Pesticide residues in honey bee (Apis mellifera) pollen collected in two ornamental plant nurseries in Connecticut: Implications for bee health and risk assessment

Honey bees (Apis mellifera L.) are one of the most important managed pollinators of agricultural crops. While potential effects of agricultural pesticides on honey bee health have been investigated in some settings, risks to honey bees associated with exposures occurring in the plant nursery setting have received little attention. We sought to identify and quantify pesticide levels present in honey bee-collected pollen harvested in two ornamental plant nurseries (i.e., Nursery A and Nursery B) in Connecticut. From June to September 2018, pollen was collected weekly from 8 colonies using bottom-mounted pollen traps. Fifty-five unique pesticides (including related metabolites) were detected: 24 insecticides, 20 fungicides, and 11 herbicides. Some of the pesticide contaminants detected in the pollen had not been applied by the nurseries, indicating that the honey bee colonies did not exclusively forage on pollen at their respective nursery. The average number of pesticides per sample was similar at both nurseries (i.e., 12.9 at Nursery A and 14.2 at Nursery B). To estimate the potential risk posed to honey bees from these samples, we utilized the USEPA's BeeREX tool to calculate risk quotients (RQs) for each pesticide within each sample. The median aggregate RQ for nurse bees was 0.003 at both nurseries, well below the acute risk level of concern (LOC) of ≥0.4. We also calculated RQs for larvae due to their increased sensitivity to certain pesticides. In total, 6 samples had larval RQs above the LOC (0.45-2.51), resulting from the organophosphate insecticide diazinon. Since 2015, the frequency and amount of diazinon detected in pollen increased at one of our study locations, potentially due to pressure to reduce the use of neonicotinoid insecticides. Overall, these data highlight the importance of considering all life stages when estimating potential risk to honey bee colonies from pesticide exposure.

Effect of injectable progestin-only contraceptives, depot medroxyprogesterone acetate and norethisterone enanthate, on cytokine production during T-cell activation

PROBLEM

There is paucity of human data about the effects of depot medroxyprogesterone (DMPA) and norethisterone enanthate (Net-En) use on systemic immune function, which may have implications for reproductive tract infection susceptibility and transmissibility. We sought to evaluate the impact of injectable contraceptive use on T-cell responsiveness using T cells exposed in vivo and tested ex vivo.

METHODS

Peripheral blood mononuclear cells were obtained from healthy, HIV-negative women after 30, 90 and 180 days of DMPA, norethisterone enanthate (Net-En) or copper intrauterine device (Cu-IUD) contraceptive use. Cells were stimulated ex vivo with phorbol myristate acetate and ionomycin, stained and analysed using flow cytometry. Mixed-effects linear models were used to evaluate change in proportions of T cells producing IFN-γ, TNF-α, IL-4 and IL-13.

RESULTS

Compared with baseline, decreased proportions of IFN-γ-producing CD4+ and CD8+ T cells (p = .003, p = .006, respectively) and TNF-α-producing CD4+ and CD8+ T cells (p = .039, p = .034, respectively) were observed after 180 days of DMPA use. Decreased IL-4-producing CD4+ and CD8+ T cells (p = .045 and p = .024, respectively) were noted after 180 days of Net-En use. Decreased IL-4-producing CD4+ T cells were observed after 30 days (p = .035) and not after 180 days of DMPA use (p = .49). There were no changes in proportion of T cells producing IL-13 in DMPA users, nor any changes in IFN-γ, TNF-α and IL-13 in Net-En and Cu-IUD users.

CONCLUSION

In vivo exposure of CD4+ and CD8+ T cells to typical pharmacologic concentrations of DMPA does not cause broad suppression to stimuli; however, depletion of specific cytokine-producing T cells may occur after prolonged DMPA use.

Zim CHIC: A cohort study of immune changes in the female genital tract associated with initiation and use of contraceptives

Problem

Contraceptive hormones are systemically active, potent, and likely to invoke biological responses other than known fertility regulation impacts. We hypothesized that initiation of depot medroxyprogesterone acetate (DMPA) would increase genital HIV‐target‐cells and soluble immune mediators compared with baseline and initiation of other contraceptive methods.

