Mobile point-of-care MRI demonstration of a normal volunteer in a telemedicine-equipped ambulance.

OBJECTIVE: Several centers have implemented ambulances equipped with CT scanners and telemedicine capabilities, known as mobile stroke units (MSU), to expedite acute stroke care delivery in the pre-hospital setting. While MSUs have been shown to improve outcomes compared with standard emergency medical management, there are limitations to incorporating CT, including radiation exposure to emergency medical services personnel. Recently, a portable, low-field strength MRI (Swoop®, Hyperfine, Inc., Guilford, CT) received FDA clearance for in-hospital use. Here, as proof-of-concept, we explore the possibility of performing MRI in a telemedicine-equipped ambulance during active transport. MATERIALS AND METHODS: In this initial technical demonstration, we imaged an MR phantom and a normal human volunteer using a standard stroke protocol during active ambulance transport. RESULTS: Images of the MR phantom and volunteer were successfully obtained and were immediately available for viewing in the hospital PACS system. The images were deemed of diagnostic quality by the radiologist. Active motion correction maintained superior image quality despite vehicle and scanner motion. In-plane, low contrast resolution of greater than 4 × 4 mm was achieved. Average transmit speeds were calculated to be 3.54 Megabits/second and upload data rates varied while in transit ranging from 8.54 to 4.13 Megabits/second. CONCLUSION: While MRI is not yet ready for clinical use in the MSU setting, our initial experience suggests potential technological feasible of this approach following future technical and MRI sequence development. Additional studies, incorporating patients, would be required to determine clinical feasibility.

Supervised walking improves cardiorespiratory fitness, exercise tolerance, and fatigue in women with primary Sjögren's syndrome: a randomized-controlled trial.

OBJECTIVE: The aim of this study was to evaluate the safety and effectiveness of a supervised walking program in women with primary Sjögren's syndrome (pSS). METHODS: Forty-five sedentary women fulfilling the American European Consensus Criteria for pSS were randomized to a training group (TG, n = 23) or control group (CG, n = 22). Patients in the TG were submitted to supervise walking three times a week for 16 weeks. The patients of the CG were instructed to not perform any kind of regular physical exercise. Physical fitness [maximum oxygen uptake (VO2max) and distance], EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI), hematological tests, and Medical Outcomes Study 36 (SF-36) were assessed at baseline and week 16. In addition, EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI), Functional Assessment of Chronic Illness Therapy Fatigue Subscale (FACIT-fatigue), and Beck Depression Inventory (BDI) were measured prior to intervention, after 8 and 16 weeks. Patient global assessment of response to therapy was completed at the final assessment. An intent-to-treat analysis was performed. RESULTS: After 16 weeks, the mean change of VO2max (ml/kg/min), distance, and FACIT-fatigue were higher in the TG than in the CG (p = 0.016, p = 0.043 and p = 0.030, respectively). Improved cardiorespiratory fitness was associated with improvements in fatigue scores and physical components of quality of life (SF-36). Furthermore, improved fatigue scores were associated with reduced depression and improvements in the physical and mental components of SF-36. Overall, 95.4% of patients in the TG rated themselves as clinically improved versus 62% of the patients in the CG (p = 0.049). There was no flare in disease activity and no serious adverse events with exercise. CONCLUSIONS: This supervised walking program was demonstrated to be feasible and safe with improvements in cardiorespiratory fitness, exercise tolerance, fatigue, and patient perception of improvement in pSS patients. TRIAL REGISTRATION: Clinical Trials.gov ID, number NCT02370225.

Plasmonic and SERS performances of compound nanohole arrays fabricated by shadow sphere lithography.

