Response to Antibiotic Treatment of Bacterial Vaginosis Predicts the Effectiveness of LACTIN-V (Lactobacillus crispatus CTV-05) in the Prevention of Recurrent Disease

OBJECTIVES

Live biotherapeutic products (LBPs) containing vaginal Lactobacillus crispatus are promising adjuvant treatments to prevent recurrent bacterial vaginosis (BV) but may depend on the success of initial antibiotic treatment.

METHODS

A post hoc analysis of data collected during the phase 2b LACTIN-V randomized control trial (L. crispatus CTV-05) explored the impact of clinical BV cure defined as Amsel criteria 0 of 3 (excluding pH, per 2019 Food and Drug Administration guidance) 2 days after completion of treatment with vaginal metronidazole gel on the effectiveness of an 11-week LACTIN-V dosing regimen to prevent BV recurrence by 12 and 24 weeks.

RESULTS

At enrollment, 88% of participants had achieved postantibiotic clinical BV cure. The effect of LACTIN-V on BV recurrence compared with placebo differed by initial clinical BV cure status. The LACTIN-V to placebo risk ratio of BV recurrence by 12 weeks was 0.56 (95% confidence interval, 0.35-0.77) among participants with initial clinical BV cure after metronidazole treatment and 1.34 (95% confidence interval, 0.47-2.23) among participants without postantibiotic clinical BV cure. Among women receiving LACTIN-V, those who had achieved postantibiotic clinical BV cure at enrollment reached higher levels of detectable L. crispatus CTV-05 compared with women failing to achieve postantibiotic clinical BV cure.

CONCLUSIONS

LACTIN-V seems to only decrease BV recurrence in women with clinical cure of BV after initial antibiotic treatment. Future trials of LBPs should consider limiting enrollment to these women.

Economic evaluation of the Very Early Rehabilitation in SpEech (VERSE) intervention

INTRODUCTION

There is limited evidence on the costs and outcomes of patients with aphasia after stroke. The aim of this study was to estimate costs in patients with aphasia after stroke according to the aphasia therapies provided.

METHODS

A three-arm, prospective, randomized, parallel group, open-label, blinded endpoint assessment trial conducted in Australia and New Zealand. Usual ward-based care (Usual Care) was compared to additional usual ward-based therapy (Usual Care Plus) and a prescribed and structured aphasia therapy program in addition to Usual Care (the VERSE intervention). Information about healthcare utilization and productivity were collected to estimate costs in Australian dollars for 2017-18. Multivariable regression models with bootstrapping were used to estimate differences in costs and outcomes (clinically meaningful change in aphasia severity measured by the WAB-R-AQ).

RESULTS

Overall, 202/246 (82%) participants completed follow-up at 26 weeks. Median costs per person were $23,322 (Q1 5,367, Q3 52,669, n = 63) for Usual Care, $26,923 (Q1 7,303, Q3 76,174, n = 70) for Usual Care Plus and $31,143 (Q1 7,001. Q3 62,390, n = 69) for VERSE. No differences in costs and outcomes were detected between groups. Usual Care Plus was inferior (i.e. more costly and less effective) in 64% of iterations, and in 18% was less costly and less effective compared to Usual Care. VERSE was inferior in 65% of samples and less costly and less effective in 12% compared to Usual Care.

CONCLUSION

There was limited evidence that additional intensively delivered aphasia therapy within the context of usual acute care provided was worthwhile in terms of costs for the outcomes gained.

Establishing a Chinese older hip fracture registry for older patients: a Delphi study to define the focus and key variables for this registry

A national hip fracture registry does not yet exist in China. This is the first to recommend a core variable set for the establishment of a Chinese national hip fracture registry. Thousands of Chinese hospitals will build on this and improve the quality of management for older hip fracture patients. The rapidly ageing population of China already experiences over half a million hip fractures every year. Many countries have developed national hip fracture registries to improve the quality of hip fracture management, but such a registry does not exist in China. The study is aimed at determining the core variables of a national hip fracture registry for older hip fracture patients in China. A rapid literature review was conducted to develop a preliminary pool of variables from existing global hip fracture registries. Two rounds of an e-Delphi survey were conducted with experts. The e-Delphi survey used a Likert 5-point scale and boundary value analysis to filter the preliminary pool of variables. The list of core variables was finalised following an online consensus meeting with the experts. Thirty-one experts participated. Most of the experts have senior titles and have worked in a corresponding area for more than 15 years. The response rate of the e-Delphi was 100% for both rounds. The preliminary pool of 89 variables was established after reviewing 13 national hip fracture registries. With two rounds of the e-Delphi and the expert consensus meeting, 86 core variables were recommended for inclusion in the registry. This study is the first to recommend a core variable set for the establishment of a Chinese national hip fracture registry. The further development of a registry to routinely collect data from thousands of hospitals will build on this work and improve the quality of management for older hip fracture patients in China.

Telomere DNA length regulation is influenced by seasonal temperature differences in short-lived but not in long-lived reef-building corals

Telomeres are environment-sensitive regulators of health and aging. Here,we present telomere DNA length analysis of two reef-building coral genera revealing that the long- and short-term water thermal regime is a key driver of between-colony variation across the Pacific Ocean. Notably, there are differences between the two studied genera. The telomere DNA lengths of the short-lived, more stress-sensitive Pocillopora spp. colonies were largely determined by seasonal temperature variation, whereas those of the long-lived, more stress-resistant Porites spp. colonies were insensitive to seasonal patterns, but rather influenced by past thermal anomalies. These results reveal marked differences in telomere DNA length regulation between two evolutionary distant coral genera exhibiting specific life-history traits. We propose that environmentally regulated mechanisms of telomere maintenance are linked to organismal performances, a matter of paramount importance considering the effects of climate change on health.

Pervasive tandem duplications and convergent evolution shape coral genomes

BACKGROUND

Over the last decade, several coral genomes have been sequenced allowing a better understanding of these symbiotic organisms threatened by climate change. Scleractinian corals are reef builders and are central to coral reef ecosystems, providing habitat to a great diversity of species.

RESULTS

In the frame of the Tara Pacific expedition, we assemble two coral genomes, Porites lobata and Pocillopora cf. effusa, with vastly improved contiguity that allows us to study the functional organization of these genomes. We annotate their gene catalog and report a relatively higher gene number than that found in other public coral genome sequences, 43,000 and 32,000 genes, respectively. This finding is explained by a high number of tandemly duplicated genes, accounting for almost a third of the predicted genes. We show that these duplicated genes originate from multiple and distinct duplication events throughout the coral lineage. They contribute to the amplification of gene families, mostly related to the immune system and disease resistance, which we suggest to be functionally linked to coral host resilience.

