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1.
Front Cardiovasc Med ; 10: 1018203, 2023.
Article in English | MEDLINE | ID: mdl-36926047

ABSTRACT

Background: Acute decompensated heart failure (HF) and cardiogenic shock (CS) frequently are refractory to conservative treatment and require mechanical circulatory support (MCS). We report our early clinical experience and evaluate patient outcomes with the newer generation surgical Impella 5.5. Methods: Seventy patients that underwent Impella 5.5 implantation between October 2019 and December 2021 at a single center were enrolled in this study. Pre-operative characteristics, peri-operative clinical course information, and post-operative outcomes were retrospectively collected. Results: Fifty-seven (81%) patients survived to discharge, and 51 (76%) patients survived at the time of the first 30 days post-discharge visit. Thirty-one patients (44%) received Impella support for a bridge to advanced surgical heart failure therapy (transplant or durable left ventricular assist device [LVAD]), 27 (39%) cases were used for a bridge to recovery/decision and 12 (17.1%) cases was used for planned perioperative support for high-risk cardiac surgery procedure. Conclusion: Our results suggest that Impella 5.5 provides favorable survival in the management of HF and CS, particularly used for a bridge to heart transplant or LVAD. Early extubation and mobilization with high flow circulatory support allowed effective tailoring of MCS approaches from peri-operative support for high-risk cardiac surgery, bridge to recovery, and to advanced surgical heart failure therapy.

2.
J Nucl Cardiol ; 30(3): 1283-1285, 2023 06.
Article in English | MEDLINE | ID: mdl-35277832
3.
Ophthalmol Sci ; 2(2): 100130, 2022 Jun.
Article in English | MEDLINE | ID: mdl-36249687

ABSTRACT

Purpose: To examine the association of baseline choroidal sublayers metrics with the risk of diabetic retinopathy (DR) progression over 2 years, with adjustment for confounding factors that affect choroidal measurements. Design: Prospective, observational cohort study. Participants: One hundred three eyes from 62 patients with diabetes mellitus (DM). Methods: Patients were followed up at 6-month intervals for at least 2 years. Choroidal metrics including choroidal area, choroidal thickness (CT), and choroidal vascularity index were measured for both (1) the choriocapillaris plus Sattler's layer and (2) the Haller's layer within the subfoveal and parafoveal region. Cox proportional models were constructed to estimate the relationship between baseline choroidal metrics and DR progression, adjusted for intereye correlation, established risk factors (i.e., duration of DM, glycated hemoglobin [HbA1c] level, body mass index [BMI], use of insulin, and mean arterial blood pressure [MABP]) and confounding factors of choroidal measurements (i.e., age and axial length). Additional predictive value of choroidal metrics was assessed using the C-statistic. Main Outcome Measures: Hazard ratios (HRs) calculated by Cox proportional hazards model to demonstrate the associations between baseline choroidal metrics and DR progression. Results: After adjusting for age, axial length, and intereye correlation, choroidal metrics in Haller's layer at baseline that were associated with a higher risk of DR progression included increases in subfoveal choroidal area (HR, 2.033; 95% confidence interval [CI], 1.179-3.505; P = 0.011), subfoveal plus parafoveal choroidal area (HR, 1.909; 95% CI, 1.096-3.326; P = 0.022), subfoveal CT (HR, 2.032; 95% CI, 1.181-3.498; P = 0.010), and subfoveal plus parafoveal CT (HR, 1.908; 95% CI, 1.097-3.319; P = 0.022). These associations remained statistically significant after additionally adjusting for duration of DM, HbA1c level, BMI, use of insulin, and MABP. Addition of these choroidal metrics significantly improved the discrimination for DR progression when compared with established risk factors alone (e.g., duration of DM and HbA1c; increase in C-statistic ranged from 8.08% to 9.67% [P < 0.05]). Conclusions: Eyes with a larger choroidal area and CT in Haller's layer at baseline were associated with a higher risk of DR progression over 2 years.

