Glycosaminoglycan-mediated lipoprotein uptake protects cancer cells from ferroptosis.

Lipids are essential for tumours because of their structural, energetic, and signaling roles. While many cancer cells upregulate lipid synthesis, growing evidence suggests that tumours simultaneously intensify the uptake of circulating lipids carried by lipoproteins. Which mechanisms promote the uptake of extracellular lipids, and how this pool of lipids contributes to cancer progression, are poorly understood. Here, using functional genetic screens, we find that lipoprotein uptake confers resistance to lipid peroxidation and ferroptotic cell death. Lipoprotein supplementation robustly inhibits ferroptosis across numerous cancer types. Mechanistically, cancer cells take up lipoproteins through a pathway dependent on sulfated glycosaminoglycans (GAGs) linked to cell-surface proteoglycans. Tumour GAGs are a major determinant of the uptake of both low and high density lipoproteins. Impairment of glycosaminoglycan synthesis or acute degradation of surface GAGs decreases the uptake of lipoproteins, sensitizes cells to ferroptosis and reduces tumour growth in mice. We also find that human clear cell renal cell carcinomas, a distinctively lipid-rich tumour type, display elevated levels of lipoprotein-derived antioxidants and the GAG chondroitin sulfate than non-malignant human kidney. Altogether, our work identifies lipoprotein uptake as an essential anti-ferroptotic mechanism for cancer cells to overcome lipid oxidative stress in vivo, and reveals GAG biosynthesis as an unexpected mediator of this process.

Cerebrospinal Fluid Testing in Leptomeningeal Progression of HER2-Negative Breast Cancer Reveals HER2 Positivity, Leading to HER2-Targeted Therapy: A Case Report.

The treatment of breast cancer is largely determined by protein expression assays of estrogen receptor, progesterone receptor, and Her2/neu (HER2) status. These prognostic markers may vary due to tumor heterogeneityor the evolution of prognostic markers throughout the course of treatment. This report presents a case of a patient who initially presented with HER2-negative breast cancer and had rapidly progressed on numerous lines of treatment. An analysis of cerebrospinal fluid via next-generation sequencing and biopsy of metastasis to the liver identified HER2-positive cancer, which allowed for the use of trastuzumab deruxtecan, a HER2-targeted therapy. This led to an excellent clinical response with improvement in performance status and quality of life. This case report demonstrates the importance of continuing to follow a patient's cancer pathology to open the doors for other opportunities for treatment. Cancer has the potential to evolve and there is a benefit of obtaining rebiopsies to ensure the correct targeted therapies are provided to the patient.

Ascorbate depletion increases quiescence and self-renewal potential in hematopoietic stem cells and multipotent progenitors.

Ascorbate (vitamin C) limits hematopoietic stem cell (HSC) function and suppresses leukemia development by promoting the function of the Tet2 tumor suppressor. In humans, ascorbate is obtained from the diet while in mice it is synthesized in the liver. In this study, we show that deletion of the Slc23a2 ascorbate transporter severely depleted ascorbate from hematopoietic cells. Slc23a2 deficiency increased HSC reconstituting potential and self-renewal potential upon transplantation into irradiated mice. Slc23a2 deficiency also increased the reconstituting and self-renewal potential of multipotent hematopoietic progenitors (MPPs), conferring the ability to long-term reconstitute irradiated mice. Slc23a2-deficient HSCs and MPPs divided much less frequently than control HSCs and MPPs. Increased self-renewal and reconstituting potential were observed particularly in quiescent Slc23a2-deficient HSCs and MPPs. The effect of Slc23a2 deficiency on MPP self-renewal was not mediated by reduced Tet2 function. Ascorbate thus regulates quiescence and restricts self-renewal potential in HSCs and MPPs such that ascorbate depletion confers MPPs with long-term self-renewal potential.

Developing a Text Messaging Intervention to Prevent Binge and Heavy Drinking in a Military Population: Mixed Methods Development Study.