CONCLUSIONS

At large, we show the importance of duplicated genes to inform the biology of reef-building corals and provide novel avenues to understand and screen for differences in stress resilience.

Optimizing the vaginal microbiome as a potential strategy to reduce heterosexual HIV transmission

Bacterial vaginosis (BV) is a proinflammatory genital condition characterized by high vaginal bacterial diversity and a paucity of Lactobacillus species. BV has been linked to an elevated risk of HIV acquisition among HIV-negative women and of forward HIV transmission to male sex partners among women living with HIV (adjusted hazard ratios of 1.69 and 3.17, respectively), potentially by eliciting genital inflammation in women with BV and their male sex partners. BV is also highly prevalent among women in sub-Saharan Africa, suggesting that BV treatment may have potential as an HIV prevention strategy. BV is typically treated with antibiotics but recurrence rates are high, possibly because treatment does not directly promote Lactobacillus growth. More recently, BV treatment strategies incorporating live biotherapeutic lactobacilli have led to sustained optimization of the vaginal microbiome and a decrease in inflammatory biomarkers previously associated with HIV susceptibility. Future studies are urgently needed to evaluate BV treatment strategies that can optimize the vaginal microbiome in the long term through colonization with H₂ O₂ -producing vaginal lactobacilli and to assess whether vaginal microbiota optimization is able to reduce the risk of HIV transmission.

Soluble E-cadherin: A marker of genital epithelial disruption

PROBLEM

The genital epithelial barrier is a crucial first line of defence against HIV, and epithelial disruption may enhance HIV susceptibility. Assessment of genital epithelial integrity requires biopsies, but their collection is not practical in many research settings. A validated biomarker of genital epithelial barrier integrity would therefore be useful. The purpose of this study was to evaluate soluble E-cadherin (sE-cad) as a marker of genital epithelial disruption.

METHOD OF STUDY

Using in vitro models of endocervical and foreskin epithelial cells, we assessed changes in sE-cad, IL-6, IL-1β, and IL-1α levels following mechanical disruption. We also assessed changes in sE-cad levels in vivo in cervicovaginal secretions after epithelial disruption by endocervical cytobrush sampling in Canadian women, and assessed the relationship between levels of sE-cad in coronal sulcus swabs to membrane-bound E-cadherin in the overlying foreskin tissue in Ugandan men.

RESULTS

sE-cad levels immediately increased after in vitro epithelial physical disruption with the degree of elevation dependent on the extent of disruption, as did levels of IL-1β and IL-1α; this was followed by a delayed increase in IL-6 levels. In vivo results confirmed that sE-cad levels in cervicovaginal secretions were elevated 6 h after cytobrush sampling when compared to baseline. Furthermore, levels of sE-cad in the prepuce were inversely correlated with the amount of membrane-bound E-cadherin of overlying tissue.

CONCLUSION

Our results validate the use of sE-cad as a marker of epithelial disruption and demonstrate that the processes of physical disruption and inflammation in the genital tract are strongly intertwined.

Treatment Success Following Standard Antibiotic Treatment for Bacterial Vaginosis Is Not Associated With Pretreatment Genital Immune or Microbial Parameters

Background

Bacterial vaginosis (BV) is a proinflammatory genital condition associated with adverse reproductive health outcomes, including increased HIV incidence. However, BV recurrence rates are high after standard antibiotic treatment. While the composition of the vaginal microbiota before BV treatment may be linked to BV recurrence, it is unclear whether the preceding genital immune milieu is predictive of treatment success.

Methods

Here we assessed whether baseline vaginal soluble immune factors or the composition of the vaginal microbiota predicted treatment success 1 month after metronidazole treatment in 2 separate cohorts of women with BV, 1 in the United States and 1 in Kenya; samples within 48 hours of BV treatment were also available for the US cohort.

Results

Neither soluble immune factors nor the composition of the vaginal microbiota before BV treatment was associated with treatment response in either cohort. In the US cohort, although the absolute abundances of key vaginal bacterial taxa pretreatment were not associated with treatment response, participants with sustained BV clearance had a more pronounced reduction in the absolute abundance of Gardnerella vaginalis immediately after treatment.

Conclusions

Pretreatment immune and microbial parameters were not predictive of BV treatment success in these clinical cohorts.

187 ‘OUR LANGUAGE’: AN INITIATIVE TO RAISE STAFF AWARENESS OF THE IMPACT OF OUR CHOICE OF WORDS ON PATIENTS

Background

In a hospital specialising in older persons’ rehabilitation, the Speech & Language Therapy team (SLT) commenced an initiative to raise awareness of the impact of all staff’s language on patients. Our language can either support or undermine patient well-being. Supportive language is easy-to-follow, everyday English and respects each person’s autonomy (‘Would you like help to eat?’). Unnecessary jargon or impersonal words can be undermining (e.g. ‘He needs supervision with feeding’). This is supported by national and international guidance tools such as the online ‘Plain Language Style Guide’ by the Health Service Executive Health Promotion Unit and National Adult Literacy Agency.

Methods

Quality improvement methodology was adopted to facilitate an ongoing, flexible approach. SLT delivered pilot workshops on person-centred language to ward staff. Afterward, staff spent a week self-identifying examples of language that could be improved during their work day. Examples were collated and presented back to teams. Online feedback surveys were conducted. Trolley rounds were then rolled out with quiz-style exercises to raise staff awareness across the hospital. Examples of person-centred language generated by staff were shown on rolling videos in key areas across the hospital.

Results

Staff engaged actively in workshop and trolley activities generating a range of examples of more person-centred language. Surveys revealed a new awareness of the need to adapt our language. Several months later, staff continue to demonstrate increased vigilance with their choice of words and regularly consult SLT for advice on language in clinical sessions, documentation or signage. There is still room for improvement in the language used in other areas such as Care Planning Meetings and clinical documentation.

Conclusion

This initiative has started to increase staff awareness of the importance of our choice of words to patient well-being. With the support of hospital management, this initiative will be continued, reviewed and reported on a rolling basis.

P-263 Clinical factors influencing the incidence of tripronuclear zygotes in IVF

Study question

Is the incidence of tripronuclear zygotes (3PN) in IVF cycles influenced by clinical, patient and treatment parameters?

Summary answer

Tripronuclear zygotes incidence in IVF cycles was influenced by Antral Follicle Count, number of oocytes retrieved, sperm progressive motility, and the use of fresh semen.

What is known already

Tripronuclear zygotes are indicative of abnormal fertilisation and are not routinely considered suitable for transfer. It is therefore important to optimise their detection and minimise their occurrence. Tripronuclear zygotes can originate as a result of the combination of one maternal and two paternal sets of chromosomes (fertilisation of a haploid oocyte by two haploid spermatozoa or by one diploid spermatozoon) or the combination of one paternal and two maternal sets of chromosomes (fertilisation of a diploid oocyte by one haploid spermatozoon) (1).