Several plasmonic compound nanohole arrays (CNAs), such as triangular nanoholes and fan-like nanoholes with multiple nanotips and nanogaps, are designed by a simple and efficient shadow sphere lithography technique by tuning the sphere mask size, the deposition and azimuthal angles, substrate temperature T S , and the number of deposition steps N. Compared with conventional circular nanohole arrays, the CNAs show more hot spots and exhibit new transmission speaks. Systematic finite-difference time-domain calculations indicate that different resonance modes excited by the various shaped and sized nanoholes are responsible for the enhanced plasmonic performances of CNAs. Compared to the CNA samples with only one circular hole in the unit cell, the Raman scattering intensity of the CNA with multiple triangular nanoholes, nanogaps, and nanotips can be enhanced up to 5-fold. These CNAs, due to the strong resonance due to the multiple structural features, are promising applications as optical filters, plasmonic sensors, and surface-enhanced spectroscopies.

Comparative Proteomic Analysis of Liver Steatosis and Fibrosis after Oral Hepatotoxicant Administration in Sprague-Dawley Rats.

The past decade has seen an increase in the development and clinical use of biomarkers associated with histological features of liver disease. Here, we conduct a comparative histological and global proteomics analysis to identify coregulated modules of proteins in the progression of hepatic steatosis or fibrosis. We orally administered the reference chemicals bromobenzene (BB) or 4,4'-methylenedianiline (4,4'-MDA) to male Sprague-Dawley rats for either 1 single administration or 5 consecutive daily doses. Livers were preserved for histopathology and global proteomics assessment. Analysis of liver sections confirmed a dose- and time-dependent increase in frequency and severity of histopathological features indicative of lipid accumulation after BB or fibrosis after 4,4'-MDA. BB administration resulted in a dose-dependent increase in the frequency and severity of inflammation and vacuolation. 4,4'-MDA administration resulted in a dose-dependent increase in the frequency and severity of periportal collagen accumulation and inflammation. Pathway analysis identified a time-dependent enrichment of biological processes associated with steatogenic or fibrogenic initiating events, cellular functions, and toxicological states. Differentially expressed protein modules were consistent with the observed histology, placing physiologically linked protein networks into context of the disease process. This study demonstrates the potential for protein modules to provide mechanistic links between initiating events and histopathological outcomes.

Tuning the plasmonic properties of silver nanopatterns fabricated by shadow nanosphere lithography.

Regular silver (Ag) nanopatterns, from disconnected nanotriangles to well coupled triangular clusters of nanoparticles, were prepared by shadow nanosphere lithography at different incident angles θ from 0° to 20° with continuous azimuthal rotation. The resulting nanopatterns were consistent with predictions by numerical calculations and Monte Carlo simulations of adatoms with high diffusivity. The visible localized surface plasmon resonance of these nanopatterns was tuned by θ systematically due to the change in size, shape, and arrangement of Ag nanopatterns. These resonances were consistent with finite-difference time-domain simulations using realistic nanopatterns based upon scanning electron micrographs. Such a simple fabrication strategy can be used to optimize surface enhanced Raman scattering substrate fabrication, as well as other plasmonics based applications.

Effect of lunar phase on frequency of psychogenic nonepileptic events in the EMU.

INTRODUCTION: Studies of the effect of a full moon on seizures have yielded mixed results, despite a continuing prevailing belief regarding the association of lunar phase with human behavior. The potential effect of a full moon on psychogenic nonepileptic events has not been as well studied, despite what anecdotal accounts from most epilepsy monitoring unit (EMU) staff would suggest. METHODS: We obtained the dates and times of all events from patients diagnosed with psychogenic nonepileptic events discharged from our EMU over a two-year period. The events were then plotted on a 29.5-day lunar calendar. Events were also broken down into lunar quarters for statistical analysis. RESULTS: We found a statistically significant increase in psychogenic nonepileptic events during the new moon quarter in our EMU during our studied timeframe. CONCLUSION: Our results are not concordant with the results of a similarly designed past study, raising the possibility that psychogenic nonepileptic events are not influenced by lunar phase.

Detection of dichlorvos adducts in a hepatocyte cell line.

