A European survey of older peoples' preferences, and perceived barriers and facilitators to inform development of a medication-related fall-prevention patient portal.

PURPOSE: Falls are a major and growing health care problem in older adults. A patient portal has the potential to provide older adults with fall-prevention advice to reduce fall-risk. However, to date, the needs and preferences regarding a patient portal in older people who have experienced falls have not been explored. This study assesses content preferences, potential barriers and facilitators with regard to using a patient portal, as perceived by older people who have experienced falls, and explores regional differences between European participants. METHODS: We conducted a survey of older adults attending an outpatient clinic due to a fall or fall-related injury, to explore their content preferences, perceived barriers, and facilitators with respect to a fall-prevention patient portal. Older adults (N = 121, 69.4% female, mean age: 77.9) were recruited from seven European countries. RESULTS: Almost two-thirds of respondents indicated they would use a fall-prevention patient portal. The portal would preferably include information on Fall-Risk-Increasing Drugs (FRIDs), and ways to manage other related/relevant medical conditions. Facilitators included a user-friendly portal, with easily accessible information and physician recommendations to use the portal. The most-commonly-selected barriers were privacy issues and usage fees. A family member's recommendation to use the portal was seemingly more important for Southern and Eastern European participants compared to the other regions. CONCLUSION: The majority of older people with lived falls experience expressed an interest in a fall-prevention patient portal providing personalized treatment advice to prevent further falls. The results will be used to inform the development of a fall-prevention patient portal. The fall-prevention patient portal is intended to be used in addition to a consultation with a physician. Future research is needed to explore how to prevent falls in older patients who are not interested in a fall-prevention patient portal.

Factors associated with impairment in gait speed in older people with clinically normal gait. A cross-sectional study.

BACKGROUND: Health professionals commonly use gait speed in the evaluation of functional status in older people. However, only a limited number of studies have assessed gait speed in the absence of disorders of gait, using confounding factors and exclusion criteria coming from studies conducted in younger people. Our study aims to analyse which factors are associated with gait speed in older people with normal clinical gait. METHODS: An observational cross-sectional study was conducted in 119 community-dwelling residents without relevant comorbidities (Charlson index < 2), preserved function (Barthel > 85) and normal gait by visual exploration. Exclusion criteria included suffering from any illness that could modify the characteristics of gait, terminal status or the presence of an acute medical illness in the past 3 months. We used a stepwise linear regression of several variables (sociodemographic characteristics, cognition, body composition, drugs, falls, sarcopenia, frailty and physical activity) on 6-metre gait speed. RESULTS: The mean age was 78 years (range 70-96 years) and 71.4% were women. Variables that remained associated with gait speed in the multivariate final model were age (B = - 0.020, p < 0.001); gender (B = - 0.184, p < 0.001); waist-to-height ratio (B = - 0.834, p = 0.002); number of falls (B = - 0.049, p = 0.003) and the number of Fried's frailty criteria (B = - 0.064, p = 0.019). CONCLUSION: Falls, frailty and the waist-to-height ratio modify gait speed in older people with normal gait. Studies analysing the potential effect of several factors on gait speed should consider them as confounding factors.

EuGMS Task and Finish group on Fall-Risk-Increasing Drugs (FRIDs): Position on Knowledge Dissemination, Management, and Future Research.

Falls are a major public health concern in the older population, and certain medication classes are a significant risk factor for falls. However, knowledge is lacking among both physicians and older people, including caregivers, concerning the role of medication as a risk factor. In the present statement, the European Geriatric Medicine Society (EuGMS) Task and Finish group on fall-risk-increasing drugs (FRIDs), in collaboration with the EuGMS Special Interest group on Pharmacology and the European Union of Medical Specialists (UEMS) Geriatric Medicine Section, outlines its position regarding knowledge dissemination on medication-related falls in older people across Europe. The EuGMS Task and Finish group is developing educational materials to facilitate knowledge dissemination for healthcare professionals and older people. In addition, steps in primary prevention through judicious prescribing, deprescribing of FRIDs (withdrawal and dose reduction), and gaps in current research are outlined in this position paper.

EuGMS Task and Finish group on Fall-Risk-Increasing Drugs (FRIDs): Position on Knowledge Dissemination, Management, and Future Research.