Method of Study

We collected cervical cytobrushes and cervicovaginal fluid from healthy Zimbabwean women aged 18‐34 to assess immune cell populations, cytokines, and innate anti‐HIV activity at baseline and after 30, 90, and 180 days use of DMPA (n = 38), norethisterone enanthate (n = 41), medroxyprogesterone acetate/estradiol cypionate (n = 36), levonorgestrel implant (n = 43), etonogestrel implant (n = 47), or copper intrauterine device (Cu‐IUD) (n = 45). Cells were quantified by flow cytometry, cytokines were detected by multiplex assays, and innate anti‐HIV activity was assessed by in vitro HIV challenge.

Results

Compared to baseline, the number of cervical HIV target cells (#CD4 cells P < .04 and #CD11c cells P < .04), the concentration of the inflammatory cytokine IL‐1β (P < .01), and the innate in vitro anti‐HIV activity (P < .001) significantly decreased following DMPA initiation. In Cu‐IUD users, genital HIV target cells increased (#CD4 cells P < .001, #CD4CCR5 cells P = .02, #CD4CD69 cells P < .001, #CD8CD69 P = .01, and #CD11c cells P = .003) at day 30 and resolved by day 180. IFN‐γ (P < .001), IL‐1β (P < .001), IL‐6 (P < .001), IL‐8 (P < .001), IL‐10 (P < .01), and RANTES (P < .001) were also significantly increased at day 30. Minimal alterations were observed following initiation of subdermal implantable contraceptives.

Conclusions

This head‐to‐head study compared six contraceptives and found increased HIV target cells and cervical inflammation temporally associated with Cu‐IUD initiation. Use of hormonal contraception, including DMPA, did not increase cervical HIV target cells or inflammation.

Clinical Trial Number: NCT02038335

Optimization of processing female genital tissue samples for lymphocyte analysis by flow cytometry

PROBLEM

A variety of methods have been used to process cervical cytobrush and genital tissue for flow cytometric evaluation of immune cell populations. We sought to optimize genital tract specimen processing and to determine if blood could be used as a model for assessment of tissue processing methods.

METHOD OF STUDY

Cervical cytobrushes, PBMCs, and genital tissue samples (cervical and endometrial biopsies) were subjected to varying processing conditions to characterize the effects on cell yields, lymphocyte viability, and surface receptors. We exposed PBMC and tissue specimens to varied collagenase types, concentrations, and exposure durations and cytobrushes to immediate vs delayed processing with/without vortexing.

RESULTS

PBMCs and tissues exposed to varying enzymatic digestion conditions demonstrated stability of some cell surface receptors, including CD3⁺ , CD4⁺ , and CD8⁺ , while others, including CCR6⁺ , were cleaved when exposed to any concentration of collagenase B, or ≥0.25 mg/mL of collagenase D. We observed increased CD69 expression (marker of cell activation) after exposure to collagenase B. Neither a 2-hour delay in cytobrush processing nor vortexing at a setting of 50% for 30 seconds had significant impacts on viability or quantities of genital immune cells of interest.

CONCLUSION

Although tissue digestion with collagenase D was sufficient to recover and analyze cells from endometrial biopsy specimens, cervical biopsy specimens required a limited exposure to collagenase B at 1 mg/mL to optimize cell yield and viability for cytometric analysis. PBMCs can be used as a model to assess the impact of tissue processing on co-receptor expression and to optimize methods prior to study implementation.

Depot medroxyprogesterone acetate and norethisterone enanthate differentially impact T-cell responses and expression of immunosuppressive markers

PROBLEM

Injectable contraceptive use may impact immune cell responsiveness and susceptibility to infection. We measured responsiveness of T-cells from women before and after initiating depot medroxyprogesterone acetate (DMPA) or norethisterone enanthate (Net-En).

METHOD OF STUDY

Peripheral blood mononuclear cells collected from women aged 18-34 years prior to, at steady state, and nadir concentrations after initiating DMPA (n = 30) or Net-En (n = 36) and from women initiating copper intrauterine device (CU-IUD; n = 32) were stimulated with phorbol myristate acetate and analyzed using flow cytometry. We evaluated percentage change in T-cells expressing programmed cell death-1 (PD-1) and cytotoxic T-lymphocyte associated protein-4 (CTLA-4).

