Oxidation of cis-Diamminediacetato PtII with Hydrogen Peroxide Can Give Rise to Two Isomeric PtIV Products.

The oxidation of cis-[Pt(NH3 )2 (OAc)2 ] with H2 O2 yields a mixture of two isomers: ctc-[Pt(NH3 )2 (OH)2 (OAc)2 ] and ctc-[Pt(NH3 )2 (OH)(OAc)(OH)(OAc)]. Following modification with 4-phenylbutyric (PhB) anhydride, two isomers were separated and characterized; the symmetric ctc-[Pt(NH3 )2 (PhB)2 (OAc)2 ] (1) and the nonsymmetric ctc-[Pt(NH3 )2 (PhB)(OAc)(PhB)(OAc)] (2). They differ in their log P values and despite having similar cellular uptake and similar DNA platination levels, the symmetric ctc-[Pt(NH3 )2 (OH)2 (OAc)2 ] is more than 4-fold more potent than the nonsymmetric isomer in a panel of 4 cancer cell lines.

Imaging of sleep-disordered breathing in adults.

Sleep-disordered breathing (SDB) is a term that includes several chronic conditions in which partial or complete cessation of breathing occurs multiple times throughout the night. Central sleep apnoea (CSA) is uncommon and defined by the episodic cessation of airflow without respiratory effort. Lesions involving the respiratory centre in the brainstem or the origin of the phrenic nerve from the mid-cervical cord are the commonest structural causes of CSA; magnetic resonance imaging (MRI) will demonstrate the lesion and frequently suggest the likely aetiology. In contrast, obstructive sleep apnoea (OSA) is defined as upper airway obstruction despite ongoing respiratory effort. Repetitive episodes of narrowing or closure of the upper airway are the predominant cause leading to snoring and OSA, respectively. OSA affects 33-40% of the adult population and is associated with multiple adverse health consequences, including a significantly increased risk of serious morbidity and mortality. The incidence is increasing proportionally to the worldwide rise in obesity. Imaging, performed primarily without the involvement of radiologists, has been integral to understanding the anatomical basis of SDB and especially OSA. This article will review the pathophysiology, imaging findings, and sequelae of these common conditions. The role of imaging both in suggesting the incidental diagnoses of SDB and in the investigation of these conditions when the diagnosis is suspected or has been established are also discussed.

Saccharomyces cerevisiae boulardii CNCM I-1079 affects health, growth, and fecal microbiota in milk-fed veal calves.

The objective of this study was to investigate the effect of one specific strain of yeast, Saccharomyces cerevisiae boulardii CNCM I-1079 (SCB), on the growth performance, health, and fecal bacterial profile of veal calves. A total of 84 animals were enrolled in an experiment at a commercial veal farm for a total of 7 wk. Calves were fed twice a day with a milk replacer meal during the entire experiment and were randomly assigned to receive daily either SCB supplementation (10 × 109 cfu/d) or a placebo (CON). Individual feed intake and body weight were monitored on a daily and weekly basis, respectively. Fecal samples were collected at arrival to the veal facility (wk 0) and additional samples were taken on d 14 (wk 2) and d 49 (wk 7). These samples were subjected to 16S rRNA gene amplicon sequencing using Illumina MiSeq (Illumina Inc., San Diego, CA) to examine the bacterial profiles and real-time quantitative PCR to quantify Saccharomyces cerevisiae and specific bacterial groups. The significant increase of S. cerevisiae in the feces of SCB calves at wk 2 and 7 compared with wk 0 (respectively 1.7 × 107, 1.2 × 107, and 2.2 × 105 copy number of S. cerevisiae/g of feces) indicates a good survival of that yeast strain along the gastrointestinal tract. Supplementation of SCB did not improve overall growth performance with regard to average daily gain (ADG), final body weight, and feed intake. Nevertheless, a total of 69.1% of nonsupplemented calves had diarrhea and 28.6% experienced severe diarrhea, whereas 50.0% of the calves supplemented with SCB had diarrhea and 9.5% experienced severe diarrhea. With respect to antibiotic use, 89.7% of the diarrheic calves recorded in the CON group were treated, whereas only 66.7% of the SCB diarrheic calves received an antibiotic. In addition, diarrheic calves supplemented with SCB maintained an ADG similar to nondiarrheic animals, whereas the CON diarrheic calves had a significantly lower ADG in comparison with nondiarrheic CON calves. Fecalibacterium was the most predominant bacterial genus in fecal samples of nondiarrheic and diarrheic calves supplemented with SCB, whereas fecal microbiota was predominated by Collinsella in diarrheic calves from the CON group. Live yeast supplementation in milk replacer led to a decrease of diarrhea in milk-fed veal calves and the fecal microbiota of diarrheic calves maintained a healthy community similar to nondiarrheic animals, with Fecalibacterium being the predominant genus.

