Treating Benign Ovarian Lesions in the Pediatric Population: A Single Institution's Retrospective Investigation of Laparoscopy Versus Open Repair

Background: Benign ovarian lesions in the pediatric population have variable risk of recurrence or development of metachronous lesions, leading to variations in operative approach. Our study compares outcomes with differing surgical approaches to better elucidate risk of recurrent or metachronous lesions, time to development of these lesions, and hospital length of stay to determine if one operative approach has superior outcomes. Methods: We retrospectively examined data from Indiana University Health facilities from 2002 to 2020. Patients ≤18 years old who underwent surgical management of a benign ovarian lesion were included. Patients were categorized as undergoing oophorectomy versus ovarian sparing surgery (OSS), with open and laparoscopic approaches. Significance was defined as P < .05. Results: We identified 127 patients who underwent an open (n = 65) versus laparoscopic (n = 55) surgical approach. Patients undergoing open surgery had a greater mean size of lesion (P = .05) and longer length of stay (P < .01). Complication rates (P = .1), rates of developing a metachronous or recurrent lesion postoperatively (P = .47), and time to formation of additional lesions were similar between groups (P = .25). The incidence of identifying an additional lesion after surgery was 14.2% (n = 18) in the mean time of 29.5 ± 31.6 months [SEM 7.5]. Risk of developing a metachronous lesion was similar regardless of the operative approach. Surgery for recurrent ovarian lesions was rare and occurred in only 1 case. Conclusions: Laparoscopic surgery was performed for smaller lesions and was associated with a shorter length of hospital stay. Laparoscopic and OSS was found to have no increased risk of developing metachronous lesions nor increased reoperative risk compared with traditional open and oophorectomy techniques.

Defining Practice Readiness in Pediatric Surgery Fellowship: A Qualitative Analysis

INTRODUCTION

While competency-based training is at the forefront of educational innovation in General Surgery, Pediatric Surgery training programs should not wait for downstream changes. There is currently no consensus on what it means for a pediatric surgery fellow to be "practice-ready". In this study, we aimed to provide a framework for better defining competency and practice readiness in a way that can support the Milestones system and allow for improved assessment of pediatric surgery fellows.

METHODS

For this exploratory qualitative study, we developed an interview guide with nine questions focused on how faculty recognize competency and advance autonomy among pediatric surgery fellows. Demographic information was collected using an anonymous online survey platform. We iteratively reviewed data from each interview to ensure adequate information power was achieved to answer the research question. We used inductive reasoning and thematic analysis to determine appropriate codes. Additionally, the Dreyfus model was used as a framework to guide interpretation and contextualize the responses. Through this method, we generated common themes.

RESULTS

A total of 19 pediatric surgeons were interviewed. We identified four major themes from 127 codes that practicing pediatric surgeons associate with practice-readiness of a fellow: skill-based competency, the recognition and benefits of struggle, developing expertise and facilitating autonomy, and difficulties in variability of evaluation. While variability in evaluation is not typically included in the concept of practice readiness, assessment and evaluation were described by study participants as essential aspects of how practicing pediatric surgeons perceive practice readiness and competency in pediatric surgery fellows. Competency was further divided into interpersonal versus technical skills. Sub-themes within struggle included personal and professional struggle, benefits of struggle and how to identify and assist those who are struggling. Autonomy was commonly stated as variable based on the attending.

CONCLUSION

Our analysis yielded several themes associated with practice readiness of pediatric surgery fellows. We aim to further refine our list of themes using the Dreyfus Model as our interpretive framework and establish consensus amongst the community of pediatric surgeons in order to define competency and key elements that make a fellow practice-ready. Further work will then focus on establishing assessment metrics and educational interventions directed at achieving such key elements.

How far We Go For Surgery: Distance to Pediatric Surgical Care in Indiana

INTRODUCTION

Despite increasing numbers of pediatric surgery training programs, access to pediatric surgical care remains limited in non-academic and rural settings. We aimed to characterize demographic and patient factors associated with increased distance to selected pediatric surgical procedures in Indiana.

METHODS

This IRB-approved retrospective review analyzed pediatric patients undergoing appendectomy, cholecystectomy, umbilical hernia repair, pyloromyotomy, and video assisted thoracic surgery (VATS) procedures from 2019 through 2021. Data was obtained from an electronic medical record warehouse and the Indiana Hospital Association. Travel distance was calculated as driving distance between patient address and hospital ZIP codes. Statistics were performed in R, with p < 0.05 indicating significance.

