Measuring and improving student engagement in clinical training

PURPOSE

Volunteer service learning activities, including Student Run Clinics (SRCs), are becoming an increasingly popular extracurricular component of medical education. While there are reports that student clinicians generally enjoy their educational experiences at SRCs, it is not understood how to optimize and measure student engagement in them. To identify key drivers of student engagement a tool was created to measure volunteer experience at the Crimson Care Collaborative (CCC), a primary care SRC.

METHODS

CCC volunteers were asked to complete an online engagement survey. Cross-sectional survey data were collected for 149 CCC volunteers (53% response rate).

RESULTS

Multivariate linear regression showed that overall 'likelihood to recommend CCC to a friend' was significantly associated with students' perception of the clarity of their role within the clinic, frequency of interprofessional interactions, and overall quality of medical education. Students who volunteer more frequently and for longer periods of time had higher engagement scores.

CONCLUSIONS

Measuring engagement is feasible in volunteer settings. Engagement appears to be dependent on both structural and experiential components. Easily modifiable components of job design (role definition, expected frequency of volunteering), are key drivers of volunteer engagement.

Genomewide differential expression profiling of long non-coding RNAs in androgenetic alopecia in a Chinese male population

BACKGROUND

Androgenetic alopecia (AGA), or male pattern baldness (MPB), is the most common form of hair loss in males. A combination of genetic and androgen causes have been suggested as factors that contribute to the development of AGA. However, the specific molecular mechanisms that underly AGA remain largely unknown. Long non-coding RNAs (lncRNAs), a new class of regulatory non-coding RNAs that are longer than 200 nucleotides, have been shown to play important roles in a number of cellular processes, including transcription, chromosome remodelling and post-transcriptional processing. The dysregulation of lncRNAs is associated with many forms of diseases, but it remains unknown whether lncRNAs are associated with AGA.

OBJECTIVE

The aim of this study was to identify AGA-associated lncRNAs and predict the potential roles of these lncRNAs in AGA.

METHODS

A genomewide microarray was used to identify lncRNAs that are differentially expressed between AGA and adjacent normal tissues. Real-time qRT-PCR was used to validate the microarray data.

RESULTS

A large number of lncRNAs were differentially expressed (fold change >2.4) between AGA and adjacent normal tissues. Of these, 770 were upregulated and 1373 were downregulated. Moreover, pathway analysis revealed that 53 functional pathways were associated with the upregulated transcripts, while 11 pathways were associated with the downregulated transcripts.

CONCLUSION

To our knowledge, this is the first study to investigate AGA-associated lncRNAs. lncRNA profiles are altered in AGA, and these lncRNAs and their target genes may serve as novel candidates for preventing and treating AGA.

A Robust and Affordable Table Indexing Approach for Multi-isocenter Dosimetrically Matched Fields

Purpose  Radiotherapy treatment planning of extended volume typically necessitates the utilization of multiple field isocenters and abutting dosimetrically matched fields in order to enable coverage beyond the field size limits. A common example includes total lymphoid irradiation (TLI) treatments, which are conventionally planned using dosimetric matching of the mantle, para-aortic/spleen, and pelvic fields. Due to the large irradiated volume and system limitations, such as field size and couch extension, a combination of couch shifts and sliding of patients are necessary to be correctly executed for accurate delivery of the plan. However, shifting of patients presents a substantial safety issue and has been shown to be prone to errors ranging from minor deviations to geometrical misses warranting a medical event. To address this complex setup and mitigate the safety issues relating to delivery, a practical technique for couch indexing of TLI treatments has been developed and evaluated through a retrospective analysis of couch position. Methods The indexing technique is based on the modification of the commonly available slide board to enable indexing of the patient position. Modifications include notching to enable coupling with indexing bars, and the addition of a headrest used to fixate the head of the patient relative to the slide board. For the clinical setup, a Varian Exact Couch^TM (Varian Medical Systems, Inc, Palo Alto, CA) was utilized. Two groups of patients were treated: 20 patients with table indexing and 10 patients without. The standard deviations (SDs) of the couch positions in longitudinal, lateral, and vertical directions through the entire treatment cycle for each patient were calculated and differences in both groups were analyzed with Student's t-test. Results The longitudinal direction showed the largest improvement. In the non-indexed group, the positioning SD ranged from 2.0 to 7.9 cm. With the indexing device, the positioning SD was reduced to a range of 0.4 to 1.3 cm (p < 0.05 with 95% confidence level). The lateral positioning was slightly improved (p < 0.05 with 95% confidence level), while no improvement was observed in the vertical direction. Conclusions The conventional matched field TLI treatment is error-prone to geometrical setup error. The feasibility of full indexing TLI treatments was validated and shown to result in a significant reduction of positioning and shifting errors.