BACKGROUND: Alcohol misuse is the fourth leading cause of death in the United States and a significant problem in the US military. Brief alcohol interventions can reduce negative alcohol outcomes in civilian and military populations, but additional scalable interventions are needed to reduce binge and heavy drinking. SMS text messaging interventions could address this need, but to date, no programs exist for military populations. OBJECTIVE: We aimed to develop an SMS text messaging intervention to address binge and heavy drinking among Airmen in Technical Training in the US Air Force. METHODS: We implemented a 2-phase, mixed methods study to develop the SMS text messaging intervention. In phase 1, a total of 149 respondents provided feedback about the persuasiveness of 49 expert-developed messages, preferences regarding message frequency, timing and days to receive messages, and suggested messages, which were qualitatively coded. In phase 2, a total of 283 respondents provided feedback about the persuasiveness of 77 new messages, including those developed through the refinement of messages from phase 1, which were coded and assessed based on the Behavior Change Technique Taxonomy (BCTT). For both phases, mean persuasiveness scores (range 1-5) were calculated and compared according to age (aged <21 or ≥21 years) and gender. Top-ranking messages from phase 2 were considered for inclusion in the final message library. RESULTS: In phase 1, top-rated message themes were about warnings about adverse outcomes (eg, impaired judgment and financial costs), recommendations to reduce drinking, and invoking values and goals. Through qualitative coding of suggested messages, we identified themes related to warnings about adverse outcomes, recommendations, prioritizing long-term goals, team and belonging, and invoking values and goals. Respondents preferred to receive 1 to 3 messages per week (124/137, 90.5%) and to be sent messages on Friday, Saturday, and Sunday (65/142, 45.8%). In phase 2, mean scores for messages in the final message library ranged from 3.31 (SD 1.29) to 4.21 (SD 0.90). Of the top 5 highest-rated messages, 4 were categorized into 2 behavior change techniques (BCTs): valued self-identity and information about health consequences. The final message library includes 28 BCTT-informed messages across 13 BCTs, with messages having similar scores across genders. More than one-fourth (8/28, 29%) of the final messages were informed by the suggested messages from phase 1. As Airmen aged <21 years face harsher disciplinary action for alcohol consumption, the program is tailored based on the US legal drinking age. CONCLUSIONS: This study involved members from the target population throughout 2 formative stages of intervention development to design a BCTT-informed SMS text messaging intervention to reduce binge and heavy drinking, which is now being tested in an efficacy trial. The results will determine the impact of the intervention on binge drinking and alcohol consumption in the US Air Force.

Sex differences in US military personnel with insomnia, obstructive sleep apnea, or comorbid insomnia and obstructive sleep apnea.

STUDY OBJECTIVES: The aim of this study was to evaluate sex-related differences in symptoms of sleep disorders, sleep-related impairment, psychiatric symptoms, traumatic brain injury, and polysomnographic variables in treatment-seeking military personnel diagnosed with insomnia, obstructive sleep apnea (OSA), or comorbid insomnia and OSA (COMISA). METHODS: Participants were 372 military personnel (46.2% women, 53.8% men) with an average age of 37.7 (standard deviation = 7.46) years and median body mass index of 28.4 (5.50) kg/m2. Based on clinical evaluation and video-polysomnography, participants were diagnosed with insomnia (n = 118), OSA (n = 118), or COMISA (n = 136). Insomnia severity, excessive daytime sleepiness, sleep quality, nightmare disorder, sleep impairment, fatigue, posttraumatic stress disorder, anxiety, depression symptoms, and traumatic brain injury were evaluated with validated self-report questionnaires. Descriptive statistics, parametric and nonparametric t-tests, and effect sizes were used to assess sex differences between men and women. RESULTS: There were no significant differences between women and men with insomnia or OSA in sleep-related symptoms, impairment, or polysomnography-based apnea-hypopnea index. Military men with COMISA had a significantly greater apnea-hypopnea index as compared to military women with COMISA, but women had greater symptoms of nightmare disorder, posttraumatic stress disorder, and anxiety. CONCLUSIONS: In contrast to civilian studies, minimal differences were observed in self-reported sleep symptoms, impairment, and polysomnography metrics between men and women diagnosed with the most frequent sleep disorders in military personnel (ie, insomnia, OSA, or COMISA) except in those with COMISA. Military service may result in distinct sleep disorder phenotypes that differ negligibly by sex. CITATION: Mysliwiec V, Pruiksma KE, Matsangas P, et al. Sex differences in US military personnel with insomnia, obstructive sleep apnea, or comorbid insomnia and obstructive sleep apnea. J Clin Sleep Med. 2024;20(1):17-30.

