Social determinants of health and health inequities in breast cancer screening: a scoping review

Introduction

This scoping review aims to highlight key social determinants of health associated with breast cancer screening behavior in United States women aged ≥40  years old, identify public and private databases with SDOH data at city, state, and national levels, and share lessons learned from United States based observational studies in addressing SDOH in underserved women influencing breast cancer screening behaviors.

Methods

The Arksey and O'Malley York methodology was used as guidance for this review: (1) identifying research questions; (2) searching for relevant studies; (3) selecting studies relevant to the research questions; (4) charting the data; and (5) collating, summarizing, and reporting results.

Results

The 72 included studies were published between 2013 and 2023. Among the various SDOH identified, those related to socioeconomic status (n = 96) exhibited the highest frequency. The Health Care Access and Quality category was reported in the highest number of studies (n = 44; 61%), showing its statistical significance in relation to access to mammography. Insurance status was the most reported sub-categorical factor of Health Care Access and Quality.

Discussion

Results may inform future evidence-based interventions aiming to address the underlying factors contributing to low screening rates for breast cancer in the United States.

Temporal Changes in Innate and Adaptive Immunity During Sepsis as Determined by ELISpot

Background

The inability to evaluate host immunity in a rapid quantitative manner in patients with sepsis has severely hampered development of novel immune therapies. The ELISpot assay is a functional bioassay that measures the number of cytokine-secreting cells and the relative amount of cytokine produced at the single-cell level. A key advantage of ELISpot is its excellent dynamic range enabling a more precise quantifiable assessment of host immunity. Herein, we tested the hypothesis on whether the ELISpot assay can detect dynamic changes in both innate and adaptive immunity as they often occur during sepsis. We also tested whether ELISpot could detect the effect of immune drug therapies to modulate innate and adaptive immunity.

Methods

Mice were made septic using sublethal cecal ligation and puncture (CLP). Blood and spleens were harvested serially and ex vivo IFN-γ and TNF-α production were compared by ELISpot and ELISA. The capability of ELISpot to detect changes in innate and adaptive immunity due to in vivo immune therapy with dexamethasone, IL-7, and arginine was also evaluated.

Results

ELISpot confirmed a decreased innate and adaptive immunity responsiveness during sepsis progression. More importantly, ELISpot was also able to detect changes in adaptive and innate immunity in response to immune-modulatory reagents, for example dexamethasone, arginine, and IL-7 in a readily quantifiable manner, as predicted by the reagents known mechanisms of action. ELISpot and ELISA results tended to parallel one another although some differences were noted.

Conclusion

ELISpot offers a unique capability to assess the functional status of both adaptive and innate immunity over time. The results presented herein demonstrate that ELISpot can also be used to detect and follow the in vivo effects of drugs to ameliorate sepsis-induced immune dysfunction. This capability would be a major advance in guiding new immune therapies in sepsis.

Using Patient-Centered Dissemination and Implementation Frameworks and Strategies in Palliative Care Settings for Improved Quality of Life and Health Outcomes: A Scoping Review

BACKGROUND

There is a need for patient-provider dissemination and implementation frameworks, strategies, and protocols in palliative care settings for a holistic approach when it comes to addressing pain and other distressing symptoms affecting the quality of life, function, and independence of patients with chronic illnesses. The purpose of this scoping review is to explore patient-centered D&I frameworks and strategies that have been adopted in PC settings to improve behavioral and environmental determinants influencing health outcomes through evidence-based programs and protocols.

METHODS

The five step Arksey and O'Malley's (2005) York methodology was adopted as a guiding framework: (1) identifying research questions; (2) searching for relevant studies; (3) selecting studies relevant to the research questions; (4) charting the data; and (5) collating, summarizing, and reporting results.

RESULTS

Only 6 out of the 38 (16%) included studies applied a D&I theory and/or framework. The RE-AIM framework was the most prominently cited (n = 3), followed by the Diffusion of Innovation Model (n = 2), the CONNECT framework (n = 1), and the Transtheoretical Stages of Change Model (n = 1). The most frequently reported ERIC strategy was strategy #6 "Develop and organize quality monitoring systems", as it identified in all 38 of the included studies.

CONCLUSION

This scoping review identifies D&I efforts to translate research into practice in U.S. palliative care settings. Results may contribute to enhancing future D&I initiatives for dissemination/adaptation, implementation, and sustainability efforts aiming to improve patient health outcomes and personal satisfaction with care received.

Cardiopulmonary Toxicity from Intensity Modulated Proton Therapy for Thymic Malignancies

PURPOSE/OBJECTIVE(S)

Use of radiation therapy for thymic malignancies is limited by excess dose to organs at risk (OARs) including heart, lung, and esophagus. Intensity Modulated Proton Therapy with Pencil Beam Scanning (IMPT/PBS) allows the conformality benefits of volumetric modulated arc therapy (VMAT) combined with dosimetry benefits of protons making it an exciting tool to treat thymic tumors. Very limited clinical data are reported with the use of IMPT/PBS to treat thymic malignancies. This study evaluates the incidence of acute and delayed toxicities among patients who underwent IMPT/PBS for thymic tumors.

MATERIALS/METHODS

Our single center retrospective study identified 27 patients with diagnosis of either thymic carcinoma or thymoma who received IMPT/PBS between 2015 and 2022. Patient demographics, IMPT treatment details and clinical outcomes (toxicity, recurrence, and survival) were recorded. Frequency distributions are described for primary endpoints of acute (≤ 90 days) and late (>90 days) toxicity graded using CTCAE version 5.0. Specific toxicities assessed were dermatitis, esophagitis, pneumonitis, pulmonary fibrosis, and cardiac toxicity. Recurrence and survival data were analyzed as secondary endpoint using Kaplan-Meier method.

RESULTS

Median follow-up was 22 months. Median age of the patients was 59 years (range, 30-87), predominantly female (55%), and white (66%), and stage ¾ (72%). Histologically showed mainly thymoma (59%) and Masaoka stage ¾ (70%). Surgery prior to IMPT was performed in 19 (70%) patients; of whom 5 patients had positive margins. Chemotherapy was used in 12 (44%) patients. Median IMPT dose was 50.4 GyE. Patients were primarily planned with 2 or 3 fields (81%), coplanar distribution (74%), using SFO technique (70%). Robust planning was performed accounting for 5 mm margin and 3.5-5% range uncertainty. All patients required use of range shifter ranging from 2-5 cm. Median of Heart-mean (10.3 GyE), Heart-max (54 GyE), Lung-mean (8.1 GyE), Lung V20 Gy (16.1%), Lung-V30 Gy (11.4%), Esophagus-mean (10.3 GyE) and Cord-Max (1.4 GyE). QACT was performed in 21 (77%) patients with replan needed in 5 of them. Only 1 (3.7%) patient had a grade 3+ acute toxicity (dermatitis) and only 2 (7.4%) patients had a grade 3+ late toxicity (both pulmonary). No patients had any acute or delayed cardiac-related adverse effects following PBT treatment. One (3.7%) patient had an infield recurrence of malignancy and 6 had out-of-field metastatic failure. Local control and overall survival were 74.1% and 85.2%, respectively.