RESULTS

Compared to baseline, there were decreased numbers of CD4+CTLA4+ (P < .001) and CD8+CTLA4+ (P < .01) T-cells following ex vivo stimulation challenge at steady state DMPA concentrations and no differences at nadir concentrations (P = .781 and P = .463, respectively). In Net-En users, no differences in CD4+CTLA4+ T-cells at steady state (P = .087) and nadir concentrations (P = .217) were observed. DMPA users had fewer CD4+PD-1+ (P < .001) and CD8+PD-1+ (P < .001) T-cells at nadir concentrations. Number of CD4+PD-1+ and CD8+PD-1+ T-cells decreased at steady state concentration (P = .002 and P = .001, respectively) and at nadir concentrations after Net-En initiation (P < .001 and P < .001). In CU-IUD users, there were no changes in number of CD4+CTLA4+ (P = .426) and CD8+CTLA4+ (P = .169) and no changes in CD4+PD-1+ (P = .083) and CD8+PD-1+ (P = .936) compared to baseline.

CONCLUSION

Activation of T-cells in response to ex vivo stimulation is suppressed at steady state DMPA concentration and resolves at nadir concentration, suggesting DMPA immunosuppressive effects may be transient.

Changes in genital tract immune cell populations after initiation of intrauterine contraception

OBJECTIVE

The primary target cells for the human immunodeficiency virus (HIV) infection in the genital tract are CD4 T cells that express CCR5 on the surface. Alterations in genital tract T cells that express CCR5 could impact HIV acquisition risk. We hypothesized that, when compared with baseline, the use of a hormonal intrauterine device (IUD) would alter HIV target cells (primarily CCR5+ CD4 cells) in the female genital tract more than a nonhormonal IUD.

STUDY DESIGN

Thirty-four healthy HIV-negative women aged 18-40 years who were seeking an IUD for contraception were assigned randomly to receive a levonorgestrel IUD or a copper T380A IUD. A parallel group of 8 control women who did not need contraception was also enrolled. Genital tract mucosal immune cell populations that were collected by cervical cytobrush and endometrial biopsy before and 2 months after IUD placement were analyzed by flow cytometry. Mean differences in cell number and percent that expressed receptors from baseline to follow-up examination were evaluated with the use of paired Student t tests.

RESULTS

Neither IUD altered the number of T cells within the upper and lower genital tracts. Levonorgestrel IUD users had a decrease in T cells that expressed the HIV coreceptor CCR5 in the endometrium and cervix after 2 months of use compared with baseline. There was a decrease in activated endometrial T cells in levonorgestrel IUD users and a decrease in activated cervical T cells in copper IUD users after 2 months of IUD use, compared with baseline.

CONCLUSION

Women who use IUDs have reduced expression of the CCR5 HIV coreceptor on T cells in the endometrium and cervix compared with expression before IUD placement. These findings suggest that susceptibility to HIV infection would not be increased by IUD use.

Recalcitrance of bacterial vaginosis among herpes-simplex-virus-type-2-seropositive women

AIM

The multifactorial etiology of bacterial vaginosis (BV) impedes development of effective treatment and prevention strategies. Herein, we evaluated the effects of herpes simplex virus type 2 (HSV-2), a suspected BV risk factor, on vaginal flora composition.

MATERIALS AND METHODS

  Correlations between HSV-2 infection and BV were prospectively explored among 12 HSV-2-seropositive women with asymptomatic BV who were asked to collect daily vaginal swab specimens for Gram stain analysis of vaginal flora and determination of HSV-2 shedding frequencies during the 1month before and after metronidazole therapy.

RESULTS

Unlike prior longitudinal studies that reported rapid fluctuations in vaginal flora composition and frequent episodes of spontaneously resolving BV, we found that 99.4% (310/312) of vaginal smears collected before initiation of metronidazole were consistent with a diagnosis of BV. Effectiveness of metronidazole therapy was also much lower than previously reported in studies not restricting enrollment to HSV-2-seropositive women; we observed a BV recurrence rate of 89% in the first month after completion of therapy while the median time to this recurrence occurred only 14days after treatment.

CONCLUSIONS

Our study demonstrates BV recalcitrance among HSV-2-infected women and provides additional evidence for a linkage between this chronic viral infection and abnormal vaginal flora. Additional work will be needed to define mechanisms responsible for this correlation and to determine if vaginal flora health of HSV-2-infected women is improved by medications that suppress HSV-2 shedding.