Per- and polyfluoroalkyl substances (PFAS) in final treated solids (Biosolids) from 190 Michigan wastewater treatment plants.

Trends in concentration, distribution, and variability of per- and polyfluoroalkyl substances (PFAS) in biosolids are characterized using an extensive dataset of 350 samples from 190 wastewater treatment plants (WWTPs) across Michigan. All samples are comprised of final treated solids generated at the end of the wastewater treatment process. Concentrations of both individual and Σ24 PFAS are lognormally distributed, with Σ24 PFAS concentrations ranging from 1-3200 ng/g and averaging 108 ± 277 ng/g dry wt. PFAS with carboxyl and sulfonic functional groups comprise 29% and 71% of Σ24 PFAS concentrations, respectively, on average. Primary sample variability in concentration is associated with long-chain PFAS with higher tendency for partitioning to biosolids. Short-chain carboxylic compounds, most notably PFHxA, are responsible for secondary concentration variability. Usage of FTSA and PFBS replacements to long-chain sulfonic compounds also contributes to variance in biosolids concentrations. Sulfonamide precursor compounds as a collective group are detected at a similar frequency as PFOS and often have higher concentrations. Trends in PFAS enrichment for individual PFAS vary at least 3 orders-of-magnitude and generally increase with compound hydrophobicity; however, partitioning of PFAS onto solids in WWTPs is a complex process not easily described nor constrained using experimentally-derived partitioning coefficients.

Decreasing alcohol use among young adults presenting for service in the U.S. Air Force: An epidemiological surveillance study.

U.S. surveys demonstrate recent decreases in the prevalence of alcohol use and binge drinking among young adults. The current study aims to determine whether similar trends are evident in a similarly aged cohort of service members in the US Air Force to inform ongoing prevention efforts. Participants were 103,240 Air Force personnel in entry-level training between 2016 and 2019. Participants anonymously completed the AUDIT (Alcohol Use Disorder Identification Test) regarding their pre-service drinking. Logistic regression analyses and the Cochran-Armitage test were conducted to measure population trends over the study duration with stratification by age (<21 vs. ≥21) and evaluation of specific alcohol behaviors. Between 2016 and 2019, the proportion of young service members endorsing any alcohol use significantly decreased for both the <21 group (i.e. from 38.9% to 32.6%) and the ≥21 group (i.e. from 80.6% to 77.5%). Among those who endorsed drinking, a decrease over time in binge use was also observed from 46.6% to 37.8% for the <21 group and from 34.2% to 27.5% for the ≥21 group. Responses to other specific alcohol risk items and total AUDIT scores also demonstrated decreases. Binge use and risky drinking remained disproportionately common among those under the legal drinking age. It is encouraging to observe a shift toward abstinence and decreased binge use among this population of young military recruits. However, given the risk for many adverse health and legal consequences in this population, more work is needed to prevent problematic drinking, especially among those under the legal drinking age.

Long-duration monitoring and mass balance of PFAS at a wastewater treatment plant following the release of aqueous film-forming foam concentrate.

