Integrated microwave photonic notch filter using a heterogeneously integrated Brillouin and active-silicon photonic circuit

Microwave photonics (MWP) has unlocked a new paradigm for Radio Frequency (RF) signal processing by harnessing the inherent broadband and tunable nature of photonic components. Despite numerous efforts made to implement integrated MWP filters, a key RF processing functionality, it remains a long-standing challenge to achieve a fully integrated photonic circuit that can merge the megahertz-level spectral resolution required for RF applications with key electro-optic components. Here, we overcome this challenge by introducing a compact 5 mm × 5 mm chip-scale MWP filter with active E-O components, demonstrating 37 MHz spectral resolution. We achieved this device by heterogeneously integrating chalcogenide waveguides, which provide Brillouin gain, in a complementary metal-oxide-semiconductor (CMOS) foundry-manufactured silicon photonic chip containing integrated modulators and photodetectors. This work paves the way towards a new generation of compact, high-resolution RF photonic filters with wideband frequency tunability demanded by future applications, such as air and spaceborne RF communication payloads.

Faculty clinical articles: a regular update for the oral healthcare team

The Faculty of Dental Surgery of the Royal College of Surgeons of England and British Dental Journal have teamed up to provide a regular series of short articles on different aspects of clinical and academic dentistry. This series will provide concise insight into a diverse range of topics with the aim of providing regular ongoing professional development for all members of the oral healthcare team. We begin here, with a short update on the Faculty and overview of the series' aims.

The Faculty of Dental Surgery at the Royal College of Surgeons of England and British Dental Journal have teamed up to provide a regular series of short articles on different aspects of clinical and academic dentistry.

Aims to provide insight into a diverse range of topics commissioned from a wide spectrum of authors in an accessible and succinct format.

This initiative coincides with a new era for the FDSRCS and Royal College of Surgeons of England as the faculty moves into a new building, and combined with the British Dental Journal, it is hoped that this series will be enjoyed by all members of the oral healthcare team.

High-resolution Spatiotemporal Dynamics of Harmful Algae in the Indian River Lagoon (Florida)-A Case Study of Aureoumbra lagunensis, Pyrodinium bahamense, and Pseudo-nitzschia

The Indian River Lagoon (IRL), located on the east coast of Florida, is a complex estuarine ecosystem that is negatively affected by recurring harmful algal blooms (HABs) from distinct taxonomic/functional groups. Enhanced monitoring was established to facilitate rapid quantification of three recurrent bloom taxa, Aureoumbra lagunensis, Pyrodinium bahamense, and Pseudo-nitzschia spp., and included corroborating techniques to improve the identification of small-celled nanoplankton (<10 μm in diameter). Identification and enumeration of these target taxa were conducted during 2015-2020 using a combination of light microscopy and species-specific approaches, specifically immunofluorescence flow cytometry as well as a newly developed qPCR assay for A. lagunensis presented here for the first time. An annual bloom index (ABI) was established for each taxon based on occurrence and abundance data. Blooms of A. lagunensis (>2×10⁸ cells L^-1) were observed in all six years sampled and across multiple seasons. In contrast, abundance of P. bahamense, largely driven by the annual temperature cycle that moderates life cycle transitions and growth, displayed a strong seasonal pattern with blooms (10⁵-10⁷ cells L^-1) generally developing in early summer and subsiding in autumn. However, P. bahamense bloom development was delayed and abundance was significantly lower in years and locations with sustained A. lagunensis blooms. Pseudo-nitzschia spp. were broadly distributed with sporadic bloom concentrations (reaching 10⁷ cells L^-1), but with minimal concentrations of the toxin domoic acid detected (<0.02 μg L^-1). In summer 2020, multiple monitoring tools characterized a novel nano-cyanobacterium bloom (reaching 10⁹ cells L^-1) that coincided with a decline in A. lagunensis and persisted into autumn. Statistical and time-series analyses of this spatiotemporally intensive dataset highlight prominent patterns in variability for some taxa, but also identifies challenges of characterizing mechanisms underlying more episodic yet persistent events. Nevertheless, the intersect of temperature and salinity as environmental proxies proved to be informative in delineating niche partitioning, not only in the case of taxa with long-standing data sets but also for seemingly unprecedented blooms of novel nanoplanktonic taxa.

TAMI-31. GLIOBLASTOMA GENETIC DRIVERS DICTATE THE FUNCTION OF TUMOR-ASSOCIATED MACROPHAGES/MICROGLIA AND RESPONSES TO CSF1R INHIBITION

Tumor-associated macrophages/microglia (TAMs) are prominent microenvironment components in human glioblastoma (GBM) that are potential targets for anti-tumor therapy. However, TAM depletion by CSF1R inhibition showed mixed results in clinical trials. We hypothesized that GBM subtype-specific tumor microenvironment convey distinct sensitivities to TAM targeting. We generated syngeneic PDGFB-driven and RAS-driven GBM models that resemble proneural-like and mesenchymal-like gliomas, and determined the effect of TAM targeting by CSF1R inhibitor PLX3397 on glioma growth and progression. We also investigated the co-targeting of TAMs and angiogenesis on PLX3397-resistant RAS-driven GBM. Using single-cell transcriptomic profiling, we further explored differences in tumor microenvironment compositions and functions between the proneural-like and mesenchymal-like glioma models. We found that the growth of PDGFB-driven tumors was markedly inhibited by PLX3397. In contrast, depletion of TAMs at the early phase accelerated RAS-driven tumor growth and had no effects on other proneural and mesenchymal human GBM models. In addition, PLX3397-resistant RAS-driven tumors did not respond to PI3K signaling inhibition. Single-cell transcriptomic profiling revealed that PDGFB-driven gliomas induced expansion and activation of pro-tumor microglia, whereas mesenchymal RAS-driven gliomas elicited TAMs enriched in pro-inflammatory and angiogenic signaling. Co-targeting of TAMs and angiogenesis decreased cell proliferation and tumor mass in RAS-driven gliomas. Our work identifies functionally distinct TAM subpopulations in the growth of different glioma subtypes. Notably, we uncover a potential responsiveness of resistant mesenchymal-like gliomas to combined anti-angiogenic therapy and CSF1R inhibition. These data highlight the importance of microenvironment landscape characterization to optimally stratify glioma patients for TAM-targeted therapy.