The toxicity of dichlorvos (DDVP), an organophosphate (OP) pesticide, classically results from modification of the serine in the active sites of cholinesterases. However, DDVP also forms adducts on unrelated targets such as transferrin and albumin, suggesting that DDVP could cause perturbations in cellular processes by modifying noncholinesterase targets. Here we identify novel DDVP-modified targets in lysed human hepatocyte-like cells (HepaRG) using a direct liquid chromatography-mass spectrometry (LC-MS) assay of cell lysates incubated with DDVP or using a competitive pull-down experiments with a biotin-linked organophosphorus compound (10-fluoroethoxyphosphinyl-N-biotinamidopentyldecanamide; FP-biotin), which competes with DDVP for similar binding sites. We show that DDVP forms adducts to several proteins important for the cellular metabolic pathways and differentiation, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and actin. We validated the results using purified proteins and enzymatic assays. The study not only identified novel DDVP-modified targets but also suggested that the modification directly inhibits the enzymes. The current approach provides information for future hypothesis-based studies to understand the underlying mechanism of toxicity of DDVP in non-neuronal tissues. The MS data have been deposited to the ProteomeXchange with identifier PXD001107.

Patterns of gene expression associated with recovery and injury in heat-stressed rats.

BACKGROUND: The in vivo gene response associated with hyperthermia is poorly understood. Here, we perform a global, multiorgan characterization of the gene response to heat stress using an in vivo conscious rat model. RESULTS: We heated rats until implanted thermal probes indicated a maximal core temperature of 41.8°C (Tc,Max). We then compared transcriptomic profiles of liver, lung, kidney, and heart tissues harvested from groups of experimental animals at Tc,Max, 24 hours, and 48 hours after heat stress to time-matched controls kept at an ambient temperature. Cardiac histopathology at 48 hours supported persistent cardiac injury in three out of six animals. Microarray analysis identified 78 differentially expressed genes common to all four organs at Tc,Max. Self-organizing maps identified gene-specific signatures corresponding to protein-folding disorders in heat-stressed rats with histopathological evidence of cardiac injury at 48 hours. Quantitative proteomics analysis by iTRAQ (isobaric tag for relative and absolute quantitation) demonstrated that differential protein expression most closely matched the transcriptomic profile in heat-injured animals at 48 hours. Calculation of protein supersaturation scores supported an increased propensity of proteins to aggregate for proteins that were found to be changing in abundance at 24 hours and in animals with cardiac injury at 48 hours, suggesting a mechanistic association between protein misfolding and the heat-stress response. CONCLUSIONS: Pathway analyses at both the transcript and protein levels supported catastrophic deficits in energetics and cellular metabolism and activation of the unfolded protein response in heat-stressed rats with histopathological evidence of persistent heat injury, providing the basis for a systems-level physiological model of heat illness and recovery.

Discovery and Optimization of Tambjamines as a Novel Class of Antileishmanial Agents.

Leishmaniasis is a neglected tropical disease that is estimated to afflict over 12 million people. Current drugs for leishmaniasis suffer from serious deficiencies, including toxicity, high cost, modest efficacy, primarily parenteral delivery, and emergence of widespread resistance. We have discovered and developed a natural product-inspired tambjamine chemotype, known to be effective against Plasmodium spp, as a novel class of antileishmanial agents. Herein, we report in vitro and in vivo antileishmanial activities, detailed structure-activity relationships, and metabolic/pharmacokinetic profiles of a large library of tambjamines. A number of tambjamines exhibited excellent potency against both Leishmania mexicana and Leishmania donovani parasites with good safety and metabolic profiles. Notably, tambjamine 110 offered excellent potency and provided partial protection to leishmania-infected mice at 40 and/or 60 mg/kg/10 days of oral treatment. This study presents the first account of antileishmanial activity in the tambjamine family and paves the way for the generation of new oral antileishmanial drugs.

Plasma Blood Levels of Tafenoquine following a Single Oral Dosage in BALBc Mice with Acute Babesia microti Infection That Resulted in Rapid Clearance of Microscopically Detectable Parasitemia.