4.
Environ Toxicol Chem ; 39(12): 2462-2474, 2020 12.
Article in English | MEDLINE | ID: mdl-33025637

ABSTRACT

Mercury is found in Arctic marine mammals that are important in the diet of northern Indigenous peoples. The objectives of the present long-term study, spanning a 45-yr period, were to 1) investigate the temporal trends of total mercury (THg; muscle and liver) and selenium (Se; liver) in ringed seals (Pusa hispida) from different regions of the Canadian Arctic; and 2) examine possible relationships with age, diet, and climate parameters such as air temperature, precipitation, climatic indices, and ice-coverage. Ringed seals were collected by hunters in northern communities in the Beaufort Sea, Central Arctic, Eastern Baffin Island, Hudson Bay, and Ungava/Nunatsiavut regions (Canada) between 1972 and 2017. Mercury levels did not change through time in seal liver, but THg levels in muscle decreased in seals from Hudson Bay (-0.91%/yr) and Ungava/Nunatsiavut (-1.30%/yr). Carbon stable isotope values in seal muscle decreased significantly through time in 4 regions. Selenium-to-THg ratios were found to be >1 for all years and regions. Variation partitioning analyses across regions indicated that THg trends in seals were mostly explained by age (7.3-21.7%), climate parameters (3.5-12.5%), and diet (up to 9%); climate indices (i.e., Arctic and North Atlantic Oscillations, Pacific/North American pattern) explained the majority of the climate portion. The THg levels had a positive relationship with Arctic Oscillation for multiple regions. Associations of THg with air temperature, total precipitation, and sea-ice coverage, as well as with North Atlantic Oscillation and Pacific/North American pattern were found to vary with tissue type and geographical area. Environ Toxicol Chem 2020;39:2462-2474. © 2020 Her Majesty the Queen in Right of Canada. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Fisheries and Oceans Canada.


Subject(s)
Climate , Environmental Monitoring , Mercury/analysis , Seals, Earless/metabolism , Air , Animals , Arctic Regions , Canada , Female , Geography , Ice Cover , Liver/metabolism , Male , Muscles/metabolism , Rain , Selenium/metabolism , Temperature , Time Factors
5.
PLoS One ; 15(7): e0235926, 2020.
Article in English | MEDLINE | ID: mdl-32645116

ABSTRACT

PURPOSE: To evaluate the changes in the retinochoroidal vasculature in patients with exogenous obesity using swept-source optical coherence tomography (SS-OCT) and OCT angiography (OCTA). METHODS: In this prospective study, 60 patients diagnosed with obesity (47 males) (mean age: 46.47±10.9 years) were included, of which 30 patients underwent bariatric surgery (Group A), and 30 patients underwent conservative management (exercise/diet) (Group B). Parameters including choroidal thickness (CT), choroidal vascularity index (CVI) and retinal capillary density index (CDI) and arteriovenous ratio (AVR) were measured at the baseline and three months follow up. 30 eyes (30 age and gender-matched) of normal participants were included for comparison. RESULTS: Baseline CT was lower in 60 participants with obesity compared to controls. Compared with normal subjects, subjects with obesity had higher mean CVI (0.66±0.02 versus 0.63±0.04; p<0.01), smaller FAZ area (0.26±0.07 versus 0.45±0.32; p<0.01), higher CDI (superficial plexus: 0.7±0.04 versus 0.68±0.06; p = 0.04, deep plexus: 0.38±0.02 versus 0.35±0.06; p = 0.01), and lower AVR (0.68±0.05 versus 0.70±0.03 versus; p<0.01). At 3-month after intervention, CT showed a significant increase in participants from Group A (329.27±79µm; p<0.01) but not in Group B from baseline. No significant change was noted in CVI or CDI at 3-month in either group compared to baseline. AVR significantly increased in Group B (p = 0.03). CONCLUSION: Subclinical changes in retinochoroidal vasculature occurs in participants with exogenous obesity compared to healthy subjects. Surgical intervention (bariatric surgery) may have a favorable outcome on the choroidal thickness in these patients.