Proton pump inhibitor use and the risk of peritoneal dialysis associated peritonitis

BACKGROUND

The use of proton-pump inhibitors (PPI) has been associated with an increased risk of developing spontaneous bacterial peritonitis in patients with cirrhosis. Whether PPI use confers a similar risk in developing peritonitis in peritoneal dialysis (PD) patients remains unclear.

METHODS

Patients on PD were retrospectively identified. Data such as PPI use during PD, underlying diagnoses, comorbidities, and baseline serum tests were collected. Univariable and multivariable analysis was conducted using logistic regression to assess whether PPI use and other factors were associated with PD peritonitis.

RESULTS

57 patients were identified with a median(interquartile range(IQR)) age of 65.0(51.5-74.0) years. The median(IQR) time on PD was 29.0(17.5-45.0) months. 28 patients were on a PPI during PD. 57% of the PPI group went on to develop peritonitis, compared to 31% of patients without PPI exposure (OR=2.96, 95% CI:[1.00, 8.78], p=0.050). Months on PD (OR=1.03, 95% CI:[1.00, 1.06], p=0.026), serum urea (OR=0.88, 95% CI:[0.80, 0.97], p=0.017), congestive cardiac failure (OR=5.44, 95% CI:[1.29, 23.00], p=0.021) and renovascular disease (OR=14.59, 95% CI:[1.68, 126.67], p=0.015) were identified as possible risk factors for peritonitis on univariable analysis. Following adjustment for covariates, serum urea, but not PPI use, was associated with PD peritonitis (OR=0.87, 95% CI:[0.78,0.98], p=0.020).

CONCLUSION

PPI use during PD was not associated with peritonitis. Due to the small number of patients and the limited number of studies investigating the effect of PPI use on PD peritonitis, further research is needed. This article is protected by copyright. All rights reserved.

OLIG2 maintenance is not essential for diffuse intrinsic pontine glioma cell line growth but regulates tumor phenotypes

BACKGROUND

Diffuse intrinsic pontine glioma (DIPG) is a pediatric lethal high-grade brainstem glioma with no effective therapies. OLIG2 (oligodendrocyte transcription factor 2) was reported to be critical for the growth of a DIPG cell line CCHMC-DIPG-1. Surprisingly, we found that the CCHMC-DIPG-1 cells express little OLIG2 and exhibit a mesenchymal phenotype, which raised a question regarding the role of OLIG2 in the growth of DIPG cells.

METHODS

We evaluated the function of OLIG2 in different DIPG cell lines through molecular and genetic approaches and performed transcriptomic and genomic landscape profiling including whole-genome bisulfite sequencing, RNA-seq, ATAC-seq, and ChIP-seq. shRNA-mediated knockdown and CRISPR-Cas9-mediated knockout approaches were utilized to assess OLIG2 functions in DIPG cell growth.

RESULTS

We found that DIPG cells are phenotypically heterogeneous and exhibit the characteristics of distinct malignant gliomas including proneural, classical, and mesenchymal subtypes. OLIG2 knockdown did not impact the growth of CCHMC-DIPG-1 cells, wherein OLIG2 is epigenetically silenced. Moreover, OLIG2 deletion did not substantially impair OLIG2-expressing proneural-like DIPG growth but led to an upregulation of HIPPO-YAP1 and epidermal growth factor receptor (EGFR) signaling and a tumor phenotype shift. Targeting HIPPO-YAP1 and EGFR signaling in OLIG2-deficient DIPG cells inhibited tumor cell growth.

CONCLUSIONS

Our data indicate that OLIG2 is dispensable for DIPG growth but regulates the phenotypic switch of DIPG tumor cells. OLIG2 downregulation leads to deregulation of adaptive YAP1 and EGFR signaling. Targeting YAP1 and EGFR pathways inhibits the growth of OLIG2-deficient DIPG cells, pointing to a therapeutic potential by targeting adaptive signaling to treat DIPG tumors with nominal OLIG2 expression.

Trends and outcomes of open, laparoscopic, and robotic inguinal hernia repair in the veterans affairs system

PURPOSE

Robotic inguinal hernia repair (RHR) is an evolving technique but is comparatively expensive and has yet to show superior outcomes versus open (OHR) or laparoscopic (LHR) approaches. The utilization and clinical outcomes of RHR have not been reported within the veterans affairs (VA) system. This study analyzes trends in utilization and 30-day post-operative outcomes between OHR, LHR, and RHR in veterans.

METHODS

This is a retrospective review of patients that underwent inguinal herniorrhaphy using the Veterans Affairs Quality Improvement Program database. Multivariable analysis of outcomes was performed adjusting for pre-operative confounding covariates between OHR, LHR, and RHR. Trends in utilization, complication rates, and operative times were also reported.

RESULTS

From 2008-2019, 124,978 cases of inguinal herniorrhaphy were identified: 100,880 (80.7%) OHR, 18,035 (14.4%) LHR, and 6063 (4.9%) RHR. Compared to LHR, RHR was associated with 4.94 times higher odds of complications, 100 min longer mean operative time, and 1.5 days longer median length of stay (LOS). Compared to OHR, RHR was associated with 5.92 times higher odds of complications, 57 min longer mean operative time, and 1.1 days longer median LOS. Utilization of RHR and LHR significantly increased over time. RHR complication rates decreased over time (2008: 20.8% to 2019: 3.2%) along with mean operative times (2008: 4.9 h to 2019: 2.8 h; p < 0.05).