Study design, size, duration

This is a retrospective study of 550 IVF cycles performed between April 2018- April 2021, in a single UK clinic. IVF cycles either within (group 1) or exceeding (group 2) the key performance indicator (KPI) for the incidence of 3PN (<6%) (2), were assessed for associations with quantitative cycle variables. Proportion of 3PN per cycle was assessed for associations with qualitative variables. Cycles using donor oocytes (n = 73) were excluded for analyses assessing patient (maternal) parameters.

Participants/materials, setting, methods

Continuous variables including age, body mass index, Antral Follicle Count (AFC), anti-Mullerian hormone (AMH), oocytes recovered, timing from sperm production to insemination or oocyte recovery to insemination, sperm concentration, progressive motility and morphology were analysed by Mann-Whitney U Test. Qualitative variables including patient ethnicity, own/donor oocyte source, fresh/frozen sperm, stimulation regimen and oocyte recovery needle were analysed by logistic regression assuming binomial errors. Significance was assumed at p < 0.05.

Main results and the role of chance

There was no difference between groups where 3PN incidence exceeded or fell within the KPI when procedure timings and clinical parameters were assessed. There was also no relationship between patient characteristics (age, body mass index, AMH levels, ethnicity, oocyte source (own/donor)), semen concentration or semen morphology and the proportion of 3PN per cycle. However, number of oocytes retrieved in group 2 was significantly higher than group 1 (group 1, n cycles = 307, median oocytes retrieved = 8; group 2, n cycles = 170, median oocytes retrieved = 12 [95% CI -4, -1]) (p < 0.001). Similarly, AFC was significantly increased in group 2 (group 1, n cycles = 254, median AFC = 11; group 2, cycles n = 150, median AFC = 13 [95% CI -4, -1]) (p = 0.009). Likewise, the mean sperm motility parameters were higher for cycles exceeding the 6% 3PN KPI, with 64.6 ± 0.91% vs 68.8 ± 1.11% total motility (p = 0.004), and 57.1 ± 0.97% vs 61.7 ± 1.2% progressive motility (p = 0.003) for group 1 and 2 respectively. Proportion of 3PN per cycle was also significantly higher with fresh semen compared to frozen (6.6 ± 0.39% vs 4.7 ± 0.51%) (p = 0.006).

Limitations, reasons for caution

This is a retrospective study of a single UK clinic. Further analysis, expanding sample size, are required to confirm these findings.

Wider implications of the findings

Our finding that number of oocytes recovered influences 3PN incidence is in agreement with previous studies (3, 4). Fresh and high progressively motile sperm may be more capable of zona pellucida penetration leading to polyspermy and 3PN. Adjustment of sperm concentration at insemination could be considered in higher risk circumstances.

Trial registration number

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Single-agent anti-PD-1 or combined with ipilimumab in patients with mucosal melanoma: an international, retrospective, cohort study

BACKGROUND

Mucosal melanoma (MM) is a rare melanoma subtype with distinct biology and poor prognosis. Data on the efficacy of immune checkpoint inhibitors (ICIs) is limited. We determined the efficacy of ICIs in MM, analysed by primary site and ethnicity/race.

PATIENTS AND METHODS

Retrospective cohort study from 25 cancer centres in Australia, Europe, USA and Asia. Patients with histologically confirmed MM were treated with anti-PD1+/-ipilimumab. Primary endpoints were response rate (RR), progression-free survival (PFS), overall survival (OS) by primary site (naso-oral, urogenital, anorectal, other), ethnicity/race (Caucasian, Asian, Other) and treatment. Univariate and multivariate Cox proportional hazard model analyses were conducted.

RESULTS

In total, 545 patients were included: 331 (63%) Caucasian, 176 (33%) Asian and 20 (4%) Other. Primary sites included 113 (21%) anorectal, 178 (32%) urogenital, 206 (38%) naso-oral and 45 (8%) other. 348 (64%) received anti-PD1 and 197 (36%) anti-PD1/ipilimumab. RR, PFS and OS did not differ by primary site, ethnicity/race or treatment. RR for naso-oral was numerically higher for anti-PD1/ipilimumab (40%, 95% CI 29-54%) compared with anti-PD1 (29%, 95% CI 21-37%). 35% of patients that initially responded progressed. Median duration of response (mDOR) was 26 months (95% CI 18-NR [Not Reached]). Factors associated with short PFS were ECOG PS ≥3 (p<0.01), LDH >ULN (p=0.01), lung metastases (p<0.01) and ≥1 previous treatments (p<0.01). Factors associated with short OS were ECOG PS ≥1 (p<0.01), LDH >ULN (p=0.03), lung metastases (p<0.01) and ≥1 previous treatments (p<0.01).

CONCLUSIONS

MM has poor prognosis. Treatment efficacy of anti-PD1+/-ipilimumab was similar and did not differ by ethnicity/race. Naso-oral primaries had numerically higher response to anti-PD1/ipilimumab, without difference in survival. The addition of ipilimumab did not show greater benefit over anti-PD1 for other primary sites. In responders, mDOR was short and acquired resistance was common. Other factors, including site and number of metastases were associated with survival.

Sustained effect of LACTIN-V (Lactobacillus crispatus CTV-05) on genital immunology following standard bacterial vaginosis treatment: results from a randomised, placebo-controlled trial

Background

Bacterial vaginosis might increase HIV risk by eliciting genital inflammation and epithelial barrier disruption, whereas vaginal Lactobacillus crispatus is associated with immune quiescence and HIV protection. We investigated the effect of a live biotherapeutic containing L crispatus CTV-05 (LACTIN-V) on genital immunology and key vaginal bacteria.

Methods

This substudy included women aged 18–45 years who participated in the randomised, placebo-controlled, phase 2b trial of LACTIN-V to reduce bacterial vaginosis recurrence, conducted at four universities and hospitals in the USA. Women with negative results for sexually transmitted infection, pregnancy, and urinary tract infection were provided a 5-day course of vaginal metronidazole 0·75% gel. Those who met at least three of four clinical Amsel criteria for bacterial vaginosis and had a Nugent score of 4–10 from Gram staining were eligible. Participants in the LACTIN-V trial were randomly assigned (2:1) to receive either LACTIN-V or placebo, applied vaginally once per day for 5 days during the first week and then twice per week for 10 more weeks. Follow-up visits occurred 4, 8, 12, and 24 weeks after enrolment. Soluble immune factors and the absolute abundance of bacterial taxa were assayed by mutliplex ELISA and quantitative PCR. The primary outcomes were vaginal levels of IL-1α and soluble E-cadherin at 24 weeks (ie, 13 weeks after treatment cessation).