Subject(s)
Choroid/physiology , Obesity/pathology , Retina/physiology , Adult , Bariatric Surgery , Case-Control Studies , Choroid/blood supply , Exercise , Female , Humans , Male , Middle Aged , Prospective Studies , Retinal Vessels/physiology , Weight Loss
6.
Subst Abuse ; 14: 1178221820924026, 2020.
Article in English | MEDLINE | ID: mdl-32518481

ABSTRACT

Healthcare systems are implementing value-based payment (VBP) arrangements in efforts to incentivize cost-effective, high quality of care. These arrangements represent a major shift for substance use disorder (SUD) treatment providers who may need to make changes to their clinical and business operations to meet new demands for quality under value-based contracts. This qualitative study was conducted in the context of New York State's efforts to implement VBP among SUD treatment providers to understand their experiences, challenges, and needs. Five focus groups were conducted across the State with a total of 68 treatment professionals. Content analysis was conducted and five themes emerged. First, competing demands, limited workforce and technology infrastructure, and perceived lack of information were leading to overwhelmed administrators. Second, confusion and financial fear was being driven by the need for new clinical roles, business practices, and external partnerships. Third, providers were undertaking a number of measures to address workforce needs. Fourth, providers were building new business models and clinical practices. Fifth, providers desired more support and information. As VBP models are being adopted, healthcare systems should identify ways to mitigate challenges and support SUD treatment providers that may have limited resources to address complex workforce, client, and infrastructure needs.

8.
Article in English | MEDLINE | ID: mdl-31035536

ABSTRACT

Mosquitoes continue to be a major threat to global health, and the ability to reliably monitor, catch, and kill mosquitoes via passive traps is of great importance. Global, low-cost, and easy-to-use outdoor devices are needed to augment existing efforts in mosquito control that combat the spread of disease, such as Zika. Thus, we have developed a modular, portable, non-powered (passive), self-contained, and field-deployable device suitable for releasing volatiles with a wide range of applications such as attracting, repelling, and killing mosquitoes. This unique device relies on a novel nested wick and two-reservoir design that achieves a constant release of volatiles over several hundred hours. Devices loaded with one of either two compounds, geraniol or 1-methylpiperazine (MP), were tested in a controlled environment (32 °C and 70% relative humidity), and both compounds achieved a constant release from our devices at a rate of 2.4 mg/h and 47 mg/h, respectively. The liquid payload can be volatile attractants or repellants as well as mosquitocide-containing feeding solutions for capture and surveillance. This low-cost device can be utilized for both civilian and military mosquito control purposes, but it will be particularly important for protecting those in economically repressed environments, such as sub-Saharan Africa and Central and South America.


Subject(s)
Acyclic Monoterpenes , Insect Repellents , Mosquito Control/instrumentation , Mosquito Vectors , Piperazines , Zika Virus Infection/prevention & control , Animals , Culicidae/virology , Humans , Zika Virus/isolation & purification , Zika Virus Infection/transmission
10.
RSC Adv ; 9(41): 23752-23763, 2019 Jul 29.
Article in English | MEDLINE | ID: mdl-35530619

ABSTRACT

The real-time, colorimetric detection of analytes via aptamer-gold nanoparticle technology has proven to be an important, emerging technique within the medical field. Of global health importance, the ability to detect vector mosquito species, such as the Aedes (Ae.) aegypti mosquito, and transmitted arboviruses, such as Zika virus, is paramount to mosquito control and surveillance efforts. Herein, we describe the detection of Ae. aegypti salivary protein for vector identification and the detection of Zika virus to assess mosquito infection status by aptamer-gold nanoparticle conjugates. Key to optimization of these diagnostics were gold nanoparticle capping agents and aptamer degree of labelling (i.e., the amount of aptamers per gold nanoparticle). In the present study, detection was achieved for as little as 10 ng Ae. aegypti salivary protein and 1.0 × 105 PFU live Zika virus. These aptamer-gold nanoparticle conjugate diagnostics could one day prove to be useful as deployable nano-based biosensors that provide easy-to-read optical read outs through a straightforward red-to-blue colour change either within a diagnostic solution or atop a card/membrane-based biosensor.

11.
J Chromatogr A ; 1573: 156-160, 2018 Oct 26.
Article in English | MEDLINE | ID: mdl-30224281

ABSTRACT

A rapid thermal desorption-gas chromatography-electron ionization-mass spectrometry (TD-GC-EI-MS) method for airborne transfluthrin detection is studied. Active air sampling of 9 L over 1 h at 23 °C through a Tenax®-loaded tube resulted in efficient capture of airborne transfluthrin. Subsequent thermal desorption was employed to achieve an LOD of 2.6 ppqv (parts per quadrillion by volume). A minimum primary desorption temperature of 300 °C is necessary for optimal recovery of sample from the Tenax® adsorbent. The matrix effects of indoor air lead to an error of 10.9% and 10.5% recovery of sample (10 pg and 100 pg loaded tubes, respectively). The linear range was 74-74,000 ppqv with a correlation coefficient of 0.9981. Active air sampling of a novel passive release device revealed a ∼150 pg/L airborne concentration gradient over 1 m, providing spatial characterization of the device's performance. This efficient method allows for the remote collection of samples and rapid analysis of airborne transfluthrin from industrial applications, optimization studies of commercial products as well as domestic/household monitoring.