CONCLUSION

While this study demonstrated inferior outcomes after RHR, the temporal trends are encouraging. This may be due to increased surgeon experience with robotics. Further prospective data will elucidate the role of RHR as this technique increases.

Human myelomeningocele risk and ultra-rare deleterious variants in genes associated with cilium, WNT-signaling, ECM, cytoskeleton and cell migration

Myelomeningocele (MMC) affects one in 1000 newborns annually worldwide and each surviving child faces tremendous lifetime medical and caregiving burdens. Both genetic and environmental factors contribute to disease risk but the mechanism is unclear. This study examined 506 MMC subjects for ultra-rare deleterious variants (URDVs, absent in gnomAD v2.1.1 controls that have Combined Annotation Dependent Depletion score ≥ 20) in candidate genes either known to cause abnormal neural tube closure in animals or previously associated with human MMC in the current study cohort. Approximately 70% of the study subjects carried one to nine URDVs among 302 candidate genes. Half of the study subjects carried heterozygous URDVs in multiple genes involved in the structure and/or function of cilium, cytoskeleton, extracellular matrix, WNT signaling, and/or cell migration. Another 20% of the study subjects carried heterozygous URDVs in candidate genes associated with gene transcription regulation, folate metabolism, or glucose metabolism. Presence of URDVs in the candidate genes involving these biological function groups may elevate the risk of developing myelomeningocele in the study cohort.

Low-RF-loss and large-rejection reconfigurable Brillouin-based RF photonic bandpass filter

We present a high-performance radio frequency (RF) photonic bandpass filter enabled by combining on-chip Brillouin scattering with a suppressed carrier phase modulation scheme. We achieve a low RF loss of 5 dB and a large stopband rejection of more than 40 dB, which represents a significant improvement of 20 dB to the RF passband gain and 31 dB to the RF rejection ratio over traditional modulation schemes under the same optical power consumption. We further demonstrate filter reconfigurability including multiple passbands, wide frequency (1-20 GHz), and bandwidth tunability (30-350 MHz) without compromising the RF performance.

CBMT-31. HDAC INHIBITION DIMINISHES THE GROWTH OF ENDOGENOUS IDH MUTANT GLIOMAS

Histone deacetylase inhibitors (HDACi’s) have emerged as a promising class of drugs for treatment of malignancies such as glioblastoma (GBM). Several studies have demonstrated the anti-tumor property of HDACi’s against GBM in both in vitro and in vivo experiments. Nonetheless, in clinical trials, HDACi only marginally increased overall survival of patients with GBM. The mixed results of trials with HDACi’s in glioma have prompted us to hypothesize that improved selection of patients by tumor characteristics could enhance the efficacy of therapy. We specifically tested the effects of valproic acid (VPA), a HDACi and an antiepileptic drug against IDH mutant gliomas. We have previously demonstrated that our IDH mutant glioma cell lines have gene expression and methylation patterns highly similar to IDH mutant tumors in situ. Mutant IDH1 alters the epigenetic landscape of gliomas leading to the hypermethylation phenotype and transcriptional repression of genes. This repression of genes may contribute to tumorigenesis and progression of IDH mutant gliomas. We found that VPA inhibits the growth of patient-derived IDH1 mutant glioma lines. In addition, RNA sequencing analysis of vehicle and VPA-treated IDH1 mutant glioma cells showed de-repression of several genes previously shown to be downregulated in IDH1 mutant glioma cell lines. We also treated cells with another HDACi LBH589 and found that both VPA and LBH589 upregulates similar gene sets suggesting that HDAC inhibition promotes de-repression of previously repressed genes. Ongoing studies are aimed at determining the molecular mechanism by which VPA regulates the growth of IDH1 mutant tumors.

RADI-14. FRAMELESS STEREOTACTIC RADIOSURGERY ON THE GAMMA KNIFE ICON: EARLY EXPERIENCE FROM 42 PATIENTS WITH BRAIN METASTASES

BACKGROUND: The Gamma Knife (GK) Icon uses a Cone-Beam CT (CBCT) scanner and an infrared camera system to support the delivery of frameless radiosurgery. There are limited data on patients treated with frameless GK radiosurgery (GKRS) for brain metastases. OBJECTIVE: To describe the early experience, process, technical details, and short-term outcomes with frameless GKRS for brain metastases at our institution. METHODS: We describe our patient selection and workflow for frameless GKRS in detail. Because of the short interval of follow-up, we provide crude rates of local control. RESULTS: 42 patients had a total of 96 brain metastases. Median age was 69. 77 intact lesions were treated definitively, 18 cavities postoperatively, and 1 had GKRS for recurrence after resection. 11 patients underwent repeat GKRS to the same area. Median dose was 20Gy in 1 fraction (range: 14–21), 24Gy in 3 fractions (range: 19.5–27), and 25Gy in 5 fractions (Range: 25–30). Median treatment time was 23.7 minutes (Range: 7.3 – 85.5). 29 patients had a follow-up MRI in our records after completing GKRS. Median follow-up time was 105 days (Range: 16 – 314). 16 local recurrences (LR) were identified in 9 patients. An additional 6 patients had distant brain recurrence without LR. Crude mean time between GKRS and LR was 101 days (range 44–161 days). There were 6 patients with grade 1, 3 with grade 2, 2 with grade 3, and 1 with grade 4 toxicity. We found an improvement in workflow and a greater number of patients eligible for GKRS due to the ability to fractionate treatments. CONCLUSION: We report a large cohort of consecutive patients with brain metastases treated with frameless GKRS. We look forward to studies with longer follow-up to provide valuable data on clinical outcomes and to further our understanding of the radiobiology of hypofractionation in the brain.