Previous studies of mice infected with Babesia microti have shown that a single dose of tafenoquine administered orally is extremely effective at decreasing microscopically detectable parasitemia. However, a critical limitation of studies to date is the lack of data concerning the plasma levels of tafenoquine that are needed to treat babesiosis. In the current study, we begin to address this gap by examining the plasma levels of tafenoquine associated with the rapid reduction of B. microti patent parasitemia in a mouse model of babesiosis. In the current study, we infected BALB/c mice with 1 × 107B. microti-infected red blood cells. Two days post-infection, mice were treated with 20 mg/kg of tafenoquine succinate or vehicle control administered orally by gavage. Parasitemia and plasma levels of tafenoquine were evaluated every 24 h post-treatment for 96 h. This allowed us to correlate blood plasma levels of tafenoquine with reductions in parasitemia in treated mice. Consistent with previous studies, a single oral dose of 20 mg/kg tafenoquine resulted in a rapid reduction in parasitemia. Plasma levels of tafenoquine 24 h post-administration ranged from 347 to 503 ng/mL and declined thereafter. This blood plasma tafenoquine level is similar to that achieved in humans using the current FDA-approved dose for the prevention of malaria.

Phylotranscriptomics Shed Light on Intrageneric Relationships and Historical Biogeography of Ceratozamia (Cycadales).

Ceratozamia Brongn. is one of the species-rich genera of Cycadales comprising 38 species that are mainly distributed in Mexico, with a few species reported from neighboring regions. Phylogenetic relationships within the genus need detailed investigation based on extensive datasets and reliable systematic approaches. Therefore, we used 30 of the known 38 species to reconstruct the phylogeny based on transcriptome data of 3954 single-copy nuclear genes (SCGs) via coalescent and concatenated approaches and three comparative datasets (nt/nt12/aa). Based on all these methods, Ceratozamia is divided into six phylogenetic subclades within three major clades. There were a few discrepancies regarding phylogenetic position of some species within these subclades. Using these phylogenetic trees, biogeographic history and morphological diversity of the genus are explored. Ceratozamia originated from ancestors in southern Mexico since the mid-Miocene. There is a distinct distribution pattern of species through the Trans-Mexican Volcanic Belt (TMVB), that act as a barrier for the species dispersal at TMVB and its southern and northern part. Limited dispersal events occurred during the late Miocene, and maximum diversification happened during the Pliocene epoch. Our study provides a new insight into phylogenetic relationships, the origin and dispersal routes, and morphological diversity of the genus Ceratozamia. We also explain how past climatic changes affected the diversification of this Mesoamerica-native genus.

IL-10/ß-Endorphin-Mediated Neuroimmune Modulation on Microglia during Antinociception.

Microglia are glial cells centrally related to pathophysiology and neuroimmunological regulation of pain through microglia-neuron crosstalk mechanisms. In contrast, anti-inflammatory mechanisms guided by immunological effectors such as IL-10 trigger the secretion of analgesic substances, culminating in the differential expression of genes encoding endogenous opioid peptides, especially ß-endorphin. Thus, when ß-endorphin binds to the µ-opioid receptor, it generates neuronal hyperpolarization, inhibiting nociceptive stimuli. This review aimed to summarize the recent advances in understanding the mechanism by which IL-10/ß-endorphin can reduce pain. For this, databases were searched for articles from their inception up until November 2022. Two independent reviewers extracted the data and assessed the methodological quality of the included studies, and seventeen studies were considered eligible for this review. Several studies have demonstrated the impact of IL-10/ß-endorphin in reducing pain, where IL-10 can stimulate GLP-1R, GRP40, and α7nAChR receptors, as well as intracellular signaling pathways, such as STAT3, resulting in increased ß-endorphin expression and secretion. In addition, molecules such as gabapentinoids, thalidomide, cynandione A, morroniside, lemairamin, and cinobufagin, as well as non-pharmacological treatments such as electroacupuncture, reduce pain through IL-10 mediated mechanisms, reflecting a microglia-dependent ß-endorphin differential increase. This process represents a cornerstone in pain neuroimmunology knowledge, and the results obtained by different studies about the theme are presented in this review.