Falls are a major public health concern in the older population, and certain medication classes are a significant risk factor for falls. However, knowledge is lacking among both physicians and older people, including caregivers, concerning the role of medication as a risk factor. In the present statement, the European Geriatric Medicine Society (EuGMS) Task and Finish group on fall-risk-increasing drugs (FRIDs), in collaboration with the EuGMS Special Interest group on Pharmacology and the European Union of Medical Specialists (UEMS) Geriatric Medicine Section, outlines its position regarding knowledge dissemination on medication-related falls in older people across Europe. The EuGMS Task and Finish group is developing educational materials to facilitate knowledge dissemination for healthcare professionals and older people. In addition, steps in primary prevention through judicious prescribing, deprescribing of FRIDs (withdrawal and dose reduction), and gaps in current research are outlined in this position paper.

How nurses cope with death in the Paediatric Intensive Care Unit. / Afrontamiento de las enfermeras ante la muerte del paciente en la Unidad de Cuidado Intensivo Pediátrico.

The death of a child in the Paediatric Intensive Care Unit (PICU) is difficult, the loss generates feelings of sadness and pain; this study highlights the different coping strategies used by nurses to manage this situation and find the strength to provide care at the end of life. OBJECTIVE: Explore the strategies used by nurses in the PICU in coping with death. METHODS: Study conducted in the city of Manizales, Colombia, during the months of October, November and December. A qualitative, hermeneutical phenomenological approach was used. The method of intentional sampling for the selection of participating nurses (n=10) working in PICU, in-depth interviews were conducted for the construction of the information and the data were analyzed according to the procedures proposed by Cohen, Kahn and Steeves. RESULTS: Nurses use coping strategies focused on emotions: they inhibit their feelings towards the patient and their family; they use communication and prayer with the patient, as well as accompaniment to alleviate the suffering of the family. CONCLUSION: UCIP nurses develop coping strategies for end-of-life care using spiritual resources and communication with the family who require ongoing support, reflecting on death and accompanying the child in its transcendence.

Life cycle assessment of carbon capture and utilization from ammonia process in Mexico.

Post-combustion CO2 capture (PCC) of flue gas from an ammonia plant (AP) and the environmental performance of the carbon capture utilization (CCU) technology for greenhouse gas (GHG) emissions to an enhanced oil recovery (EOR) system in Mexico was performed as case study. The process simulations (PS) and life cycle assessment (LCA) were used as supporting tools to quantify the CO2 capture and their environmental impacts, respectively. Two scenarios were considered: 1) the AP with its shift and CO2 removal unit and 2) Scenario 1 plus PCC of the flue gas from the AP primary reformer (AP-2CO2) and the global warming (GW) impact. Also, the GW of the whole of a CO2-EOR project, from these two streams of captured CO2, was evaluated. Results show that 372,426 tCO2/year can be PCC from the flue gas of the primary reformer and 480,000 tons/y of capacity from the AP. The energy requirement for solvent regeneration is estimated to be 2.8 MJ/kgCO2 or a GW impact of 0.22 kgCO2e/kgCO2 captured. GW performances are 297.6 kgCO2e emitted/barrel (bbl) for scenario one, and 106.5 kgCO2e emitted/bbl for the second. The net emissions, in scenario one, were 0.52 tCO2e/bbl and 0.33 tCO2e/bbl in scenario two. Based on PS, this study could be used to evaluate the potential of CO2 capture of 4080 t/d of 4 ammonia plants. The integration of PS-LCA to a PCC study allows the applicability as methodological framework for the development of a cluster of projects in which of CO2 could be recycled back to fuel, chemical, petrochemical products or for enhanced oil recovery (EOR). With AP-2CO2, "CO2 emission free" ammonia production could be achieved.

Inhibition of quorum-sensing-dependent virulence factors and biofilm formation of clinical and environmental Pseudomonas aeruginosa strains by ZnO nanoparticles.

UNLABELLED: Quorum quenching decreases Pseudomonas aeruginosa virulence factors and biofilm formation, alleviating infections in animal models. Nevertheless, it is usually performed in laboratory strains such as PAO1 and PA14, and studies involving clinical or environmental isolates are scarce. In this work, the effects of ZnO nanoparticles, a potent quorum and virulence quencher for the PAO1 strain, were tested in six clinical strains from cystic fibrosis patients, a furanone C-30 resistant clinical strain from urine, two PA14 gallium resistant mutants, a PA14 C-30 resistant mutant and four environmental isolates. ZnO nanoparticles effectively decreased elastase, pyocyanin, and biofilm formation for most of the strains; regardless their origin or their resistance against the canonical quorum quencher C-30 or the novel antimicrobial gallium. The data indicate ZnO nanoparticles may have a broad spectrum for the quorum quenching of relevant strains and that may be an alternative to treat Ps. aeruginosa recalcitrant infections. SIGNIFICANCE AND IMPACT OF THE STUDY: Virulence inhibition by quorum quenchers in Pseudomonas aeruginosa is usually tested in laboratory strains and studies of their effects in relevant clinical and environmental strains are scarce. This study is significant as the effects of ZnO nanoparticles in QS-dependent virulence factor production were tested in six clinical strains from cystic fibrosis patients, a C-30 resistant clinical strain from urine, two PA14 gallium resistant mutants, a PA14 C-30 resistant mutant, and four environmental isolates. ZnO nanoparticles decreased elastase, pyocyanin, and biofilms for most of the strains; indicating they have broad spectrum and may be an alternative to treat Ps. aeruginosa infections.