Skipping breakfast and non-high-density lipoprotein cholesterol level in school children: a preliminary analysis.

OBJECTIVE: The objective of the study is to examine whether the increased levels of non-high-density lipoprotein cholesterol (non-HDL-c) are associated with skipping breakfast among school children. STUDY DESIGN: A cross-sectional survey was conducted among 539 school children aged 8-12 years from the Niagara Region of Canada. METHODS: Non-fasting finger blood was taken for total cholesterol (total-c) and HDL-c measurements. Non-HDL-c was calculated as the difference between total-c and HDL-c. The information of skipping breakfast in a week was obtained from a questionnaire, which was categorized into three groups, i.e., none, 1-3 times and 4 + times. Demographic information and other related variables were described by the three breakfast-skipping groups. RESULTS: Approximately 44% of children (n = 182) reported skipping breakfast. There were significant differences between the three groups in the means of total-c, non-HDL-c, body mass index, waist circumference, proportions of overall health excellent, eating dinner with parent and skipping breakfast that affects learning (P < 0.05). The number of days of skipping breakfast was weakly correlated to the level of non-HDL-c (r = 0.145, P < 0.0001). Multiple regression results indicated that every one more time of skipping breakfast would increase approximately 0.05 mmol/L level of non-HDL-c (P < 0.01), on average, after adjusting for those aforementioned potential confounding variables. The adjusted mean levels of non-HDL-c were 2.77, 2.94 and 3.07 mmol/L for none, skipping 1-3 times and skipping 4 + times of breakfast, respectively; the mean differences between none and the other two groups were statistical significant (P < 0.05). CONCLUSION: Non-HDL-c levels is positively associated with the number of skipping breakfast among school children, and further research is needed to confirm this relationship.

NLRP3 as a potentially novel biomarker for the management of osteoarthritis.

Osteoarthritis (OA) was previously thought of as 'wear and tear' as humans age, however there is increasing evidence to support an inflammatory theory. The nucleotide-binding and oligomerization domain-like receptor containing protein 3 (NLRP3) inflammasome has been implicated in the pathogenesis of a number of arthritic disorders, producing proinflammatory cytokines and degradative enzymes such as Interleukin-1 beta (IL-1ß), Tumour necrosis factor alpha (TNF-α) and Matrix metalloproteinase-3 (MMP-3) which drive cartilage degeneration and synovial inflammation. This review aims to summarise the evidence of NLRP3 involvement in OA. Currently, treatment options focus on management of the disease and to date there is no cure. The development of novel biomarkers for OA could improve diagnosis, treatment and management. Importantly, this review provides detail on the involvement of the NLRP3 inflammasome in OA pathology and how its members could act as potential biomarkers to assist clinical decisions.

Amorphous Silicon with Extremely Low Absorption: Beating Thermal Noise in Gravitational Astronomy.

Amorphous silicon has ideal properties for many applications in fundamental research and industry. However, the optical absorption is often unacceptably high, particularly for gravitational-wave detection. We report a novel ion-beam deposition method for fabricating amorphous silicon with unprecedentedly low unpaired electron-spin density and optical absorption, the spin limit on absorption being surpassed for the first time. At low unpaired electron density, the absorption is no longer correlated with electron spins, but with the electronic mobility gap. Compared to standard ion-beam deposition, the absorption at 1550 nm is lower by a factor of ≈100. This breakthrough shows that amorphous silicon could be exploited as an extreme performance optical coating in near-infrared applications, and it represents an important proof of concept for future gravitational-wave detectors.

Baseline characteristics and outcomes of children with cancer in the English-speaking Caribbean: A multinational retrospective cohort.