Metabolic characterization of isocitrate dehydrogenase (IDH) mutant and IDH wildtype gliomaspheres uncovers cell type-specific vulnerabilities

Background

There is considerable interest in defining the metabolic abnormalities of IDH mutant tumors to exploit for therapy. While most studies have attempted to discern function by using cell lines transduced with exogenous IDH mutant enzyme, in this study, we perform unbiased metabolomics to discover metabolic differences between a cohort of patient-derived IDH1 mutant and IDH wildtype gliomaspheres.

Methods

Using both our own microarray and the TCGA datasets, we performed KEGG analysis to define pathways differentially enriched in IDH1 mutant and IDH wildtype cells and tumors. Liquid chromatography coupled to mass spectrometry analysis with labeled glucose and deoxycytidine tracers was used to determine differences in overall cellular metabolism and nucleotide synthesis. Radiation-induced DNA damage and repair capacity was assessed using a comet assay. Differences between endogenous IDH1 mutant metabolism and that of IDH wildtype cells transduced with the IDH1 (R132H) mutation were also investigated.

Results

Our KEGG analysis revealed that IDH wildtype cells were enriched for pathways involved in de novo nucleotide synthesis, while IDH1 mutant cells were enriched for pathways involved in DNA repair. LC-MS analysis with fully labeled ¹³C-glucose revealed distinct labeling patterns between IDH1 mutant and wildtype cells. Additional LC-MS tracing experiments confirmed increased de novo nucleotide synthesis in IDH wildtype cells relative to IDH1 mutant cells. Endogenous IDH1 mutant cultures incurred less DNA damage than IDH wildtype cultures and sustained better overall growth following X-ray radiation. Overexpression of mutant IDH1 in a wildtype line did not reproduce the range of metabolic differences observed in lines expressing endogenous mutations, but resulted in depletion of glutamine and TCA cycle intermediates, an increase in DNA damage following radiation, and a rise in intracellular ROS.

Conclusions

These results demonstrate that IDH1 mutant and IDH wildtype cells are easily distinguishable metabolically by analyzing expression profiles and glucose consumption. Our results also highlight important differences in nucleotide synthesis utilization and DNA repair capacity that could be exploited for therapy. Altogether, this study demonstrates that IDH1 mutant gliomas are a distinct subclass of glioma with a less malignant, but also therapy-resistant, metabolic profile that will likely require distinct modes of therapy.

A Simple Automated Method for Detecting Recurrence in High-Grade Glioma

Our aim was to develop an automated multiparametric MR imaging analysis of routinely acquired imaging sequences to identify areas of focally recurrent high-grade glioma. Data from 141 patients treated with radiation therapy with a diagnosis of high-grade glioma were reviewed. Strict inclusion/exclusion criteria identified a homogeneous cohort of 12 patients with a nodular recurrence of high-grade glioma that was amenable to focal re-irradiation (cohort 1). T1WI, FLAIR, and DWI data were used to create subtraction maps across time points. Linear regression was performed to identify the pattern of change in these 3 imaging sequences that best correlated with recurrence. The ability of these parameters to guide treatment decisions in individual patients was assessed in a separate cohort of 4 patients who were treated with radiosurgery for recurrent high-grade glioma (cohort 2). A leave-one-out analysis of cohort 1 revealed that automated subtraction maps consistently predicted the radiologist-identified area of recurrence (median area under the receiver operating characteristic curve = 0.91). The regression model was tested in preradiosurgery MRI in cohort 2 and identified 8 recurrent lesions. Six lesions were treated with radiosurgery and were controlled on follow-up imaging, but the remaining 2 lesions were not treated and progressed, consistent with the predictions of the model. Multiparametric subtraction maps can predict areas of nodular progression in patients with previously treated high-grade gliomas. This automated method based on routine imaging sequences is a valuable tool to be prospectively validated in subsequent studies of treatment planning and posttreatment surveillance.

Ethnicity and risk of lower limb amputation in people with Type 2 diabetes: a prospective cohort study

AIM

Lower limb amputation is a serious complication of diabetic foot disease and there are unexplained ethnic variations in incidence. This study investigates the risk of amputation among different ethnic groups after adjusting for demographic, socio-economic status and clinical variables.

METHODS

We used primary care data from a large national multi-ethnic cohort of patients with Type 2 diabetes in New Zealand and linked hospital records. The primary outcome was time from initial data collection to first lower limb amputation. Demographic variables included age of onset and duration since diabetes diagnosis, gender, ethnicity and socio-economic status. Clinical variables included smoking status, height and weight, blood pressure, HbA1c , total cholesterol/HDL ratio and albuminuria. Cox proportional hazards models were used.

RESULTS

There were 892 lower limb amputations recorded among 62 002 patients (2.11 amputations per 1000 person-years), followed for a median of 7.14 years (422 357 person-years). After adjusting for demographic and socio-economic variables and compared with Europeans, Māori had the highest risk [hazard ratio (HR) 1.84 (95%CI:1.54-2.19)], whereas East Asians [HR 0.18, (0.08-0.44)] and South Asians [HR 0.39 (0.22-0.67)] had the lowest risk. Adjusting for available clinical variables reduced the differences but they remained substantial [HR 1.61 (1.35-1.93), 0.23 (0.10-0.56) and 0.48 (0.27-0.83), respectively].

CONCLUSIONS

Ethnic groups had significantly different risk of lower limb amputation, even after adjusting for demographic and some major clinical risk factors. Barriers to care should be addressed and intensive prevention strategies known to reduce the incidence of lower limb amputations could be prioritized to those at greatest risk.