Structural and electronic study of neutral, positive, and negative small rhodium clusters [Rh(n), Rh(n)(+), Rh(n)(-) ; n = 10-13].

We have carried out a systematic study for the determination of the structure and the fundamental state of neutral and ionic small rhodium clusters [Rhn, Rhn(+), Rhn(-); n = 10-13] using ab initio Hartree-Fock methods with a LANL2DZ basis set. A range of spin multiplicities is investigated for each cluster. We present the bond lengths, angles, and geometric configuration adopted by the clusters in its minimum energy conformation showing the differences when the clusters have different number of unpaired electrons. Also we report the vertical ionization potential and the adiabatic one calculated by the Koopmans' theorem.

Human and ecotoxicological impacts assessment from the Mexican oil industry in the Coatzacoalcos region, as revealed by the USEtox model.

Human and ecotoxicological impacts were analyzed in the lower basin of the Coatzacoalcos River (Veracruz, State in Mexico). High pollution levels of contaminants from the oil industry have been reported in natural streams and the Coatzacoalcos River and in their sediments. USEtox model was employed to evaluate environmental fate, exposure, and effect of nine organic compounds (polycyclic aromatic hydrocarbons and one of which was in the group of polychlorinated biphenyls), a heavy metal (lead), and the effect of the industrial wastewater emitted into the river, on the Coatzacoalcos region. Most of these compounds are highly toxic; they bioaccumulate in human and animal tissue, mainly in the fatty tissues and can damage different organs and systemic targets such as the liver, kidney, hormonal system, nervous system, etc., of both humans and wildlife. The model estimates that 96% (3,247 kg/day) of organic compounds is transferred from the water into air, whereas only 4% (151 kg/day) remains in the water. In addition, it predicts that humans are mainly exposed to polychlorinated biphenyls (PCBs) congeners (28 and 153) by eating contaminated fish, due to PCBs accumulating in the fish fat tissue. The number of cases of cancer and noncancer (1 in 862 habitants per additional kilogram) is expected to have an increment due to the higher PCBs exposure of human population. Genetic damages in fishes, earthworms, and toads have been observed and related to higher exposure to organic compounds. The relationship between the field reported data and those one predicted by the USEtox model have been confirmed empirically by using the nonparametric correlation analysis (Spearman's rho). Based on the USEtox model, the environmental stress in the Coatzacoalcos industrial zone is between 2 and 6 orders of magnitude over geometric mean of acute aquatic EC50s. We think that USEtox model can be used to expand the number of substances that have the current water quality guidelines to improve the water management in Mexico.

Dual time point 2-deoxy-2-[18F]fluoro-D-glucose PET/CT: nodal staging in locally advanced breast cancer.

AIM: To assess dual time point 2-deoxy-2-[(18)F]fluoro-D-glucose (18)(F)FDG PET-CT accuracy in nodal staging and in detection of extra-axillary involvement. MATERIAL AND METHODS: Dual time point [(18)F] FDG PET/CT scan was performed in 75 patients. Visual and semiquantitative assessment of lymph nodes was performed. Semiquantitative measurement of SUV and ROC-analysis were carried out to calculate SUV(max) cut-off value with the best diagnostic performance. Axillary and extra-axillary lymph node chains were evaluated. RESULTS: Sensitivity and specificity of visual assessment was 87.3% and 75%, respectively. SUV(max) values with the best sensitivity were 0.90 and 0.95 for early and delayed PET, respectively. SUV(max) values with the best specificity were 1.95 and 2.75, respectively. Extra-axillary lymph node involvement was detected in 26.7%. CONCLUSION: FDG PET/CT detected extra-axillary lymph node involvement in one-fourth of the patients. Semiquantitative lymph node analysis did not show any advantage over the visual evaluation.