CONCLUSION

In this largest single-institution analysis of IMPT/PBS experience, we note extremely low incidence of grade 3+ acute or late toxicity with excellent local control and overall survival. No marginal failures were noted. In a patient population at high risk of cardiopulmonary radiation toxicities, IMPT/PBS should be strongly explored as a possible treatment option.

Potential drug-drug interactions among hospitalised TB patients

BACKGROUND: Hospitalised TB patients are at heightened risk for developing drug-drug interactions (DDIs) due to overlapping CYP450 enzyme and/or drug transporter biotransformation of anti-TB drugs and co-medications given for treating TB-associated comorbidities. We aimed to compare the occurrence, characterisation and determinants of database identified potential DDIs (pDDIs) associated with first-line anti-TB drugs and other co-medications using a subscription and free access drug information database.METHOD: This was a single-centre retrospective study to assess pDDIs between first-line anti-TB drugs and other medications for comorbidities among hospitalised TB patients using IBM Micromedex^® and Drugs.com.RESULTS: On multivariate regression analysis, hospitalised TB patients with comorbidities such as diabetes mellitus, HIV infection and hypertension, longer hospitalisation, and patients administered with more than seven drugs during their hospital stay were associated with increased risk for the occurrence of pDDIs. Significant discrepancies were observed in the detection and severity of pDDIs between IBM Micromedex and Drugs.com.CONCLUSION: We recommend using free access drug information database to a subscription drug information database in drug interaction screening protocols in clinics for enhanced identification of pDDIs and reducing monetary burden in resource-limited settings.

OC-045 AMBULATORY HERNIA SURGERY IN PRIMARY CARE

Background

Approximately 100,000 hernia repairs are performed in the UK annually, the vast majority in hospital usually under general anaesthetic. Due to increased pressure on hospital facilities especially after the COVID-19 pandemic the waiting times for non-emergency surgery for benign conditions has increased. This study outlines the development and feasibility of a dedicated ambulatory primary care hernia service and examines the outcomes achieved between November 2018 and November 2021.

Methods

We prospectively analysed of records of 212 patients who underwent hernia repair in a primary care centre during the above period. Inclusion criteria were a) BMI<35 b) uncomplicated inguinal or umbilical hernia c) non recurrent hernia. The techniques used were Lichtenstein mesh repair for inguinal hernias and a primary sutured repair for ventral hernias. All procedures were performed as day-cases under local anaesthesia without sedation. All patients were telephoned by a healthcare professional a day after their operation. The primary outcomes of the study were length of stay, immediate complications and the secondary outcome was cost effectiveness.

Results

The median length of post-operative stay was 26 minutes. Complications were low and seen only in 5 patients and managed conservatively. The cost of hernia repair in primary care in UK is only £1012 when compared to £1800 in an NHS hospital.

Conclusion

Routine elective abdominal wall hernia repairs can be performed in a primary care setting, safely, with good clinical outcomes and clear economic benefits. However, this depends on the availability of surgeons and adequate funds to establish the service.

O-133 Association between normal-range paternal serum free thyroxine concentrations and outcomes of assisted reproductive technologies

Study question

Are paternal serum free thyroxine (FT4) concentrations within the reference range associated with outcomes of assisted reproductive technologies (ART)?

Summary answer

Men of older reproductive age (≥ 35 years old) with low FT4 concentrations within the reference range are associated with a decreased live birth rate.

What is known already

The impact of maternal thyroid dysfunction on ART outcomes has been widely elucidated. However, few studies have investigated the impact of paternal thyroid dysfunction on ART outcomes. Our previous study showed a detrimental impact of paternal subclinical hypothyroidism (SCH) on the clinical outcomes of ART. Patients with SCH had relatively lower concentrations of FT4 compared to those with euthyroidism. Therefore, it remains to be determined whether the detrimental impacts of paternal SCH on ART outcomes arise from low concentrations of FT4.

Study design, size, duration

This retrospective cohort study included 4,066 couples who received 4,894 ART treatment cycles in our clinic between 1 April 2016 and 31 August 2021.

Participants/materials, setting, methods

The differences in sperm parameters and ART outcomes across the paternal FT4 tertiles were compared using generalised linear models or generalised estimation equation models. The primary outcomes were the clinical pregnancy rate (CPR) and live birth rate (LBR), and the secondary outcomes were sperm parameters, fertilisation rate, good-quality embryo rate, blastocyst formation rate, and implantation rate.

Main results and the role of chance

The mean ages of the males and their female partners were 33.0 and 31.0 years, respectively. No significant differences are observed in the sperm parameters and ART outcomes across the paternal FT4 tertiles in the overall population. However, stratified analysis of men aged ≥ 35 shows a non-significantly lower CPR in the lower paternal FT4 tertile (adjusted rate: 0.36, 95% CI: 0.27–0.45) relative to the middle (adjusted rate: 0.45, 95% CI: 0.38–0.53) and upper (adjusted rate: 0.43, 95% CI: 0.36–0.51) tertiles. The adjusted LBR is 0.21 (95% CI: 0.15–0.30) for men aged ≥ 35 in the lower FT4 tertile (p = 0.024, with reference to the upper tertile), 0.27 (95% CI: 0.21–0.35) for those in the middle tertile and 0.30 (95% CI: 0.23–0.38) for those in the upper tertile. No differences in these outcomes are seen among men aged &lt; 35. The nonlinear smoothing curve obtained by using FT4 as a continuous variable further supports these findings.

Limitations, reasons for caution

Due to the retrospective design of the study, a causal relationship between paternal FT4 concentrations and ART outcomes could not be established. In addition, the study participants were patients who sought fertility treatment, which may have biased the results when we analysed the associations between FT4 concentrations and sperm parameters.

Wider implications of the findings

These results suggest that in older men, low paternal FT4 concentrations, although within the reference range, are associated with worse ART outcomes, especially LBR. Future prospective studies are warranted to confirm the detrimental effects of low paternal FT4 concentrations on ART outcomes.