Findings

Between Feb 21, 2020 and March 18, 2021, we characterised genital immune parameters and the vaginal microbiota in a subset of 66 highly adherent participants who were randomly selected, with no exclusion criteria, from those who had attended all study follow-up visits (n=166) in the larger LACTIN-V clinical trial (n=288). 32 (48%) participants received LACTIN-V and 34 (52%) received placebo. LACTIN-V treatment was significantly associated with lower concentrations of the proinflammatory cytokine IL-1α (β coefficient 0·310, SE 0·149; p=0·042) and soluble E-cadherin (0·429, 0·199; p=0·035), a biomarker of epithelial barrier disruption.

Interpretation

Vaginal administration of LACTIN-V following standard bacterial vaginosis therapy resulted in a sustained reduction in genital inflammation and a biomarker of epithelial integrity. The potential of LACTIN-V to reduce HIV susceptibility merits further investigation.

Funding

Canadian Institutes of Health Research and the National Institutes of Health National Institute of Allergy and Infectious Diseases.

Metronidazole treatment rapidly reduces genital inflammation through effects on bacterial vaginosis-associated bacteria rather than lactobacilli

BACKGROUND

Bacterial vaginosis (BV) causes genital inflammation and increases HIV risk, while a vaginal microbiota dominated by Lactobacillus species is associated with immune quiescence and relative HIV protection. BV treatment reduces genital inflammation, but it is unclear whether this is driven by a decrease in BV-associated bacteria or an increase in Lactobacillus.

METHODS

To evaluate the short-term impact of standard BV treatment on genital immunology and the vaginal microbiota, vaginal swabs were collected immediately before and after metronidazole treatment for BV and analyzed with multiplex ELISA, metagenomic sequencing, and quantitative polymerase chain reaction.

RESULTS

Topical metronidazole treatment rapidly reduced vaginal levels of proinflammatory cytokines, chemokines, and soluble immune markers of epithelial barrier disruption. Although the vaginal microbiota shifted to dominance by L. iners or L. jensenii, this proportional shift was primarily driven by a 2-4 log10 fold reduction in BV-associated bacteria absolute abundance; BV treatment induced no change in the absolute abundance of L. crispatus or L. iners, and only minor (<1 log10 fold) increases in L. gasseri and L. jensenii that were not independently associated with reduced inflammation in multivariable models.

CONCLUSION

The genital immune benefits that are associated with Lactobacillus dominance following BV treatment were not directly attributable to an absolute increase in lactobacilli, but rather to the loss of BV-associated bacteria.TRAIL REGISTRATION. Participants were recruited as part of a randomized controlled trial (NCT02766023) from 2016 to 2020.

FUNDING

Canadian Institutes of Health Research (PJT-156123) and the National Institute of Allergy and Infectious Diseases (HHSN2722013000141 and HHSN27200007).

Beyond bacterial vaginosis: vaginal lactobacilli and HIV risk

HIV incidence continues to be unacceptably high in Eastern and Southern Africa, with women disproportionately affected. An increased per-contact risk of HIV acquisition among African, Caribbean, and other Black (ACB) women has been associated with the higher prevalence of bacterial vaginosis (BV) in these communities, wherein the vaginal microbiota is predominated by diverse pro-inflammatory anaerobic bacteria. However, while the vaginal microbiota in BV-free women is typically predominated by one of several different Lactobacillus spp., the degree of HIV protection afforded by a Lactobacillus-predominant vaginal microbiota also varies considerably. Specifically, L. crispatus is associated with an immunoregulatory genital immune environment, exclusion of BV-associated bacteria, and reduced HIV risk. In contrast, less HIV protection or exclusion of BV-associated bacteria and fewer immune benefits have been associated with L. iners-which is unfortunately the most common Lactobacillus species among ACB women. These species-specific clinical differences are underpinned by substantial genomic differences between Lactobacillus species: for instance, the much smaller genome of L. iners lacks the coding sequence for D-lactic acid dehydrogenase and cannot produce the D-lactate isomer that enhances HIV trapping in mucus but encodes for epithelial cell toxins and stress resistance proteins that may enhance bacterial survival in the context of microbiota and environmental fluctuations. While more studies are needed to elucidate whether differences in HIV protection between Lactobacillus species are due to direct genital immune effects or the exclusion of proinflammatory BV-associated bacteria, the current body of work suggests that for BV treatment to succeed as an HIV prevention strategy, it may be necessary to induce a vaginal microbiota that is predominated by specific (non-iners) Lactobacillus species. Video abstract.

1115 Does the Published Evidence Support Cell Transplantation in Liver Disease?

Introduction

Although a significant body of evidence proposes a role for cell transplantation as a bridge or alternative to orthotopic liver transplantation for a range of liver disorders, this therapy is not performed in the United Kingdom. Several cell types, including human hepatocytes and mesenchymal stem cells, have been assessed for safety and efficacy, with numerous transfusion protocols. In this review we critically evaluated published human studies of hepatocyte transplantation in respect of (i) methods used to evaluate efficacy of therapy, particularly the use of validated prognostic scores for liver disease (MELD or Child-Pugh), and (ii) discrepancies in patient outcomes between studies using different cell types and transfusion protocols.

Method

We reviewed 20 studies on cell transplantation as an alternative to orthotopic liver transplantation. Patient demographics, study design and outcome measures were compared. Outcome measures were post-cell transplant patient survival to (i) the end of the follow-up window, (ii) receipt of a liver transplant, or (iii) death.

Results

Inconsistencies found in study protocols included strategies for cell transfusion, post-transplant immunosuppression and follow-up interval and duration. Comparison of results was complicated by the outcome measures themselves, as neither receipt of a graft nor mortality can be represented in the prognostic scores used. Furthermore, many studies reported biochemistry data which could not be incorporated into MELD/Child-Pugh score format.

Conclusions

Meta-analysis of hepatocyte transplant studies is not possible on account of methodological inconsistencies and lack of large, controlled trials. These may be important factors preventing wider adoption of this intervention.

1702 A Proforma To Improve Documentation of Surgical Ward Rounds

Aim

The ward round is an important vehicle in the care of surgical inpatients. Good quality documentation is essential in recording patient progress over time and communicating clearly between multidisciplinary team (MDT) members. This quality improvement project aimed to implement a standardised proforma to improve the quality of ward round documentation, improving MDT communication and patient safety.

Method

Ward round entries from an elective surgical unit at a District General Hospital were retrospectively reviewed using a fifteen-item checklist to assess quality of documentation. These criteria were divided into:

A re-audit was performed following introduction of a ward round proforma using the same criteria.