Subject(s)
Air Pollutants/analysis , Cyclopropanes/analysis , Environmental Monitoring/methods , Fluorobenzenes/analysis , Gas Chromatography-Mass Spectrometry , Environmental Monitoring/instrumentation , Polymers/chemistry
12.
Am J Phys Med Rehabil ; 97(7): 514-522, 2018 07.
Article in English | MEDLINE | ID: mdl-29465443

ABSTRACT

OBJECTIVE: This study describes characteristics and trends of inpatient rehabilitation among cancer patients within the United States over a 13-yr period. DESIGN: This was a retrospective study of data from the Uniform Data System for Medical Rehabilitation from 2002 to 2014. Patients older than 17 yrs admitted to inpatient rehabilitation facilities with a diagnosis of malignant cancer were included. Trends of rehabilitation outcomes including length of stay, Functional Independence Measure (FIM) Instrument scores, and discharge location were examined. RESULTS: Data from 115,570 cancer patients were evaluated. Mean age was 66 ± 14 yrs and 49% were women. Mean length of stay decreased over time (2002: 14 days to 2014: 13 days; P < 0.0005). Patient's admission total FIM scores decreased over time (2002: 68 ± 18 to 2014: 61 ± 16; P < 0.0005). The FIM change score increased over time (2002: 19 ± 16 to 2014: 25 ± 17; P < 0.0005). The greatest significant functional gains occurred in self care and transfers. Most patients (>70%) were discharged to the community. CONCLUSIONS: Cancer patients receiving acute inpatient rehabilitation demonstrated significant improvements in functional outcomes from admission to discharge. Cancer patients became more independent in important activities of daily living, thereby potentially reducing caregiver burden and ensuring safer discharges back to the community. This study suggests potential benefit of inpatient rehabilitation for appropriate cancer patients.


Subject(s)
Inpatients/statistics & numerical data , Neoplasms/rehabilitation , Patient Discharge/statistics & numerical data , Rehabilitation/organization & administration , Activities of Daily Living , Adult , Aged , Female , Humans , Male , Middle Aged , Outcome Assessment, Health Care , Recovery of Function , Rehabilitation Centers , Retrospective Studies , United States
13.
Am J Cardiol ; 117(6): 901-5, 2016 Mar 15.
Article in English | MEDLINE | ID: mdl-26813739

ABSTRACT

Heart failure (HF) affects millions of Americans and causes financial burdens because of the need for rehospitalization. For this reason, health care systems and patients alike are seeking methods to decrease readmissions. We assessed the potential for reducing readmissions of patients with postacute care HF through an educational program combined with enhanced external counterpulsation (EECP). We examined 99 patients with HF who were referred to EECP centers and received heart failure education and EECP treatment within 90 days of hospital discharge from March 2013 to January 2015. We compared observed and predicted 90-day readmission rates and examined results of 6-minute walk tests, Duke Activity Status Index, New York Heart Association classification, and Canadian Cardiovascular Society classification before and after EECP. Patients were treated with EECP at a median augmentation pressure of 280 mm Hg (quartile 1 = 240, quartile 3 = 280), achieved as early as the first treatment. Augmentation ratios varied from 0.4 to 1.9, with a median of 1.0 (quartile 1 = 0.8, quartile 3 = 1.2). Only 6 patients (6.1%) had unplanned readmissions compared to the predicted 34%, p <0.0001. The average increase in distance walked was 52 m (18.4%), and the median increase in Duke Activity Status Index was 9.95 points (100%), p values <0.0001. New York Heart Association and Canadian Cardiovascular Society classes improved in 61% and 60% of the patients, respectively. In conclusion, patients with HF who received education and EECP within 90 days of discharge had significantly lower readmission rates than predicted, and improved functional status, walk distance, and symptoms.