Approximately 760 liters (200 gallons) of first-generation, PFOS-dominant, Aqueous Film-Forming Foam (AFFF) concentrate entered the sanitary sewer after an accidental release at the Kalamazoo/Battle Creek International Airport and migrated 11.4 km to the Kalamazoo Water Reclamation Plant. Near-daily sampling of influent, effluent, and biosolids generated a high-frequency, long-duration dataset used to understand the transport and fate of accidental PFAS releases to wastewater treatment plants, identify AFFF concentrate composition, and perform a plant-wide PFOS mass balance. Monitored influent concentrations exhibited sharp PFOS declines after 7 days post-spill, yet effluent discharges remained elevated due to return activated sludge (RAS) recirculation, resulting in the exceedance of Michigan's Surface Water Quality Value for 46 days. Mass balance estimates indicate 1.292 kg PFOS entering the plant and 1.368 kg leaving. Effluent discharge and sorption to biosolids account for 55% and 45% of estimated PFOS outputs, respectively. Identification of AFFF formulation and reasonable agreement between computed influent mass and reported spill volume demonstrates effective isolation of the AFFF spill signal and increases confidence in the mass balance estimates. These findings and related considerations provide critical insight for performing PFAS mass balances and developing operational procedures for accidental spills that minimize PFAS releases to the environment.

Integrated Genomic DNA/RNA Profiling vs Fluorescence in Situ Hybridization in the Detection of MYC and BCL2 (and BCL6) Rearrangements in Large B-Cell Lymphomas: Updates Amid the New WHO Classification of Lymphoid Neoplasms.

OBJECTIVES: Large B-cell lymphomas (LBCLs) are a heterogeneous group of lymphoid neoplasms whose molecular and cytogenetic profile has predictive and prognostic implications. The concept of double-hit lymphomas (DHLs) was recently updated in the fifth edition of the World Health Organization classification, with the exclusion of MYC and BCL6 rearranged tumors from the group. Now, DHLs are referred to as diffuse large B-cell lymphoma/high-grade B-cell lymphoma with MYC and BCL2 rearrangements. Fluorescence in situ hybridization (FISH) is the current gold standard for detecting rearrangements in LBCLs, but comprehensive genomic profiling (CGP) has recently been suggested to be at least as accurate as FISH in classifying these neoplasms and providing additional genetic information. METHODS: We analyzed a cohort of 131 patients in whom FISH and CGP studies were performed as part of our normal clinical workflow and compared the effectiveness of FISH and CGP in detecting these clinically relevant rearrangements. RESULTS: Our findings are in agreement with our previously published study, which analyzed a cohort of 69 patients, supporting our hypothesis that the best approach to maximize detection of DHLs while limiting waste seems to be a combination of CGP and MYC break-apart FISH testing, the latter to capture the presence of non-IGH::MYC events. CONCLUSIONS: Our study supports the combined use of FISH and GCP rather than either method alone to better detect MYC and BCL2 (and BCL6) gene rearrangements.

Tobacco quitline performance: Comparing the impacts of early cessation and proactive re-engagement on callers' smoking status at follow-up at 12 months.

INTRODUCTION: While tobacco Quitlines are effective in the promotion of smoking cessation, the majority of callers who wish to quit still fail to do so. The aim of this study was to determine if 12-month tobacco Quitline smoking cessation rates could be improved with re-engagement of callers whose first Quitline treatment failed to establish abstinence. METHODS: In an adaptive trial, 614 adult smokers, who were active duty, retired, and family of military personnel with TRICARE insurance who called a tobacco Quitline, received a previously evaluated and efficacious four-session tobacco cessation intervention with nicotine replacement therapy (NRT). At the scheduled follow-up at 3 months, callers who had not yet achieved abstinence were offered the opportunity to re-engage. This resulted in three caller groups: 1) those who were abstinent, 2) those who were still smoking but willing to re-engage with an additional Quitline treatment; and 3) individuals who were still smoking but declined re-engagement. A propensity score-adjusted logistic regression model was generated to compare past-7-day point prevalence abstinence at 12 months post Quitline consultation. RESULTS: Using a propensity score adjusted logistic regression model, comparison of the three groups resulted in higher odds of past-7-day point prevalence abstinence at follow-up at 12 months for those who were abstinent at 3 months compared to those who re-engaged (OR=9.6; 95% CI: 5.2-17.8; Bonferroni adjusted p<0.0001), and relative to those who declined re-engagement (OR=13.4; 95% CI: 6.8-26.3; Bonferroni adjusted p<0.0001). There was no statistically significant difference in smoking abstinence between smokers at 3 months who re-engaged and those who declined re-engagement (OR=1.39; 95% CI: 0.68-2.85). CONCLUSIONS: Tobacco Quitlines seeking to select a single initiative by which to maximize abstinence at follow-up at 12 months may benefit from diverting additional resources from the re-engagement of callers whose initial quit attempt failed, toward changes which increase callers' probability of success within the first 3 months of treatment. TRIAL REGISTRATION: This study is registered at clinicaltrials.gov (NCT02201810).