Results

The pre-intervention arm included 41 entries and the post-intervention arm included 27 entries. Improvements were seen in twelve of the fifteen criteria assessed. The greatest improvements were seen in documentation of management plans; documentation of discharge plan improved from 58.5% to 100%, VTE prophylaxis from 42% to 100% and drain/ catheter plan from 42 to 93%. Documentation of two criteria (signature and bleep) decreased and documentation of date remained at 100%.

Conclusions

The use of a standardised proforma improves documentation of surgical ward rounds, particularly patient’s’ onward management plans. Further modifications to the proforma could aim to improve documentation of bleep and signature.

Transcriptomic analysis of eyelid pigmentation in Hereford cattle

The study of skin color in cattle holds both economic and scientific interest. Several ocular diseases of cattle have been associated with low pigmentation of the eyelids, including ocular squamous cell carcinoma and infectious keratoconjunctivitis, the two most common ocular diseases affecting cattle production. Although low eyelid pigmentation is a well-known risk factor for various ocular diseases, the genetic and biological basis of this relationship is largely unknown. We investigated the transcriptome of eyelid skin in Hereford cattle using RNA-sequencing technology. Two contrasting groups were evaluated: steers that were completely pigmented and steers with no pigmentation in both eyelids. Most of the up-regulated genes in pigmented samples are directly implicated in melanogenesis and melanosome development, whereas up-regulated genes in non-pigmented samples are implicated in cancer development and the immune system, among other functions. Interestingly, network analysis comparing pigmented vs. non-pigmented samples revealed significant differences in the co-expression patterns of genes related to melanosome, pigmentation and defense response to bacteria, showing higher gene activity, greater co-expression patterns and tighter co-regulation mechanisms in pigmented samples. Overall, our findings indicate that bovine eyelid pigmentation depends on the expression of many genes involved not only in pigmentation and melanosome function but also related to inflammatory response, infection and tumoral pathways.

New Mexico Female Miners Have Lower Odds for COPD than Their Male Counterparts

Chronic obstructive pulmonary disease (COPD) is a significant cause of morbidity among miners. There is an increasing number of women in the mining industry and the differences in their risk for COPD compared to men miners are not understood. Our objective is to compare the odds for COPD between male and female miners. Using cross-sectional data from the Mining Dust in the United States (MiDUS) Cohort, that included New Mexico miners between 1989 and 2018, we compared the odds for airflow obstruction or chronic bronchitis between women and men. There were 299 women in this diverse cohort of 7,464 miners. Compared to men, female miners reported lower cumulative smoking but higher prevalence of current smoking. Multivariable analysis showed that women miners had significantly lower odds for having airflow obstruction (OR 0.40; 95% CI (0.26, 0.6)) and chronic bronchitis (OR 0.31, 95% CI (0.19, 0.53)) than men. Future studies need to determine whether this sex difference is explained by residual confounders or true biological difference.

Internal parasitic burdens in brown rats (Rattus norvegicus) from Grenada, West Indies

This study identified the endoparasites in Brown rat (Rattus norvegicus) during May to July 2017 in Grenada, West Indies. A total of 162 rats, 76 females and 86 males were trapped from St. George and St. David parishes in Grenada. The collected fecal samples were examined for parasitic eggs and/or oocysts using simple fecal flotation technique. Adult parasites found in the intestinal tract were examined for identification. The overall prevalence of intestinal parasites among rats was 79 %.

Ten helminth species were recovered, several of which were reported for the first time in rodents in Grenada. The internal parasites consist of seven nematodes (Angiostrongylus spp., Nippostrongylus braziliensis, Heterakis spumosa, Strongyloides ratti, Aspiculuris tetraptera, Syphacia spp. and Protospirura spp.), one cestode (Hymenolepsis diminuta), one acanthocephalan (Moniliformis moniliformis) and one protozoa species (Eimeria spp.). The most prevalent zoonotic species were Angiostrongylus spp. (35.2%), Hymenolepsis diminuta (7.4%) and Moniliformis moniliformis (3.1%). Several nonzoonotic endoparasites; which included Nippostrongylus braziliensis (50.6%), Heterakis spumosa (15.4%), Strongyloides ratti (43.2%), Aspiculuris tetraptera (2.5%), Syphacia spp. (1.9%), Protospirura spp. (1.2%) and Eimeria spp. (4.7%) were also identified. The most prevalent parasites were Nippostrongylus brasiliensis (50.6%), Strongyloides ratti (43.2%) and Angiostrongylus spp. (35.2%). Co-infections occurred with up to six species per rat showing different combinations of parasitic infections.

Novel genetic polymorphisms associated with carcass traits in grazing Texel sheep

Improving meat production traits has increased its importance in sheep breeding. We report novel associations of SNP present in genes related to lipid metabolism and growth with several carcass traits in purebred Texel lambs. Expected progeny differences (EPD) predictions from 461 animals from the Central Progeny Testing of Texel breed in Uruguay were used for the association analysis. Live weights at different stages, ultrasound and post-mortem traits were analyzed. Markers in several genes were associated with growth, carcass and meat quality traits. Among others: PPARGC1A with valuable cuts weight, hot carcass weight and carcass fatness; DGAT1 with live weights, fat thickness, rib-eye area and shoulder weight; CAST with birth weight and fat thickness; GHR with birth weight and carcass fatness, and GHRHR with live weights and fat thickness. Genotypic effects ranged from 0.035 to 0.923 (DGAT1 vs. weaning weight) units of phenotypic SD. Most of the associations described are novel in sheep breeding, deserving further analyses.

Comprehensive re-evaluation of historical von Willebrand disease diagnosis in association with whole blood platelet aggregation and function

INTRODUCTION

Diagnosis of von Willebrand disease (VWD) is challenging, particularly for type 1. The current diagnostic guidelines emphasize simultaneous bleeding symptoms and von Willebrand factor (VWF) levels of <30-40 IU/dL. Historical diagnoses require updated evaluation. We assessed the accuracy of past VWD diagnoses in our comprehensive care center with the standardized bleeding score (BS) and central laboratory analysis, focusing on VWF-dependent platelet functions in whole blood.

METHODS

Our study comprised 83 adults with prior VWD who were diagnosed a median of 20 years ago. We assessed BS, VWF antigen and activity (minimum of 3 measurements), FVIII, PFA-100^® , and platelet aggregation via Multiplate^® . Genetic testing was targeted to types 3, 2N, 2B, and equivocal cases.

RESULTS

All 13/13 (100%) type 3 and 29/32 (90%) type 2, but only 10/38 (26%) of type 1 (overall 52/83 (63%)) patients met the current criteria for VWD. All confirmed cases had abnormal BS, impaired PFA-100^® , and decreased or absent ristocetin-induced platelet aggregation (RIPA), except subtype 2B. VWF, FVIII, RIPA, and PFA correlated with BS including all study subjects. Ten of the 38 patients with previous type 1 had low VWF (35-50 IU/dL) and variable VWF-dependent platelet function. Altogether, 21/83 patients (25%) had repeatedly normal VWF:RCo (>50 IU/dL).