Trial registration number

Not applicable

711 Effect of Roux-En-Y Gastric Bypass on HbA1c As Well As Number of Medications in Diabetic Patients

Aim

Roux en Y gastric bypass (RYGB) is known to ameliorate Type 2 Diabetes Mellitus (T2DM) in morbidly obese patients. We aimed to determine both the reduction in the glycosylated haemoglobin (HbA1c) and the number of anti-diabetic medications (including insulin) in diabetic patients undergoing RYGB over a five-year period.

Method

We reviewed data of diabetic patients (n = 530) who underwent RYGB from January 2012 – December 2017, including those with a minimum of a 2-year post-operative follow up (n = 47). Preoperatively, BMI, HbA1c and the number of anti-diabetic medications and the duration of T2DM since diagnosis were recorded. These measurements were repeated at the end of the two year follow up.

Results

At the time of enrolment in the bariatric programme, the median BMI was 42.5 (range, 31.7-61.5) kg/m2, mean duration of T2DM was 58 months and median HbA1c was 59 (37-118) mmol/mol. The mean number of anti-diabetic medications taken, including insulin, was 2. At the end of 2-year follow-up, the median BMI was 32 (range, 24-41) kg/m2 and HbA1c was 41(range, 33-91) mmol/mol. 15 patients (31.9%) still required anti-diabetic medication, 12 of whom had a diagnosis of T2DM for 3 years or more at time of enrolment.

Conclusions

RYGB is strongly associated with a resolution of T2DM in morbidly obese patients. In those who were not resolved, the number of anti-diabetic medications taken and HbA1c were reduced. The impact of the surgery is dependent on the duration of T2DM since diagnosis preoperatively.

1544 The Doctor Will Call You Now – Patients’ Perspective of The Implementation of Telephone Clinics in the COVID-19 Era

Aim

During the first wave of the COVID-19 pandemic, clinical guidelines advised the implementation of remote consultations with the aim of preventing viral transmission. Guidance included the introduction of telephone clinics and in March 2020, these were initiated for General Surgery at our rural DGH. The aim of this study was to review patients’ perspectives of these remote consultations.

Method

Using telephone clinic schedules, the first 100 patients of the telephone clinics were retrospectively identified. A survey was created using Google forms and questions covered patient demographics, as well as patients’ opinions on the organisation and efficacy of the clinic. The survey was completed via a telephone conversation with each patient between June to August 2020.

Results

72 patients consented to participate (age range: 24-80 years; 65% female). 44% of consultations were follow up, with 23% of patients having their initial appointment remotely. Although 82% of patients were able to discuss all concerns, nearly half of patients (43%) felt not having a face-to-face appointment affected their consultation. 78% of patients preferred remote consultations during the pandemic, but beyond this specific situation, 53% felt that in the future they would still prefer a face-to-face consultation. 57.6% of patients rated the newly implemented telephone consultations as 10/10.

Conclusions

The majority of patient feedback was positive. However, outside of the COVID-19 pandemic, our patients would prefer the traditional face-to-face consultation format. This outcome has been demonstrated in other similar studies worldwide, as it enables patients to be examined by and meet their surgeon prior to potential surgery.

1464 Breaking Tradition – A Rural DGH’s Experience of The Management of Acute Appendicitis During the First Wave of the COVID-19 Pandemic

Aim

Acute appendicitis (AA) is the most common abdominal surgical emergency in the UK and traditionally, operative management is the mainstay of treatment. However, during the first wave of the COVID-19 pandemic, ACPGBI discouraged laparoscopy, due to potential risks of aerosol viral transmission. We aimed to review clinical outcomes of patients treated for AA at our DGH prior to and after the change in ACPGBI guidance.

Method

The first 30 patients treated for AA prior to (Group A) and following the update in ACPGBI guidance (Group B), were identified.

Results

Group A: 7% managed conservatively vs 93% operative management. Group B: 74% managed conservatively vs 26% operative management. No statistically significant difference was seen in the rate of post-operative complications, or readmission. In Group B, of those managed conservatively and then readmitted, 75% underwent an operation (RR &lt; 1.00). The average length of stay (LOS) of those managed conservatively in Group A was 3.5 days vs 2.4 days in Group B (p &lt; 0.05). Statistically significant differences in LOS were also observed in patients who underwent surgery - Group A 5.5 day vs 8.25 days in Group B (p &lt; 0.001).

Conclusions

In conclusion, the change in ACPGBI guidance in the early stages of the COVID-19 pandemic, saw statistically significant differences in LOS at our DGH. A shorter LOS in those conservatively managed in Group B could be explained by hospital bed pressures. An increase in LOS for Group B patients with operative management is understandable, as only cases of complicated AA, or those readmitted underwent emergency surgery.

287 COVID-19 and Surgical Specialties – Lessons Learnt: A Rural DGH Perspective

Introduction

The COVID-19 pandemic has seen the restructuring of surgical services worldwide. We aimed to evaluate pre-operative planning and post-operative outcomes in expedited colorectal surgery (ECRS), emergency general surgery (EGS), and emergency orthopaedic surgery (EOS) during the COVID-19 era at our rural hospital.

Method

This was a prospective observational cohort study. Electronic hospital systems identified adult patients who underwent ECRS, major EGS or EOS at our site, from the start of the UK lockdown.

Results

Following exclusion criteria, 98 patients were included in data analysis. Post-operative respiratory complications were seen in 27.8% of ECRS patients, 13.3% of EGS patients and 4% of EOS patients. 2 patients were diagnosed with COVID-19, with 1 COVID-19 associated mortality. Length of hospital stay was reduced for EOS in the COVID-19 setting and this was found to be statistically significant (p value &lt;0.001).

Conclusions

When compared to the literature, COVID-19 related complications in surgical patients were found to be lower at our rural hospital. This could be due to regional variation in the prevalence of COVID-19. If there were to be a second surge, we suggest NHS Trusts should be given the autonomy to make local decisions on modifying their elective caseload, rather than following a national ‘one-size-fits-all’ guideline.

CT predictive model for torsion angle as a marker for risk of necrosis in patients with adnexal torsion

AIM

To assess the feasibility of preoperative computed tomography (CT) prediction of torsion angle for stratifying the risk of necrosis in patients with adnexal torsion.

MATERIALS AND METHODS

In this multicentre, retrospective study, 72 patients underwent preoperative CT and surgically verified adnexal torsion. Surgeons identified the torsion angle and adnexal necrosis requiring adnexectomy. The twisted angles were compared between conservative surgery group and salpingo-oophorectomy group. Variables included demographic, pathological and CT details. Logistic analysis was used to identify the indicators of twisted angle associated with high-risk necrosis.