Predictors of Re-Engagement after Relapse in a Tobacco Quit Line Intervention: Secondary Analysis from a Randomized Clinical Trial.

People who smoke often make several quit attempts before successfully maintaining abstinence. Therefore, incorporating re-engagement for people who fail to initially quit could increase quit attempts and ultimately increase cessation rates. Within the context of quit line-based interventions, it remains unknown what characteristics are associated with re-engagement. The purpose of this study was to assess associations between demographic and motivational characteristics, tobacco use, and initial intervention engagement with re-engagement in a tobacco quit line intervention. Among 372 adults who reported smoking three months after initiating a quit line-facilitated quit attempt as part of a larger randomized clinical trial, associations between personal characteristics (e.g., age, gender, nicotine dependence, and confidence in their ability to quit smoking) and initial intervention engagement (number of completed counseling sessions and use of nicotine replacement therapy (NRT)) with re-engagement (accepting an offer to re-initiate the quit line intervention) were determined using multivariable logistic regression modeling. Compared to non-White participants, White participants had lower odds of re-engaging (OR: 0.42, 95% CI: 0.23, 0.75). Number of initial counseling sessions completed was associated with re-engaging. NRT use during the initial intervention was not associated with re-engaging. Initial intervention engagement is important in the process of re-engagement, specifically attending counseling sessions. Exploration of associations between initial intervention engagement and potentially modifiable motivational factors is needed to be potentially leveraged in future interventions to maintain continued engagement in cessation among adults who smoke.

A comprehensive evaluation of insomnia, obstructive sleep apnea and comorbid insomnia and obstructive sleep apnea in US military personnel.

STUDY OBJECTIVES: The aim of this study was to characterize the sleep disorders of insomnia, obstructive sleep apnea (OSA), and comorbid insomnia and OSA (COMISA) in active duty military personnel. METHODS: Prospective observational study of 309 military personnel with a mean age of 37.17 years (SD = 7.27). Participants served in four branches of the U.S. military (47.9% Air Force, 38.8% Army, 11.3% Navy, and 1.9% Marines). Sleep diagnoses were rendered after video-polysomnography and a clinical evaluation. Validated self-report measures assessed insomnia severity, excessive daytime sleepiness, sleep quality, disruptive nocturnal behaviors, nightmare disorder, shift work disorder (SWD), sleep impairment, fatigue, posttraumatic stress disorder (PTSD) symptoms, anxiety, depression, and traumatic brain injury (TBI). General linear models and Pearson chi-square tests were used for between-group differences in data analyses. RESULTS: Insomnia was diagnosed in 32.7%, OSA in 30.4% and COMISA in 36.9%. Compared to military personnel with OSA alone, those with insomnia only and COMISA had significantly greater insomnia severity, disruptive nocturnal behaviors, sleep-related impairment, rates of nightmare disorder, and poorer sleep quality (all Ps < .05). They also reported greater symptoms of fatigue, PTSD, anxiety, and depression (all Ps < .05). There were no significant differences among the three sleep disorder diagnostic groups on sleepiness, SWD, or TBI. CONCLUSIONS: Military personnel with insomnia only and COMISA overall report worsened symptoms of sleep disorders, sleep-related impairment, fatigue, and psychiatric disorders than those with OSA. Results highlight the importance of a comprehensive assessment for sleep-related impairment, sleep, and comorbid disorders in military personnel with clinically significant sleep disturbances.

Easy-To-Perform Dual Immunohistochemistry Can Solve Problems in Hematopathology.