Phenomenological Model of the Growth of Ultrasmooth Silver Thin Films Deposited with a Germanium Nucleation Layer

The structural properties of optically thin (15 nm) silver (Ag) films deposited on SiO2/Si(100) substrates with a germanium (Ge) nucleation layer were studied. The morphological and crystallographical characteristics of Ag thin films with different Ge nucleation layer thicknesses were assessed by cross-sectional transmission electron microscopy (XTEM), reflection high-energy electron diffraction (RHEED), X-ray diffractometry (XRD), grazing incidence X-ray diffractometry (GIXRD), X-ray reflection (XRR), and Fourier transform infrared spectroscopy (FTIR). The surface roughness of Ag thin films was found to decrease significantly by inserting a Ge nucleation layer with a thickness in the range of 1 to 2 nm (i.e., smoothing mode). However, as the Ge nucleation layer thickness increased beyond 2 nm, the surface roughness increased concomitantly (i.e., roughing mode). For the smoothing mode, the role of the Ge nucleation layer in the Ag film deposition is discussed by invoking the surface energy of Ge, the bond dissociation energy of Ag-Ge, and the deposition mechanisms of Ag thin films on a given characteristic Ge nucleation layer. Additionally, Ge island formation, the precipitation of Ge from Ag-Ge alloys, and the penetration of Ge into SiO2 are suggested for the roughing mode. This demonstration of ultrasmooth Ag thin films would offer an advantageous material platform with scalability for applications such as optics, plasmonics, and photonics.

Attitudes of patients with metastatic breast cancer toward research biopsies

BACKGROUND

Research studies involving human tissue are increasingly common. However, patients' attitudes toward research biopsies are not well characterized, particularly when the biopsies are carried out outside the context of therapeutic trials.

PATIENTS AND METHODS

One hundred sixty patients with metastatic breast cancer (MBC) from two academic (n = 80) and two community (n = 80) hospitals completed a 29-item self-administered survey to evaluate their willingness to consider providing research purposes only biopsies (RPOBs) (as a stand-alone procedure) and additional biopsies (ABs) (additional needle passes at the time of a clinically indicated biopsy).

RESULTS

Eighty-two (51%) of 160 patients would consider having RPOBs, of which 42 (53%) and 40 (50%) patients were from academic and community hospitals, respectively. Patients who had more prior biopsies were less likely to consider RPOBs (RR = 0.6, 95% CI: 0.4-1.0, P = 0.03). Of 160 patients, 115 (72%) patients would consider having ABs. Of these, 64 (80%) and 51 (64%) patients from academic and community hospitals, respectively, would consider ABs (RR = 1.2, 95% CI: 1.0-1.5, P = 0.03).

CONCLUSIONS

Many patients with MBC in both academic and community settings report willingness to consider undergoing biopsies for research. Further research is needed to understand ethical, logistical and provider-based barriers to broader participation in such studies.

Abstract P2-16-04: Attitudes of metastatic breast cancer patients towards research biopsies

Background: In the era of molecularly targeted therapy, developing an understanding of the molecular basis of cancer is a principal or secondary goal of many research studies. For this reason, studies collecting tissue for research purposes are increasingly common. Understanding patients' attitudes towards research biopsies may lead to improvement in accrual to research biopsy studies.

Methods: Patients with metastatic breast cancer from two academic and two community hospitals completed a self-administered paper survey consisting of 29 questions in clinic to evaluate their willingness to consider providing additional biopsies (additional biopsy performed with a clinically indicated biopsy) and research purposes only biopsies (RPOB) (research biopsy performed as a stand alone procedure).

Results: 160 patients (n = 80 academic, n=80 community) completed the survey, with a response rate of 98%. As expected, demographic variables differed between sites, with patients from academic sites likely to be younger (p = 0.01), more educated (p = 0.002), employed (p = 0.01), have prior trial participation (P &lt;0.001) and have a longer travel time (P &lt;0.0001). 64 (80%) academic patients and 51 (64%) community patients would definitely or probably consider additional biopsies. 42 (53%) academic patients and 40 (50%) community patients would consider RPOB.

In univariate analyses of patients' willingness to have additional biopsies, patients in academic sites were more likely to agree to additional biopsies than those at community sites (RR = 1.2, 95% CI 1.0–1.5, p = 0.03). Statistically significant differences based on demographic characteristics such as age, education, marital status, prior trial participation, number of prior biopsies, and travel time were not observed.

For RPOB, patients having had more prior biopsies were less likely to consider research biopsies (RR = 0.6, 95% CI 0.4–1.0, p = 0.03). The following variables did not reach statistical significance: type of practice, age, education, marital status, prior trial participation, and travel time.

Patients' willingness in both academic and community sites to consider RPOB declined with more invasive biopsies. Although differences were observed, none were statistically significant between academic and community; skin (56%, 65%), bone marrow (30%, 27%), breast (43%, 49%) or liver (24%, 19%).

Of the 13/160 (8%) patients who would not consider additional biopsies, the most common reasons cited included pain or discomfort (n = 8/13, 62%), risk of biopsy (n = 8/13, 62%) and anxiety related to the biopsy (n = 6/13, 46%). Of the 37/160 (23%) patients who would not consider RPOB, the most common reasons cited included pain or discomfort (n = 23/37, 62%), risk of biopsy (n = 15/37, 41%) and inconvenience of the procedure to the patient (n = 13/37, 35%).

Conclusions: The majority of patients in this study indicated they would consider research biopsies, with a larger proportion willing to consider additional biopsies; patients seen at academic hospitals were more likely to consider additional biopsies compared to those seen at community hospitals. Breast cancer patients' willingness to undergo research biopsies may be higher than generally expected by clinicians and may not be the primary barrier to obtaining research biopsies.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-16-04.

Exercise in the community for people with minimal gait impairment due to MS: an assessor-blind randomized controlled trial

Background:

While there is an increasing body of evidence supporting the efficacy of exercise in people with multiple sclerosis (MS), additional information on the effectiveness of combining aerobic and resistance training, and yoga is required.

Objectives:

This study evaluated the effectiveness of community exercise interventions for people with MS having minimal gait impairment.