RESULTS

The necrosis associated with adnexal torsion treated with adnexectomy was performed more often in patients with a torsion angle of ≥720° (odds ratio [OR]=7, 95% confidence interval [CI]: 1.314-37.295, p=0.023). The enlarged twisted pedicle (OR=14.592, 95% CI: 2.048-103.953, p=0.007) and pedicle haemorrhage (OR=5.612, 95% CI: 1.088-28.941, p=0.039) can predict a torsion angle of ≥720°, and area under the receiver operating characteristic (ROC) curve (AUC=0.758±0.058) was generated with the combined variables.

CONCLUSION

The risk of adnexal necrosis is high in patients with torsion angle of ≥720°. CT findings of enlarged twisted pedicle and pedicle haemorrhage can be used to predict torsion angle of ≥720° and can imply adnexal necrosis indirectly.

Abstract SP125: Rescue DNA repair pathway and tumor immunity

Defects in DNA damage response (DDR) is a major factor that predispose normal cells to acquire oncogenic mutations. However, after a tumor develops, cancer cells manage their survival by repairing DNA damage resulting from unchecked DNA replication. Cancer cells can use the alternative or backup (rescue) DNA repair programs to overcome their DDR defects and cope with genotoxic lesions. For example, breast cancer cells with deficiency in homologous recombination (HR) can repair their DNA by either relying on other highly expressed HR-related proteins (such as RAD51 or PARP1), or by using other DNA repair mechanisms such as break-induced replication, alternative nonhomologous end joining (ALT-NHEJ) and basal excision repair (BER). Since DNA repair pathways operate in related networks in cancers in general and breast cancers in particular, it is likely that factor/s that play important roles in multiple DNA repair pathways may serve as a critical component of backup DNA repair pathways that breast cancer cells get addicted to survive and to become therapy resistant. One way these rescue DNA repair pathway factor/s may promote breast cancer progression is by shaping tumor immune microenvironment. Consistent with that, DNA damage and DNA repair pathways in general have been shown to regulate multiple arms of the immune response including antigenicity or tumor mutational burden (TMB) and regulation of immune checkpoint protein levels. Our studies suggest that rescue DNA repair pathways may support tumor progression and therapy response by promoting tumor cell intrinsic and extrinsic mechanisms of immunosuppression. Our results reveal that factors associated with backup DNA repair pathwaysmay promote immunosuppression by altering cGAS-STING and Type I Interferon (IFN) signaling pathways. Furthermore, using a specific inhibitor that targets rescue DNA repair pathway signaling, we show altered levels of several proteins involved in antigen processing and presentation, including proteasome/Immunoproteasome subunits and MHC I protein subunits, which are essential for the detection of cancer cells by cytotoxic T cells. Importantly, our pre-clinical and clinical data suggest that approaches aimed at successfully targeting rescue DNA repair factor(s) may promote anti-tumor immunity and will have promising clinical outcomes for treating breast cancer patients.

Citation Format: M Rao. Rescue DNA repair pathway and tumor immunity [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SP125.

Impact of catheter ablation for atrial flutter on mortality and hospital readmission rates in patients with heart failure and preserved ejection fraction

Background

The availability of real-world data regarding the impact of the catheter ablation in patients with concomitant atrial flutter (AFL) and heart failure with preserved ejection fraction (HFpEF) is limited.

Methods

2016 and 2017 National Readmission Database (NRD) was subjected to appropriate ICD-10 codes to identify and extract patients having coexistent atrial flutter and heart failure with preserved ejection fraction including who had undergone ablation. At 1 year, all-cause mortality was utilized as the primary outcome while readmissions due to AFL, heart failure (HF) and any other causes were designated as secondary outcomes. Kaplan Meier curves were used for a time to event analysis. Cox proportional hazard regression was used to generate hazard ratios.

Results

Out of a total 6099 patients with AFL and HFpEF, 906 (14.85%) underwent catheter ablation. At 1 year all cause mortality (3%, vs. 4.4%, HR: 0.661, 95% CI: 0.444–0.985, p=0.042) and readmissions due to AFL (2.3% vs. 5.3%, HR: 0.424, 95% CI: 0.272–0.661, p&lt;0.001) were significantly less among ablation group. Readmission due to HF (9.3% vs. 9.7%, HR: 0.938, 95% CI: 0.745–1.182, p=0.587) and other causes (37% vs.40.3%, HR: 0.926, 95% CI: 0.825–1.040, p=0.193) did not show any significant difference in outcomes at the end of 1 year.

Conclusion

The utilization of catheter ablation amongst AFL patients with concomitant HFpEF showed a significant reduction in all-cause mortality and readmission due to AFL. However, it did not show any significant changes in readmissions due to HF or other causes at the end of one year.

Outcomes of AFL and HFpEF

Funding Acknowledgement

Type of funding source: None

Extra-abdominal manifestations of retroperitoneal infection: a case of popliteal sinus secondary to duodenal ulcer

Retroperitoneal abscesses can be gastrointestinal, urological or vascular in origin, and can spread via the retrofascial compartment through the psoas muscle to the lower limb. We describe the case of a 73-year-old woman with right knee pain for three weeks, a cellulitic right thigh and cholestatic liver function tests. A purulent sinus developed in the popliteal fossa and computed tomography of the abdomen revealed a right-sided retroperitoneal collection with gas, extending to the right pelvis and inguinal region. The popliteal fossa sinus and retroperitoneal collection were identified as a single pathology through computed tomography, magnetic resonance imaging and culture of identical organisms. At laparotomy, perforated duodenal ulcer disease was identified as the cause of the retroperitoneal abscess. Clinicians should seek to exclude retroperitoneal sources of infection in cases of lower leg infection, including perforated duodenal ulcer, caecal adenocarcinoma and appendicitis.

The ORNATE India Project: United Kingdom-India Research Collaboration to tackle visual impairment due to diabetic retinopathy

INTRODUCTION

The ORNATE India project is funded by the UK Research and Innovation (UKRI) through the Global Challenges Research Fund. The aim is to build research capacity and capability in India and the UK to tackle global burden of diabetes-related visual impairment. As there are over 77 million people with diabetes in India, it is challenging to screen every person with diabetes annually for sight-threatening diabetic retinopathy (DR). Therefore, alternate safe approaches need to be developed so that those at-risk of visual impairment due to DR is identified promptly and treated.