Subject(s)
Counterpulsation , Exercise Test , Heart Failure/therapy , Myocardial Ischemia/therapy , Patient Education as Topic , Patient Readmission/statistics & numerical data , Aged , Chronic Disease , Counterpulsation/methods , Exercise Tolerance , Female , Heart Failure/diagnosis , Heart Failure/epidemiology , Humans , Male , Middle Aged , Myocardial Ischemia/diagnosis , Myocardial Ischemia/epidemiology , Quality of Life , Severity of Illness Index , Texas/epidemiology , Treatment Outcome , Walking
14.
Ann Surg Oncol ; 22(9): 2869-75, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25783679

ABSTRACT

BACKGROUND: Preoperative irradiation reduces local recurrence of soft tissue sarcomas (STSs), but major wound complication rates approach 25-35 %. Using a novel neoadjuvant chemoradiation protocol, we prospectively documented functional outcomes and quality of life (QOL) and hypothesized a lower major wound complication rate. METHODS: Patients with STS deep to muscular fascia were treated with 3 days of doxorubicin (30 mg/day) and 10 days of irradiation (300 cGy/day) followed by limb-sparing surgery. Wound complications were assessed, and functional assessment and QOL were followed prospectively using the Toronto Extremity Salvage Score (TESS), Musculoskeletal Tumor Society (MSTS), and Short Form (SF)-36 questionnaires preoperatively and 6 and 12 months postoperatively. RESULTS: Altogether, 52 consecutive patients were accrued during 2006-2011. Overall, 80.8 % of STSs were >5 cm, and 67.3 % involved the lower extremity. Seven (13.5 %) major wound complications occurred, all requiring reoperation. Preoperative scores for TESS, MSTS, and SF-36 physical (PCS) and mental (MCS) health components were 83.3, 86.7, 40.6, and 49.4, respectively. There were no differences seen 6 months postoperatively. By 12 months, however, patients showed improved functional scores (TESS 93.0, p = 0.02; MSTS 93.3, p < 0.01) and QOL scores (PCS 45.1, p = 0.02; MCS = 52.9, p = 0.05). No differences in scores were seen between patients with or without wound complications. CONCLUSIONS: Patients treated with our neoadjuvant chemoradiation protocol had stable QOL and functional scores 6 months postoperatively and showed improvement by 12 months. Importantly, the major wound complication rate was low.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Chemoradiotherapy , Neoadjuvant Therapy , Quality of Life , Sarcoma/complications , Wounds and Injuries/etiology , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Limb Salvage , Male , Middle Aged , Neoplasm Grading , Neoplasm Staging , Preoperative Care , Prognosis , Prospective Studies , Young Adult
15.
Environ Toxicol Chem ; 33(11): 2463-71, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25264143

ABSTRACT

Mercury (Hg) has been detected in polar bear brain tissue, but its biological effects are not well known. Relationships between Hg concentrations and neurochemical enzyme activities and receptor binding were assessed in the cerebellum, frontal lobes, and occipital lobes of 24 polar bears collected from Nunavik (Northern Quebec), Canada. The concentration-response relationship was further studied with in vitro experiments using pooled brain homogenate of 12 randomly chosen bears. In environmentally exposed brain samples, there was no correlative relationship between Hg concentration and cholinesterase (ChE) activity or muscarinic acetylcholine receptor (mAChR) binding in any of the 3 brain regions. Monoamine oxidase (MAO) activity in the occipital lobe showed a negative correlative relationship with total Hg concentration. In vitro experiments, however, demonstrated that Hg (mercuric chloride and methylmercury chloride) can inhibit ChE and MAO activities and muscarinic mAChR binding. These results show that Hg can alter neurobiochemical parameters but the current environmental Hg exposure level does have an effect on the neurochemistry of polar bears from northern Canada.