Immunohistochemical analysis has become an integral component in the diagnostic work up of hematopoietic neoplasms. It is not uncommon that visualization of single protein expression by immunohistochemistry among cells of interest may become a difficult task. Common scenarios of such include extensive colonization of germinal centers in the differential diagnosis of marginal zone lymphoma and follicular lymphoma, low-level bone marrow involvement by lymphoma and paucity of neoplastic lymphocytes in the setting of numerous background reactive lymphocytes, among others. For this reason, we have developed a variety of easy-to-employ dual-color dual-antibody immunohistochemical assays to aid in solving these diagnostic dilemmas. Herein, we share examples of our use of dual immunohistochemistry to illustrate its beneficial and practical objective.

Nonlymphoid Hematopoietic Diseases Presenting in Bone, Soft Tissue, and Other Extranodal Sites.

CONTEXT.­: Although rare in everyday practice, the initial presentation of hematopoietic neoplasms other than lymphoma in the musculoskeletal system and other extranodal sites can generate challenging diagnostic problems for surgical pathologists. OBJECTIVE.­: To review the morphologic and immunophenotypic features of various nonlymphoid hematopoietic diseases presenting at extranodal sites, with emphasis on the inherent diagnostic pitfalls and differential diagnoses of these entities to aid surgical pathologists in their accurate recognition. DATA SOURCES.­: Cases reviewed herein represent both in-house and consult cases seen at our institution between 2010 and 2021. CONCLUSIONS.­: Entities that present in this way include myeloid neoplasms and histiocytic/dendritic cell neoplasms. These tumors commonly cause nonspecific symptoms, and their histologic appearance can overlap with a variety of benign neoplasms and reactive processes. This can lead to delay in diagnosis and intervention with potentially lifesaving therapy; thus, accurate and expedient recognition is of paramount importance.

Per- and Polyfluorinated Alkyl Substances (PFAS) cycling within Michigan: Contaminated sites, landfills and wastewater treatment plants.

Concentrations of Per- and Polyfluorinated Alkyl Substances (PFAS) from public and private sources in Michigan compiled for wastewater treatment plants (WWTPs) (influent, effluent, biosolids), contaminated sites, and landfill leachates reveal complex cycling within the natural and engineered environment. Analysis of 171 contaminated sites in Michigan by source release indicate four dominant PFAS sources - landfills, aqueous film-forming foams (AFFF), metal platers, and automotive/metal stamping - account for 75% of the contamination. Diverse chemical signatures were observed for leachates collected from 19 landfills (mostly type II municipal) with the dominant PFAS ranging from perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) to shorter-chained compounds, perfluorohexanoic acid (PFHxA), perfluorobutanoic acid (PFBA), and perfluorobutanesulfonic acid (PFBS). Analysis of PFAS carbon chain length as a function of landfill age shows the transition of C8s in leachate from older landfills to C4s and C6s in younger landfills, consistent with the phasing out and replacement of C8s. PFAS mass flux in leachate for landfills studied range between 5 - 2,000 g/yr and are highest for active landfills, which generate greater leachate volumes and contain fresh PFAS wastes. Detailed study of 10 WWTPs with industrial pretreatment programs indicate numerous chemical transformations across the plants that yield effluent PFAS concentrations as much as 19 times greater than influent, attributed to transformations of unmeasured precursors in the influent to measured, stable PFAS in the effluent. PFOA, PFHxA, perfluoropentanoic acid (PFPeA), PFBA, and PFBS show the greatest increases across the plant ranging from 20% to nearly 2,000%. PFOS concentrations decreased across 6 WWTPs, consistent with a strong tendency to adsorb onto biosolids. Estimated mass of discharge of (mostly unregulated) PFAS from WWTPs to receiving waters range from 40 g/yr to 128 kg/yr.

Degree of polarization of photoluminescence from facets of InP as a function of strain: some experimental evidence.