BACKGROUND: English-speaking Caribbean (ESC) childhood cancer outcomes are unknown. PROCEDURE: Through the SickKids-Caribbean Initiative (SCI), we established a multicenter childhood cancer database across seven centers in six ESC countries. Data managers entered patient demographics, disease, treatment, and outcome data. Data collection commenced in 2013, with retrospective collection to 2011 and subsequent prospective collection. RESULTS: A total of 367 children were diagnosed between 2011 and 2015 with a median age of 5.7 years (interquartile range 2.9-10.6 years). One hundred thirty (35.4%) patients were diagnosed with leukemia, 30 (8.2%) with lymphoma, and 149 (40.6%) with solid tumors. A relative paucity of children with brain tumors was seen (N = 58, 15.8%). Two-year event-free survival (EFS) for the cohort was 48.5% ± 3.2%; 2-year overall survival (OS) was 55.1% ± 3.1%. Children with acute lymphoblastic leukemia (ALL) and Wilms tumor (WT) experienced better 2-year EFS (62.1% ± 6.4% and 66.7% ± 10.1%), while dismal outcomes were seen in children with acute myeloid leukemia (AML; 22.7 ± 9.6%), rhabdomyosarcoma (21.0% ± 17.0%), and medulloblastoma (21.4% ± 17.8%). Of 108 deaths with known cause, 58 (53.7%) were attributed to disease and 50 (46.3%) to treatment complications. Death within 60 days of diagnosis was relatively common in acute leukemia [13/98 (13.3%) ALL, 8/26 (30.8%) AML]. Despite this, traditional prognosticators adversely impacted outcome in ALL, including higher age, higher white blood cell count, and T-cell lineage. CONCLUSIONS: ESC childhood cancer outcomes are significantly inferior to high-income country outcomes. Based on these data, interventions for improving supportive care and modifying treatment protocols are under way. Continued data collection will allow evaluation of interventions and ensure maximal outcome improvements.

Thin high numerical aperture metalens.

We designed, fabricated, and characterized a thin metalens in an amorphous silicon film of diameter 30 µm, focal length equal to the incident wavelength 633 nm. The lens is capable of simultaneously manipulating the state of polarization and phase of incident light. The lens converts a linearly polarized beam into radially polarized light, producing a subwavelength focus. When illuminated with a linearly polarized Gaussian beam, the lens produces a focal spot whose size at full-width half-maximum intensity is 0.49λ and 0.55λ (λ is incident wavelength). The experimental results are in good agreement with the numerical simulation, with the simulated focal spot measuring 0.46λ and 0.52λ. This focal spot is less than all other focal spots obtained using metalenses.

Surfactants and their role in wound cleansing and biofilm management.

Surfactants are widely used as detergents, emulsifiers, wetting agents, foaming agents and dispersants in the cosmetics, hygiene, food and oil industries. Their use in a clinical setting is also common, particularly within the field of wound care. Many wound cleansers contain surfactants and subsequently there is available data that shows the growing potential of these wound cleansers in the enhancement of wound closure. The presence of microorganisms in wounds has been recognised as a significant factor that delay healing. In complex or chronic wounds that are complicated by biofilms, persistent inflammation or the production of non-viable tissue and slough, the use of surfactants has been shown to aid in the removal of these barriers to wound healing. The use of concentrated surfactant(poloxamer) based wound dressings represent an important component of wound management. Consequently, this article will discuss the effect of clinically used surfactants, with specific focus on a concentrated poloxamer for use against wound biofilm.

A phase I, pharmacokinetic and pharmacodynamic study of GSK2256098, a focal adhesion kinase inhibitor, in patients with advanced solid tumors.

BACKGROUND: Focal adhesion kinase (FAK) is important in cancer growth, survival, invasion, and migration. The purpose of this study was to determine the maximum tolerated dose (MTD), safety, pharmacokinetics (PK), and pharmacodynamics (PD) of the FAK inhibitor, GSK2256098, in cancer patients. PATIENTS AND METHODS: The dose of GSK2256098 was escalated, in cohorts of patients with advanced cancer, from 80 to 1500 mg, oral twice daily (BID), until the MTD was determined. Serial blood samples were obtained from all patients, and the PK was determined. Paired tumor biopsies were obtained in select patients, and the level of phospho-FAK (pFAK) was determined. RESULTS: Sixty-two patients (39 males, 23 females; median age 61 y.o., range 21-84) received GSK2256098. Dose-limiting toxicities of grade 2 proteinuria (1000 mg BID), grade 2 fatigue, nausea, vomiting (1250 mg BID), and grade 3 asthenia and grade 2 fatigue (1500 mg BID) were reported with the MTD identified as 1000 mg BID. The most frequent adverse events (AEs) were nausea (76%), diarrhea (65%), vomiting (58%), and decreased appetite (47%) with the majority of AEs being grades 1-2. The PK was generally dose proportional with a geometric mean elimination half-life range of 4-9 h. At the 750, 1000, and 1500 mg BID dose levels evaluated, the pFAK, Y397 autophosphorylation site, was reduced by ∼80% from baseline. Minor responses were observed in a patient with melanoma (-26%) and three patients with mesothelioma (-13%, -15%, and -17%). In the 29 patients with recurrent mesothelioma, the median progression-free survival was 12 weeks with 95% CI 9.1, 23.4 weeks (23.4 weeks merlin negative, n = 14; 11.4 weeks merlin positive, n = 9; 10.9 weeks merlin status unknown, n = 6). CONCLUSIONS: GSK2256098 has an acceptable safety profile, has evidence of target engagement at doses at or below the MTD, and has clinical activity in patients with mesothelioma, particularly those with merlin loss.

