacionados usando cinco modelos (Langmuir, Freundlich, Temkin, DR e Redlich-Peterson) e foram melhor ajustados ao modelo de Langmuir, o que indicaria que o processo é realizado em centros ativos energeticamente homogêneos, o valor de qe o máximo foi de 50,25 mg/g. Os resultados obtidos demonstram que o BCT pode ser usado como um biossorvente eficiente para o tratamento de águas contaminadas com Pb (II).

The role of trust in health information from medical authorities in accepting the HPV vaccine among African American parents.

This research examines how and why trust in health information from medical authorities (i.e., doctors or health care professionals and government health agencies) predicts acceptance of the HPV vaccine for one's child among African American parents. A survey of African American parents recruited from community venues revealed that low trust in health information from government health agencies was associated with less favorable attitudes and intentions toward vaccinating their child against HPV. Trust in health information from a doctor or health care professional did not predict vaccine acceptance. Mediation analyses indicated that the relationship between trust in health information from government health agencies and vaccine acceptance was partially mediated by perceived vaccine efficacy. Implications of the findings on communicating to the African American community about the HPV vaccine are discussed.

The association between razor clam consumption and memory in the CoASTAL Cohort.

This study represents a preliminary effort to examine the possible impacts of chronic, low level Domoic Acid (DA) exposure on memory in the CoASTAL cohort. Five hundred thirteen men and women representing three Native American Tribes were studied with standard measures of cognition and razor clam consumption (a known vector of DA exposure) over a four year period. In addition, a pilot metric of DA concentration exposure was used which took into consideration average DA concentration levels in source beaches as well as consumption. Based upon GEE analysis, controlling for age, sex, race, year, education level, tribe, and employment status, findings indicated that high razor clam consumers (15 or more per month) had isolated decrements on some measures of memory (p=.02 to .03), with other cognitive functions unaffected. The relatively lower memory scores were still within normal limits, thus not clinically significant. The pilot DA exposure metric had no association with any aspect of cognition or behavior. There is a possible association between long term, low level exposure to DA through heavy razor clam consumption and memory. The availability of a reliable biological marker for human exposure to DA is needed.

Communities advancing the studies of Tribal nations across their lifespan: Design, methods, and baseline of the CoASTAL cohort.

The CoASTAL cohort represents the first community cohort assembled to study a HAB related illness. It is comprised of three Native American tribes in the Pacific NW for the purpose of studying the health impacts of chronic, low level domoic acid (DA) exposure through razor clam consumption. This cohort is at risk of domoic acid (DA) toxicity by virtue of their geographic location (access to beaches with a history of elevated DA levels in razor clams) and the cultural and traditional significance of razor clams in their diet. In this prospective, longitudinal study, Wave 1 of the cohort is comprised of 678 members across the lifespan with both sexes represented within child, adult and geriatric age groups. All participants are followed annually with standard measures of medical and social history; neuropsychological functions, psychological status, and dietary exposure. DA concentration levels are measured at both public and reservation beaches where razor clams are sourced and multiple metrics have been piloted to further determine exposure. Baseline data indicates that all cognitive and psychological functions are within normal limits. In addition there is considerable variability in razor clam exposure. Therefore, the CoASTAL cohort offers a unique opportunity to investigate the potential health effects of chronic, low level exposure to DA over time.

Perception of risk for Domoic Acid related health problems: A Cross-cultural study.