Role of primary T-cell immunodeficiency and hepatitis B coinfection on spontaneous clearance of hepatitis C: The BC Hepatitis Testers Cohort

T-cell host immune response against hepatitis C virus (HCV) has been suggested to play an important role in determining HCV infection outcome. However, data from human studies are not available. This study examined the effect of primary T-cell deficiency along with other factors on the spontaneous clearance of HCV in a large population-based cohort in British Columbia, Canada. The BC Hepatitis Testers Cohort includes all individuals tested for HCV in BC in 1990-2013 linked with data on their medical visits, hospitalizations and prescription drugs. HCV-positive individuals with at least one valid HCV PCR test on/after HCV diagnosis (n=46 783) were included in this study. To examine factors associated with the spontaneous clearance of HCV, multivariable logistic regression was fitted on the full sample, and Cox proportional hazards model on the HCV seroconverters. Spontaneous clearance was observed in 25.1% (n=11 737) of those tested for HCV. After adjusting for potential confounders, the odds of spontaneous clearance of HCV was lower in people with primary T-cell immunodeficiency (adjusted odds ratio [aOR]: 0.55, 95% CI: 0.32-0.94), and higher in females (aOR: 1.61, 95% CI: 1.54-1.68) and in those coinfected with HBV (aOR: 2.31, 95% CI: 1.93-2.77). Similar results were observed in HCV seroconverters except HBV coinfection was not significant. In conclusion, primary T-cell immunodeficiency is associated with a lower spontaneous clearance of HCV while female sex and coinfection with HBV are associated with a higher spontaneous clearance.

Using a handheld stereo depth camera to overcome limited field-of-view in simulation imaging for radiation therapy treatment planning

PURPOSE

A correct body contour is essential for reliable treatment planning in radiation therapy. While modern medical imaging technologies provide highly accurate patient modeling, there are times when a patient's anatomy cannot be fully captured or there is a lack of easy access to computed tomography (CT) simulation. Here, we provide a practical solution to the surface contour truncation problem by using a handheld stereo depth camera (HSDC) to obtain the missing surface anatomy and a surface-surface image registration to stich the surface data into the CT dataset for treatment planning.

METHODS

For a subject with truncated simulation CT images, a HSDC is used to capture the surface information of the truncated anatomy. A mesh surface model is created using a software tool provided by the camera manufacturer. A surface-to-surface registration technique is used to merge the mesh model with the CT and fill in the missing surface information thereby obtaining a complete surface model of the subject. To evaluate the accuracy of the proposed approach, experiments were performed with the following steps. First, we selected three previously treated patients and fabricated a phantom mimicking each patient using the corresponding CT images and a 3D printer. Second, we removed part of the CT images of each patient to create hypothetical cases with image truncations. Next, a HSDC was used to image the 3D-printed phantoms and the HSDC-derived surface models were registered with the hypothetically truncated CT images. The contours obtained using the approach were then compared with the ground truth contours derived from the original simulation CT without image truncation. The distance between the two contours was calculated in order to evaluate the accuracy of the method. Finally, the dosimetric impact of the approach is assessed by comparing the volume within the 95% isodose line and global maximum dose (D_max ) computed based on the two surface contours for the breast case that exhibited the largest contour variation in the treated breast.