Previous work demonstrated a good fit to the degree of polarization (DOP) of luminescence measurements on {110} facets of InP using a simple dependence of DOP of luminescence on strain: ${-}{K_e} ({e_1} - {e_3})$, where ${K_e}$ is a positive calibration constant, and ${e_1}$ and ${e_3}$ are normal components of strain in the plane of the facet and along $\langle 1\bar 10\rangle$ and $\langle 001\rangle$ directions [Appl. Opt.43, 1811 (2004)APOPAI0003-693510.1364/AO.43.001811]. Recent analytic modeling, which by necessity to be analytic must make simplifying assumptions, has suggested that unless the measurements are along crystallographic axes, the dependence of the DOP of luminescence on strain is more complicated: ${-}{K_e} (1.315 {e_1} - 0.7987 {e_3})$ for measurements from an InP facet, with a similar "excess" ${e_1}$ for GaAs [Appl. Opt.59, 5506 (2020)APOPAI0003-693510.1364/AO.394624]. In this work, we fit finite element simulations (FEM) to DOP measurements of the photoluminescence from facets of InP bars with ${\{111\} _B}$ v-grooves that have been placed in a cylindrical bending moment. We find that the more complicated dependence of DOP on strain, as derived by the analytic model, fits the data better than the previously assumed simple dependence. This finding thus corroborates the analytical model and should have an impact on understanding the strain-dependent operation of optoelectronic devices.

Micro-distribution of arsenic and polycyclic aromatic hydrocarbons and their interaction in Pteris vittata L.

Interactive effects of inorganic arsenic (As) species and polycyclic aromatic hydrocarbons (PAHs) on their uptake, accumulation and translocation in the hyperaccumulator Pteris vittata L. (P. vittata) were studied hydroponically. The presence of PAHs hindered As uptake and acropetal translocation by P. vittata, decreasing As concentrations by 29.8%-54.5% in pinnae, regardless of the initial As speciation. The inhibitive effect of PAHs was 1.6-8.7 times greater for arsenite [As(III)] than for arsenate [As(V)]. Similarly, inorganic As inhibited the uptake of fluorene (FLU) and benzo[a]pyrene (BaP) by P. vittata roots by 0.4%-21.7% and by 33.1%-69.7%, respectively. Interestingly, coexposure to As and PAHs slightly enhanced the translocation of PAHs by P. vittata with their concentrations increased 0.3 to 0.8 times in shoots, except for the As(III)+BaP treatment. The antagonistic interaction between As and PAHs uptake is likely caused by competitive inhibition or oxidative stress injury. By using synchrotron radiation micro X-ray fluorescence imaging, high concentrations of As were found distributed throughout the microstructures far from main vein of the pinnae when coexposed with PAHs, the opposite of what was observed with exposure to As only. PAHs could also significantly inhibit the accumulation and distribution of As in vascular bundles in rachis treated with As(III). The results of two-photon laser scanning confocal microscopy revealed that PAHs were mainly distributed in the vascular cylinder, epidermal cells, vascular bundles, epidermis and vein tissues, and this was independent of As speciation and treatment. This work offers new positive evidence for the interaction between As and PAHs in P. vittata, presents new information on the underlying mechanisms for interactions of As and PAHs affecting their uptake and translocation within P. vittata L., and provides direction for future research on the mechanisms of PAHs uptake by plants.

Gastrointestinal Tract Lymphomas.

CONTEXT.­: The gastrointestinal (GI) tract is the most common site of extranodal non-Hodgkin lymphoma, accounting for 20% to 40% of all extranodal lymphomas. The majority of these are systemic processes secondarily involving the GI tract. Primary GI lymphomas are less common, accounting for approximately 10% to 15% of all non-Hodgkin lymphomas. Most non-Hodgkin lymphomas involving the GI tract are of B-cell lineage, of which diffuse large B-cell lymphoma is the most common subtype, irrespective of location. OBJECTIVE.­: To review the lymphoproliferative neoplasms of B-cell and T-cell lineage involving the luminal GI tract according to the most prevalent subtypes at each anatomic site. DATA SOURCE.­: Systematic search of the PubMed database for updated literature on GI lymphoma epidemiology, subtypes, clinical, endoscopic, and genetic findings. Histologic images are derived from our collection of clinical cases. CONCLUSIONS.­: The GI tract is the most common site of extranodal lymphoproliferative neoplasms. Recognition of the most frequently encountered GI lymphomas is imperative for patient management and treatment.