METHODS

The project team utilised diverse global health strategies and research methods to co-design work packages to build research capacity and capability to ensure effective, affordable and efficient DR services are made available for the population. The strategies and methods employed included health system strengthening; implementation science; establishing care pathways; co-designing collaborative studies on affordable technologies, developing quality standards and guidelines to decrease variations in care; economic analysis; risk modelling and stratification. Five integrated work packages have been developed to deal with all aspects of DR care. These included implementation of a DR screening programme in the public health system in a district in Kerala, evaluating regional prevalence of diabetes and DR and assessing ideal tests for holistic screening for diabetes and its complications in 20 areas in India, utilising artificial intelligence on retinal images to facilitate DR screening, exploring biomarker and biosensor research to detect people at risk of diabetes complications, estimating cost of blindness in India and risk modelling to develop risk-based screening models for diabetes and its complications. A large collaborative network will be formed to propagate research, promote shared learning and bilateral exchanges between high- and middle-income countries to tackle diabetes-related blindness.

Outcomes and risk factors of cholecystectomy in high risk patients: A case series

Introduction

Many studies looked at outcomes and risk factors in laparoscopic cholecystectomies in general, including a few studies on risk factors and scoring systems in predicting conversion to open surgery. Little data has been produced on high-risk patients undergoing cholecystectomy. Identifying risk factors in this group could help stratify decision making regarding best management strategies.

The aim of this study was to investigate outcomes of laparoscopic cholecystectomies in patients with ASA 3 and 4.

Methods

Data was collected and collated from a prospectively maintained database of all laparoscopic cholecystectomies performed by 13 general surgeons in a single unit. Case notes were reviewed for all patients with ASA 3 and 4 between 2013 and 2017. Data analysis was performed using R studio v 3.4.

Results

244 cases were reviewed. Common bile duct was dilated in 52 cases (21.31%). Gall bladder wall was thick in 102 (41.8%) of the patients. Surgery was elective in 203 (83.2%) of the patients. ERCP was performed in 41 (16.9%) of the patients prior to surgery. 150 patients (62.2%) stayed for 1 day while 36 (14.9%) stayed for 2 days and the remaining 55 (22.9%) stayed for 3 days or more. Complications occurred in 37 (15.16%) of the patients while 23 (9.43%) of the patients were readmitted. 7 patients (2.87%) returned to theatre and 8 (3.28%) stayed in ITU post-op. Two patients died (0.82%).

Conclusion

Laparoscopic cholecystectomies in higher risk populations are safe. Alternative methods such as cholecystostomy and ERCP may be of benefit in these patients.

•

Gallstone disease represents a significant volume of elective and emergency work in the United Kingdom.

•

The primary aim of the study was to explore the factors that lead to complications in high risk patients (ASA 3-4).

•

Histological gallbladder thickness and emergency surgery were the factors most strongly associated with negative outcomes.

•

Age greater than 65 as an independent variable does not lead to an increase in negative outcomes.

•

Cholecystectomy is a relatively safe procedure in what is typically considered higher risk patients.

Morphology and innervation of brachioradialis and flexor carpi radialis and their utility in tendon transfer surgeries: A Cadaveric Study

INTRODUCTION

The Brachioradialis (BR) muscle flap is easy to harvest, provides a stable coverage to the cubital fossa as it is well vascularized. The BR andflexor carpi radialis (FCR) tendons are utilized in tendon transfer to restore the normal hand function. Therefore, the present study describes the morphology of the muscle bellies and the tendons of BR and FCR along with their pattern of innervation.

MATERIALS AND METHODS

The study was carried out on 27 upper limbs of formalin-fixed, adult human cadavers. Length and width of the bellies of BR and FCR were measured. The number of motor branches and their distances from the bi-epicondylar line was measured.

RESULTS

The mean lengths of BR and FCR bellies were 21.22±2.18cm and 16.15±2.39cm, and the lengths of their tendons were, 12.67±1.13cm and 12.48±1.72cm respectively. BR received a single motor branch in 19 upper limbs. However, FCR received single motor branch in 25 limbs as a common trunk. One upper limb received three motor branches to BR, and two upper limbs received two motor branches to FCR. The most proximal and distal branches to the BR were ranged between 6.3-2.2cm proximal to the bi-epicondylar line. Those to the FCR were ranged between 3.5-6.9cm distal to the bi-epicondylar line.

CONCLUSION

The motor branches to the BR and FCR are variable in their origin, and the knowledge of such variations is essential for identifying them while performing selective neurotomy surgeries.

Abstract 3860: Discovery and characterization of novel anti-cancer small molecule inhibitors of Sec61

Secreted and membrane proteins play key roles in malignant transformation and tumor growth, including autocrine growth factor expression, receptor oncogene signal transduction pathways, metastasis, and immune system evasion. The biogenesis of most secreted and transmembrane proteins involves cotranslational translocation of nascent polypeptides into the endoplasmic reticulum through the Sec61 translocon. Broad inhibition of protein secretion can be mediated by natural product-derived Sec61 inhibitors that also possess anti-tumor activity, suggesting that Sec61 represents an untapped therapeutic target for cancer treatment. Here we describe a process for discovering and evaluating novel Sec61 inhibitors with varying degrees of selectivity for therapeutically relevant targets in oncology.

We used HEK293 reporter cell lines stably transfected to express secreted and transmembrane proteins of interest fused to luciferase to enable high-throughput screening of potential inhibitors of Sec61-dependent protein secretion. As expected, target selectivity was largely dependent on respective signal sequences. However, full-length protein constructs were found to be 5-10 fold less sensitive to inhibition compared to reporters containing only the signal sequence plus 10 amino acids, suggesting that additional interactions beyond the signal sequence are involved in promoting cotranslational translocation. To verify that novel compounds specifically targeted Sec61, we found that compounds were unable to inhibit the activity of luciferase localized to the cytosol and had reduced potency in reporter cells expressing a Sec61 mutant known to confer resistance to published inhibitors such as cotransin, mycolactone, and apratoxin. We assessed compound selectivity using a library of 37 transiently expressed Sec61-client proteins of therapeutic relevance, revealing 4 distinct chemical scaffolds differentiated by target selectivity profile. Consistent with data from published compounds, broad inhibitors of protein secretion had anti-tumor activity. Of particular interest were compounds able to block expression of multiple immune checkpoints including PD-1, PD-L1, CTLA-4, and CD96. Activity in primary cells, such as receptor expression on activated T-cells and cytokine release from stimulated PBMC, was assessed to verify specificity. Compounds with adequate in vitro metabolic stability were tested in mice for pharmacokinetics as well as inhibition of target protein secretion and global inhibition of Sec61 activity.