Biological responses in rats exposed to cigarette smoke and Middle East sand (dust).

Respiratory symptoms are frequently reported in personnel deployed to the Middle East. This project characterized the respiratory toxicity of inhaled Iraqi sand (IS). Adult rats underwent a 6-wk inhalation to air or mainstream cigarette smoke (MSCS) (3 h/d, 5 d/wk) that included exposure to IS or crystalline silica (1 mg/m(3), 19 h/d, 7 d/wk) or air during the last 2 weeks. Assessments included motor activity, whole-body plethysmography, cytological and biochemical analysis of bronchoalveolar lavage fluid, lung metal burden, nasal and lung pathology, and changes in lung protein and gene expression. A number of metals including nickel, manganese, vanadium, and chromium were detected in IS. Elevated lung parenchyma aluminum, silica, barium, manganese, and vanadium concentrations were seen in IS-exposed rats, suggesting that several metals present in IS are bioavailable. Rats exposed to IS only developed mild inflammation in the anterior nose and lung. Silica inhalation was associated with some pulmonary responses that were not seen in IS-exposed rats, such as mild laryngeal and tracheal inflammation, mild tracheal epithelial hyperplasia, and elevated lung silica concentrations. MSCS inhalation with or without co-exposure to either IS or silica resulted in changes consistent with pulmonary inflammation and stress response. Rats exposed to MSCS and silica had more widespread airway lesions when compared with rats exposed to MSCS only. Silica-exposed rats had more robust pulmonary gene expression and proteomic responses than that seen in IS-exposed rat. Our studies show that the respiratory toxicity of IS is qualitatively similar to or less than that seen following short-term silica exposure.

Lead and copper in pigeons (Columbia livia) exposed to a small arms-range soil.

Small arms-range (SAR) soils can be contaminated with metals from spent copper (Cu)-jacketed bullets. Avian species are particularly at risk because they are exposed to lead (Pb) through ingestion of grit, soil intake from preening, or ingestion of contaminated food near ranges. Examination of the effects of Pb on birds at ranges have mainly focused on intake and toxicity of Pb shot pellets or fragments; however, Pb in soils may be an important pathway of exposure. To evaluate the uptake and effects of Pb from an actual range, the soil fraction (<250 µm) from a contaminated SAR soil was used to dose pigeons (Columbia livia) for 14 days at low (2700 µg Pb and 215 µg Cu/d) and high (5400 µg Pb and 430 µg Cu/d) doses. At the end of the study, blood Pb and erythrocyte protoporphyrin were determined, and tissues were analyzed for Pb and Cu. Results showed that Pb was absorbed in a dose-response manner in blood, tissues, and feathers, and erythrocyte protoporphyrin, a biomarker of early Pb effect, was increased at blood Pb levels >50 µg/dL. Four tissues showed differential retention of Pb, with kidney having the highest concentration followed by liver, brain, and heart, whereas Cu levels were not changed. To examine possible interactions with other metals, amendments of either Cu or tungstate were made to the soil sample. Although these amendments seemed to decrease the absorption of Pb, the results were ambiguous compared with sodium chloride controls. Overall, this study showed that intake of SAR soils contaminated with Pb and Cu causes an increase in Pb body burdens in birds and that the response can be modulated by amending soils with salts of metals.

Analysis of secreted proteins as an in vitro model for discovery of liver toxicity markers.