CONCLUSION

von Willebrand disease is associated with impaired VWF-dependent whole blood platelet functions that match traditional VWF measurements. We detected normal VWF in 25% of historically diagnosed patients, mainly type 1 patients, implying that there is a need to systematically re-evaluate historical VWD diagnoses.

Identification of a Tissue-Restricted Isoform of SIRT1 Defines a Regulatory Domain that Encodes Specificity

The conserved NAD⁺-dependent deacylase SIRT1 plays pivotal, sometimes contrasting, roles in diverse physiological and pathophysiological conditions. In this study, we uncover a tissue-restricted isoform of SIRT1 (SIRT1-ΔE2) that lacks exon 2 (E2). Candidate-based screening of SIRT1 substrates demonstrated that the domain encoded by this exon plays a key role in specifying SIRT1 protein-protein interactions. The E2 domain of SIRT1 was both necessary and sufficient for PGC1α binding, enhanced interaction with p53, and thus downstream functions. Since SIRT1-FL and SIRT1-ΔE2 were found to have similar intrinsic catalytic activities, we propose that the E2 domain tethers specific substrate proteins. Given the absence of SIRT1-ΔE2 in liver, our findings provide insight into the role of the E2 domain in specifying "metabolic functions" of SIRT1-FL. Identification of SIRT1-ΔE2 and the conserved specificity domain will enhance our understanding of SIRT1 and guide the development of therapeutic interventions.

Abstract 827: Statistical analyses of stable housekeeping gene expression in cancer post-irradiation

Ionizing radiation (IR) can induce DNA damage in human cells and result in changes in gene expression. The changes could also include some of the commonly used housekeeping genes (HKG), and thus making them unstable over the time period after being exposed to radiation. Normalization of housekeeping genes is critical for understanding gene expression post-irradiation. Toward the validation of stable HKGs, cancer cell lines from head and neck, non-small cell lung and pancreas were irradiated to 2, 4 and 6 Gy IR doses. Statistical analysis of RNA expression of fourteen HKGs measured at 5 min to 48hrs post-irradiation reveal tradition HKGs such as beta-actin (ACTB) and glucose-6-phosphate-dehydrogenase (G6PD) to be unstable, while TATA-Box Binding Protein (TBP) and Importin 8 (IPO8) was identified as stable HKGs in non-small lung and pancreas cell across all IR doses and time. Interestingly in head and neck cancer, TBP is also found stable across all IR doses and time. The statistical framework used for identification and validation of HKGs can serve as a reliable metric for quantifying gene expression post-irradiation.

Citation Format: Albert R. Wang, Gopal Iyer, Sean Brennan, Shay Bourgeois, Eric Armstrong, Pari Shah, Paul M. Harari. Statistical analyses of stable housekeeping gene expression in cancer post-irradiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 827. doi:10.1158/1538-7445.AM2017-827

An equivalence study: Are patient-completed and telephone interview equivalent modes of administration for the EuroQol survey?

Background

To determine if the EuroQol Health Related Quality of Life survey produces equivalent results when administered by phone interview or patient-completed forms.

Methods

People awaiting hip or knee arthroplasty at a major metropolitan hospital participated. They were randomly assigned to receive the EuroQol Health Related Quality of Life survey via telephone, followed by a patient completed form 1 week later, or vice versa. Equivalence was determined using two one-sided tests (TOST) based on minimal clinically-important differences for the visual analogue scale (VAS) and the summary Utility Index. Cohen’s Kappa scores were computed to determine agreement for the individual EuroQoL Likert scale items.

Results

Seventy-six from 90 (84%) participants completed the survey twice. Based on limits set at ±7 and ±0.11 for the VAS and Utility Index, respectively, equivalence was established between the two methods of administration for both the VAS (mean difference 0.05 [90% CI −3.76–3.67]) and the Utility Index (mean difference 0.06 [90% CI 0.02–0.11]). Varying levels of agreement, ranging from slight to substantial (κ = 0.17–0.67), were demonstrated for the individual health domains. The order of telephone and patient-completed survey administration had no significant effect on results.

Conclusions

Equivalent results are obtained between telephone and patient-completed administration for the VAS and Utility Index of the EuroQol Survey in people with advanced hip or knee osteoarthritis. The limits of agreement for the individual health domains vary which prevents the accurate interpretation of real change in these items across modes.

Twelve tips for applying the science of learning to health professions education

Findings from the science of learning have clear implications for those responsible for teaching and curricular design. However, this data has been historically siloed from educators in practice, including those in health professions education. In this article, we aim to bring practical tips from the science of learning to health professions educators. We have chosen to organize the tips into six themes, highlighting strategies for 1) improving the processing of information, 2) promoting effortful learning for greater retention of knowledge over time, 3) applying learned information to new and varied contexts, 4) promoting the development of expertise, 5) harnessing the power of emotion for learning, and 6) teaching and learning in social contexts. We conclude with the importance of attending to metacognition in our learners and ourselves. Health professions education can be strengthened by incorporating these evidence-based techniques.

Evaluation of a two-question screening tool in the detection of intimate partner violence in a primary healthcare setting in South Africa

Introduction: Intimate partner violence has been recognised globally as a human rights violation. It is universally under-diagnosed and the institution of timeous multi-faceted interventions has been noted to benefit intimate partner violence victims. Currently the concept of using a screening tool to detect intimate partner violence has not been widely explored in a primary healthcare setting in South Africa, and for this reason the current study was undertaken. The objectives of this study were: (1) to determine the operating characteristics of a two-question screening tool for intimate partner violence (Women Abuse Screening Tool–short); and (2) to estimate the prevalence of intimate partner violence among women attending an outpatient department, using a validated questionnaire (Women Abuse Screening Tool). Methods: A cross-sectional study was conducted prospectively at the outpatient department of a primary care hospital, with systematic sampling of one in eight women over a period of three months. Participants were asked about their experience of intimate partner violence during the past 12 months. The Women Abuse Screening Tool–short was used to screen patients for intimate partner violence. To verify the result of the screening, women were also asked the remaining questions from the full Women Abuse Screening Tool. Results: Data were collected from 400 participants, with a response rate of 99.3%. Based on the results for the Women Abuse Screening Tool, the prevalence of intimate partner violence in the sample was 32%. The Women Abuse Screening Tool–short was shown to have a sensitivity of 45.2% and specificity of 98%. Conclusion: With its high prevalence, intimate partner violence is a health problem at this facility. The Women Abuse Screening Tool–short lacks sufficient sensitivity and therefore is not an ideal screening tool for this primary care ambulatory setting. The low sensitivity can be attributed to the participants’ understanding of the screening questions, which utilise Eurocentric definitions of intimate partner violence.  Improvement in the sensitivity of the Women Abuse Screening Tool–short in this setting may be achieved by lowering the threshold for a positive result.