RESULTS

There were 6835 operations performed, and half of all operations (46%) were performed at institutions with fellowship-trained pediatric surgeons. The median travel distance for all operations was 13 miles (range 0-182); the shortest was for laparoscopic appendectomy (9 miles, IQR[0-20]). The longest distances were for pyloromyotomy (51 miles, IQR[14-84]) and VATS procedures (57 miles, IQR[13-111]), of which, nearly all were performed at tertiary pediatric care centers (97% and 93%, respectively). There was a significant linear and quadratic effect of age on travel distance (p < 0.001), with younger patients requiring farther travel. On multivariable linear regression, age and procedure type had the largest effect on travel distance (Eta squared 0.03, p < 0.001).

CONCLUSION

Younger age and more specialized procedures, including VATS and pyloromyotomy, were associated with increased travel distance. This highlights regionalization of these procedures to urban areas with pediatric care centers, while others are performed closer to home.

LEVEL OF EVIDENCE

III TYPE OF STUDY: Retrospective comparative study.

Peripheral Veno-Arterial-Extracorporeal Membrane Oxygenation for Refractory Septic Shock in Children: A Multicenter Review

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is utilized as a rescue therapy in the management of pediatric patients with refractory septic shock. Multiple studies support the use of a central cannulation strategy in these patients. This study aimed to assess the survival of and identify mortality risk factors in pediatric patients supported with peripheral veno-arterial (VA) ECMO in the setting of septic shock.

METHODS

We retrospectively reviewed and compared clinical characteristics of 40 pediatric patients supported with peripheral VA ECMO for refractory septic shock, at two tertiary care children's hospitals from 2006 to 2020. Our hypothesis was that peripheral VA ECMO is effective in supporting cardiac function and improving tissue oxygenation in most pediatric patients with refractory septic shock.

RESULTS

The overall rate of survival to discharge was 52.5%, comparable to previously reported survival for pediatric sepsis on ECMO. With the exclusion of patients with an oncologic process, the survival rate rose to 62.5%. There was a statistically significant difference in mean pump flow rates within 2 hours of initiation of ECMO between survivors and non-survivors (98 mL/kg/min vs 76 mL/kg/min, P  =  .050). There was no significant difference between pre-ECMO vasoactive inotropic score (VIS) in survivors and non-survivors. A faster decrease in VIS in the first 24 hours was associated with lower mortality.

CONCLUSIONS

From this large case series, we conclude that peripheral VA ECMO is a safe and effective modality to support pediatric patients with refractory septic shock, provided there is establishment of high ECMO pump flows in the first few hours after cannulation and improvement in the VIS.

Transversus Abdominis Plane Block VS. Local Wound Infiltration for Elective Minimally Invasive Cholecystectomy in Children: A Prospective Randomized Trial

BACKGROUND

The efficacy of transversus abdominis plane (TAP) block versus local anesthetic wound infiltration (LWI) in pediatric laparoscopic surgery is largely unknown. The objective of this study was to prospectively analyze this in minimally invasive cholecystectomy. We hypothesized that TAP block would be superior to LWI in terms of pain control and post-operative complications.

METHODS

We conducted a prospective, randomized, single-blinded, controlled trial between 2017 and 2022 after obtaining Institutional Review Board (IRB) approval. After randomization, patients received a standard amount of ropivacaine via either 1) ultrasound-guided TAP block after general anesthesia induction or 2) local injection at port insertion by the operating surgeon. We collected data including operative time, pain scores, and medication usage post-operatively. We used descriptive statistics to report all endpoints and compared data with t-tests and Fisher's exact tests. A p-value less than 0.05 was considered statistically significant.

RESULTS

We enrolled 85 patients (43 LWI, 42 TAP). Mean [standard deviation] age and body mass index (BMI) in the LWI and TAP groups were 14.8 [1.9] and 14.7 [2] years and 29.9 [7.2] and 27.4 [8.2] kilogram/meter2 (kg/m2) respectively. We did not find any significant differences in postoperative opioid use, pain scores, and gastrointestinal symptoms. TAP patients had significantly longer time between anesthesia-start and procedure-start (p < 0.001), although total time under anesthesia was not significantly different (p = 0.540).

CONCLUSION

There are no significant differences between equal administration of local anesthetic by TAP block and surgeon administered LWI during minimally invasive cholecystectomy.

TYPE OF STUDY

Randomized clinical trial.

LEVEL OF EVIDENCE

Level II.

Neonatal Carotid Artery and Internal Jugular Vein Management Practices at Extracorporeal Membrane Oxygenation Decannulation: No Standard Approach

BACKGROUND

There are currently no commonly accepted standardized guidelines for management of cervical vessels at neonatal extracorporeal membrane oxygenation (ECMO) decannulation. This study investigates neonatal ECMO decannulation practices regarding management of the carotid artery and internal jugular vein, use of post-repair anticoagulation, and follow-up imaging.