Methods:

A multi-centred, block-randomised, assessor-blinded, controlled trial was conducted. Participants were randomised in groups of eight to physiotherapist (PT)-led exercise ( n = 80), yoga ( n = 77), fitness instructor (FI)-led exercise ( n = 86) and they took part in weekly community-based group exercise sessions. Those in the control group were asked not to change of their exercise habits ( n = 71). The primary outcome was the Multiple Sclerosis Impact Scale (MSIS) 29v2 physical component, measured before and after the 10-week intervention. Secondary outcomes were the MSIS 29v2 psychological component, the Modified Fatigue Impact Scale (MFIS) and the 6-Minute Walk Test (6MWT).

Results:

The group x time interaction approached significance for the MSIS-29v2 physical component ( f = 2.48, p = 0.061) and MFIS total ( f = 2.50, p = 0.06), and it was significant for the MFIS physical subscale ( f = 4.23, p = 0.006). All three exercise interventions led to a statistically significant improvement on the MSIS-29 psychological component and both the MFIS total and physical subscales, which were greater than the control ( p < 0.05). Only the PT-led and FI-led interventions significantly improved the MSIS-29 physical and 6MWT to levels greater than the control ( p < 0.05).

Conclusions:

This study provides evidence for the positive effect of exercise on the physical impact of MS and fatigue. The group nature of the classes may have contributed to the positive effects seen on the psychological impact of MS.

86 EFFECT OF LACTATION ON EMBRYO DEVELOPMENT DURING THE POSTPARTUM PERIOD IN DAIRY COWS

The aim of this study was to examine the effect of lactation and associated metabolic profiles on the ability of the reproductive tract of postpartum dairy cows to support early embryo development. Twenty-one age-matched primiparous Holstein cows were used. Immediately after calving, half of the cows were dried off while the remainder were milked twice daily. To characterise the metabolic profile of the cows, jugular blood samples were taken twice weekly starting 15 days before calving until Day 100 postpartum. At the same time, bodyweight (BW) and body condition score (BCS) were recorded. In Experiment 1, around Day 60 postpartum, the oestrous cycles of all cows were synchronized and sixty-five 2- to 4-cell in vitro-produced embryos were endoscopically transferred on Day 2 (Day 0 = oestrus) to the oviduct ipsilateral to the corpus luteum. On Day 7, the oviduct and uterus were flushed endoscopically and the number of embryos developing to the blastocyst stage was recorded. In Experiment 2, around Day 95 postpartum, cows were re-synchronized and 15 to 20 in vitro-produced blastocysts were transferred to the uterine horn ipsilateral to the corpus luteum. On Day 14, conceptuses were recovered by flushing the reproductive tract at slaughter and were measured. Jugular blood samples were taken daily from Day 0 to 7 (Exp. 1) or 14 (Exp. 2) to measure serum concentrations of progesterone. Data were analysed by ANOVA. Concentrations of NEFA and β-HB were higher (P ≤ 0.05) and glucose, insulin and IGF-1 were lower (P ≤ 0.05) in lactating compared with dry cows. BW and BCS were significantly higher in the non-lactating cows throughout the postpartum period. Recovery rates in both experiments were similar between groups (Exp. 1: 63.9 ± 7.2 vs 65.6 ± 8.6 and Exp 2: 33.3 ± 9.6 vs 39.8 ± 9.6 for dry and milking cows, respectively). In Exp. 1, of the structures recovered, significantly more developed to the blastocyst stage in the dry than in lactating cows (49.3 ± 3.8 vs 32.6.3 ± 4.4, respectively; P ≤ 0.05). Progesterone concentrations did not differ between groups. In Exp. 2, no differences were observed in terms of conceptus dimensions on Day 14 (n = 152). Progesterone concentrations were higher in lactating cows from Day 9 to 14 (P ≤ 0.05). In conclusion, this study provides evidence that at 60 days postpartum, the reproductive tract of lactating cows is compromised in its ability to support early embryo development compared with age-matched parous non-lactating cows; however, by 95 days postpartum there was no apparent difference in conceptus development, consistent with less metabolic stress as indicated by the metabolic profile. Funded by Science Foundation Ireland (SFI/07/SRC/B1156) and the Spanish Ministry of Science and Innovation (AGL2009-11810). VM was supported by an STSM award from the COST Action FAO7O2.

Harmful algal bloom species and phosphate-processing effluent: field and laboratory studies

In 2002, the Florida Department of Environmental Protection began discharging phosphate-processing effluent into Bishop Harbor, an estuary within Tampa Bay. Because of concerns that the effluent would serve as a nutrient source for blooms of the toxic dinoflagellate Karenia brevis, a field monitoring program was established and laboratory bioassays were conducted. Several harmful algal bloom (HAB) species, including Prorocentrum minimum and Heterosigma akashiwo, were observed in bloom concentrations adjacent to the effluent discharge site. Blooms of diatoms were widespread throughout Bishop Harbor. K. brevis was observed with cell concentrations decreasing with increasing proximity to the effluent discharge site. Bioassays using effluent as a nutrient source for K. brevis resulted in decreased cell yields, increased growth rates, and increased time to log-phase growth. The responses of HAB species within Bishop Harbor and of K. brevis to effluent in bioassays suggested that HAB species differ in their response to phosphate-processing effluent.

Effect of rifampin on the pharmacokinetics of Axitinib (AG-013736) in Japanese and Caucasian healthy volunteers

PURPOSE

Axitinib, a potent and selective inhibitor of vascular endothelial growth factor receptors 1, 2, 3, is metabolized by cytochrome P450 3A4 and glucuronidation. This study evaluated the effect of rifampin, a potent inducer of drug-metabolizing enzymes, on axitinib plasma pharmacokinetics. Equal numbers of Japanese and Caucasian subjects were enrolled to assess the potential differences in axitinib pharmacokinetics between the two ethnicities.

METHODS

Forty healthy volunteers were randomized to receive 5 mg axitinib alone and with 600 mg rifampin.

RESULTS

Rifampin expectedly decreased AUCinf and Cmax of axitinib (geometric mean reduced by 79 and 71%, respectively). However, differences in axitinib pharmacokinetics were not observed between Japanese and Caucasian subjects (geometric mean ratios for axitinib treatment alone for AUCinf and Cmax were 103 and 96%).