Microlens-aided focusing of linearly and azimuthally polarized laser light.

We have investigated a four-sector transmission polarization converter (4-SPC) for a wavelength of 633 nm, that enables the conversion of a linearly polarized incident beam into a mixture of linearly and azimuthally polarized beams. It was numerically shown that by placing a Fresnel zone plate of focal length 532 nm immediately after the 4-SPC, the incident light can be focused into an oblong subwavelength focal spot whose size is smaller than the diffraction limit (with width and breadth, respectively, measuring FWHM = 0.28λ and FWHM = 0.45λ, where λ is the incident wavelength and FWHM stands for full-width at half maximum of the intensity). After passing through the 4-SPC, light propagates in free space over a distance of 300 µm before being focused by a Fresnel zone plate (ZP), resulting in focal spot measuring 0.42λ and 0.81λ. The focal spot was measured by a near-field microscope SNOM, and the transverse E-field component of the focal spot was calculated to be 0.42λ and 0.59λ. This numerical result was verified experimentally, giving a focal spot of smaller and larger size, respectively, measuring 0.46λ and 0.57λ. To our knowledge, this is the first implementation of polarization conversion and subwavelength focusing of light using a pair of transmission micro-optic elements.

Malformations of the gill filaments of the ruffe Gymnocephalus cernuus (L.) (Pisces) caused by echinostomatid metacercariae.

In parasite surveys of fishes from Lake Balaton and its tributaries in Hungary, infections with metacercariae of a species of the digenean genus Echinochasmus (Trematoda: Echinostomatidae) were found in seven species of fish. In ruffe, Gymnocephalus cernuus, malformations of the gill filaments apparently caused by these infections were observed. These malformations were in the form of bifurcations of the filaments at about their mid-length. At the point where the filaments bifurcate, an Echinochasmus metacercaria was always embedded in the cartilaginous ray of the gill filament. All specimens of the ruffe were found to be infected by these metacercariae, and each ruffe specimen was infected by 30-300 metacercariae. Such a bifurcation was found in all of the ruffe specimens, but, apart from these gill malformations, the metacercariae produced only local changes in the cartilage. In the other six infected fish species, only local signs were observed in the cartilage. Experimental infections of chicks with metacercariae resulted in the finding of the sexual adult (marita) of an unidentified species of Echinochasmus. ITS sequences of the adult and metacercaria corresponded with each other, and also with a cercaria isolated from a gravel snail (Lithoglyphus naticoides), with a 99.5-100% similarity.

Estrogen-dependent regulation of human uterine natural killer cells promotes vascular remodelling via secretion of CCL2.