Swallows as indicators of environmental pollution of the Rio Grande/Rio Bravo Basin: are persistent organic pollutants a concern?

Swallows from two locations in the Rio Grande/Rio Bravo Basin and one reference site located 500 km away were analyzed for organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). Of the OC pesticides, only p,p'-DDE was observed at levels of concern (carcass geometric mean range 642 to 8511 ng/g wet weight [ww]). DDE residues in carcass were significantly greater at El Paso than at other locations. PCBs were relatively low compared with locations in the northeastern United States and the Great Lakes. Geometric mean PBDE concentrations ranged from 18 to 258 ng/g ww (280 to 3395 ng/g lipid weight). PBDE congeners 47 and 99 comprised approximately 60% of total PBDEs. Concentrations of DDE measured in swallows from El Paso in 2000 and 2005 are among the highest observed in the last 20 years along the United States-Mexico border. The results from this study indicated that swallows are still being exposed to high concentrations of DDE, which could have adverse effects on reproduction or on predators that feed on swallows.

PBDEs, PCBs, and DDE in eggs and their impacts on aplomado falcons (Falco femoralis) from Chihuahua and Veracruz, Mexico.

Eggs from aplomado falcons (Falco femoralis septentrionalis) nesting in Chihuahua and Veracruz, Mexico, were analyzed for organochlorine pesticides, PCBs, and PBDEs. p,p'-DDE was the only organochlorine found in all eggs at concentrations ranging from 0.13 to 7.85 µg/g wet weight. PCBs ranged from 0.04 to 2.80 µg/g wet weight and PBDEs from 62 to 798 ng/g lipid weight. DDE concentrations in eggs were not significantly different among regions; however, PCBs were significantly greater (P = 0.015) in Tinaja Verde, Chihuahua than in the other three regions. Also, PBDEs were significantly higher (P < 0.0001) in eggs from Veracruz than in those from Chihuahua. DDE concentrations in eggs were much lower than those associated with eggshell thinning. PBDEs and PCBs were lower than those reported in raptors from industrialized countries. Overall, contaminant concentrations observed suggest no likely impact on hatching success. The PBDE concentrations are among the first to be reported in raptor species in Mexico.

Potential effects of environmental contaminants on P450 aromatase activity and DNA damage in swallows from the Rio Grande and Somerville, Texas.

Cliff swallows (Petrochelidon pyrrhonota) and cave swallows (P. fulva) were sampled during the breeding season at several locations in the Rio Grande, Texas, to evaluate the potential effects of environmental contaminants on P450 aromatase activity in brain and gonads and DNA damage in blood cells. The tritiated water-release aromatase assay was used to measure aromatase activity and flow cytometry was used to measure DNA damage in nucleated blood cells. There were no significant differences in brain and gonadal aromatase activities or in estimates of DNA damage (HPCV values) among cave swallow colonies from the Lower Rio Grande Valley (LRGV) and Somerville. However, both brain and gonadal aromatase activities were significantly higher (P < 0.05) in male cliff swallows from Laredo than in those from Somerville. Also, DNA damage estimates were significantly higher (P < 0.05) in cliff swallows (males and females combined) from Laredo than in those from Somerville. Contaminants of current high use in the LRGV, such as atrazine, and some of the highly persistent organochlorines, such as toxaphene and DDE, could be potentially associated with modulation of aromatase activity in avian tissues. Previous studies have indicated possible DNA damage in cliff swallows. We did not observe any differences in aromatase activity or DNA damage in cave swallows that could be associated with contaminant exposure. Also, the differences in aromatase activity and DNA damage between male cliff swallows from Laredo and Somerville could not be explained by contaminants measured at each site in previous studies. Our study provides baseline information on brain and gonadal aromatase activity in swallows that could be useful in future studies.

Persistent environmental pollutants in eggs of aplomado falcons from Northern Chihuahua, Mexico, and south Texas, USA.