Subject(s)
Brain/drug effects , Methylmercury Compounds/analysis , Ursidae/metabolism , Animals , Arctic Regions , Brain/metabolism , Cholinesterases/metabolism , Environmental Exposure , Environmental Pollutants/analysis , Female , Male , Mercury/analysis , Monoamine Oxidase/metabolism , Protein Binding , Quebec
17.
Environ Res ; 114: 24-30, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22406289

ABSTRACT

Methylmercury (MeHg) is a neurotoxicant that has been found at elevated concentrations in the Arctic ecosystem. Little is known about its internal dose in wildlife such as polar bears. We measured concentrations of mercury (Hg) in three different brain regions (cerebellum, frontal lobe and brain stem) of 24 polar bears collected from the Nunavik, Canada between 2000 and 2003. Speciation of Hg was measured by High Performance Liquid Chromatography coupled to Inductively Coupled Plasma Mass Spectroscopy (HPLC-ICP-MS). Concentrations of mean total Hg in brain tissue were up to 625 times lower (0.28 ± 0.07 mg kg(-1) dry weight (dw) in frontal lobe, 0.23 ± 0.07 mg kg(-1) dw in cerebellum and 0.12 ± 0.0 3mg kg(-1) dw in brain stem) than the mean total Hg concentration previously reported in polar bear liver collected from Eastern Baffin Island. Methylmercury (MeHg) accounted for 100% of the Hg found in all three brain regions analyzed. These results suggest that polar bear might reduce the toxic effects of Hg by limiting the uptake into the brain and/or decrease the rate of demethylation so that Hg can be excreted from the brain more easily. The toxicokinetics and the blood-brain-barrier mechanisms of polar bears are still unknown and further research is required.


Subject(s)
Brain , Environmental Pollutants/analysis , Mercury/analysis , Ursidae , Animals , Arctic Regions , Canada , Methylmercury Compounds/analysis , Nunavut
18.
Environ Toxicol Chem ; 27(3): 542-53, 2008 Mar.
Article in English | MEDLINE | ID: mdl-17988182

ABSTRACT

The present study examined spatial trends of perfluoroalkyl compounds (PFCs) in liver samples from 11 populations of ringed seals (Phoca hispida) in the Canadian Arctic from 2002 to 2005. Trophic position and relative carbon sources were compared by analyzing stable nitrogen and carbon isotopes in muscle samples. Geometric mean concentrations of total C9-C15 perfluorinated carboxylates (PFCAs) ranged from 8.8 to 84 ng/g wet weight, and C9-C11 PFCAs predominated. Perfluorooctane sulfonate was the dominant PFC measured, with concentrations ranging from 6.5 to 89 ng/g wet weight, contributing between 29 and 56% of the total PFC concentration. Overall, mean PFC concentrations were similar between populations, and differences were attributed largely to elevated levels in the Gjoa Haven (Rae Strait, central Canadian Arctic archipelago) and Inukjuak populations (eastern Hudson Bay) and to lower concentrations at Pangnirtung (Cumberland Sound, Baffin Island). Mean stable nitrogen isotope ratios (+/-95% confidence intervals) ranged from 14.7 per thousand (+/-0.3 per thousand) at Nain (Labrador) to 17.9 per thousand (+/-0.7 per thousand) at Gjoa Haven, suggesting that all populations were within the same trophic level. Stable carbon isotope ratios varied widely between the seal populations, ranging from -22.9 per thousand (+/-0.2 per thousand) at Gjoa Haven to -17.7 per thousand (+/-0.4 per thousand) at Nain. The delta13C ratios from Gjoa Haven were significantly more depleted than those for other populations and may suggest a terrestrially based carbon source. The depleted stable carbon isotope ratio may explain the elevated PFC concentrations in the Gjoa Haven population. Analysis of covariance indicated that delta13C was a significant covariable for seven of nine seal populations for which delta13C values were available. After adjusting for delta13C values, concentrations of most PFCs generally were statistically greater in the Grise Fiord, Qikiqtarjuaq, Arviat, and Nain populations.


Subject(s)
Environmental Pollutants/analysis , Fluorocarbons/analysis , Phoca/metabolism , Aging , Animals , Arctic Regions , Canada , Carbon Isotopes , Environmental Monitoring , Environmental Pollutants/metabolism , Female , Liver/chemistry , Male , Nitrogen Isotopes , Sex Characteristics , Time Factors
19.
Environ Sci Technol ; 41(1): 42-9, 2007 Jan 01.
Article in English | MEDLINE | ID: mdl-17265925