Despite the wealth of sequence data and new technologies that can scan large portions of the transcriptome or proteome in a single experiment, attempts to identify human biomarkers of toxicity have been met with limited success. We have adapted an in vitro model system to identify proteins secreted by a human hepatoma-derived cell line (HepG2/C3A) in response to toxicant exposure. Using quantitative proteomics, we can find alterations in the abundance of proteins at the source of damage-liver cells-that are likely to be present in blood samples of exposed animals. In a proof of concept experiment, conditioned medium from cells exposed to ethanol was subjected to quantitative mass spectral analysis after abundant proteins were immunodepleted. Eighty-seven proteins were identified with almost half changing in abundance. Some of these were only identified in the highest treatment condition and presumably result from the release of intracellular proteins into the medium when the cell membrane is disrupted upon cell death. However, the majority of the identified proteins reflect known consequences of ethanol exposure or alcoholism. The analysis of proteins found in conditioned medium after exposure to toxicants appears to be a useful system for the expedited discovery of potential human biomarkers.

Gene expression in mouse muscle over time after nickel pellet implantation.

The transition metal nickel is used in a wide variety of alloys and medical devices. Nickel can cause a range of toxicities from allergy in humans to tumors when implanted in animals. Several microarray studies have examined nickel toxicity, but so far none have comprehensively profiled expression over an extended period. In this work, male mice were implanted with a single nickel pellet in the muscle of the right leg with the left leg used as a control. At 3 week intervals up to 12 months, nickel concentrations in bioflulids and microarrays of surrounding tissue were used to track gene expression patterns. Pellet biocorrosion resulted in varying levels of systemic nickel over time, with peaks of 600 µg L-1 in serum, while global gene expression was cyclical in nature with immune related genes topping the list of overexpressed genes. IPA and KEGG pathway analyses was used to attribute overall biological function to changes in gene expression levels, supported by GO enrichment analysis. IPA pathways identified sirtuin, mitochondria, and oxidative phosphorylation as top pathways, based predominantly on downregulated genes, whereas immune processes were associated with upregulated genes. Top KEGG pathways identified were lysosome, osteoclast differentiation, and phasgosome. Both pathway approaches identified common immune responses, as well as hypoxia, toll like receptor, and matrix metalloproteinases. Overall, pathway analysis identified a negative impact on energy metabolism, and a positive impact on immune function, in particular the acute phase response. Inside the cell the impacts were on mitochondria and lysosome. New pathways and genes responsive to nickel were identified from the large dataset in this study which represents the first long-term analysis of the effects of chronic nickel exposure on global gene expression.

Distinct patterns of gene and protein expression elicited by organophosphorus pesticides in Caenorhabditis elegans.

BACKGROUND: The wide use of organophosphorus (OP) pesticides makes them an important public health concern. Persistent effects of exposure and the mechanism of neuronal degeneration are continuing issues in OP toxicology. To elucidate early steps in the mechanisms of OP toxicity, we studied alterations in global gene and protein expression in Caenorhabditis elegans exposed to OPs using microarrays and mass spectrometry. We tested two structurally distinct OPs (dichlorvos and fenamiphos) and employed a mechanistically different third neurotoxicant, mefloquine, as an out-group for analysis. Treatment levels used concentrations of chemical sufficient to prevent the development of 10%, 50% or 90% of mid-vulval L4 larvae into early gravid adults (EGA) at 24 h after exposure in a defined, bacteria-free medium. RESULTS: After 8 h of exposure, the expression of 87 genes responded specifically to OP treatment. The abundance of 34 proteins also changed in OP-exposed worms. Many of the genes and proteins affected by the OPs are expressed in neuronal and muscle tissues and are involved in lipid metabolism, cell adhesion, apoptosis/cell death, and detoxification. Twenty-two genes were differentially affected by the two OPs; a large proportion of these genes encode cytochrome P450s, UDP-glucuronosyl/UDP-glucosyltransferases, or P-glycoproteins. The abundance of transcripts and the proteins they encode were well correlated. CONCLUSION: Exposure to OPs elicits a pattern of changes in gene expression in exposed worms distinct from that of the unrelated neurotoxicant, mefloquine. The functional roles and the tissue location of the genes and proteins whose expression is modulated in response to exposure is consistent with the known effects of OPs, including damage to muscle due to persistent hypercontraction, neuronal cell death, and phase I and phase II detoxification. Further, the two different OPs evoked distinguishable changes in gene expression; about half the differences are in genes involved in detoxification, likely reflecting differences in the chemical structure of the two OPs. Changes in the expression of a number of sequences of unknown function were also discovered, and these molecules could provide insight into novel mechanisms of OP toxicity or adaptation in future studies.