RESULTS

A systematic strategy of using a 3D HSDC to compensate for missing surface information caused by the truncation of CT images was established. Our study showed that the proposed technique was able to reliably provide the full contours for treatment planning in the case of severe CT image truncation(s). The root-mean-square error for the registration between the aligned HDSC surface model and the ground truth data was found to be 2.1 mm. The average distance between the two models was 0.4 ± 1.7 mm (mean ± SD). Maximum deviations occurred in areas of high concavity or when the skin was close to the couch. The breast tissue covered by 95% isodose line decreased by 3% and D_max increased by 0.2% with the use of the HSDC model.

CONCLUSIONS

The use of HSDC for obtaining missing surface data during simulation has a number of advantages, such as, ease of use, low cost, and no additional ionizing radiation. It may provide a clinically practical solution to deal with the longstanding problem of CT image truncations in radiation therapy treatment planning.

Obstetrics and gynecology physician knowledge of Rh immune globulin prophylaxis

BACKGROUND

Previous studies have shown that more than 20% of laboratories would have recommended inaccurate doses of Rh immune globulin (RhIG) in hypothetical cases. Efforts have been made in educating laboratories in correct dosing calculations; however, obstetricians are most often responsible for ordering RhIG. The objective of this study was to assess knowledge of RhIG indications and dosing among obstetrics and gynecology (OB/GYN) physicians in the United States.

STUDY DESIGN AND METHODS

An anonymous 17- question online survey was distributed to all OB/GYN resident and attending physicians affiliated with US residency training programs.

RESULTS

A total of 165 surveys were collected, with 139 fully completed. Ninety-two percent of respondents correctly recognized the need for RhIG in D- patients with negative antibody screens. In a scenario of a fetomaternal hemorrhage (FMH) of 45 mL, only 22% of respondents correctly chose the appropriate RhIG dosage. Of those who were correct, 10% had correctly identified 30 mL as the amount of fetal whole blood covered by one dose of RhIG, while 48% incorrectly identified 15 mL (n = 31). A total of 49.3% of respondents reported residency as the most recent formal training on RhIG dosing and 35% reported never (n = 140).

CONCLUSIONS

Our study found that OB/GYN physicians are knowledgeable regarding indications for RhIG immunoprophylaxis but were insufficient at calculating dosages in cases of FMH. More standardized education and training among OB/GYN physicians may decrease the risk of maternal alloimmunization, in part because RhIG dosage recommendations from laboratories are not standard practice.

Abstract 21: Can Telemedicine Replace an On-board Vascular Neurologist in Deciding about Tissue Plasminogen Activator Treatment? A Pre-Specified Substudy of the BEST-MSU Study

Background: Faster treatment with tPA may be achieved by optimizing prehospital triage with mobile stroke units (MSUs). The Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit (BEST-MSU) study is a prospective comparative effectiveness trial of outcomes in patients randomized to MSU or standard management (SM).

Purpose: To evaluate the inter-rater agreement for tPA eligibility between a telemedicine vascular neurologist (TM-VN) and the onboard vascular neurologist (OB-VN) in acute stroke patients seen on the MSU.

Methods: Cluster randomization of MSU and SM weeks started on August 18, 2014. On scene, both the TM-VN and OB-VN evaluated the patient and independently documented their tPA treatment decision, NIHSS and CT interpretation. Agreement was determined using Cohen’s kappa (K) statistic. TM related technical failures that impeded remote assessment were recorded.

Results: The remote TM-VN evaluated 173 patients. In 4 (2%) cases the TM-VN was not able to make a decision about tPA because of technical difficulties ( 1 case due to TM camera failure and 3 cases due to poor connectivity). The TM-VN agreed with the OB-VN on 88% of evaluations, with a K of 0.73 representing substantial agreement. Baseline NIHSS correlation between the TM-VN and OB-VN was 0.88. Agreement about ICH on CTH was a near-perfect K of 0.97.