METHODS

A survey was distributed to the 37 institutions in the Children's Hospitals Neonatal Consortium. Respondents reported their standard approach to carotid artery and internal jugular vein management (ligation or repair) at ECMO decannulation by their pediatric surgery and cardiothoracic (CT) surgery teams as well as post-repair anticoagulation practices and follow-up imaging protocols.

RESULTS

The response rate was 95%. Pediatric surgeons performed most neonatal respiratory ECMO cannulations (88%) and decannulations (85%), while all neonatal cardiac ECMO cannulations and decannulations were performed by CT surgeons. Pediatric surgeons overwhelmingly ligate both vessels (90%) while CT surgeons typically repair both vessels at decannulation (83%). Of the responding centers that repair, 28% (7) have a standard anticoagulation protocol after neck vessel repair. While 52% (13) of centers routinely image cervical vessel patency at least once post repair, most do not subsequently repeat neck vessel imaging.

CONCLUSIONS

Significant practice differences exist between pediatric and CT surgeons regarding the approach to cervical vessels at neonatal ECMO decannulation. For those centers that do repair the vessels there is little uniformity in post-repair anticoagulation or imaging protocols. There is a need to develop standardized cervical vessel management guidelines for neonatal ECMO patients and to study their impact on both short- and long-term outcomes.

LEVEL OF EVIDENCE

IV.

First-in-human study of a novel cell death tracer [99mTc]Tc-Duramycin: safety, biodistribution and radiation dosimetry in healthy volunteers

BACKGROUND

Imaging of cell death can provide an early indication of treatment response in cancer. [99mTc]Tc-Duramycin is a small-peptide SPECT tracer that recognizes both apoptotic and necrotic cells by binding to phosphatidylethanolamine present in the cell membrane. Preclinically, this tracer has shown to have favorable pharmacokinetics and selective tumor accumulation early after the onset of anticancer therapy. In this first-in-human study, we report the safety, biodistribution and internal radiation dosimetry of [99mTc]Tc-Duramycin in healthy human volunteers.

RESULTS

Six healthy volunteers (3 males, 3 females) were injected intravenously with [99mTc]Tc-Duramycin (dose: 6 MBq/kg; 473 ± 36 MBq). [99mTc]Tc-Duramycin was well tolerated in all subjects, with no serious adverse events reported. Following injection, a 30-min dynamic planar imaging of the abdomen was performed, and whole-body (WB) planar scans were acquired at 1, 2, 3, 6 and 23 h post-injection (PI), with SPECT acquisitions after each WB scan and one low-dose CT after the first SPECT. In vivo 99mTc activities were determined from semi-quantitative analysis of the images, and time-activity curves were generated. Residence times were calculated from the dynamic and WB planar scans. The mean effective dose was 7.61 ± 0.75 µSv/MBq, with the kidneys receiving the highest absorbed dose (planar analysis: 43.82 ± 4.07 µGy/MBq, SPECT analysis: 19.72 ± 3.42 μGy/MBq), followed by liver and spleen. The median effective dose was 3.61 mSv (range, 2.85-4.14). The tracer cleared slowly from the blood (effective half-life of 2.0 ± 0.4 h) due to high plasma protein binding with < 5% free tracer 3 h PI. Excretion was almost exclusively renal.

CONCLUSION

[99mTc]Tc-Duramycin demonstrated acceptable dosimetry (< 5 mSv) and a favorable safety profile. Due to slow blood clearance, optimal target-to-background ratios are expected 5 h PI. These data support the further assessment of [99mTc]Tc-Duramycin for clinical treatment response evaluation.

TRIAL REGISTRATION

NCT05177640, Registered April 30, 2021, https://clinicaltrials.gov/study/NCT05177640 .

Is the changing landscape of fellowship recruitment during COVID-19 here to stay?

BACKGROUND

The 2020 Pediatric Surgery (PS) fellowship selection process was heavily impacted by the COVID-19 pandemic. A review of lessons learned can help determine best practices for the future. The purpose of the study was to analyze the virtual interview experience and assess opportunities to improve the post-pandemic fellowship recruitment process.

STUDY DESIGN

Using a 28-question survey of Program Directors (PDs) of PS fellowships as well as a 44-question survey of applicants to PS fellowships in the US and Canada, we gathered information on the recruitment process during the COVID-19 pandemic (2020). Dichotomous, multiple choice and open-ended questions about the changes in process, platforms used, format, comparison to on-site interviews and overall satisfaction were used for objective and subjective feedback.

RESULTS

A 95% participation rate was recorded for the PD survey. 24 out of 55 programs (44%) changed their on-site interviews to virtual format due to the pandemic. Most PDs described their overall impression of virtual interviews as satisfactory (66%, 16/24) and did not have an impact on the applicant's success in the match (35/54; 65%). About 50% of PDs preferred to have on-site interviews with virtual screening in the future. While the participation rate from applicants was much less (26 of 70), responses confirmed our survey results. Majority preferred on-site interviews (17/26), 6 of which preferred virtual screening followed by on-site interviews.