Managing fatigue in patients with primary Sjögren's syndrome: challenges and solutions.

Primary Sjögren's syndrome (pSS) patients identify fatigue as their most important symptom and the one most difficult to cope with, but there are still many challenges and few solutions to manage this debilitating symptom. Promising pharmacological treatments, such as rituximab, have failed in more stringent tests including randomized controlled trials (RCTs) and meta-analysis. While non-pharmacological interventions may be safer, less costly, and address other common comorbidities, to date only aerobic exercise seems to be effective at reducing fatigue in pSS. All interventions, pharmacological or not, need to be tested in high-quality RCTs. The aim of this review is to provide an overview of fatigue management in pSS and discuss potential opportunities for future research.

Proteomic analysis of bronchoalveolar lavage fluid: effect of acute exposure to diesel exhaust particles in rats.

BACKGROUND: Inhalation of diesel exhaust particles (DEPs) is characterized by lung injury and inflammation, with significant increases in the numbers of polymorphonuclear leukocytes and alveolar macrophages. This influx of cellular infiltrates is associated with the activation of multiple genes, including cytokines and chemokines, and the production of reactive oxygen species. OBJECTIVE: The pathogenesis of the lung injury is not fully understood, but alterations in the presence or abundance of a number of proteins in the lung have been observed. Our objective in this study was to further characterize these changes and to ask whether additional changes could be discerned using modern proteomic techniques. METHODS: The present study investigates global alterations in the proteome of bronchoalveolar lavage fluid taken from rats 1, 7, or 30 days after exposure to 5, 35, or 50 mg/kg of animal weight of DEPs. RESULTS: Analysis by surface-enhanced laser desorption/ionization-time of flight mass spectrometry identified two distinct peaks that appeared as an acute response postexposure at all doses in all animals. We identified these two peaks, with mass to charge ratios (m/z) of 9,100 and 10,100, as anaphylatoxin C3a and calgranulin A by additional mass spectral investigation using liquid chromatography coupled to mass spectrometry. CONCLUSIONS: With this approach, we found a number of inflammatory response proteins that may be associated with the early phases of inflammation in response to DEP exposure. Further studies are warranted to determine whether serum levels of these proteins could be markers of diesel exhaust exposure in workers.

A novel amphibian tier 2 testing protocol: a 30-week exposure of Xenopus tropicalis to the antiandrogen flutamide.

In 1996, the U.S. Congress mandated the development of a screening program for endocrine-disrupting chemicals (EDCs) using validated test systems. Subsequently, the Endocrine Disruptor Screening and Testing Advisory Committee recommended the development of a standardized amphibian assay for tier 2 testing of EDCs. For that reason, a tier 2 testing protocol using Xenopus (Silurana) tropicalis and a 30-week, flow-through exposure to the antiandrogen flutamide from stage 46 tadpoles through sexually mature adult frogs were developed and evaluated in this pilot study. The endpoints for this study included measurements of frog body lengths and weights, liver weights, ovary/egg mass weights, testicular and ovarian histopathology, plasma vitellogenin levels, and notes on any abnormalities observed at necropsy. Increasing exposure concentrations to flutamide caused significant increases in frogs with no recognizable gonadal tissue and increased body and liver weights in male frogs, whereas the body lengths and weights decreased significantly in female frogs. Important issues must be resolved before a tier 2 amphibian assay can be further developed and validated, including the establishment of baseline values in the controls for the parameters under study; the maintenance, measurement, and timing of exposure concentrations; and the development of additional biomolecular markers of effect. This study demonstrated the feasibility of conducting long-term EDC exposure studies using X. tropicalis.