Insulin-like growth factor 1 receptor mediated tyrosine 845 phosphorylation of epidermal growth factor receptor in the presence of monoclonal antibody cetuximab

BACKGROUND

The epidermal growth factor receptor (EGFR) is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) and several other human cancers. Monoclonal antibodies, such as cetuximab that block EGFR signaling, have emerged as valuable molecular targeting agents in clinical cancer therapy. Prolonged exposure to cetuximab can result in cells acquiring resistance by a process that remains incompletely understood.

METHODS

In this study, we analyzed the immediate early molecular response of cetuximab on physical interactions between EGFR and Insulin growth factor 1 like receptor (IGF-1R) in head and neck cancer cells that are resistant to cetuximab. Co-immunoprecipitation, small molecule inhibitors against phospho-Src and IGF-1R, quantitative western blot of EGFR and Src phosphorylation, cell proliferation assays were used to suggest the role of IGF-1R mediated phosphorylation of specific tyrosine Y845 on EGFR via increased heterodimerization of EGFR and IGF-1R in cetuximab resistant cells.

RESULTS

Heterodimerization of EGFR with IGF-1R was increased in cetuximab resistant HNSCC cell line UMSCC6. Basal levels of phosphorylated EGFR Y845 showed significant increase in the presence of cetuximab. Surprisingly, this activated Y845 level was not inhibited in the presence of Src inhibitor PP1. Instead, inhibition of IGF-1R by picropodophyllin (PPP) reduced the EGFR Y845 levels. Taken together, these results suggest that heterodimerization of EGFR with IGF-1R can lead to increased activity of EGFR and may be an important platform for cetuximab mediated signaling in head and neck tumors that have become resistant to anti-EGFR therapy.

CONCLUSIONS

EGFR-IGF-1R interaction has a functional consequence of phosphorylation of EGFR Y845 in cetuximab resistant HNSCC cells and dual targeting of EGFR and IGF-1R is a promising therapeutic strategy.

Radiation exposure to comforters and carers during paediatric molecular radiotherapy

BACKGROUND

To show whether the incidental radiation exposure received by comforters and carers of children undergoing molecular radiotherapy was kept as low as reasonably achievable and was within English national dose constraints.

PROCEDURE

The radiation exposure of adult comforters and carers was routinely monitored with a whole body personal dose meter while the child was in hospital. Data were collected on iodine-131 meta-iodobenzylguanidine (¹³¹ I-mIBG), lutetium-177 DOTATATE (¹⁷⁷ Lu-DOTATATE), and iodine-131 sodium iodide (¹³¹ I-NaI) treatments.

RESULTS

Data were available for 50 treatments with high-administered activity double-infusion ¹³¹ I-mIBG and 12 single administrations; 15 ¹⁷⁷ Lu-DOTATATE treatments and 28 ¹³¹ I-NaI administrations. The median age was 7 years (1-18). The median administered activity of: ¹³¹ I-mIBG was 16.2 GBq (6.8-59 GBq) for double infusion patients and 8.1 GBq (5.26-16.25 GBq) for single administrations; ¹⁷⁷ Lu-DOTATATE was 7.2 GBq (2.5-7.5 GBq); and ¹³¹ I-NaI was 3 GBq for thyroid remnant ablation and 5.5 GBq for cancer therapy. The median number of comforters and carers for all administrations was 2 (range 1-9). The median exposure values for comforters and carers for high-administered activity ¹³¹ I-mIBG administrations was 302 µSv (0-5282 µSv); for single fraction ¹³¹ I-mIBG 163 µSv (3-3104 µSv); ¹⁷⁷ Lu-DOTATATE 6 µSv (1-79 µSv); and ¹³¹ I-NaI 37 µSv (0-274 µSv). Only one of the comforters and carers exceeded the dose constraint of 5 mSv.

CONCLUSIONS

Doses to comforters and carers were in all but one case within the dose constraint nationally recommended by the Health Protection Agency, now part of Public Health England. New evidence is presented which show that comforter and carer radiation exposure levels from paediatric molecular radiotherapy in routine clinical practice are acceptably low. Pediatr Blood Cancer 2015;62:235-239. © 2014 Wiley Periodicals, Inc.

Is walking aid height critical?

A study is reported in which 20 healthy subjects performed a non weight-bearing aided gait with elbow crutches. The crutches were adjusted to a conventional height and also to heights 2cm and 4cm above and below this setting. Temporospatial and kinetic data were acquired and the results indicated that no significant differences were demonstrated for most parameters across the various height settings. Only at the setting 4cm above conventional was there a significant increase in the abduction moment at the shoulder joint. The conclusion of the study was that height adjustment of elbow crutches with this gait was not a critical issue except at a height 4cm above the conventional setting, and that the subjective impression of the user regarding comfort was a good indicator of correctness of fit.

Phenotypic and genotypic characterization of 10 Finnish patients with von Willebrand disease type 3: discovery of two main mutations

Severe von Willebrand's disease (VWD) type 3 is a rare autosomal-recessively inherited bleeding disorder, showing considerable genotypic heterogeneity. We investigated the phenotype in correlation with the genotype in Finnish type 3 VWD patients. Ten patients previously diagnosed with VWD type 3 treated at the Coagulation Disorder Unit in Helsinki University Hospital were re-evaluated for bleeding tendency and treatment. Phenotypic characterization included coagulation and platelet function testing confirming the diagnosis. The genotype was assessed by initial screening for the common c.2435delC mutation and subsequently if needed, by analysing all 51 coding exons of the von Willebrand factor gene. Our result confirmed the diagnosis of type 3 VWD for all 10 patients. We discovered two common mutations: nine of the 20 alleles (45%) were found to carry the c.2435delC frameshift mutation, previously described to be frequent in countries surrounding the Baltic Sea. The nonsense mutation c.4975C>T (p.R1659X) was found on 8/20 (40%) of the alleles. In addition, three novel mutations, a potential splice site mutation (c.874+2T>C) and two frameshift mutations (c.1668delC and c.2072delCCinsG) were found. Seven patients were homozygous and three compound heterozygous for the reported mutations. This study indicates that mainly two mutations (c.2435delC and p.R1659X) cause the majority of type 3 VWD in Finland. This result sets future standards for the genetic testing among the Finnish type 3 VWD population.

