Annual pulses of copper-enriched sediment in a North American river downstream of a large lake following the catastrophic failure of a mine tailings storage facility.

Failures of mine tailings storage facilities (TSF) can have profound and long-lasting effects on the downstream receiving environment. Virtually all spills to date have been into river systems without large lakes that may buffer downstream impacts. In August 2014, the failure of the Mount Polley copper (Cu)-gold mine TSF in British Columbia, Canada, released ~25 × 106 m3 of water and solids; globally, this is the second largest TSF spill in history. Over 18 × 106 m3 was delivered to Quesnel Lake, which is ~9 km from the TSF and is the third deepest lake in North America, and a crucial habitat for Pacific salmon and trout populations. We determined the sediment-associated Cu concentrations and fluxes in Quesnel River, downstream of the lake, from August 2014 to February 2021 based on the analysis of >400 samples of sediment, mainly collected using a continuous-flow centrifuge. During each winter since the spill, Cu concentrations in the fluvial sediment in the upper reaches of the river (~35 km from the TSF) were elevated relative to regional background concentrations and samples collected before the spill. Maximum Cu concentrations were ~410 mg kg-1 which exceeds Canadian sediment quality guidelines for the protection of aquatic organisms (197 mg kg-1). Monitoring of Quesnel Lake since the spill shows that these annual pulses in the winter are due to resuspension of unconsolidated tailings and sediments at the bottom of Quesnel Lake, during autumnal lake turnover, which become mixed throughout the water column and subsequently flow into Quesnel River. Results show that while large lakes may buffer downstream aquatic systems from contaminated sediment, they may prolong the environmental impact. These findings are crucial in understanding how lake processes may modify the effects of TSF spills on downstream aquatic systems.

The bacterial community of Quesnel Lake sediments impacted by a catastrophic mine tailings spill differ in composition from those at undisturbed locations - two years post-spill.

The West Basin of Quesnel Lake (British Columbia, Canada) suffered a catastrophic disturbance event in August 2014 when mine tailings and scoured natural material were deposited into the lake's West Basin due to an impoundment failure at the adjacent Mount Polley copper-gold mine. The deposit covered a significant portion of the West Basin floor with a thick layer of material. Since lake sediments host bacterial communities that play key roles in the geochemical cycling in lacustrine environments, it is important to understand which groups inhabit the newly deposited material and what this implies for the ecological function of the West Basin. Here we report a study conducted two years post-spill, comparing the bacterial communities from sediments of both disturbed and undisturbed sites. Our results show that sediments from disturbed sites differed in physical and chemical properties than those in undisturbed sites (e.g. higher pH, particle size and Cu concentration). Furthermore, bacterial communities from the disturbed sites appeared to be legacy communities from the tailings impoundment, with metabolic potential revolving mainly around the cycling of S and metals, whereas the ones from the undisturbed sites were associated with the cycling of N.

A Novel Technique to Measure the Intensity of Abnormality on GI Bleeding Scans: Development, Initial Implementation, and Correlation With Conventional Angiography.

PURPOSE: Develop a technique to quantify intensity of lower gastrointestinal bleeding (LGIB) on Tc-labeled red blood cell (RBC) scintigraphy, correlate with angiography, and determine the tool's predictive value. MATERIALS AND METHODS: An IRB-approved, single institution database query of GI bleeding scans performed between January 2013 and December 2015. Reports from all studies and imaging from all positive studies were reviewed. A technique was developed for scan analysis, allowing for calculation of percent increase of activity in the region of interest (ROI, area of bleeding) and ROI in the aorta and liver (controls). Database query determined which patients underwent angiography, and which had positive angiograms. Median ROI percent increase in patients with positive scintigraphy and positive angiography was compared to those with positive scintigraphy and negative angiography. RESULTS: Of 194 bleeding scans performed during the study period, 71 were positive for active LGIB, 37 had angiography, and 9 had active contrast extravasation. The new tool was used to analyze the 37 cases with positive nuclear scans sent for angiography. Median percent increase in ROI activity was 50% in those with positive scan and positive angiogram and 26.8% in those with positive scan but negative angiogram. Using ROI percent change quartiles, we observed a statistically significant association between percent increase in ROI activity from baseline and the probability of having a positive angiogram (Cochran-Armitage trend test, P = 0.01), such that there are no positive angiogram cases when ROI change was <20% and a majority of the positive angiogram cases (67%) in the highest quartile. CONCLUSIONS: Utilization of processing protocol to determine percent increase in activity from baseline within ROI of active LGIB on scintigraphy has predictive value in determining which patients will not benefit from conventional angiography.