Taken together, our data suggest that Sec61 is a novel therapeutic target which represents a unique opportunity to both selectively block expression of multiple proteins involved in tumor growth and globally modulate protein homeostasis, resulting in tumor cell death.

Citation Format: Eric Lowe, Janet L. Anderl, Andrea R. Fan, Ying Fang, Jing Jiang, Henry W. Johnson, Christopher J. Kirk, Dustin McMinn, Tony Muchamuel, Meera Rao, Phillip P. Sharp, Jack Taunton, Jinhai Wang, Jennifer A. Whang. Discovery and characterization of novel anti-cancer small molecule inhibitors of Sec61 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3860.

Humanin levels in human seminal plasma and spermatozoa are related to sperm quality

BACKGROUND

Humanin has reportedly been expressed in testis and spermatozoa, but no study has yet reported its presence in human seminal plasma (SP).

OBJECTIVE

The aim of this study was to investigate the presence of humanin in human SP and to determine the correlation between humanin levels in SP/spermatozoa and sperm quality.

MATERIALS AND METHODS

Semen samples for SP/sperm humanin level measurement were collected from 164 patients who attended our andrology clinic for fertility evaluation. The localization of humanin in spermatozoa was evaluated using an immunofluorescence method, and SP/sperm humanin levels were measured with ELISA. Correlations between SP/sperm humanin levels and sperm parameters were analyzed.

RESULTS

Humanin was expressed in the midpiece of the spermatozoa. Humanin concentrations in the SP ranged from 24.4 to 285.1 pg/mL, with a median of 89.7 pg/mL. The SP humanin concentrations in patients with normospermia were significantly higher than those in patients with oligospermia (p < 0.001), asthenospermia (p = 0.002), and oligoasthenospermia (p < 0.001). Spearman analysis showed a positive and significant correlation between SP humanin concentration and sperm concentration (r = 0.75, p < 0.001), and progressive sperm motility (r = 0.29, p < 0.001). Sperm humanin level was significantly and positively associated with progressive sperm motility (r = 0.70, p < 0.001). In addition, a significantly higher level of humanin was found in swim-up spermatozoa than in non-swim-up spermatozoa (p = 0.03).

CONCLUSIONS

Seminal plasma and sperm humanin levels were significantly and positively correlated with sperm quality, especially sperm motility. Further studies of the origin of SP humanin and its role in spermatogenesis should be conducted.

Abstract P2-06-02: Development of a first-in-class small molecule inhibitor (EC359) targeting oncogenic LIF/LIFR signaling for the treatment of triple negative breast cancer

Background: Leukemia inhibitory factor (LIF) and its receptor LIFR are over-expressed in multiple solid tumors and play a key role in tumor growth, progression, and resistance to standard anti-cancer treatments. Triple-negative breast cancer (TNBC) lacks targeted therapies and represents a disproportional share of breast cancer (BCa) mortality. TNBC exhibits autocrine stimulation of the LIF/LIFR axis and overexpression of LIF is associated with poorer relapse-free survival in BCa patients. LIF signaling also promotes maintenance of stem cells. Therefore, targeting the LIF/LIFR axis may have therapeutic utility in TNBC.

Methods: We rationally designed a small organic molecule (EC359) that emulates the LIF/LIFR binding site and functions as a LIFR inhibitor from a library of compounds. In silico docking studies were used to identify the putative interaction of the EC359 and LIF/LIFR complex. Direct binding of EC359 to LIFR was confirmed using surface plasmon resonance (SPR) and microscale thermophoresis technique (MST) assays. In vitro activity was tested using Cell-Titer Glo, MTT, invasion, and apoptosis assays. Mechanistic studies were conducted using Western blot, reporter gene assays, and RNA-seq analysis. Xenograft, patient-derived xenograft (PDX), and patient-derived explant (PDEX) models were used for preclinical evaluation and toxicity.

Results: Molecular docking studies showed that EC359 interacts at the LIF/LIFR binding interface. SPR and MST studies confirmed direct interaction of EC359 to LIFR. EC359 reduced the growth of TNBC cells with high potency (IC50 50-100nM) and promoted apoptosis. Further, EC359 treatment reduced invasion and stemness of TNBC cells. EC359 activity is dependent on the expression levels of LIFR and showed little or no activity on TNBC cells that have low levels of LIFR or ER+ve BCa cells. Further, EC359 significantly reduced the viability of cisplatin and taxane-resistant TNBC cells and enhanced the efficacy of HDAC inhibitors. Mechanistic and biochemical studies showed that EC359 interacts with LIFR and effectively blocking LIF/LIFR interactions. EC359 also blocked LIFR interactions with other LIFR ligands such as oncostatin M, ciliary neurotrophic factor, and cardiotrophin-1. EC359 treatment attenuated the activation of LIF/LIFR driven pathways including STAT3, mTOR, AKT, and MAPK. RNA-seq analysis identified regulation of apoptosis as one of the important pathway modulated by EC359. In TNBC xenograft and PDX assays, EC359 significantly reduced tumor progression. Further, using human primary BCa PDEX cultures, we demonstrated that EC359 has the potential to substantially reduce the proliferation of human BCa. Pharmacologically, EC359 exhibited high oral bioavailability and long half-life with a wide therapeutic window.

Conclusions: EC359 is a novel targeted therapeutic agent that inhibits LIF/LIFR oncogenic signaling in TNBC via a unique mechanism of action. EC359 has the distinct pharmacologic advantages of oral bioavailability, in vivo stability, and is associated with minimal systemic side effects. (DOD BCRP grant #BC170312)

Citation Format: Viswanadhapalli S, Luo Y, Sareddy GR, Santhamma B, Zhou M, Li M, Pratap UP, Altwegg KA, Li X, Srinivasan U, Ma S, Chang A, Riveros AC, Zhang KY, Dileep KV, Pan X, Murali R, Bajda M, Raj G, Brenner A, Manthati V, Rao M, Tekmal RR, Nair HB, Nickisch KJ, Vadlamudi RK. Development of a first-in-class small molecule inhibitor (EC359) targeting oncogenic LIF/LIFR signaling for the treatment of triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-06-02.

The regulation of CIRBP by transforming growth factor beta during heat shock-induced testicular injury

BACKGROUND

Cold-inducible RNA-binding protein (CIRBP) is associated with cell stress. However, its upstream regulatory factors are still largely unknown.

OBJECTIVES

This study investigated whether CIRBP expression was regulated by transforming growth factor beta (TGF-β) during the process of heat-induced testicular damage.