CONCLUSIONS

The results support a common axitinib starting dose in both populations. Potent inducers of drug-metabolizing enzymes reduce axitinib exposure and dose adjustments may be needed for optimal efficacy.

Identification and analysis of serpin-family genes by homology and synteny across the 12 sequenced Drosophilid genomes

Background

The Drosophila melanogaster genome contains 29 serpin genes, 12 as single transcripts and 17 within 6 gene clusters. Many of these serpins have a conserved "hinge" motif characteristic of active proteinase inhibitors. However, a substantial proportion (42%) lacks this motif and represents non-inhibitory serpin-fold proteins of unknown function. Currently, it is not known whether orthologous, inhibitory serpin genes retain the same target proteinase specificity within the Drosophilid lineage, nor whether they give rise to non-inhibitory serpin-fold proteins or other, more diverged, proteins.

Results

We collated 188 orthologues to the D. melanogaster serpins from the other 11 Drosophilid genomes and used synteny to find further family members, raising the total to 226, or 71% of the number of orthologues expected assuming complete conservation across all 12 Drosophilid species. In general the sequence constraints on the serpin-fold itself are loose. The critical Reactive Centre Loop (RCL) sequence, including the target proteinase cleavage site, is strongly conserved in inhibitory serpins, although there are 3 exceptional sets of orthologues in which the evolutionary constraints are looser. Conversely, the RCL of non-inhibitory serpin orthologues is less conserved, with 3 exceptions that presumably bind to conserved partner molecules. We derive a consensus hinge motif, for Drosophilid inhibitory serpins, which differs somewhat from that of the vertebrate consensus. Three gene clusters appear to have originated in the melanogaster subgroup, Spn28D, Spn77B and Spn88E, each containing one inhibitory serpin orthologue that is present in all Drosophilids. In addition, the Spn100A transcript appears to represent a novel serpin-derived fold.

Conclusion

In general, inhibitory serpins rarely change their range of proteinase targets, except by a duplication/divergence mechanism. Non-inhibitory serpins appear to derive from inhibitory serpins, but not the reverse. The conservation of different family members varied widely across the 12 sequenced Drosophilid genomes. An approach considering synteny as well as homology was important to find the largest set of orthologues.

Child and family inclusive practice: a pilot program in a community adult mental health service

OBJECTIVE

The aim of this paper is to describe the Child and Family Inclusive Practice program (CFIP), a pilot program implemented in an adult community mental health centre in Newcastle, New South Wales, which aimed to enhance family relationships through child and family inclusive practice.

CONCLUSIONS

The CFIP used a family-focused, child-sensitive approach in which two clinicians met together with families where there was parental mental illness. Adults and children were seen together and separately. Work with parents was aimed at validating their concerns for the child, and enhancing their confidence as parents/carers. Children had the opportunity to express their concerns in a safe and protective environment and, where appropriate, were supported in their concerns if these were being put to the adult family members. The project was seen to add value to the service provision of the community mental health team, and demonstrated to clinical staff the benefits of an inclusive and whole of family approach to mental health care.

Diastolic blood pressure (dBP) and pharmacokinetics (PK) as predictors of axitinib efficacy in metastatic renal cell cancer (mRCC)

5045

Background: Axitinib (AG-013736) is an oral, potent, and selective inhibitor of VEGF receptors 1, 2, 3. An association between dBP elevation and clinical outcome has been previously reported (Rini, ASCO. 2008). The objective of this pooled analysis of two phase II mRCC studies was to explore the relationship between PK, dBP, and clinical efficacy. Methods: PK data from two phase II studies in cytokine-refractory mRCC patients (pts) and 8 single-dose healthy volunteer (HV) studies were included (n = 109 mRCC pts and 240 HV) in the population PK analysis; the efficacy analysis included mRCC pts only. PK data was analyzed using nonlinear mixed-effects modeling to estimate population PK parameters (mean and inter-individual variability). Mean steady-state area under the plasma concentration-time curve (AUC) at the end of cycle 1 and the dBP during axitinib therapy were utilized as predictors of clinical efficacy in the mRCC pts using logistic regression and Kaplan-Meier analyses. Results: The median overall survival (mOS) for mRCC pts with at least 1 dBP measurement ≥90 mmHg (n = 59) during axitinib therapy was 130 weeks vs. 42 weeks (p < 0.01) for pts without any dBP ≥90 mmHg (n = 50). The mOS of pts with an AUC below the median (605 ng.hr/ml; n = 54) was 69 weeks vs. 88 weeks (p > 0.05) for pts with an AUC above the median (n = 55). Among pts with dBP ≥90 mmHg, mOS was 120 weeks and 131 weeks (p > 0.05) for pts with AUC below and above the median (n = 23 and 36), respectively. Among pts without dBP ≥90 mmHg, mOS was 42 weeks and 43 weeks (p > 0.05) for pts with AUC below and above the median (n = 31 and 19), respectively. An 82% increase in probability of a partial response was predicted for a 10 mmHg higher dBP during therapy. There was no apparent correlation between the AUC and maximum dBP during axitinib therapy. Conclusions: dBP ≥90 mmHg during axitinib therapy is a strong predictor of clinical efficacy in patients with mRCC, and is not merely a reflection of higher axitinib drug levels. These data support an ongoing pivotal phase III trial in previously treated mRCC that incorporates a dose-titration scheme based on patient tolerance and BP.