SYSTEMIC SCLEROSIS RELATED CALCINOSIS: PATIENTS PROVIDE WHAT SPECIALISTS WANT TO LEARN.

BACKGROUND: Calcinosis is a disabling, rarely discussed manifestation of systemic sclerosis (SSc) for which the natural history and management is understood poorly. OBJECTIVES: To develop a calcinosis specific patient reported outcome measure (PROM) that can be used for future clinical research to test the effects of therapy on scleroderma related calcinosis. METHODS: Patients were selected for participation by their scleroderma physicians. Four focus groups and individual interviews were recorded and transcribed verbatim. Patients were asked to frame questions to help a physician learn if calcinosis was better, worse or the same. Patient transcripts underwent an iterative inductive process (no preconceived coding, content drives coding and analysis) by at least five independent analysts including at least one research team member with SSc. Concepts were triangulated to identify a comprehensive set of meaningful concepts with occurrence quantified per participant. RESULTS: Twenty-three patients (22/23 female, 19/23 white, with mean disease duration 14.8 years) consented and were interviewed. Responses included concepts of self-management strategies and recurrent hypotheses relating calcinosis development to trauma, Raynaud's and cold exposure. We identified discrete concepts such as the perceived association between cold exposure, Raynaud's and calcinosis severity. Calcinosis tended to present along with or soon after SSc diagnosis and remained throughout disease duration - though was not yet compared to report of first Raynaud experience. CONCLUSIONS: Patient observations and self-management behavior provide opportunities for experts to learn from and to preemptively educate physicians and patients. Patients are eager for self-management guidance. These concepts are the groundwork for PROM development. However, patients suggested a composite of scales anchored in pain, size, frequency, number and related impairment may reasonably serve as an interim instrument for SSc calcinosis.

Autologous stem cell transplantation followed by consolidation chemotherapy for patients with multiple myeloma.

Although high-dose therapy and autologous stem cell transplant (ASCT) is superior to conventional chemotherapy for treatment of myeloma, most patients relapse and the time to relapse depends upon the initial prognostic factors. The administration of non-cross-resistant chemotherapies during the post-transplant period may delay or prevent relapse. We prospectively studied the role of consolidation chemotherapy (CC) after single autologous peripheral blood stem cell transplant (auto-PBSCT) in 103 mostly newly diagnosed myeloma patients (67 patients were < or =6 months from the initial treatment). Patients received conditioning with BCNU, melphalan+/-gemcitabine and auto-PBSCT followed by two cycles of the DCEP+/-G regimen (dexamethasone, cyclophosphamide, etoposide, cisplatin+/-gemcitabine) at 3 and 9 months post-transplant and alternating with two cycles of DPP regimen (dexamethasone, cisplatin, paclitaxel) at 6 and 12 months post-transplant. With a median follow-up of 61.2 months, the median event-free survival (EFS) and overall survival (OS) are 26 and 54.1 months, respectively. The 5-year EFS and OS are 23.1 and 42.5%, respectively. Overall, 51 (49.5%) patients finished all CC, suggesting that a major limitation of this approach is an inability to deliver all planned treatments. In order to improve results following autotransplantation, novel agents or immunologic approaches should be studied in the post-transplant setting.

HIV-related knowledge and adherence to HAART.

Near perfect adherence is considered essential for patients on HAART, yet adherence to medical recommendations is rarely so high. Supportive services and reminder tools may help individuals to become adherent, yet it is difficult to determine who may need such interventions. In this study, based on data from the NYSDOH/AIDS Institute Treatment Adherence Demonstration Program, we look at the association between HIV-related knowledge and adherence, hypothesizing that a better understanding of HIV and its treatment is associated with better adherence. In analyses based on 997 participants, knowledge, as measured by five true/false questions, was significantly associated with self-reported adherence. In multivariate analysis, compared to persons with four or five items answered correctly, persons with fewer correct answers were more likely to report missed doses (OR = 1.72 for 2-3 correct, p < 0.01; OR = 2.92 for 0-1 correct, p < 0.05). Our data suggest that providers should include questions focused on knowledge of HIV in their assessments of medication readiness and need for adherence support. Similarly, providers should be diligent with respect to patient education, ensuring that each patient has the information needed to support reasoned decision making and adequate adherence.

Further evidence to support the melanocytic origin of MDA-MB-435.

BACKGROUND/AIMS: Until recently, the cell line MDA-MB-435 was widely accepted as originating from a breast cancer. However, microarray derived data have suggested that this cell line may in fact originate from an occult melanoma. This study was designed to investigate this hypothesis further. METHODS: Quantitative reverse transcription polymerase chain reaction and immunohistochemistry were used to investigate the tissue of origin of two sublines of MDA-MB-435 (MDA-MB-435 S and MDA-MB-435 HGF). The expression of a panel of genes typical of breast cells or melanocytes was analysed. RESULTS: The MDA-MD-435 cell lines expressed none of the genes characteristic of breast cancer cells but did express several genes commonly expressed by melanocytes. CONCLUSIONS: These results strongly suggest that MDA-MB-435 is indeed of melanoma origin.

Implementation of intensity-modulated laser diodes in time-resolved, pump-probe fluorescence microscopy.

We present the implementation of intensity-modulated laser diodes for applications in frequency-domain pump-probe fluorescence microscopy. Our technique, which is based on the stimulated-emission approach, uses two sinusoidally modulated laser diodes. One laser (635 nm) excites the chromophores under study, and the other laser (680 nm) is responsible for inducing stimulated emission from excited-state molecules. Both light sources are modulated in the 80-MHz range but with an offset of 5 kHz between them. The result of the interaction of the pump and the probe beams is that a cross-correlation fluorescence signal at 5 kHz is generated primarily at the focal volume. Microscope imaging at the cross-correlation signal results in images with high contrast, and time-resolved high-frequency information can be acquired without high-speed detection. A detailed experimental arrangement of our methodology is presented along with images acquired from a 4.0-mum-diameter fluorescent sphere and TOTO-3-labeled mouse STO cells. (TOTO-3 is a nucleic acid stain.) Our results demonstrate the feasibility of using sinusoidally modulated laser diodes for pump-probe imaging, creating the exciting possibility of high-contrast time-resolved imaging with low-cost laser-diode systems.

Time-resolved polarization imaging by pump-probe (stimulated emission) fluorescence microscopy.

We report the application of pump-probe fluorescence microscopy in time-resolved polarization imaging. We derived the equations governing the pump-probe stimulated emission process and characterized the pump and probe laser power levels for signal saturation. Our emphasis is to use this novel methodology to image polarization properties of fluorophores across entire cells. As a feasibility study, we imaged a 15-microm orange latex sphere and found that there is depolarization that is possibly due to energy transfer among fluorescent molecules inside the sphere. We also imaged a mouse fibroblast labeled with CellTracker Orange CMTMR (5-(and-6)-(((4-chloromethyl)benzoyl)amino)tetramethyl-rhodamine). We observed that Orange CMTMR complexed with gluthathione rotates fast, indicating the relatively low fluid-phase viscosity of the cytoplasmic microenvironment as seen by Orange CMTMR. The measured rotational correlation time ranged from approximately 30 to approximately 150 ps. This work demonstrates the effectiveness of stimulated emission measurements in acquiring high-resolution, time-resolved polarization information across the entire cell.

Idiopathic pure red cell aplasia and nonregenerative immune-mediated anemia in dogs: 43 cases (1988-1999).

OBJECTIVE: To examine clinical features, laboratory test results, treatment, and outcome of dogs with pure red cell aplasia (PRCA) and idiopathic nonregenerative immune-mediated anemia (NRIMA). DESIGN: Retrospective study. ANIMALS: 43 dogs with severe nonregenerative anemia. PROCEDURE: Medical records of dogs determined to have PRCA, NRIMA, or ineffective erythropoiesis on the basis of bone marrow analysis between 1988 and 1999 were reviewed. Criteria for inclusion were > or = 5-day history of severe nonregenerative anemia (Hct < 20%; < 60.0 x 10(3) reticulocytes/microliter) with no underlying diseases. Information was retrieved on signalment, clinical signs, laboratory test results, treatment, and outcome. RESULTS: Median age of the dogs was 6.5 years. Spayed females and Labrador Retrievers were significantly overrepresented. Median Hct was 11% with no evidence of regeneration (median, 1.5 x 10(3) reticulocytes/microliter). Direct Coombs' test results were positive in 57% of dogs. Biochemical abnormalities included hyperferremia and high percentage saturation of transferrin. Bone marrow findings ranged from PRCA (5%) to erythroid hyperplasia (55%). Myelofibrosis was common. Dogs were treated with immunosuppressive drugs and the response was complete, partial, and poor in 55, 18, and 27% of the dogs, respectively. Mortality rate was 28%. CONCLUSIONS AND CLINICAL RELEVANCE: An immune-mediated pathogenesis should be considered in dogs with severe, nonregenerative anemia, normal WBC and platelet counts, hyperferremia, mild clinical signs, and no evidence of underlying disease. Bone marrow findings range from the rare PRCA to erythroid hyperplasia. Myelofibrosis is often detected in affected dogs and may prevent bone marrow aspiration.

Detecting anxiety and depression in hospitalised elderly patients using a brief inventory.

This study validated a French language version of an inventory designed to detect symptoms of depression and anxiety [Goldberg et al, 1987] in a sample of elderly French-speaking inpatients at risk for one of these disorders. Latent trait analysis was used to replicate the structure of the symptoms in the inventory, and receiver operating characteristic analysis was used to assess the performance of the inventory as a screening measure for Major Depressive Episode and Generalised Anxiety Disorder according to DSM-IV criteria. Reflecting the ascertainment of individuals in the sample as being at risk for a disorder, prevalence of individual symptoms was high although the general structure of the inventory was found to be comparable to that found in samples of both community elderly and younger medical patients. ROC analyses showed that the subscales of inventory performed satisfactorily as screening measures for anxiety or depression but lacked specificity for each disorder. In addition to providing further evidence for the utility of this inventory to detect general psychiatric distress in elderly persons, this study provides a valid means of detecting symptoms of depression and anxiety in French speaking groups.

New time-resolved techniques in two-photon microscopy.

Microscopy is traditionally a tool for determining biological structures. Many recent advances in optical microscopy involves the incorporation of spectroscopy techniques to monitor biochemical states of microscopic structures in living cells and tissues. By minimizing tissue photodamage, two-photon excitation microscopy provides a new opportunity to study the dynamics of biological systems on time scales from nanoseconds to hours. This review will focus on a number of these new methods: two-photon time-lapse microscopy, two-photon photoactivation, two-photon correlated spectroscopy, two-photon single particle tracking and two-photon lifetime microscopy.

FITC-poly-D-lysine conjugates as fluorescent probes to quantify hapten-specific macrophage receptor binding and uptake kinetics.

A series of fluorescein derivatized poly-D-lysine (FITC-PDL) probes were used to elucidate the role of fluorescein in receptor binding of fluorescein-conjugated macromolecules to J774 murine macrophages. Poly-D-lysine served to eliminate receptor recognition of the carrier due to the biologically inert nature of the D-isomer. This concept enabled the focused investigation of the role played by fluorescein in receptor recognition, binding and internalization. Results revealed dependency of cellular uptake on polymer concentration, hapten density and accessibility. The results differed from those previously obtained with FITC-BSA in that saturating fluorescein densities on the poly-D-lysine polymer resulted in diminished rates of uptake by macrophages. Receptor-mediated endocytosis via clathrin-coated pits was concluded based on results that showed inhibition of FITC-PDL uptake by intracellular K+ depletion but not by the macropinocytosis inhibitor, amiloride. Further, FITC-PDL was found to inhibit the endocytic uptake of FITC-BSA suggesting competition between the two probes at the level of a macrophage receptor. Association rates (kon) for binding to the macrophage surface were measured for the various FITC-PDL probes based on fractional receptor occupancies. Results are discussed on the basis of receptor recognition of fluorescein in J774 macrophages and the requirements for this recognition which include appropriate spacing and accessibility of the hapten moieties to facilitate receptor crosslinking.

The impact of a multidisciplinary approach on caring for ventilator-dependent patients.

OBJECTIVE: To determine the clinical and financial outcomes of a highly structured multidisciplinary care model for patients in an intensive care unit (ICU) who require prolonged mechanical ventilation. The structured model outcomes (protocol group) are compared with the preprotocol outcomes. DESIGN: Descriptive study with financial analysis. SETTING: A twelve-bed medical-surgical ICU in a non-teaching tertiary referral center in Ogden, Utah. STUDY PARTICIPANTS: During a 54 month period, 469 consecutive intensive care patients requiring mechanical ventilation for longer than 72 hours who did not meet exclusion criteria were studied. INTERVENTIONS: A multidisciplinary team was formed to coordinate the care of ventilator-dependent patients. Care was integrated by daily collaborative bedside rounds, monthly meetings, and implementation of numerous guidelines and protocols. Patients were followed from the time of ICU admission until the day of hospital discharge. MAIN OUTCOME MEASURES: Patients were assigned APACHE II scores on admission to the ICU, and were divided into eight diagnostic categories. ICU length of stay, hospital length of stay, costs, charges, reimbursement, and in-hospital mortality were measured. RESULTS: Mortality in the preprotocol and protocol group, after adjustment for APACHE II scores, remained statistically unchanged (21-23%). After we implemented the new care model, we demonstrated significant decreases in the mean survivor's ICU length of stay (19.8 days to 14.7 days, P= 0.001), hospital length of stay (34.6 days to 25.9 days, P=0.001), charges (US$102500 to US$78500, P=0.001), and costs (US$71900 to US$58000, P=0.001). CONCLUSIONS: Implementation of a structured multidisciplinary care model to care for a heterogeneous population of ventilator-dependent ICU patients was associated with significant reductions in ICU and hospital lengths of stay, charges, and costs. Mortality rates were unaffected.

Sequence variation in the early genes E1E4, E6 and E7 of human papilloma virus type 6.

The majority of condylomata acuminata (anogenital warts) are caused by infection with Human Papilloma Virus type 6 (HPV-6). We have sequenced the HPV-6 early genes, E1-E4, E6 and E7 from wart biopsy DNA samples sourced from the UK and USA and derived a consensus sequence for these genes and the proteins they encode. When compared to the prototype HPV-6b sequence, published over 12 years ago, the E1-E4 consensus sequence showed 3/91 (3.3%) amino acid changes, the E6 consensus sequence showed 1/150 (0.7%) changes and the E7 consensus sequence showed 1/98 (1.0%) changes. Since many of the early gene sequences from biopsy material were more similar to the HPV-6a subtype than HPV-6b, this data supports the use of HPV-6a as the HPV-6 prototype.

Two-photon fluorescence lifetime imaging microscopy of macrophage-mediated antigen processing.

Two-photon fluorescence lifetime imaging microscopy was used noninvasively to monitor a fluorescent antigen during macrophage-mediated endocytosis, intracellular vacuolar encapsulation, and protease-dependent processing. Fluorescein-conjugated bovine serum albumin (FITC-BSA) served as the soluble exogenous antigen. As a relatively nonfluorescent probe in the native state, the antigen was designed to reflect sequential intracellular antigen processing events through time-dependent changes in fluorescence properties. Using two-photon lifetime imaging microscopy, antigen processing events were monitored continuously for several hours. During this time, the initial fluorescein fluorescence lifetime of 0.5 ns increased to approximately 3.0 ns. Control experiments using fluorescein conjugated poly-L-lysine and poly-D-lysine demonstrated that the increase in fluorescence parameters observed with FITC-BSA were due to intracellular proteolysis since addition of the inert D-isomer did not promote an increase in fluorescence lifetime or intensity. Comparisons of intravacuolar and extracellular FITC-dextran concentration suggested active localization of dextran in the vacuoles by the macrophage. In addition, the kinetics of degradation observed using two-photon microscopy were similar to results obtained on the flow cytometer, thus validating the use of flow cytometry for future studies.

Osteoarthritis as a determinant of an adverse coronary heart disease risk profile.

BACKGROUND: Osteoarthritis is associated with obesity, sedentary behavior and poor fitness. This study was conducted to test the hypothesis that risk factors for coronary heart disease (CHD) are more prevalent among patients with osteoarthritis than among non-arthritic adults of the same age and sex. METHODS: Forty-six patients with osteoarthritis of the hip and/or knee were evaluated; 23 non-arthritic subjects served as control group. A panel of metabolic risk factors were measured including body mass index (BMI), waist-hip ratio (WHR), blood pressure, fasting blood glucose, and serum lipids and apoproteins. RESULTS: Measures of arthritis severity confirmed marked disability and deformity in the arthritis group. Patients reported the performance of less aerobic exercise than controls. Compared with controls, patients were noted to have greater mean BMI (31.2 +/0- 5.9 versus 24.6 +/- 3.2 kg/m2, P < 0.000005), WHR (0.88 +/- 0.07 versus 0.83 +/- 0.08, P < 0.05), systolic blood pressure (140.8 +/- 17.9 versus 131.3 +/- 15.3 mmHg, P < 0.05) and fasting blood glucose (105.0 +/- 24.6 versus 93.2 +/- 7.0 mg/dl, P < 0.01), and lower mean high-density-lipoprotein cholesterol (47.9 +/- 10.9 versus 56.7 +/- 17.1 mg/dl, P < 0.05). Nonsignificant trends for higher mean diastolic blood pressure and serum triglycerides were also noted in the arthritic group. Mean estimated risk for development of CHD within 10 years of evaluation was greater in the arthritic than in the control group (21.6 +/- 14.4% versus 15.2 +/- 11.7%, P < 0.05). CONCLUSION: Patients with moderately severe to end-stage lower extremity osteoarthritis may be at advanced risk for the development of CHD by virtue of their unfavorable risk factor profile.