STUDY QUESTION: Does intrauterine biosynthesis of estrogen play an important role in early pregnancy by altering the function of uterine natural killer (uNK) cells? SUMMARY ANSWER: Estrogens directly regulate the function of human uNK cells by increasing uNK cell migration and secretion of uNK cell-derived chemokine (C-C motif) ligand 2 (CCL2) that critically facilitates uNK-mediated angiogenesis. WHAT IS KNOWN ALREADY: uNK cells are a phenotypically distinct population of tissue-resident immune cells that regulate vascular remodelling within the endometrium and decidua. Recently we discovered that decidualisation of human endometrial stromal cells results in the generation of an estrogen-rich microenvironment in areas of decidualised endometrium. We hypothesize that intrauterine biosynthesis of estrogens plays an important role in early pregnancy by altering the function of uNK cells. STUDY DESIGN, SIZE, DURATION: This laboratory-based study used primary human uNK cells which were isolated from first trimester human decidua (n = 32). PARTICIPANTS/MATERIALS, SETTING, METHODS: Primary uNK cells were isolated from first trimester human decidua using magnetic cell sorting. The impact of estrogens on uNK cell function was assessed. Isolated uNK cells were treated with estrone (E1, 10(-8) M) or estradiol (E2, 10(-8) M) alone or in combination with the anti-estrogen ICI 182 780 (ICI, 10(-6) M). uNK cell motility was assessed by transwell migration assay and time-lapse microscopy. Expression of chemokine receptors was assessed by quantitative PCR (qPCR) and immunohistochemistry, and angiogenic factors were assessed by qPCR and cytokine array. Concentrations of CCL2 in supernatants were measured by enzyme-linked immunosorbent assay. Angiogenesis was assessed in a human endometrial endothelial cell network formation assay. MAIN RESULTS AND THE ROLE OF CHANCE: Treatment with either E1 or E2 increased uNK cell migration (P = 0.0092 and P = 0.0063, respectively) compared with control. Co-administration of the anti-estrogen ICI blocked the effects of E1 and E2 on cell migration. Concentrations of C-X-C chemokine receptor type 4 (CXCR4) mRNA in uNK cells were increased by E2 treatment. The network formation assay revealed that conditioned media from uNK cells treated with E2 significantly increased human endometrial endothelial cell (HEEC) angiogenesis (P = 0.0029 versus control). Analysis of media from uNK cells treated with E2 using an antibody array identified CCL2 as the most abundant cytokine. Validation assays confirmed concentrations of CCL2 mRNA and protein were increased by E2 in uNK cells (P < 0.05 versus controls). Compared with the control, recombinant human CCL2 was found to increase HEEC network formation (P < 0.05) and neutralization of CCL2 in uNK conditioned media significantly decreased E2-dependent uNK-mediated network formation (P = 0.0006). LIMITATIONS, REASONS FOR CAUTION: Our results are based on in vitro responses of primary human cells and we cannot be certain that similar mechanisms occur in vivo in humans. Primary human uNK cells were isolated from first trimester decidua at a range of gestations (8-12 weeks), which may be a source of variation. Primary human uNK cells from non-pregnant endometrium were not assessed and therefore the responses of uNK cells to E2 treatment described in this study may be distinct to uNK cells from first trimester decidua. WIDER IMPLICATIONS OF THE FINDINGS: E2 is an essential regulator of reproductive competence. This study demonstrates a critical role for E2 in regulating cellular cross-talk within the endometrium during early pregnancy. We provide the first evidence that E2 directly regulates the function of human uNK cells by altering uNK cell migration and the secretion of uNK-derived angiogenic factors. We describe a novel mechanism of estrogen-dependent secretion of CCL2 which critically mediates uNK-dependent endometrial angiogenesis. Dysregulation of uNK cell function has been implicated in the aetiology of early implantation disorders and disorders of pregnancy. These novel findings provide unique insight into the regulation of uNK cell activity during the establishment of pregnancy in women and highlight key processes which may be targeted in future therapeutic strategies. STUDY FUNDING/COMPETING INTERESTS: Studies undertaken in the authors' laboratory were supported by MRC Programme Grant G1100356/1 to P.T.K.S. The authors have no conflicts of interest to disclose.

Subclassification of small bowel Crohn's disease using magnetic resonance enterography: a review using evidence-based medicine methodology.

Magnetic resonance enterography (MRE) has a growing role in imaging small bowel Crohn's disease (SBCD), both in diagnosis and assessment of treatment response. Certain SBCD phenotypes respond well to biologic therapy and others require surgery; MRE has an expanding role in triaging these patients. In this review, we evaluate the MRE signs that subclassify SBCD using evidence-based medicine (EBM) methodology and provide a structured approach to MRE interpretation.

Plasma IL-6 levels correlate with clinical and ultrasound measures of arthritis in patients with systemic lupus erythematosus.