The northern aplomado falcon (Falco femoralis septentrionalis) disappeared from south Texas in the 1940s. Due to great success in the release of captive-reared aplomado falcons in south Texas, there are currently more than 40 established nesting pairs in the region. Addled eggs from aplomado falcons nesting in northern Chihuahua and south Texas were analyzed to determine organochlorine (OC) and inorganic element contaminant burdens and their potential association with egg failures and effects on reproduction. Among the OCs, DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] was present at the highest concentrations (range 262-21487 ng/g wet weight) followed by polychlorinated biphenyls (PCBs, range 88-3274 ng/g ww). DDE was greater (P=0.03) in eggs from El Sueco (Chihuahua, Mexico) than in those from Matagorda Island (Texas, USA). DDE concentrations in eggs of aplomado falcons from El Sueco were elevated; however, reproductive success in the two Chihuahuan populations did not seem to be affected by DDE. DDE and metals in potential avian prey of the aplomado falcon from Matagorda Island were very low and below levels in the diet at which some negative effects might be expected. Except for mercury (Hg), metal concentrations in eggs were fairly low and were not different among locations in Chihuahua and south Texas. Hg was somewhat elevated and was greater (P<0.001) in Texas than in the Chihuahua locations. Periodic monitoring of Hg concentrations in addled eggs of aplomado falcons in south Texas is recommended to continue evaluating potential negative effects on their recovery.

Effect of the number of basis images on the detection of longitudinal tooth fractures using local computed tomography.

OBJECTIVES: To determine the effect of the number of basis images on the accuracy of local CT (LCT) in detecting longitudinal fractures and test the accuracy of terminal point assessment. METHODS: Longitudinal fractures were induced in 30 of 60 posterior teeth. LCT volumes were generated from 180, 60, 36 and 20 basis images. Ten observers determined the presence of a fracture and its terminal point. Receiver operating characteristic (ROC) analysis was used to quantify detection accuracy, and kappa statistics were used to quantify the concordance between actual and observed terminal point locations. RESULTS: A(z)-values were 0.91, 0.84, 0.74, 0.57 and 0.70 for LCT180, LCT60, LCT36, LCT20 and conventional radiography, respectively (ANOVA: P<0.0001). LCT180 and LCT60 outperformed the other modalities. The respective kappa values for terminal point assessment were 0.52, 0.40, 0.37, 0.16 and 0.32 (ANOVA: P=0.00). LCT180 and LCT60 provided better agreement. CONCLUSIONS: LCT maintained its efficacy for detecting longitudinal fractures with 60 instead of 180 basis images. Agreement between actual and observed terminal point locations was moderate for LCT60 and LCT180.

Inhibición de colinesterasa plasmática en el zorzal pardo (Turdus grayi), expuesto a diazinón en cultivos de papaya maradol en Yucatán, México / Plasma cholinesterase inhibition in the clay-colored robin (Turdus grayi) exposed to diazinon in maradol papaya crops in Yucatan, Mexico

El uso de plaguicidas organofosforados en la agricultura tiene como consecuencia que las aves que forrajean en los cultivos se puedan intoxicar con estas sustancias. Los efectos que se han observado en las aves debido a intoxicación por plaguicidas son variados, desde efectos en el comportamiento y la reproducción hasta la muerte. Uno de los insecticidas ampliamente utilizado en el cultivo de papaya maradol es el diazinón, el cual ha ocasionado diversos casos de intoxicación y muerte en aves silvestres. El objetivo del presente estudio fue el de evaluar el impacto de la aplicación de diazinón en cultivos de papaya en la actividad de la colinesterasa plasmática del zorzal pardo (Turdus grayi). Se capturaron individuos de zorzal pardo forrajeando en un cultivo de papaya al día siguiente de haber sido fumigado con diazinón a una dosis de 1,5 kg/ha en el mes de marzo y mayo respectivamente. A estas aves se les tomó una muestra de sangre de la vena braquial y se determinó la actividad enzimática en el suero. Las muestras de suero de las aves utilizadas como control se tomaron en el mismo horario y se analizaron de la misma manera. La actividad enzimática de los machos fue mayor que la de las hembras (53,52%) y la inhibición promedio de la colinesterasa fue de 49,43%. La inhibición de colinesterasa fue mayor en el mes mayo que en marzo debido probablemente a la exposición e ingestión más continua del insecticida a través del alimento y posible absorción a través de la piel. Este grado de inhibición enzimática es posible que afecte el comportamiento del zorzal pardo y en casos severos podría ocasionarle la muerte

The use of organophosphorous pesticides in agriculture can result in intoxication of birds foraging in sprayed crops. Effects on birds resulting from pesticide intoxication are varied and include behavioral and reproductive effects, including death. One widely used insecticide in Maradol papaya crops is diazinon which has been associated with various incidents of intoxication and death of wild birds. The objective of this study was to evaluate the impact of diazinon application to papaya crops on plasma cholinesterase activity of the clay-colored robin (Turdus grayi). We captured clay-colored robins foraging in a papaya crop the following day after the field had been sprayed with diazinon at a dose of 1.5 kg/ha during March and May, respectively. We took a blood sample from the brachialis vein of the birds captured and measured plasma enzymatic activity. The plasma samples from birds used as controls were taken during the same time period and were analyzed in a similar way. Enzymatic activity of males was greater than that of females (53,52%) and mean cholinesterase inhibition was 49.43%. Cholinesterase inhibition was greater during May than in March probably due to more continuous exposure and ingestion of the insecticide through food and possible absorption through the skin. This degree of enzymatic inhibition is possibly affecting the behavior of the clay-colored robin and could result in death in severe cases