[Table: see text]

Pharmacokinetics/genotype associations for major cytochrome P450 enzymes in native and first- and third-generation Japanese populations: comparison with Korean, Chinese, and Caucasian populations

Application of foreign clinical data across geographic regions can accelerate drug development. Drug disposition can be variable, and identification of factors influencing responsible pharmacokinetic/pharmacogenomic approaches could facilitate the universal application of foreign data and reduce the total amount of phase III clinical trials evaluating risks in different populations. Our objective was to establish and compare genotype (major cytochrome P450 (CYP) enzymes)/phenotype associations for Japanese (native and first- and third-generation Japanese living abroad), Caucasian, Chinese, and Korean populations using a standard drug panel. The mean metabolic ratios (MRs) for the four ethnic groups were similar except for a lower activity of CYP2D6 in Caucasians and CYP2C19 in Asians. Genotype, not ethnicity, impacted the MR for CYP2C9, CYP2C19, and CYP2D6; neither affected CYP1A2, CYP2E1, and CYP3A4/5 activities. We conclude that equivalent plasma drug concentrations and metabolic profiles can be expected for native Japanese, first- and third-generation Japanese, Koreans, and Chinese for compounds handled through these six CYP enzymes.

Comparison of selected skin decontaminant products and regimens against VX in domestic swine

An anesthetized domestic swine model was used to compare the efficacy and cross-contamination potential of selected skin decontaminant products and regimens against the chemical warfare agent, VX. Animals topically exposed to 2×, 3× or 5× LD50 VX showed typical signs of organophosphate nerve agent poisoning, including miosis, salivation, mastication, dysrhythmias, and respiratory distress prior to death. Animals were exposed to 5× LD50 VX and then decontaminated 45 min later with the reactive skin decontamination lotion (RSDL®), Fuller’s earth (FE), 0.5% hypochlorite, or soapy water. Survival was 100% when the reactive skin decontamination lotion or FE was utilized, although 50% of Fuller’s earth-decontaminated animals exhibited serious signs of VX poisoning. Decontamination of VX-treated animals with 0.5% hypochlorite was less effective but also increased survival. Soapy water was ineffective in preventing lethality. Blood cholinesterase levels were not predictive of clinical outcome in decontaminated animals. The potential of “decontaminated” VX in open wounds to cause poisoning was assessed by vigorously mixing 5× LD50 VX with the test decontaminants for 5 min and then placing the mixture onto a full-thickness skin wound. Soapy water was ineffective in preventing lethality. Although treatment with dry Fuller’s earth prevented death and all signs of organophosphate poisoning, a significant proportion of treated animals decontaminated with Fuller’s earth in aqueous suspension exhibited serious signs of organophosphate poisoning, suggesting that live agent may be desorbed from Fuller’s earth when it is exposed to a liquid environment. Animals treated with reactive skin decontamination lotion or 0.5% hypochlorite-VX mixtures showed no signs of organophosphate poisoning during the 6- h test period.

Ice Nucleation and Phase Behavior on Oligo(ethylene glycol) and Hydroxyl Self-Assembled Monolayers: Simulations and Experiments

The nucleation and phase behavior of ultrathin D2O-ice overlayers have been studied on oligo(ethylene glycol) (OEG)-terminated and hydroxyl self-assembled monolayers (SAMs) at low temperatures in ultrahigh vacuum. Infrared reflection-absorption spectroscopy (IRAS) is used to characterize the ice overlayers, the SAMs, and the interactions occurring between the ice and the SAM surfaces. Spectral simulations, based on optical models in conjunction with Maxwell Garnett effective medium theory, point out the importance of including voids in the modeling of the ice structures, with void fractions reaching 60% in some overlayers. The kinetics of the phase transition from amorphous-like to crystalline-like ice upon isothermal annealing at 140 K is found to depend on the conformational state of the supporting OEG SAM surface. The rate is fast on the helical OEG SAMs and slow on the corresponding all-trans SAMs. This difference in kinetics is most likely due to a pronounced D2O interpenetration and binding to the all-trans segments of the ethylene glycol portion of the SAM. No such penetration and binding was observed on the helical OEG SAM.

Clinical anticancer drug development: targeting the cyclin-dependent kinases

Cell division involves a cyclical biochemical process composed of several step-wise reactions that have to occur once per cell cycle. Dysregulation of cell division is a hallmark of all cancers. Genetic and epigenetic mechanisms frequently result in deranged expression and/or activity of cell-cycle proteins including the cyclins, cyclin-dependent kinases (Cdks), Cdk inhibitors and checkpoint control proteins. The critical nature of these proteins in cell cycling raises hope that targeting them may result in selective cytotoxicity and valuable anticancer activity.

Oral tobacco cessation with UK resident Bangladeshi women: a community pilot investigation

Our objective was to establish the short-term outcomes for successful tobacco cessation of a programme offering UK resident Bangladeshi women chewing paan with tobacco nicotine replacement therapy (NRT) in addition to brief advice and encouragement alone. We used a short-term longitudinal, quasi-experimental study design, in the setting of two local authority housing estates in Tower Hamlets, London. Bangladeshi women volunteers were recruited following presentations to community groups. The volunteers were assigned, after matching for age, number of paan with tobacco chewed daily and medical screening, to receive one of two tobacco cessation interventions (NRT with brief encouragement and advice, and brief advice and encouragement alone). The main outcome measures were changes in tobacco use and nicotine dependence, assessed by questionnaire and intake measures, adverse effects, and withdrawal symptoms. In total, 130 volunteers were recruited. Their mean age was 42.5 years (SD = 11.3). Mean number of paan quid with tobacco chewed daily was 10.7 (SD = 9.3) and the average age of starting to add tobacco to paan was 24 years (SD = 12). Ninety-one percent completed the 4-week trial. We found that 19.5% had stopped tobacco use, of whom 22% had received NRT, and 17% brief advice and encouragement alone. The successful members of the NRT group made a significantly greater reduction in their salivary cotinine scores at final review compared to baseline. Oral pain was reported as a barrier to successful oral tobacco cessation by 62% of the volunteers at final review. We conclude that methods identified as helping tobacco smokers successfully stop smoking can be used with Bangladeshi women chewing paan with tobacco. More research is needed to investigate these short-term outcomes and to explore the particular barriers to successful cessation for this group such as oral pain.