OBJECTIVE: The objective of this paper is to elucidate the role of specific cytokines in lupus (SLE) arthritis. METHODS: Fifty SLE and 40 RA patients had an ultrasound (US) scan of their hand as per standardized protocols. US scores were expressed per joint and as a total 'US activity' score, (sum of power Doppler (PD) and grey-scale synovial hypertrophy scores in all joints) and a total erosion score. SLE disease activity was assessed (BILAG and SELENA-SLEDAI). Plasma levels of IL-6, TNF-alpha and BLyS were measured using sandwich ELISA kits (Quantikine kits, R & D). RESULTS: On the basis of the US results SLE patients were divided into three groups: erosive arthritis (n = 20), non-erosive arthritis (n = 18) and those with a normal US scan (n = 12). Across the SLE groups plasma IL-6 levels correlated with CRP (p < 0.001), hand deformity scores (p = 0.005), BILAG musculoskeletal score (p = 0.009), wrist PD score (p = 0.01), the presence of tenosynovitis (p = 0.008) and total US activity score (p < 0.001) (which remained constant when corrected for total BILAG score). Neither TNF-alpha nor BLyS levels correlated with US or clinical measures of lupus arthritis; however, TNF-alpha correlated with total BILAG score (p < 0.001). CONCLUSION: This is the first study to examine levels of specific cytokines in a cohort of SLE patients stratified in terms of joint disease by US, where the most significant finding is that IL-6 levels correlated both with clinical and US measures of arthritis disease activity.

Rapid on-site assessment of specimens by biomedical scientists improves the quality of head and neck fine needle aspiration cytology.

OBJECTIVE: Immediate rapid on-site assessment (ROSA) of fine needle aspiration cytology (FNAC) specimens by biomedical scientists (BMS), the UK equivalent of cytotechnologists, or by pathologists may improve specimen quality and cellular adequacy rates for lymph node, head and neck and thyroid FNAC. The aim of this study was to evaluate the effect of introducing ROSA by BMS in an outpatient clinic setting. METHODS: The adequacy rate and sensitivity of histological diagnosis for lymph node, thyroid and salivary gland FNAC samples were determined before and after the introduction of BMS ROSA. The additional financial costs and time required to perform this service were also estimated. RESULTS: Thirty-one patients underwent ultrasound (US)-guided FNAC with ROSA and 151 without. ROSA reduced the number of FNAC insufficient in quality for diagnosis from 43% to 19% (P = 0.0194). The estimated additional cost for pathology per patient for ROSA was between £52.05 and £70.74, equivalent to €65.40/US $83.90 and €88.89/US $114.0, respectively, an increase of between 28% and 49% from the original cost. ROSA necessitated an additional 6 minutes clinic time per patient, reducing the number of patients that could be seen in an average clinic from 13 to 10 as well as requiring increased laboratory time for FNAC slide assessment. CONCLUSION: ROSA by suitably trained biomedical scientists and with appropriate consultant pathologist support can improve the quality of FNAC sampling for head and neck lesions. Although ROSA resulted in both additional financial and time costs, these are more than likely to be offset by a reduction in patients returning to clinic for repeat FNAC or undergoing unnecessary surgery.

Sampler for collection and analysis of low vapor pressure chemical (LVPC) particulates/aerosols.

Detection of low vapor pressure chemicals (LVPCs) such as pesticides and other toxic/hazardous materials on various environmental surfaces as well as LVPC aerosols is a significant challenge for current vapor phase detectors. We describe a novel sampling device which utilizes stainless steel screens coated with a sticky polydimethylsiloxane coating for collecting LVPCs aerosolized off of a surface. Results are presented for the collection and detection of a pesticide simulant, dimethyl methylphosphonate sorbed onto silica gel (DMMP/SG), using direct analysis in real time-cylindrical ion trap mass spectrometry (DART-CITMS).

Iturin levels on wheat spikes linked to biological control of Fusarium head blight by Bacillus amyloliquefaciens.

The TrigoCor strain of Bacillus amyloliquefaciens provides consistent control against Fusarium head blight of wheat in controlled settings but there is a lack of disease and deoxynivalenol suppression in field settings. Since production of antifungal compounds is thought to be the main mode of action of TrigoCor control, we quantified levels of a key family of antifungal metabolites, iturins, as well as monitored Bacillus populations on wheat spikes over 14 days post-application in both the greenhouse and the field. We found that initial iturin levels on spikes in the greenhouse were three times greater than on spikes in the field, but that by 3 days post-application, iturin levels were equivalent and very low in both settings. We also determined that iturins declined rapidly over a 3-day post-application period on wheat spikes in both environments, despite the presence of significant Bacillus populations. Greenhouse trials and antibiosis tests indicated that the lower iturin levels on wheat spikes in the field could be a major factor limiting disease control in field settings. Future efforts to improve Bacillus disease control on wheat spikes and in the phyllosphere of various plants should focus on maintaining higher levels of iturins over critical infection periods.