ABSTRACT

Temporal trends in perfluoroalkyl compounds (PFCs) were investigated in liver samples from two ringed seal (Phoca hispida) populations in the Canadian Arctic, Arviat (Western Hudson Bay) (1992, 1998, 2004, 2005) and Resolute Bay (Lancaster Sound) (1972, 1993, 2000, 2004, 2005). PFCs analyzed included C7-C15 perfluorinated carboxylates (PFCAs) and their suspected precursors, the 8:2 and 10:2 fluorotelomer saturated and unsaturated carboxylates (FTCAs, FTUCAs), C4, C6, C8, C10 sulfonates, and perfluorooctane sulfonamide (PFOSA). Liver samples were homogenized, liquid-liquid extracted with methyl tert-butyl ether, cleaned up using hexafluoropropanol, and analyzed by liquid chromatography with negative electrospray tandem mass spectrometry (LC-MS/MS). C9-C15 PFCAs showed statistically significant increasing concentrations during 1992-2005 and during 1993-2005 at Arviat and Resolute Bay, respectively. Doubling times ranged from 19.4 to 15.8 years for perfluorododecanoate (PFDoA) to 10.0-7.7 years for perfluorononanoate (PFNA) at Arviat and Resolute Bay but were shorter when excluding the 2005 samples. Conversely, perfluorooctane sulfonate (PFOS) and PFOSA concentrations showed maximum concentrations during 1998 and 2000 at Arviat and Resolute Bay, with statistically significant decreases from 2000 to 2005. In the case of Arviat, two consecutive decreases were measured from 1998 to 2003 and from 2003 to 2005. PFOS disappearance half-lives for seals at Arviat and Resolute Bay were 3.2 and 4.6 years. These results indicate that the ringed seals and their food web are rapidly responding to the phase out of perfluorooctane sulfonyl fluoride based compounds by 3M in 2001. Further, the relatively short doubling times of the PFCAs and PFOS disappearance half-lives support the hypothesis of atmospheric transport as the main transport mechanism of PFCs to the arctic environment.


Subject(s)
Environmental Monitoring/statistics & numerical data , Fluorocarbons/analysis , Fluorocarbons/toxicity , Phoca/metabolism , Age Factors , Analysis of Variance , Animals , Arctic Regions , Chromatography, Liquid , Female , Half-Life , Liver/chemistry , Male , Mass Spectrometry , Sex Factors , Time Factors
20.
J Toxicol Environ Health A ; 69(12): 1133-43, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16728376

ABSTRACT

Elevated concentrations of organochlorines and mercury (Hg) have been reported in marine mammals on a global scale. While risk assessments are generally based on quantifying body burdens of toxicants, much less is known about associated adverse health effects and their underlying mechanisms. The purpose of this study was to characterize the inhibitory effects of methylmercury (MeHg+), mercuric chloride (Hg2+), p,p'-DDT, Arochlor 1254, chlordane,dieldrin, lindane, and toxaphene on [3H]quinuclidinyl benzilate ([3H]-QNB) binding to the muscarinic cholinergic (mACh) receptor in cellular membranes isolated from the cerebrum of ringed seals (Phoca hispida). [3H]-QNB binding to the mACh receptor was saturable with a mean receptor density (B(max)) of 826.9 +/- 68.4 fmol/mg and ligand affinity (K(d)) of 0.31 +/- 0.04 nM. MeHg+ and Hg2+ were the only neurotoxicants that inhibited radioligand binding by greater than 50%. Hg2+ was significantly more potent at inhibiting mACh receptor binding than MeHg+ when the IC50 data were compared (IC50 = 1.92 +/- 0.06 microM versus 2.75 +/- 0.22 microM), but when the data were normalized to derive inhibition constants (K(i)) there was no statistical difference in inhibition (Hg2+ = 1.38 +/- 0.07 mM; MeHg+ = 1.26 +/- 0.12 microM). Toxaphene also inhibited mACh receptor binding by 22.4%, but this was only significant at the highest concentration tested (320 microM). Overall, these data suggest that Hg, and not organochlorines,inhibits ligand binding to the mACh receptor. These mechanistic findings may be used to support and develop specific biomarkers of Hg exposure and neurotoxicity in sensitive ecological species.


Subject(s)
Hydrocarbons, Chlorinated/toxicity , Mercuric Chloride/toxicity , Methylmercury Compounds/toxicity , Phoca/physiology , Receptors, Muscarinic/drug effects , Water Pollutants/toxicity , Animals , Cell Membrane , Cells, Cultured , Insecticides/toxicity , Receptors, Muscarinic/metabolism , Telencephalon/metabolism
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