Abstract 4536: Combination external beam and internal radiation via 131I-CLR1404 in the treatment of head and neck squamous cell carcinoma xenografts

Radiotherapy (RT) is a central treatment modality for head and neck cancer (HNC). However, optimal outcome is commonly limited by the radiation tolerance of adjacent normal tissue structures. Radiation is sometimes valuable in the setting of locoregional tumor recurrence, however the risk of significant normal tissue toxicity is substantial with repeat irradiation and can have a profound adverse impact on patient quality of life. Although technical advances including intensity modulated radiotherapy (IMRT) can reduce normal tissue effects, the problem of repeat exposure of normal tissues to radiation is frequently limiting. The radiolabeled drug 124/131I-CLR1404 is a phospholipid ether analogue (PLE) that accumulates preferentially within malignant tumors and enables internal delivery of radiation. This allows a combination of external and internal radiotherapy delivery with a goal of improving treatment outcome without enhanced normal tissue toxicities.

In this study, we characterized the ability of 131I-CLR1404 to augment RT response using xenografted mice harboring human squamous cell carcinomas (SCC). We determined tumor growth delay as well as tumor and normal tissue dose distribution of 131I-CLR-1404 via Monte Carlo simulation using PET data generated with 124I-CLR1404 imaging. Tumor growth delay was extended by 15.5 days using combined 3.7MBq 131I-CLR1404 and RT compared to RT or 131I-CLR1404 alone. In combination therapy, single dose administration of 7.4 MBq 131I-CLR1404 as well as split dosing with 2 x 3.7 MBq separated by one week showed the same additional growth delay of 27 days compared to single dose of 3.7 MBq. Monitoring drug distribution via PET/CT showed high tumor selectivity with a tumor-to-liver ratio of 6.2±0.65 and a tumor-to-muscle ratio of 6.7±0.21.

These data illustrate the tumor selectivity of the CLR1404 PLE delivery platform as well as augmentation of tumor response with combined RT and 131I-CLR1404 treatment. De-intensification of external beam radiation dose, with attendant reduction in normal tissue toxicities so common in HNC patients represents a central objective to be tested in controlled clinical trials with the ultimate goal of improving treatment outcome and quality of life for HNC patients.

Citation Format: Jarob Saker, Eric Armstrong, Bryan Bednarz, Mohammed Farhoud, Abigail Besemer, Jamey Weichert, Paul Harari. Combination external beam and internal radiation via 131I-CLR1404 in the treatment of head and neck squamous cell carcinoma xenografts. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4536. doi:10.1158/1538-7445.AM2013-4536

Genetic diversity analysis of the Uruguayan Creole cattle breed using microsatellites and mtDNA markers

The Uruguayan Creole cattle population (N = 600) is located in a native habitat in south-east Uruguay. We analyzed its genetic diversity and compared it to other populations of American Creole cattle. A random sample of 64 animals was genotyped for a set of 17 microsatellite loci, and the D-loop hyper-variable region of mtDNA was sequenced for 28 calves of the same generation. We identified an average of 5.59 alleles per locus, with expected heterozygosities between 0.466 and 0.850 and an expected mean heterozygosity of 0.664. The polymorphic information content ranged from 0.360 to 0.820, and the global FIS index was 0.037. The D-loop analysis revealed three haplotypes (UY1, UY2 and UY3), belonging to the European matriline group, with a haplotype diversity of 0.532. The history of the population, changes in the effective population size, bottlenecks, and genetic drift are possible causes of the genetic variability patterns that we detected.

Epitaxial growth of visible to infra-red transparent conducting In2O3 nanodot dispersions and reversible charge storage as a Li-ion battery anode

Unique bimodal distributions of single crystal epitaxially grown In2O3 nanodots on silicon are shown to have excellent IR transparency greater than 87% at IR wavelengths up to 4 μm without sacrificing transparency in the visible region. These broadband antireflective nanodot dispersions are grown using a two-step metal deposition and oxidation by molecular beam epitaxy, and backscattered diffraction confirms a dominant (111) surface orientation. We detail the growth of a bimodal size distribution that facilitates good surface coverage (80%) while allowing a significant reduction in In2O3 refractive index. This unique dispersion offers excellent surface coverage and three-dimensional volumetric expansion compared to a thin film, and a step reduction in refractive index compared to bulk active materials or randomly porous composites, to more closely match the refractive index of an electrolyte, improving transparency. The (111) surface orientation of the nanodots, when fully ripened, allows minimum lattice mismatch strain between the In2O3 and the Si surface. This helps to circumvent potential interfacial weakening caused by volume contraction due to electrochemical reduction to lithium, or expansion during lithiation. Cycling under potentiodynamic conditions shows that the transparent anode of nanodots reversibly alloys lithium with good Coulombic efficiency, buffered by co-insertion into the silicon substrate. These properties could potentially lead to further development of similarly controlled dispersions of a range of other active materials to give transparent battery electrodes or materials capable of non-destructive in situ spectroscopic characterization during charging and discharging.

Enhancement of radiation response with bevacizumab

Background

Vascular endothelial growth factor (VEGF) plays a critical role in tumor angiogenesis. Bevacizumab is a humanized monoclonal antibody that neutralizes VEGF. We examined the impact on radiation response by blocking VEGF signaling with bevacizumab.

Methods

Human umbilical vein endothelial cell (HUVEC) growth inhibition and apoptosis were examined by crystal violet assay and flow cytometry, respectively. In vitro HUVEC tube formation and in vivo Matrigel assays were performed to assess the anti-angiogenic effect. Finally, a series of experiments of growth inhibition on head and neck (H&N) SCC1 and lung H226 tumor xenograft models were conducted to evaluate the impact of bevacizumab on radiation response in concurrent as well as sequential therapy.

Results

The anti-angiogenic effect of bevacizumab appeared to derive not only from inhibition of endothelial cell growth (40%) but also by interfering with endothelial cell function including mobility, cell-to-cell interaction and the ability to form capillaries as reflected by tube formation. In cell culture, bevacizumab induced a 2 ~ 3 fold increase in endothelial cell apoptosis following radiation. In both SCC1 and H226 xenograft models, the concurrent administration of bevacizumab and radiation reduced tumor blood vessel formation and inhibited tumor growth compared to either modality alone. We observed a siginificant tumor reduction in mice receiving the combination of bevacizumab and radiation in comparison to mice treated with bevacizumab or radiation alone. We investigated the impact of bevacizumab and radiation treatment sequence on tumor response. In the SCC1 model, tumor response was strongest with radiation followed by bevacizumab with less sequence impact observed in the H226 model.

Conclusions

Overall, these data demonstrate enhanced tumor response when bevacizumab is combined with radiation, supporting the emerging clinical investigations that are combining anti-angiogenic therapies with radiation.