Effect of transport time, temperature, and concentration on the survival of group B streptococci in amies transport medium

The impact of transport time and temperature on survival of group B streptococci (GBS) in Amies transport medium was evaluated. Viability of 10 or more CFU of GBS was maintained for 4 days at 24 or 3 degrees C. However, there was a significant decrease in viability for GBS held at 30 degrees C for 4 days.

The Influence of Compost Amendment or Straw Mulch on the Reduction of Gas Exchange in Potato by Verticillium dahliae and Pratylenchus penetrans

Single potato plants (Solanum tuberosum cv. Superior) were grown in microplots in soil that was fumigated and then infested with Verticillium dahliae, Pratylenchus penetrans, or both to evaluate the effects of these pathogens and of cultural treatments with spent mushroom compost or straw mulch on gas exchange of potato leaves. Photosynthesis and transpiration of terminal leaflets of a cohort of similar-aged leaves were measured once a week from the time of expansion until they senesced. Over all measurements, gas exchange per unit leaf area was less for plants in microplots infested with V. dahliae or P. penetrans than for those in uninfested plots. For leaves that expanded in early June, gas exchange was similar immediately after leaf expansion but declined more quickly when microplots were infested with one or both pathogens compared to no infestation. Overall, leaf gas exchange was increased by compost amendment but not affected by straw mulch. Compost amendment prevented some of the decline in gas exchange due to infestation by one or both pathogens. For leaves that expanded in July, compost increased the gas exchange immediately after expansion in both infested and non-infested plots.

Effect of Compost Amendment or Straw Mulch on Potato Early Dying Disease

Single potato plants (Solanum tuberosum) cv. Superior were grown in field microplots to evaluate the effects of spent mushroom compost or straw mulch on early dying of potato caused by Verticillium dahliae and/or Pratylenchus penetrans. Prior to planting, soil was fumigated, placed in field microplots, and then infested with pathogens. Area under the senescence progress curve (AUSPC) was greater for plots infested with V. dahliae and/or P. penetrans than for noninfested plots. Plants grown in soil infested with both pathogens developed symptoms earlier than plants grown in soil infested with a single pathogen. Both V. dahliae and P. penetrans reduced yields; the combination of pathogens reduced marketable tuber yields by 22 to 44% (A- and B-sized tubers). Although the total number of tubers of all sizes was not affected by cultural or pathogen treatments, the addition of compost increased marketable tuber weight and decreased AUSPC. Soil amendment with spent mushroom compost may be a means of reducing the effects of potato early dying and increasing tuber yield when one or both pathogens are present.

Fluvoxamine maleate in the treatment of depression: a single-center, double-blind, placebo-controlled comparison with imipramine in outpatients

The efficacy and safety of fluvoxamine maleate, a selective serotonin reuptake inhibitor, was compared with placebo and imipramine in patients with major depressive disorder. Previous literature has cited a dose range of 100 to 300 mg/day of fluvoxamine maleate for the treatment of major depression; however, this study demonstrates that a dose range of 50 to 150 mg/day is as effective as imipramine (80-240 mg/day). After a 1- to 2-week, single-blind, placebo washout phase, 150 depressed outpatients were randomized to double-blind treatment with fluvoxamine maleate (50-150 mg/day), imipramine (80-240 mg/day), or placebo for 6 weeks. Fluvoxamine produced a significant therapeutic benefit over placebo (p < or = 0.05) as assessed by the total score on the Hamilton Rating Scale for Depression; imipramine (80-240 mg/day) produced similar results. The secondary outcome variables (i.e., Clinical Global Impression severity of illness item and 56-Item Hopkins Symptom Checklist depression factor) also showed significant differences between fluvoxamine maleate and placebo during three of the four final weeks of the study. Both fluvoxamine maleate and imipramine appeared to be safe and well tolerated by the majority of patients. As expected from the pharmacology of these agents, the imipramine groups reported more anticholinergic effects (dry mouth, dizziness, and urinary retention) and electrocardiographic effects, whereas the fluvoxamine group reported more nausea, somnolence, and abnormal ejaculation. The majority of these adverse events were mild to moderate and, with the exception of dry mouth (imipramine) and abnormal ejaculation (fluvoxamine), were transient. The data clearly demonstrate the antidepressant activity and tolerability of fluvoxamine maleate (50-150 mg/day) as compared with placebo; it is also as effective as the tricyclic antidepressant imipramine (80-240 mg/day) in patients with major depressive disorder.