Conclusions: We conclude from these results that remote VN assessment of stroke patients in the MSU via TM is clinically and technologically feasible, reliable and accurate. TM assessment of CTH and NIHSS was also comparable to the OB evaluation. These findings will allow either OB-VN or TM-VN assessment for the remainder of the study.

Telemedicine Can Replace the Neurologist on a Mobile Stroke Unit

BACKGROUND AND PURPOSE

The BEST-MSU study (Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit) is a comparative effectiveness trial in patients randomized to mobile stroke unit or standard management. A substudy tested interrater agreement for tissue-type plasminogen activator eligibility between a telemedicine vascular neurologist and onboard vascular neurologist.

METHODS

On scene, both the telemedicine vascular neurologist and onboard vascular neurologist independently evaluated the patient, documenting their tissue-type plasminogen activator treatment decision, National Institutes of Health Stroke Scale score, and computed tomographic interpretation. Agreement was determined using Cohen κ statistic. Telemedicine-related technical failures that impeded remote assessment were recorded.

RESULTS

Simultaneous and independent telemedicine vascular neurologist and onboard vascular neurologist assessment was attempted in 174 patients. In 4 patients (2%), the telemedicine vascular neurologist could not make a decision because of technical problems. The telemedicine vascular neurologist agreed with the onboard vascular neurologist on 88% of evaluations (κ=0.73).

CONCLUSIONS

Remote telemedicine vascular neurologist assessment is reliable and accurate, supporting either telemedicine vascular neurologist or onboard vascular neurologist assessment on our mobile stroke unit.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02190500.

Operator variability in scan positioning is a major component of HR-pQCT precision error and is reduced by standardized training

In this study, we determined that operator positioning precision contributes significant measurement error in high-resolution peripheral quantitative computed tomography (HR-pQCT). Moreover, we developed software to quantify intra- and inter-operator variability and demonstrated that standard positioning training (now available as a web-based application) can significantly reduce inter-operator variability.

INTRODUCTION

HR-pQCT is increasingly used to assess bone quality, fracture risk, and anti-fracture interventions. The contribution of the operator has not been adequately accounted in measurement precision. Operators acquire a 2D projection ("scout view image") and define the region to be scanned by positioning a "reference line" on a standard anatomical landmark. In this study, we (i) evaluated the contribution of positioning variability to in vivo measurement precision, (ii) measured intra- and inter-operator positioning variability, and (iii) tested if custom training software led to superior reproducibility in new operators compared to experienced operators.

METHODS

To evaluate the operator in vivo measurement precision, we compared precision errors calculated in 64 co-registered and non-co-registered scan-rescan images. To quantify operator variability, we developed software that simulates the positioning process of the scanner's software. Eight experienced operators positioned reference lines on scout view images designed to test intra- and inter-operator reproducibility. Finally, we developed modules for training and evaluation of reference line positioning. We enrolled six new operators to participate in a common training, followed by the same reproducibility experiments performed by the experienced group.

RESULTS

In vivo precision errors were up to threefold greater (Tt.BMD and Ct.Th) when variability in scan positioning was included. The inter-operator precision errors were significantly greater than the short-term intra-operator precision (p < 0.001). New trained operators achieved comparable intra-operator reproducibility to experienced operators and lower inter-operator reproducibility (p < 0.001). Precision errors were significantly greater for the radius than for the tibia.

CONCLUSION

Operator reference line positioning contributes significantly to in vivo measurement precision and is significantly greater for multi-operator datasets. Inter-operator variability can be significantly reduced using a systematic training platform, now available online ( http://webapps.radiology.ucsf.edu/refline/ ).

MR Fingerprinting of Adult Brain Tumors: Initial Experience

BACKGROUND AND PURPOSE

MR fingerprinting allows rapid simultaneous quantification of T1 and T2 relaxation times. This study assessed the utility of MR fingerprinting in differentiating common types of adult intra-axial brain tumors.

MATERIALS AND METHODS

MR fingerprinting acquisition was performed in 31 patients with untreated intra-axial brain tumors: 17 glioblastomas, 6 World Health Organization grade II lower grade gliomas, and 8 metastases. T1, T2 of the solid tumor, immediate peritumoral white matter, and contralateral white matter were summarized within each ROI. Statistical comparisons on mean, SD, skewness, and kurtosis were performed by using the univariate Wilcoxon rank sum test across various tumor types. Bonferroni correction was used to correct for multiple-comparison testing. Multivariable logistic regression analysis was performed for discrimination between glioblastomas and metastases, and area under the receiver operator curve was calculated.

RESULTS

Mean T2 values could differentiate solid tumor regions of lower grade gliomas from metastases (mean, 172 ± 53 ms, and 105 ± 27 ms, respectively; P = .004, significant after Bonferroni correction). The mean T1 of peritumoral white matter surrounding lower grade gliomas differed from peritumoral white matter around glioblastomas (mean, 1066 ± 218 ms, and 1578 ± 331 ms, respectively; P = .004, significant after Bonferroni correction). Logistic regression analysis revealed that the mean T2 of solid tumor offered the best separation between glioblastomas and metastases with an area under the curve of 0.86 (95% CI, 0.69-1.00; P < .0001).

CONCLUSIONS

MR fingerprinting allows rapid simultaneous T1 and T2 measurement in brain tumors and surrounding tissues. MR fingerprinting-based relaxometry can identify quantitative differences between solid tumor regions of lower grade gliomas and metastases and between peritumoral regions of glioblastomas and lower grade gliomas.

Body fat differences by self-reported race/ethnicity in healthy term newborns

BACKGROUND

Ethnic differences in total body fat (fat mass [FM]) have been reported in adults and children, but the timing of when these differences manifest and whether they are present at birth are unknown.

OBJECTIVES

This study aimed to assess whether ethnic differences in body fat are present at birth in healthy infants born at term, where body fat is measured using air displacement plethysmography and fat distribution by skin-fold thickness.

METHODS

Data were from a multiracial cross-sectional convenience sample of 332 term infants from four racial or ethnic groups based on maternal self-report (A, Asian; AA, non-Hispanic Black [African-American]; C, non-Hispanic White; and H, Hispanic). The main outcome measure was infant body fat at 1-3 days after birth, with age, birth weight, gestational age and maternal pre-pregnancy weight as covariates.

RESULTS

Significant effects for race (P = 0.0011), sex (P = 0.0051) and a race by sex interaction (P = 0.0236) were found. C females had higher FM than C males (P = 0.0001), and AA females had higher FM than AA males (P = 0.0205). C males had less FM than A males (P = 0.0353) and H males (P = 0.0001).

CONCLUSION

Race/ethnic and sex differences in FM are present in healthy term newborns. Although the implications of these differences are unclear, studies beginning in utero and birth set the stage for a life course approach to understanding disease later in life.

Longitudinal analysis of cartilage T2 relaxation times and joint degeneration in African American and Caucasian American women over an observation period of 6 years - data from the Osteoarthritis Initiative

OBJECTIVES

To investigate the change in cartilage T2 values and structural degeneration in knee joints over 72 months in women of African American (AA) vs Caucasian American (CA) ethnicity.

METHODS

Knee 3T magnetic resonance imaging (MRIs) from baseline, 24, 48 and 72 months visits of 100 AA and 100 CA women from the Osteoarthritis Initiative (OAI) were assessed for cartilage T2 values and whole-organ magnetic resonance imaging (WORMS) score. Subjects were pair-matched by age, body mass index (BMI), Kellgren-Lawrence (KL) score, clinical site and subcohort within the OAI. We compared the rate of change in whole knee cartilage T2 values and WORMS cartilage, bone marrow edema pattern (BMEP) and meniscus scores between the two ethnic groups using mixed random effects models.

RESULTS

At 24 and 48 months 60 subjects and at 72 months 45 subjects per group were available for analysis resulting in 38 complete pairs with data of all time points. Compared to CA, cartilage T2 values in AA increased at a significantly faster rate at baseline (AA: 0.45 ms/y, CA: 0.35 ms/y, P = 0.029) and averaged over 6 years (AA: 0.36 ms/y, CA: 0.27 ms/y, P = 0.039) with changes in both groups reaching a plateau by 48 months. Cartilage, meniscus and BMEP scores tended to increase in both groups during follow up, but rates of change did not differ by ethnicity.

CONCLUSION

Cartilage T2 values increased faster over 72 months in AA than CA, however changes in WORMS cartilage, meniscus and BMEP scores did not differ. T2 values may be able to distinguish ethnicity-related differences of cartilage degeneration at an early stage before differences in structural joint degeneration appear.

Physiology and Pathophysiology of Sodium Channel Inactivation

Voltage-gated sodium channels are present in different tissues within the human body, predominantly nerve, muscle, and heart. The sodium channel is composed of four similar domains, each containing six transmembrane segments. Each domain can be functionally organized into a voltage-sensing region and a pore region. The sodium channel may exist in resting, activated, fast inactivated, or slow inactivated states. Upon depolarization, when the channel opens, the fast inactivation gate is in its open state. Within the time frame of milliseconds, this gate closes and blocks the channel pore from conducting any more sodium ions. Repetitive or continuous stimulations of sodium channels result in a rate-dependent decrease of sodium current. This process may continue until the channel fully shuts down. This collapse is known as slow inactivation. This chapter reviews what is known to date regarding, sodium channel inactivation with a focus on various mutations within each NaV subtype and with clinical implications.

Pulmonary Th17 Antifungal Immunity Is Regulated by the Gut Microbiome

Commensal microbiota are critical for the development of local immune responses. In this article, we show that gut microbiota can regulate CD4 T cell polarization during pulmonary fungal infections. Vancomycin drinking water significantly decreased lung Th17 cell numbers during acute infection, demonstrating that Gram-positive commensals contribute to systemic inflammation. We next tested a role for RegIIIγ, an IL-22-inducible antimicrobial protein with specificity for Gram-positive bacteria. Following infection, increased accumulation of Th17 cells in the lungs of RegIIIγ(-/-) and Il22(-/-) mice was associated with intestinal segmented filamentous bacteria (SFB) colonization. Although gastrointestinal delivery of rRegIIIγ decreased lung inflammatory gene expression and protected Il22(-/-) mice from weight loss during infection, it had no direct effect on SFB colonization, fungal clearance, or lung Th17 immunity. We further show that vancomycin only decreased lung IL-17 production in mice colonized with SFB. To determine the link between gut microbiota and lung immunity, serum-transfer experiments revealed that IL-1R ligands increase the accumulation of lung Th17 cells. These data suggest that intestinal microbiota, including SFB, can regulate pulmonary adaptive immune responses.

Postoperative Pain Management Among Dominican and American Health-Care Providers: A Qualitative Analysis

BACKGROUND

U.S. practitioners have prescribed opioid analgesics increasingly in recent years, contributing to what has been declared an opioid epidemic by the U.S. Centers for Disease Control and Prevention (CDC). Opioids are used frequently in the preoperative and postoperative periods for patients undergoing total joint replacement in developed countries, but cross-cultural comparisons of this practice are limited. An international medical mission such as Operation Walk Boston, which provides total joint replacement to financially vulnerable patients in the Dominican Republic, offers a unique opportunity to compare postoperative pain management approaches in a developed nation and a developing nation.

METHODS

We interviewed American and Dominican surgeons and nurses (n = 22) during Operation Walk Boston 2015. We used a moderator's guide with open-ended questions to inquire about postoperative pain management and factors influencing prescribing practices. Interviews were recorded and transcripts were analyzed using content analysis.

RESULTS

Providers highlighted differences in the patient-provider relationship, pain medication prescribing variability, and access to medications. Dominican surgeons emphasized adherence to standardized pain protocols and employed a paternalistic model of care, and American surgeons reported prescribing variability and described shared decision-making with patients. Dominican providers described limited availability of potent opioid preparations in the Dominican Republic, in contrast to American providers, who discussed opioid accessibility in the United States.

CONCLUSIONS

Our findings suggest that cross-cultural comparisons provide insight into how opioid prescribing practices, approaches to the patient-provider relationship, and medication access inform distinct pain management strategies in American and Dominican surgical settings. Integrating lessons from cross-cultural pain management studies may yield more effective pain management strategies for surgical procedures performed in the United States and abroad.

Pain management among Dominican patients with advanced osteoarthritis: a qualitative study

Background

Advanced osteoarthritis and total joint replacement (TJR) recovery are painful experiences and often prompt opioid use in developed countries. Physicians participating in the philanthropic medical mission Operation Walk Boston (OpWalk) to the Dominican Republic have observed that Dominican patients require substantially less opioid medication following TJR than US patients. We conducted a qualitative study to investigate approaches to pain management and expectations for postoperative recovery in patients with advanced arthritis undergoing TJR in the Dominican Republic.

Methods

We interviewed 20 patients before TJR about their pain coping mechanisms and expectations for postoperative pain management and recovery. Interviews were conducted in Spanish, translated, and analyzed in English using content analysis.

Results

Patients reported modest use of pain medications and limited knowledge of opioids, and many relied on non-pharmacologic therapies and family support to cope with pain. They held strong religious beliefs that offered them strength to cope with chronic arthritis pain and prepare for acute pain following surgery. Patients exhibited a great deal of trust in powerful others, expecting God and doctors to cure their pain through surgery.

Conclusion

We note the importance of understanding a patient’s individual pain coping mechanisms and identifying strategies to support these coping behaviors in pain management. Such an approach has the potential to reduce the burden of chronic arthritis pain while limiting reliance on opioids, particularly for patients who do not traditionally utilize powerful analgesics.

Revisiting the physiological roles of SGLTs and GLUTs using positron emission tomography in mice

KEY POINTS

Glucose transporters are central players in glucose homeostasis. There are two major classes of glucose transporters in the body, the passive facilitative glucose transporters (GLUTs) and the secondary active sodium-coupled glucose transporters (SGLTs). In the present study, we report the use of a non-invasive imaging technique, positron emission tomography, in mice aiming to evaluate the role of GLUTs and SGLTs in controlling glucose distribution and utilization. We show that GLUTs are most significant for glucose uptake into the brain and liver, whereas SGLTs are important in glucose recovery in the kidney. This work provides further support for the use of SGLT imaging in the investigation of the role of SGLT transporters in human physiology and diseases such as diabetes and cancer.

ABSTRACT

The importance of sodium-coupled glucose transporters (SGLTs) and facilitative glucose transporters (GLUTs) in glucose homeostasis was studied in mice using fluorine-18 labelled glucose molecular imaging probes and non-invasive positron emission tomography (PET) imaging. The probes were: α-methyl-4-[F-18]-fluoro-4-deoxy-d-glucopyranoside (Me-4FDG), a substrate for SGLTs; 4-deoxy-4-[F-18]-fluoro-d-glucose (4-FDG), a substrate for SGLTs and GLUTs; and 2-deoxy-2-[F-18]-fluoro-d-glucose (2-FDG), a substrate for GLUTs. These radiolabelled imaging probes were injected i.v. into wild-type, Sglt1(-/-) , Sglt2(-/-) and Glut2(-/-) mice and their dynamic whole-body distribution was determined using microPET. The distribution of 2-FDG was similar to that reported earlier (i.e. it accumulated in the brain, heart, liver and kidney, and was excreted into the urinary bladder). There was little change in the distribution of 2-FDG in Glut2(-/-) mice, apart from a reduction in the rate of uptake into liver. The major differences between Me-4FDG and 2-FDG were that Me-4FDG did not enter the brain and was not excreted into the urinary bladder. There was urinary excretion of Me-4FDG in Sglt1(-/-) and Sglt2(-/-) mice. However, Me-4FDG was not reabsorbed in the kidney in Glut2(-/-) mice. There were no differences in Me-4FDG uptake into the heart of wild-type, Sglt1(-/-) and Sglt2(-/-) mice. We conclude that GLUT2 is important in glucose liver transport and reabsorption of glucose in the kidney along with SGLT2 and SGLT1. Complete reabsorption of Me-4FDG from the glomerular filtrate in wild-type mice and the absence of reabsorption in the kidney in Glut2(-/-) mice confirm the importance of GLUT2 in glucose absorption across the proximal tubule.

Abstract P1-14-17: Pathologic complete response rate with doxorubicin and cyclophosphamide followed by weekly paclitaxel with trastuzumab and pertuzumab in patients with HER2-positive early stage breast cancer: A single institution experience

Background:

Trastuzumab and pertuzumab (HP) with standard chemotherapy is approved for use in the neoadjuvant setting. We performed a retrospective analysis of patients (pts) treated with dose-dense doxorubicin and cyclophosphamide (AC) → paclitaxel, trastuzumab, pertuzumab (THP) in the neoadjuvant setting. Here we report the pathologic complete response (pCR) rate.

Methods:

We abstracted medical records of patients who were treated with pertuzumab-based therapy in the neoadjuvant setting from September 1, 2013 to March 1, 2015. Charts were analyzed for pt demographics, stage of breast cancer, pathology reports, surgical data, and information on systemic therapy.

Results:

Charts from 66 pts were reviewed; 60 pts were evaluable for pCR defined as absence of invasive disease in the breast, and 6 were not (3-no anthracycline, 1-incomplete chart, 1-no surgery yet, 1-metastatic). Median age was 47 years (range 28-68 years). Of 60 pts, 52 (86%) had operable breast cancer (T1-3, N0-1, M0) of which 7 had clinical stage I disease (T1N0)]; 7 (12%) had locally advanced disease (T2-3, N2-3, M0 or T4a-c, any N, M0), and 1 (2%) had inflammatory breast cancer (T4d, any N, M0). 49 (82%) and 11 (18%) had hormone receptor (HR)-positive and negative diseases, respectively. All patients had HER2-positive breast cancer defined as immunohistochemistry (IHC) 3+ and/or fluorescent in-situ hybridization (FISH) of &gt; 2.0. 30 pts (50%) underwent mastectomy and lumpectomy, respectively. Out of 60 evaluable pts, 41 (68%) had pCR; 32/49 (65%) with HR-positive and 9/11 (82%) with HR-negative diseases had pCR, respectively. Overall 58/60 (97%) pts completed neoadjuvant therapy; 2 did not (1 developed Steven Johnson Syndrome after one cycle of AC and 1 developed pneumonitis after third weekly dose of T with HP).

Conclusions:

At our single center experience the pCR rate of dose dense AC→THP is high at 68 %. These data are similar to results seen in the TRYPHAENA study, and we await the results from the BERENICE trial evaluating pCR as a secondary endpoint.

Patient Demographics Age, years &lt;4525 (42%)45-5419 (32%)&gt;5516 (26%) ECOG Performace Status 031 (52%)129 (48%) Hormone receptor (HR) status HR+ Her2+49 (82%)HR- Her2+11 (18%) Status of Her-2 Positivity IHC positive52 (86%)FISH positive8 (14%) Median tumor size2.6cm (range: 1-8.4cm) Stage Operable (T1-2, N0-1, M0)52 (86%)Operable Stage I7 (12%)Operable Stage II/III45 (74%)Locally advanced (T2-3, N2-3, M0 or T4a-c, any N, M0))7 (12%)Inflammatory (T4d, any N, M0)1 (2%) Type of surgery Lumpectomy30 (50%)Mastectomy30 (50%)

Citation Format: Singh JC, Sugarman S, Jones L, Boafo C, Patil S, Schweber S, Yu A, Argolo D, Modi S, Iyengar N, Smyth L, Norton L, Baselga J, Hudis C, Dang C. Pathologic complete response rate with doxorubicin and cyclophosphamide followed by weekly paclitaxel with trastuzumab and pertuzumab in patients with HER2-positive early stage breast cancer: A single institution experience. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-14-17.