Regional variation and relationships between the contaminants dde and selenium and stable isotopes in swallows nesting along the Rio Grande and one reference site, Texas, USA.

Cave swallows (Petrochelidon fulva) and cliff swallows (P. pyrrhonota) nest in numerous colonies throughout the Texas portion of the Rio Grande along the U.S. border with Mexico. We collected swallows during 1999 and 2000 from eight locations along the Rio Grande to determine if delta15N and delta13C values could be used to predict 1,1-di-(p-chlorophenyl-)2,2-dichloroethene (DDE) and selenium (Se) contaminant burdens in insectivorous birds nesting across a geographic gradient in the Texas-Mexico border and to discern if stable isotopes could help discriminate between local versus nonlocal acquisition of contaminants. We analysed delta15N and delta13C in liver and muscle and DDE and Se in swallow carcasses. Within individuals, delta15N was higher in liver than in muscle of both species by an average of 1.34%, whereas delta13C was 0.145% higher in muscle than in liver. Significant differences occurred among locations in delta15N and delta13C values in liver and muscle of both species. Cave swallows from three locations in the Lower Rio Grande Valley were more enriched in delta15N than swallows from other sites. In general, swallows nesting in more northern latitudes along the Rio Grande had lower delta15N and delta13C values than those nesting farther south. Concentrations of DDE were significantly greater in swallows from El Paso, Llano Grande, and Pharr than in those from Brownsville, Falcon Lake, Laredo, Del Rio, and a reference site outside the Rio Grande. All swallows (n = 21) from El Paso, Llano Grande, and Pharr had DDE concentrations > or = 3 microg g(-1) wet weight (ww), a value three times greater than the estimated threshold in avian prey that could cause potential reproductive failures in raptors. Concentrations of Se also were significantly greater in El Paso and Del Rio than at other locations. Most Se concentrations were not of concern for direct effects on birds or their predators. Principal component analysis indicated some positive correlations between delta15N and delta13C values in tissues and contaminant concentrations in carcass; however, analysis of covariance suggested a stronger effect of location on concentrations of DDE and Se. At the local level (Llano Grande and Pharr) there was a significant positive correlation between delta15N in liver and DDE concentrations in swallow carcasses; however, Se concentrations were not significantly correlated with isotopes even at the local level. Our results provide a good database of delta15N and delta13C values for insectivorous birds nesting along the Rio Grande. Similar ecologies for cave and cliff swallows and their abundance and wide distribution along the Rio Grande make them ideal indicators of environmental pollution of this portion of the Texas-Mexico border.

Residues of toxaphene in insectivorous birds (Petrochelidon spp.) from the Rio Grande, Texas.

Although it has been documented that wildlife in the Rio Grande Valley (RGV) contain increased concentrations of organochlorine (OC) contaminants, particularly DDE, little has been published on residues of toxaphene throughout this major North American watershed. In this study, 28 liver composites from adult swallows (Petrochelidon spp.) collected along the Rio Grande from 1999 through 2000 were analyzed for toxaphene residues using congener-specific gas chromatography-electron-capture negative ionization-mass spectrometry. Estimated total toxaphene concentrations ranged from 12 to 260 ng/g wet wt and were highest in samples from the lower RGV near Llano Grande Lake in Hidalgo and Cameron counties (Texas). Toxaphene congener profiles were relatively invariant throughout the watershed and were dominated by 2,2,5-endo,6-exo,8,8,9,10-octachlorobornane (P-42a or B8-806) with lesser amounts of several other Cl(7)-Cl(9) compounds, many of which remain unidentified. Petrochelidon spp. liver profiles appear to be intermediate in complexity between those in invertebrates and fish (more complex) and mammals (less complex) and differs somewhat from those reported for other avian species. In addition to other legacy OC contaminants, toxaphene residues were most concentrated in the lower RGV and accumulated at up to hundreds of parts per billion in these insect-eating birds, underscoring their utility as avian bioindicators of persistent organic pollutants.