CONCLUSION

Components of virtual screening and interviews were found to have benefits financially and from both time and stress perspectives, and thus might survive past the pandemic. LEVELS OF EVIDENCE LEVEL IV: .

Success in pediatric surgery: An updated survey of Program Directors 2020

BACKGROUND

One of the most competitive surgical sub-specialty fellowships remains Pediatric Surgery (PS), which requires candidates to develop a strong and research-oriented curriculum vitae. Although some objective factors of matriculation are known, factors for the interview selection and ranking per the program directors (PDs) have not been reviewed in over a decade.

METHODS

A web-based survey of US and Canadian PS program directors (PDs) (n = 58) was used to evaluate a comprehensive list of factors in the selection criteria for PS fellowships. A mix of dichotomous, ranking, five-point Likert scale, and open-ended questions evaluated applicant characteristics, ABSITE scores, research productivity, interview day, and rank order criteria.

RESULTS

Fifty-five programs responded to the survey for a 95% participation rate. PDs desired an average of two years in dedicated research and weighted first authorship and total number of publications heavily. Only 38% of programs used an ABSITE score cutoff for offering interviews; however, the majority agreed that an overall upward trend was important. Quality letters of recommendation, especially from known colleagues, carried weight when deciding to offer interviews. Interview performance, being a team player, observed interpersonal interactions, perceived operative skills and patient care, and leadership were some of the notable factors when finalizing rank lists.

CONCLUSIONS

A multitude of factors define a successful matriculant, including quality of letters of recommendation, quality and quantity of publications, supportive phone calls, observed interactions, interview performance, perceptions of being team player with leadership skills as well as perceptions of good operative skills and patient care.

LEVEL OF EVIDENCE

Type II.

TYPE OF STUDY

Prognostic (retrospective).

Uncomplicated gastroschisis care in the US and Kenya: Treatment at two tertiary care centers

BACKGROUND

Gastroschisis is a common birth defect with < 5% mortality in high income countries, but mortality in sub Saharan Africa remains high. We sought to compare gastroschisis management strategies and patient outcomes at tertiary pediatric referral centers in the United States and Kenya.

METHODS

This retrospective chart review examined uncomplicated gastroschisis patients treated at Riley Hospital for Children in Indianapolis, USA (n = 110), and Shoe4Africa Children's Hospital in Eldoret, Kenya (n = 75), from 2010 to 2018. Analyzed were completed using Chi square, Fisher's exact, and independent samples t tests and medians tests at the 95% significance level.

RESULTS

Survival in the American cohort was double that of the Kenyan cohort (99.1% vs 45.3%, p< 0.001). Sterile bag use for bowel containment was lower in Kenya (81.3% vs 98.1%, p< 0.001), but silo use was comparable at both institutions (p = 0.811). Kenyan patients had earlier median enteral feeding initiation (4vs 10 days, p< 0.001) and accelerated achievement of full enteral feeding (10vs 23 days, p< 0.001), but none received TPN. Despite earlier feeding, Kenyan patients displayed a higher prevalence of wound infections (70.8% vs 17.1%, p< 0.001) and sepsis (43.9% vs 4.8%, p< 0.001). In Kenya, survivors and non survivors displayed no difference in sterile bag use, hemodynamic stability, all cause infection rates, or antibiotic free hospital days. Defect closure (p< 0.001) and enteral feeding initiation (p< 0.001) were most predictive of survival.

CONCLUSION

Improving immediate response strategies for gastroschisis in Kenya could improve survival and decrease infection rates. Care strategies in the US can center on earlier enteral feeding initiation to reduce time to full feeding.

LEVEL OF EVIDENCE

Level III.

Early prediction of tumor response after radiotherapy in combination with cetuximab in nasopharyngeal carcinoma using 99m Tc-duramycin imaging

PURPOSE

^99mTc-duramycin imaging enables specific visualization of cell death qualitatively and quantitatively. This study aimed to investigate the potential of ^99mTc-duramycin imaging in the early prediction of the curative effect of radiotherapy in combination with or without cetuximab in a nasopharyngeal carcinoma (NPC) model.

METHODS

Male BALB/c mice bearing NPC xenografts were randomized into four groups (six mice each group). Group 1 received radiotherapy (RT, 15 Gy/mouse) in combination with cetuximab (CTX, 2 mg/mouse), group 2 received RT (15 Gy/mouse), group 3 was treated using CTX (2 mg/mouse), and group 4, the control group, was treated using a vehicle. ^99mTc-duramycin imaging was performed before treatment and 24 h after treatment to evaluate tumor response. