Aquatic Vegetation, an Understudied Depot for PFAS

Per- and polyfluoroalkyl substances (PFAS) are a class of manufactured chemicals that have been extensively utilized worldwide. We hypothesize that the presence, uptake, and accumulation of PFAS in aquatic vegetation (AV) is dependent upon several factors, such as the physiochemical properties of PFAS and proximity to potential sources. In this study, AV was collected from eight locations in Florida to investigate the PFAS presence, accumulation, and spatiotemporal distribution. PFAS were detected in AV at all sampling locations, with a range from 0.18 to 55 ng/g sum (∑)PFAS. Individual PFAS and their concentrations varied by sampling location, time, and AV species. A total of 12 PFAS were identified, with the greatest concentrations measured in macroalgae. The average bioconcentration factor (BCF) among all samples was 1225, indicating high PFAS accumulation in AV from surface water. The highest concentrations, across all AV types, were recorded in the Indian River Lagoon (IRL), a location with a history of elevated PFAS burdens. The present study represents the first investigation of PFAS in naturally existing estuarine AV, filling an important gap on PFAS partitioning within the environment, as well as providing insights into exposure pathways for aquatic herbivores. Examining the presence, fate, and transport of these persistent chemicals in Florida's waterways is critical for understanding their effect on environmental, wildlife, and human health.

PFAS surveillance in abiotic matrices within vital aquatic habitats throughout Florida

Per- and polyfluoroalkyl substances (PFAS) are a group of manufactured chemicals that are resistant to degradation and thus persistent in the environment. The presence, uptake, and accumulation of PFAS is dependent upon the physiochemical properties of the PFAS and matrix, as well as the environmental conditions since the time of release. The objective of this study was to measure the extent of PFAS contamination in surface water and sediment from nine vulnerable aquatic systems throughout Florida. PFAS were detected at all sampling locations with sediment exhibiting greater PFAS concentrations when compared to surface water. At most locations, elevated concentrations of PFAS were identified around areas of increased human activity, such as airports, military bases, and wastewater effluents. The results from the present study highlight the ubiquitous presence of PFAS in vital Florida waterways and filled an important gap in understanding the distribution of PFAS in dynamic, yet vulnerable, aquatic environments.

A general pattern of trade-offs between ecosystem resistance and resilience to tropical cyclones

Tropical cyclones drive coastal ecosystem dynamics, and their frequency, intensity, and spatial distribution are predicted to shift with climate change. Patterns of resistance and resilience were synthesized for 4138 ecosystem time series from n = 26 storms occurring between 1985 and 2018 in the Northern Hemisphere to predict how coastal ecosystems will respond to future disturbance regimes. Data were grouped by ecosystems (fresh water, salt water, terrestrial, and wetland) and response categories (biogeochemistry, hydrography, mobile biota, sedentary fauna, and vascular plants). We observed a repeated pattern of trade-offs between resistance and resilience across analyses. These patterns are likely the outcomes of evolutionary adaptation, they conform to disturbance theories, and they indicate that consistent rules may govern ecosystem susceptibility to tropical cyclones.

A Research Framework to Integrate Cross-Ecosystem Responses to Tropical Cyclones

Tropical cyclones play an increasingly important role in shaping ecosystems. Understanding and generalizing their responses is challenging because of meteorological variability among storms and its interaction with ecosystems. We present a research framework designed to compare tropical cyclone effects within and across ecosystems that: a) uses a disaggregating approach that measures the responses of individual ecosystem components, b) links the response of ecosystem components at fine temporal scales to meteorology and antecedent conditions, and c) examines responses of ecosystem using a resistance–resilience perspective by quantifying the magnitude of change and recovery time. We demonstrate the utility of the framework using three examples of ecosystem response: gross primary productivity, stream biogeochemical export, and organismal abundances. Finally, we present the case for a network of sentinel sites with consistent monitoring to measure and compare ecosystem responses to cyclones across the United States, which could help improve coastal ecosystem resilience.

Targeted biological therapies reach the heart: the case of serelaxin for heart failure

Acute heart failure (AHF) is one of the most important causes of mortality, morbidity and rising healthcare costs. Despite this, there has been minimal advancement in the management of AHF and the treatment continues to focus on symptomatic improvement using vasodilators, diuretics and inotropes, none of which have shown any mortality benefits. Though originally thought of as a reproductive hormone, relaxin is now recognized as a potent vasodilator that modulates systemic and renal vascular tone, resulting in pre- and after-load reduction and a decrease in cardiac workload. A single intravenous infusion of relaxin over 48 hours has been shown to provide significant dyspnea relief among AHF patients, with an ongoing study to evaluate its potential for mortality benefit. This article provides an insight into the pharmacology of this novel therapy for AHF with an eye towards future clinical applications.

Prostate cancer update

Prostate cancer continues to be the most commonly diagnosed malignancy in men of the western world. Its diagnosis, evaluation, and treatment therapies are constantly evolving. This paper summarizes and clarifies the most up-to-date information on prostate cancer prevention and treatment.

Therapeutic alteration of insulin-dependent diabetes mellitus progression by T cell tolerance to glutamic acid decarboxylase 65 peptides in vitro and in vivo

We have reported previously that nonobese diabetic (NOD) fetal pancreas organ cultures lose the ability to produce insulin when maintained in contact with NOD fetal thymus organ cultures (FTOC). Initial studies indicated that exposure to glutamic acid decarboxylase (GAD65) peptides in utero resulted in delay or transient protection from insulin-dependent diabetes mellitus (IDDM) in NOD mice. We also found that exposure of young adult NOD mice to the same peptides could result in acceleration of the disease. To more closely examine the effects of early and late exposure to diabetogenic Ags on T cells, we applied peptides derived from GAD65 (GAD AA 246-266, 509-528, and 524-543), to our "in vitro IDDM" (ivIDDM) model. T cells derived from NOD FTOC primed during the latter stages of organ culture, when mature T cell phenotypes are present, had the ability to proliferate to GAD peptides. ivIDDM was exacerbated under these conditions, suggesting that GAD responsiveness correlates with the ivIDDM phenotype, and parallels the acceleration of IDDM we had seen in young adult NOD mice. When GAD peptides were present during the initiation of FTOC, GAD proliferative responses were inhibited, and ivIDDM was reduced. This result suggests that tolerance to GAD peptides may reduce the production of diabetogenic T cells or their capacity to respond, as suggested by the in utero therapies studied in NOD mice.

Prospective study of correlations between biopsy-detected high grade prostatic intraepithelial neoplasia, serum prostate specific antigen concentration, and race

BACKGROUND

High grade prostatic intraepithelial neoplasia (HGPIN), a premalignant lesion of the prostate gland, is more common in black men than in white men. The influence of HGPIN on the serum prostate specific antigen (PSA) concentration is controversial, and correlations between HGPIN and PSA in black men and white men have not been investigated.

METHODS

Between January 1992 and December 1998, 411 black men and 639 white men with suspected prostate carcinoma underwent an initial benign prostate biopsy at a single medical center. The presence or absence of HGPIN in the biopsy specimens was determined by one uropathologist.

RESULTS

HGPIN was identified in 8.9% of the specimens. When stratified by PSA concentration (< 4.0 ng/mL, 4.0-9.9 ng/mL, and > or = 10.0 ng/mL), HGPIN was associated with an increased PSA concentration only among men with PSA concentrations < 4.0 ng/mL (P = 0.01). The prevalence of HGPIN in the black and white patients was 13.4% and 5.9%, respectively (P < 0.0001), and was significantly greater in black men than in white men with PSA concentrations < 4.0 ng/mL (P = 0.002). Among the patients with PSA concentrations < 4.0 ng/mL, black race was an independent predictor of an increased PSA concentration when adjusted for patient age, prostate volume, and the presence or absence of HGPIN (P = 0.03).

CONCLUSIONS

HGPIN is more common in black men than in white men and may produce an increase in the PSA concentration. However, racial differences in the prevalence of HGPIN may not contribute to racial differences in PSA concentrations among men with no clinical or histologic evidence of carcinoma.

Prostate cancer detection in Black and White men with abnormal digital rectal examination and prostate specific antigen less then 4 ng./ml

PURPOSE

Prostate cancer is more common in black than in white American men. Experience in a longitudinal prostate cancer screening program implies that cancer detection is greater in black than in white men with an abnormal digital rectal examination and prostate specific antigen (PSA) less than 4 ng./ml. We investigated potential racial differences in cancer detection in men treated in clinical practice who had an abnormal digital rectal examination and PSA less than 4 ng./ml.

MATERIALS AND METHODS

Between January 1992 and December 1999 prostate biopsy was done at a Veterans Affairs Medical Center in 179 black and 357 white men with an abnormal digital rectal examination, PSA less than 4 ng./ml. and no history of prostate surgery. Significant racial differences in demographic and clinical parameters were limited to PSA, which was higher in black men (p = 0.01).

RESULTS

Cancer was detected in 38 black (21%) and 65 white (18%) men (p = 0.42). There were no significant racial differences in the PSA adjusted cancer detection rate or in the Gleason score of detected disease. In men with PSA less than 1.0, 1.0 to 1.9, 2.0 to 2.9 and 3.0 to 3.9 ng./ml. the detection rate was 4%, 15%, 27% and 29%, respectively.

CONCLUSIONS

In clinical practice prostate cancer detection appears to be equivalent in black and white men when an abnormal digital rectal examination is the only indication of malignancy.

Residual public repertoires to self

The consensus view about the constitution of the T cell receptor repertoire has shifted greatly even during this decade. Although the discovery of autoimmunity in the fifties had clearly shown that a repertoire must exist directed against self antigens, the extent of this repertoire was not fully appreciated. In our work we have tried to elucidate the nature of the antigenic specificities against which this self-directed repertoire is directed. The non-tolerized (residual) self-directed repertoire is a direct consequence of the hierarchy of antigenic determinant display, and is the most important influence in the organism's choice of which T cells to delete. Certain determinants remain "silent" and are neither displayed in the thymus nor in the periphery: these are a heterogeneous group which are invisible to T cells for a variety of reasons. One reason relates to the processing and presentation of determinants, and a second derives from the nature of the T cell receptor (TcR) and the avidity of the T cell for its target specificity.

An automated semiquantitative B and T cell clonality assay

BACKGROUND

Rearrangements of the antigen receptor genes in B and T cells generate products of unique length and sequence. Polymerase chain reaction (PCR) assays are routinely used to identify clonal lymphocyte populations by detecting clonal V-J rearrangements or chromosomal translocations within these antigen receptor loci. Multiple primer sets are, however, required to detect the majority of clonal B- and T-cell malignancies. Products from the individual reactions must be analyzed separately to avoid misinterpretation. Moreover, small clonal populations remain difficult to identify. To address these difficulties, we propose that an integrated fluorescence-based approach to clonal B- and T-cell detection would simultaneously identify both B- and T-cell neoplasia; increase amplicon resolution, analytic sensitivity, and assay throughput; produce more comprehensive and semiquantitative data useful for evaluation of hematologic malignancies; and eliminate labor intensive agarose and polyacrylamide gel electrophoresis.

METHODS AND RESULTS

Samples were genomic DNA and cDNA. Differentially labeled primers were used to amplify regions diagnostic for B- and T-cell clonality in a single plate with a single thermocycler program. Combined amplicon products underwent capillary electrophoresis for high resolution fractionation and differential fluorescence detection and quantification. Data were automatically analyzed and archived. In a comparative analysis of a variety of clinical samples, this automated and integrated B- and T-cell assay showed >94% agreement (33 of 35 results) with individual B- and T-cell PCR assays. Furthermore, this assay had an overall monoclonality detection rate of 100%, and as little as 100 ng of sample DNA yielded complete B- and T-cell clonality test results. The limit of detection was approximately 10-2 cells, and amplicons were sized to within 0.1 basepair. Serial dilutions of clonal B- and T-cell lines comprising a coded proficiency panel were identified and correctly ranked. Specificity was 100% as determined by analysis of 18 control samples that were all negative for B- and T-cell clonality.

CONCLUSIONS

Our data show that this automated and integrated B- and T-cell clonality assay system is a sensitive and specific tool useful for rapid identification of clonal lymphocyte populations and will likely have broad clinical applications.

NOD fetal thymus organ culture: an in vitro model for the development of T cells involved in IDDM

This paper introduces a model which incorporates fetal thymus organ culture (FTOC) from NOD mice to replicate thymic development of diabetogenic T cells. NOD fetal pancreas organ culture (FPOC) co-cultured with 13-16 day NOD FTOC for an additional 14-21 days produced less insulin than FPOC cultured alone. Insulin production from the FTOC of non-diabetic strains C57BL/6 and BALB/c was not inhibited by co-culture with FTOC from their syngeneic counterparts. Sections of the NOD co-cultures showed peri-islet infiltration with lymphocytes. Insulin reduction by FTOC/FP co-culture was prevented by co-culture of the NOD FT with FT from immunologically incompetent C.B-17 SCID/SCID mice. Co-culture of NOD FP with NOD FT prior to the development of T cells prevented generation of diabetogenic FTOC. Thus, early exposure of NOD T cell precursors to the thymic stromal elements of C.B-17 SCID/SCID FT or to islet antigens can negatively select for diabetogenic T cells or activate immuno-regulatory cells that can suppress diabetogenic T cell activity. The addition of blocking F(ab')2 fragments of anti-CD3epsilon monoclonal antibody to NOD FTOC/FP co-cultures prevented insulin reduction, implicating a role for TcR-mediated recognition in this "in vitro IDDM" model. The addition of activating whole anti-CD3epsilon caused the complete ablation of insulin production in FTOC/FP co-cultures from all strains tested. Transfer of unprimed syngeneic FTOC cells to prediabetic NOD mice prevented the onset of IDDM while transfer of islet-cell primed FTOC/FP cells slightly increased disease incidence. These data suggest that while diabetogenic T cells are present in the FT, they are normally suppressed, even after organ culture. However, these cells can induce the destruction of islet cells, in vitro and in vivo, if they are appropriately activated with pancreatic tissue.

Randomized placebo-controlled study of the effects of simvastatin on haemostatic variables, lipoproteins and free fatty acids. The Oxford Cholesterol Study Group

The Oxford Cholesterol Study is a randomized placebo-controlled trial designed primarily to assess the effects of simvastatin on blood cholesterol levels and side-effects in preparation for a large, long-term trial of the effects of cholesterol-lowering drug therapy on mortality. At present there is only limited evidence from randomized comparisons of the effects of HMG-CoA reductase inhibitors, such as simvastatin, on thrombogenic, as distinct from atherogenic, pathways in coronary heart disease. The present sub-study was carried out to assess the effects of simvastatin on a range of haemostatic variables, as well as on free fatty acids and on lipoprotein fractions not studied in detail previously. At an average of about 2 years after starting study treatment, non-fasting blood samples were obtained from a sequential sample of 162 participants who had been randomly allocated to receive 40 mg (54 patients) or 20 mg (57 patients) daily simvastatin or matching placebo treatment (51 patients). Only patients who reported taking their study treatment and who were not known to be diabetic or to be taking some other lipid lowering treatment were to be included. The principal comparisons were to be of those allocated simvastatin (i.e. 20 and 40 mg doses combined) vs those allocated placebo. Among patients allocated simvastatin, marginally significant lower factor VII antigen levels (12.10% +/- 6.08 of standard; 2P < 0.05) and non-significantly lower factor VII coagulant activity (8.24% +/- 4.99 of standard) and fibrinogen concentrations (0.10 +/- 0.08 g. l-1) were observed. In contrast, plasminogen activator inhibitor activity was significantly higher (2.62 +/- 1.03 IU; 2P < 0.01) among patients allocated simvastatin. No significant differences were seen in the other haemostatic factors studied (e.g. prothrombin fragment 1.2, factor XII and C1 inhibitor). Total free fatty acid concentration was marginally significantly reduced (2P = 0.02) with simvastatin, but none of the reductions in individual free fatty acids was significant. Lipoprotein fractions were only measured among patients allocated 40 mg daily simvastatin or placebo. Compared with placebo, simvastatin produced significant decreases not only in LDL cholesterol (1.74 +/- 0.15 mmol.1(-1): 2P < 0.0001) but also in VLDL cholesterol (0.28 +/- 0.08 mmol.1(-1); 2P < 0.001) and IDL cholesterol (0.17 +/- 0.03 mmol.1(-1); 2P < 0.0001). There were also lower triglyceride levels associated with LDL (0.07 +/- 0.01 mmol.1(-1); 2P < 0.0001), IDL (0.03 +/- 0.01 mmol.1(-1); 2P < 0.01) and VLDL (0.27 +/- 0.14; 2P = 0.05). The effects of simvastatin on haemostatic variables appear to be far less marked than its lipid effects. Given the associations of haemostatic factors with coronary heart disease incidence, larger randomized comparisons of the HMG-CoA reductase inhibitors (and of the newer fibrates which may produce greater effects) are needed to provide more reliable estimates of the extent to which they influence these variables.

Educational imagery and the allied health educator

Educational imagery is a classroom teaching methodology that allows students to mentally isolate themselves and to use their natural abilities to daydream or fantasize in ways that accomplish educational objectives. Educational imagery is used to facilitate decision making, clarify values, memorize, incorporate behavioral outcomes of teaching, and reinforce cognitive concepts. The technique can help allied health students prepare for the clinical setting. The behavioral components, ethical concerns, and decision making that will occur in the clinical setting can be rehearsed in the classroom before the actual experience by guiding students' imagination. This article describes the nature of imagery and its sources, describes how to implement the strategy in the classroom, and gives examples of educational imagery strategies for the allied health disciplines.