MATERIALS AND METHODS

Ten male adult ICR mice were allocated to heat treatment (scrotal hyperthermia at 43 °C for 30 min, n = 5) and control group (n = 5); CIRBP and TGF-β1, TGF-β2, and TGF-β3 expression levels in the testis in mRNA and protein were analyzed. Then, we conducted in vivo and in vitro studies to investigate the regulatory effects of TGF-β on CIRBP. In the in vivo study, male adult ICR mice were subjected to testicular hyperthermia followed by a local testicular injection of TGF-β antagonist (non-selective TGF-β I/II receptor inhibitor, 5 μg or 10 μg). In the in vitro study, GC2-spd cells were cultured under 43 °C for 30 min or with different TGF-β isoforms (10 ng/mL), and CIRBP expression levels in the testis and GC2-spd cells were analyzed 24 and 48 h, respectively, after treatment.

RESULTS

As a result, heat treatment significantly downregulated the relative CIRBP mRNA and protein expression (p = 0.006 and 0.011), and significantly upregulated TGF-β2 and TGF-β3 expression levels (p = 0.022 and 0.04, for mRNA, and p = 0.001 for both protein levels). Local testicular injection of 10 μg TGF-β antagonist significantly attenuated heat-induced histological damage to the testes and CIRBP downregulation (p = 0.038). Furthermore, TGF-β2 and TGF-β3 significantly downregulated CIRBP mRNA and protein expression in GC2-spd cells (all p < 0.01), exerting a similar effect to heat treatment.

DISCUSSION AND CONCLUSION

Our in vivo and in vitro experiments demonstrated that heat-induced CIRBP downregulation in the testes was mediated by the upregulation of TGF-β. Further studies are needed to clarify the molecular mechanisms underlying these processes.

^{129}Xe-Rb Spin-Exchange Optical Pumping with High Photon Efficiency

Here we present a Rb-^{129}Xe spin-exchange optical pumping polarizer capable of rapid generation of large volumes of highly polarized ^{129}Xe gas. Through modeling and measurements we maximize the ^{129}Xe nuclear spin polarization output to enable the generation of polarized ^{129}Xe gas imaging volumes (300  cm^{3}) every 5 min within a clinical setting. Our model is verified by experiment to correctly predict the optimum Rb vapor density for maximum ^{129}Xe nuclear polarization for a flux 3.4  W/cm^{2} of circularly polarized Rb D_{1} photons incident on an 80 cm long cylindrical optical cell. We measure a ^{129}Xe magnetization production efficiency of η_{pr}=1.8%, which approaches the photon efficiency limit η_{γ}=3.3% of this system and enables the polarization of 2.72×10^{22} ^{129}Xe spins per hour, corresponding to 1013  cm^{3} of 100% polarized ^{129}Xe at STP. This magnetization production rate is threefold higher than the highest previously published ^{129}Xe magnetization production rate and has enabled routine clinical lung magnetic resonance imaging (MRI) with hyperpolarized ^{129}Xe doses available on demand at run time, as well as high-SNR ^{129}Xe MRI of the human brain and kidneys.

Maximal Fluctuations of Confined Actomyosin Gels: Dynamics of the Cell Nucleus

We investigate the effect of stress fluctuations on the stochastic dynamics of an inclusion embedded in a viscous gel. We show that, in nonequilibrium systems, stress fluctuations give rise to an effective attraction towards the boundaries of the confining domain, which is reminiscent of an active Casimir effect. We apply this generic result to the dynamics of deformations of the cell nucleus, and we demonstrate the appearance of a fluctuation maximum at a critical level of activity, in agreement with recent experiments [E. Makhija, D. S. Jokhun, and G. V. Shivashankar, Proc. Natl. Acad. Sci. U.S.A. 113, E32 (2016)PNASA60027-842410.1073/pnas.1513189113].

Propionyl-CoA carboxylase pcca-1 and pccb-1 gene deletions in Caenorhabditis elegans globally impair mitochondrial energy metabolism

Propionic acidemia (PA) is a classical inborn error of metabolism with high morbidity that results from the inability of the propionyl-CoA carboxylase (PCC) enzyme to convert propionyl-CoA to methylmalonyl-CoA. PA is inherited in an autosomal recessive fashion due to functional loss of both alleles of either PCCA or PCCB. These genes are highly conserved across evolutionarily diverse species and share extensive similarity with pcca-1 and pccb-1 in the nematode, Caenorhabditis elegans. Here, we report the global metabolic effects of deletion in a single PCC gene, either pcca-1 or pccb-1, in C. elegans. Animal lifespan was significantly reduced relative to wild-type worms in both mutant strains, although to a greater degree in pcca-1. Mitochondrial oxidative phosphorylation (OXPHOS) capacity and efficiency as determined by direct polarography of isolated mitochondria were also significantly reduced in both mutant strains. While in vivo quantitation of mitochondrial physiology was normal in pccb-1 mutants, pcca-1 deletion mutants had significantly increased mitochondrial matrix oxidant burden as well as significantly decreased mitochondrial membrane potential and mitochondrial content. Whole worm steady-state free amino acid profiling by UPLC revealed reduced levels in both mutant strains of the glutathione precursor cysteine, possibly suggestive of increased oxidative stress. Intermediary metabolic flux analysis by GC/MS with 1,6-¹³C₂-glucose further showed both PCC deletion strains had decreased accumulation of a distal tricarboxylic acid (TCA) cycle metabolic intermediate (+1 malate), isotopic enrichment in a proximal TCA cycle intermediate (+1 citrate), and increased +1 lactate accumulation. GC/MS analysis further revealed accumulation in the PCC mutants of a small amount of 3-hydroxypropionate, which appeared to be metabolized in C. elegans to oxalate through a unique metabolic pathway. Collectively, these detailed metabolic investigations in translational PA model animals with genetic-based PCC deficiency reveal their significantly dysregulated energy metabolism at multiple levels, including reduced mitochondrial OXPHOS capacity, increased oxidative stress, and inhibition of distal TCA cycle flux, culminating in reduced animal lifespan. These findings demonstrate that the pathophysiology of PA extends well beyond what has classically been understood as a single PCC enzyme deficiency with toxic precursor accumulation, and suggest that therapeutically targeting the globally disrupted energy metabolism may offer novel treatment opportunities for PA.

SUMMARY

Two C. elegans model animals of propionic acidemia with single-gene pcca-1 or pccb-1 deletions have reduced lifespan with significantly reduced mitochondrial energy metabolism and increased oxidative stress, reflecting the disease's broader pathophysiology beyond a single enzyme deficiency with toxic precursor accumulation.

Filtration Markers, Cardiovascular Disease, Mortality, and Kidney Outcomes in Stable Kidney Transplant Recipients: The FAVORIT Trial

Cystatin C and beta-2-microglobulin (B2M) are filtration markers associated with adverse outcomes in nontransplant populations, sometimes with stronger associations than for creatinine. We evaluated associations of estimated glomerular filtration rate from cystatin C (eGFR_cys ), B2M (eGFR_B2M ), and creatinine (eGFR_cr ) with cardiovascular outcomes, mortality, and kidney failure in stable kidney transplant recipients using a case-cohort study nested within the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) Trial. A random subcohort was selected (N = 508; mean age 51.6 years, median transplant vintage 4 years, 38% women, 23.6% nonwhite race) with enrichment for cardiovascular events (N = 306; 54 within the subcohort), mortality (N = 208; 68 within the subcohort), and kidney failure (N = 208; 52 within the subcohort). Mean eGFR_cr , eGFR_cys , and eGFR_B2M were 46.0, 43.8, and 48.8 mL/min/1.73m² , respectively. After multivariable adjustment, hazard ratios for eGFR_cys and eGFR_B2M <30 versus 60+ were 2.02 (95% confidence interval [CI] 1.09-3.76; p = 0.03) and 2.56 (1.35-4.88; p = 0.004) for cardiovascular events; 3.92 (2.11-7.31) and 4.09 (2.21-7.54; both p < 0.001) for mortality; and 9.49 (4.28-21.00) and 15.53 (6.99-34.51; both p < 0.001) for kidney failure. Associations persisted with additional adjustment for baseline eGFR_cr . We conclude that cystatin C and B2M are strongly associated with cardiovascular events, mortality, and kidney failure in stable kidney transplant recipients.

Multiple selection filters ensure accurate tail-anchored membrane protein targeting

Accurate protein localization is crucial to generate and maintain organization in all cells. Achieving accuracy is challenging, as the molecular signals that dictate a protein's cellular destination are often promiscuous. A salient example is the targeting of an essential class of tail-anchored (TA) proteins, whose sole defining feature is a transmembrane domain near their C-terminus. Here we show that the Guided Entry of Tail-anchored protein (GET) pathway selects TA proteins destined to the endoplasmic reticulum (ER) utilizing distinct molecular steps, including differential binding by the co-chaperone Sgt2 and kinetic proofreading after ATP hydrolysis by the targeting factor Get3. Further, the different steps select for distinct physicochemical features of the TA substrate. The use of multiple selection filters may be general to protein biogenesis pathways that must distinguish correct and incorrect substrates based on minor differences.

Transient scrotal hyperthermia affects human sperm DNA integrity, sperm apoptosis, and sperm protein expression

This prospective randomized clinical study is aimed to evidence the reproductive impairment of frequent scrotal heat exposure. A total of 20 normozoospermic subjects were randomly divided into two groups to undergo testicular warming in a 43 °C water bath 10 times, for 30 min each time; the subjects in group 1 underwent testicular warming for 10 consecutive days and those in group 2 once every 3 days. Sperm chromatin structure assay (SCSA), sperm mitochondrial membrane potential (MMP), apoptosis, and seminal plasma-soluble Fas (sFas) were analyzed before treatment and every 2 weeks after, for a total of 10 times. In group 1, some critical proteins involved in heat stress, hypoxia, structure, and function of sperm mitochondria and flagella were evaluated before hyperthermia and 2, 6, 10, and 16 weeks after hyperthermia. Both groups showed a reversible increase in the proportion of spermatozoa with a disrupted MMP (both p < 0.05 when the minimums were compared with baseline levels, the same below), sperm apoptosis (both p < 0.01) and high DNA stainability (both p < 0.05). The sFas concentration in both groups showed no obvious changes except one: the value at week 2 was significantly increased over baseline in group 1 (p = 0.036). The level of Bcl-2 decreased significantly at weeks 6 and 10 (p = 0.017 and 0.05, respectively) and recovered to baseline at week 16. Proteins involved in heat stress and mitochondria functions were up-regulated, whereas in flagella structure and function was down-regulated (all p < 0.05). This study demonstrated that transient and frequent scrotal hyperthermia severely and reversibly damaged spermatogenesis, consecutive heat exposure had more serious effects than intermittent exposure, whereas intermittent exposure led to a later recovery of sperm damage.

Norepinephrine and acetylcholine changes during electrically-induced atrial fibrillation episodes in canine models

Atrial fibrillation (AF) is the most prevalent heart rhythm disorder, and autonomic nervous system (ANS) is important to AF. This study aims to identify whether changes in transmitters released by ANS could reflect their activities. The right atrium (RA) groups (1-40V) included RA500 and RA1000. While ANS groups received high-frequency electrical stimulation (1-8V, 20 Hz, 2 ms), including left stellate ganglion stimulation (LSGS) andleft cervical vagus trunk stimulation (LVTS). The induced rate of AF, duration and atrial effective refractory period (AERP) were measured. The blood was drawn for evaluation of norepinephrine (NE) and acetylcholine (Ach) concentrations. At 12-hours, RA tissue was dissected and compared against un-stimulated controls. While AF was induced by all groups, duration and AERP were significantly different between RA pacing groups and ANS-stimulated groups, respectively (P&lt;0.05). Specific changes in profile of NE and Ach were associated with modality of stimulation. RA1000 tended to display most significant changes (P&lt;0.05) compared to other groups while variables concentration levels were observed in other groups. In conclusion, electrically-induced AF initiated by various modalities of stimulation showed different changes in serum and RA tissues. Fast frequency pacing caused significant atrial electrical remodeling, including ANS activity change.

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

A full account of our efforts toward an asymmetric redox bicycloisomerization reaction is presented in this article. Cyclopentadienylruthenium (CpRu) complexes containing tethered chiral sulfoxides were synthesized via an oxidative [3 + 2] cycloaddition reaction between an alkyne and an allylruthenium complex. Sulfoxide complex 1 containing a p-anisole moiety on its sulfoxide proved to be the most efficient and selective catalyst for the asymmetric redox bicycloisomerization of 1,6- and 1,7-enynes. This complex was used to synthesize a broad array of [3.1.0] and [4.1.0] bicycles. Sulfonamide- and phosphoramidate-containing products could be deprotected under reducing conditions. Catalysis performed with enantiomerically enriched propargyl alcohols revealed a matched/mismatched effect that was strongly dependent on the nature of the solvent.