Risk perception is a complex process that refers to the way people approach, think about and interpret risks in their environment. An important element of risk perception is that it is culturally situated. Since HAB's can present a health risk in many places around the world, looking at cultural parameters for understanding and interpreting risks are important. This study examined how two different groups of people perceive the potential health risks of low level exposure to domoic acid (DA) through razor clam consumption. The risk perceptions of Washington State, USA coastal dwelling Native American nations (NA) were compared to that of a community sample of recreational razor clam harvesters (CRH). Overall, the findings support the hypothesis that cultural and community specific contexts impact the perception of risk of a DA related illness. Specifically, the NA sample was distinguished by worrying more about ocean pollution, attributing DA risks to climate change, expressing concerns about the potential impact of DA on future generations, and feeling better informed than the CRH group. The CRH group were more likely to attribute the DA problem to anthropogenic or industrial causes; and view the risk of health problems as lower than that associated with smoking, high cholesterol, anxiety or depression, alcoholism, high blood pressure or obesity. The CRH group was also more likely to turn to the media for DA related information. Both groups trust the decisions of state and tribe health and natural resources officials and demonstrated a complex pattern of findings that involved gender. It was recommended that risk communication and outreach activities are designed to take into consideration factors that specifically apply to each cultural community.

The association between razor clam consumption and memory in the CoASTAL cohort.

This study represents a preliminary effort to examine the potential impacts of chronic, low level domoic acid (DA) exposure on memory in the CoASTAL cohort over the first four years of data collection (Wave 1). Five hundred and thirteen adult men and women representing three Native American Tribes were studied annually with standard measures of cognition and razor clam consumption (a known vector of DA exposure) over a four-year period. In addition, a pilot metric of DA concentration exposure was used which took into consideration average DA concentration levels in source beaches, as well as the amount consumed. Based upon generalized estimating equations (GEE) analysis, controlling for age, sex, race, year, education level, tribe, and employment status, findings indicated that high razor clam consumers (15 or more per month) had isolated decrements on some measures of memory (p=0.02-0.03), with other cognitive functions unaffected. The relatively lower memory scores were still within normal limits, and were thus not clinically significant. The pilot DA exposure metric had no association with any other aspect of cognition or behavior. There is a possible association between long-term, low-level exposure to DA through heavy razor clam consumption and memory functioning.

Perception of risk for domoic acid related health problems: A cross-cultural study.

Risk perception is a complex process that refers to the way people approach, think about, and interpret risks in their environment. An important element of risk perception is that it is culturally situated. Since HABs can present a health risk in many places around the world, looking at cultural parameters for understanding and interpreting risks is important. This study examined how two different groups of people perceive the potential health risks of low-level exposure to domoic acid (DA) through razor clam consumption. The risk perceptions of Washington State, USA coastal dwelling Native American nations (NA) were compared to that of a community sample of recreational razor clam harvesters (CRH). Overall, the findings support the hypothesis that cultural and community specific contexts impact the perception of risk of a DA related illness. Specifically, the NA sample was distinguished from the CRH group in particular, by their worries about ocean pollution, attribution of DA risks to climate change, concerns about the potential impact of DA on future generations, and feeling of being better informed than the CRH group. The CRH group was more likely to attribute the DA problem to anthropogenic or industrial causes and view the risk of health problems from DA as lower than those associated with smoking, high cholesterol, anxiety or depression, alcoholism, high blood pressure or obesity. The CRH group was also more likely to turn to the media for DA-related information. Both groups trusted the decisions of state and tribe health and natural resources officials, and demonstrated a complex pattern of findings that involved gender. In summary, risk communication and outreach activities should be designed to take into consideration the specific factors that are unique to each cultural community.

Communities advancing the studies of Tribal nations across their lifespan: Design, methods, and baseline of the CoASTAL cohort.

The CoASTAL cohort represents the first community cohort assembled to study a HAB-related illness. It is comprised of three Native American tribes in the Pacific NW for the purpose of studying the health impacts of chronic, low level domoic acid (DA) exposure through razor clam consumption. This cohort is at risk of DA toxicity by virtue of their geographic location (access to beaches with a history of elevated DA levels in razor clams) and the cultural and traditional significance of razor clams in their diet. In this prospective, longitudinal study, Wave 1 of the cohort was comprised of 678 members across the human lifespan, with both sexes represented within child, adult, and geriatric age groups. All participants were followed annually with standard measures of medical and social history; neuropsychological functions, psychological status, and dietary exposure. DA concentrations were measured at both public and reservation beaches where razor clams are acquired. Multiple metrics were piloted to further determine exposure. Baseline data indicated that all cognitive and psychological functions were within normal limits. In addition, there was considerable variability in razor clam exposure. Therefore, the CoASTAL cohort offers a unique opportunity to investigate the potential health effects of chronic, low level exposure to DA over time.

Message Framing, Perceived Susceptibility, and Intentions to Vaccinate Children Against HPV Among African American Parents.

This research examines the interaction effect of message framing (gain vs. loss) and perceived susceptibility (i.e., perceived likelihood that one's child is at risk of contracting HPV) on African American parents' intentions to vaccinate their children against HPV. Results of an experiment (N = 193) in which parents were exposed to either a gain-framed or loss-framed message about HPV vaccination revealed a significant interaction between message framing and perceived susceptibility when parents were required to pay for the vaccine. The specific pattern of interaction suggested that parents who perceived their children to be at high risk of contracting HPV were more persuaded by the gain-framed message, whereas those who believed their children to be at low risk of contracting HPV were more persuaded by the loss-framed message. Implications of the findings for HPV vaccination messaging are discussed.

Admission hyperglycemia is predictive of outcome in critically ill trauma patients.

OBJECTIVES: There is a paucity of data evaluating whether hyperglycemia at admission is associated with adverse outcome in trauma patients. Our objectives were to determine whether admission hyperglycemia was predictive of outcome in critically ill trauma patients. METHODS: Prospective data were collected daily on 1,003 consecutive trauma patients admitted to the intensive care unit over a 2-year period. Diabetics were excluded. Patients were stratified by admission serum glucose level (<200 mg/dL vs. > or =200 mg/dL) age, gender, Injury Severity Score, and other preexisting risk factors. Outcome was measured by incidence of infection, ventilator days, hospital length of stay and intensive care unit length of stay, and mortality. Multiple linear regression models were used to determine level of significance. RESULTS: Two hundred fifty-five of 1,003 (25%) patients were admitted with hyperglycemia over the study period. The majority (78%) of the admissions were caused by blunt injury. Male patients accounted for the majority of the study population (73%); however, female patients were more likely to be hyperglycemic at admission (p = 0.015). Patients with hyperglycemia had an overall greater infection rate and hospital length of stay. The hyperglycemic group had a 2.2-times greater risk of mortality when adjusted for age and Injury Severity Score. CONCLUSION: Hyperglycemia at admission is an independent predictor of outcome and infection in trauma patients. Future investigation on the effects of hyperglycemia are warranted.

A time-dependent analysis of intensive care unit pneumonia in trauma patients.

BACKGROUND: Appropriate and timely antibiotic therapy to treat pneumonia in trauma patients is extremely important. We evaluated the incidence and microbiology of pneumonia stratified by days postadmission and risk factors. METHODS: Prospective data were collected on 714 trauma patients admitted to the intensive care unit over a 1-year period. Pneumonia was classified as community acquired (CAP) (< or = 3 days), early nosocomial (ENP) (4-6 days), or late nosocomial (LNP) (> or = 7 days). In addition, pneumonia was classified as CAP only, nosocomial only (NI), or combination (CAP and NI, or ENP and LNP) pneumonia. Strict institutional guidelines were followed for diagnosis. RESULTS: One hundred eighty-two patients (25%) were diagnosed with 204 pneumonias over the study period. One hundred twenty-five (61%) of these pneumonias were ventilator associated. Staphylococcus aureus and Haemophilus influenzae were the most common pathogens isolated. Twenty-one percent of patients with CAP acquired an LNP (p < 0.025), in which Pseudomonas was the most common organism. Haemophilus caused LNP in 12% of patients. Cancer (p < 0.01), liver failure (p < 0.05), and age (p < 0.01) were predictive of nontypical pathogens in patients with CAP and ENP (p < 0.05). Obesity was most predictive of increased ventilator days (p < 0.001) and intensive care unit length of stay (p < 0.001). Increased age, alcohol abuse, and field airway were most predictive of mortality. CONCLUSION: Unanticipated pathogens were isolated in each class of pneumonia. The clinician must be aware of significant risk factors that may predispose patients to pathogens that are not ordinarily covered with standard antibiotic therapy.

Admission serum albumin is predicitve of outcome in critically ill trauma patients.

There is a paucity of data evaluating serum albumin on admission as a predictor of outcome in adult trauma patients. Our objectives were to evaluate whether or not hypoalbuminemia on admission is a predictor of adverse outcome in trauma patients. Prospective data was collected daily on 1023 patients over a 2-year period. Patients were stratified by serum albumin level on admission, age, gender, injury severity, and comorbid conditions. Outcome was measured by ICU and hospital length of stay, ventilator days, incidence of infection, and mortality. Student t test, chi2, and multilinear regression analysis were used to determine level of significance. Blunt injuries accounted for the majority (78%) of the admissions. The mean age of the study population was 43+/-21 years with a mean Injury Severity Score (ISS) of 21.4+/-12. The majority of patients were male (74.5%). The mean albumin level on admission was 2.9+/-1.8. Five hundred ninety-three (58%) patients were admitted with a serum albumin level of > or =2.6 as compared to 430 patients (42%) with an admission albumin level of <2.6. Patients with a lower serum albumin level were found to have a significantly greater ICU (17.1 vs 14.2 days) and hospital length of stay (17.3 vs 20.1 days, P'< 0.05), ventilator days (11.1 vs 13.5 days, P < 0.05), and mortality (P = 0.008) when matched for age and injury severity. The relative risk of infection and mortality increased greater than 2.5-fold in patients with increased age and low serum albumin when analyzed by multilinear regression analysis, P < 0.001. An admission serum albumin level of <2.6 g/dL is a significant independent predictor of morbidity and mortality in trauma patients. The combination of increased age and low albumin level was most predictive of infection and mortality. Early nutrition should be considered in these high-risk patients.

Reclassification of urinary tract infections in critically ill trauma patients: a time-dependent analysis.

BACKGROUND: Successful treatment of urinary tract infections (UTIs) in the trauma ICU requires early recognition and timely, appropriate antibiotic therapy. We evaluated the incidence and microbiology of UTIs stratified by days post-admission and risk factors. METHODS: Prospective data were collected on 1,172 trauma patients admitted to the ICU over a two-year period. Infections were classified as Community Acquired (CA, < or = 3 days), Early Nosocomial (EN, 4-6 days), Mid-Nosocomial (MN, 7-10 days) and Late Nosocomial (LN > 10 days). Criteria of the U.S. Centers for Disease Control and Prevention (CDC) were used for diagnosis. RESULTS: Two hundred twenty patients (19%) were diagnosed with a total of 235 UTIs. Thirtysix patients were diagnosed with multiple UTIs. Escherichia coli, Enterococcus sp. and Candida sp. were the most common pathogens isolated. One thousand one hundred fifty-one patients had a Foley catheter placed (mean duration, 1 +/- 11 days) with a CDC device-related infection rate (no. of catheter-associated UTIs/1000 catheter days) of 18. Patients admitted with a CA infection were significantly older (p < 0.001) and had a higher mortality rate (39% vs. 15%, p = 0.001). Unanticipated pathogens in this group included Enterococcus, Candida, and Pseudomonas. Women were more likely to be admitted with a CA infection (5% vs. 1%, p < 0.001) or acquire an NI infection (23% vs. 15%, p < 0.001). Obesity was highly predictive of increased Foley catheter days, and thus UTI, by multivariate analysis (p < 0.001). CONCLUSIONS: Escherichia coli was the most common pathogen in all nosocomial infection categories. Increased age, gender, and obesity, in addition to catheter-days, were significant risk factors for UTI in trauma patients. Specific risk factors may predispose patients to pathogens that are not ordinarily covered by usually-chosen antibiotic therapy.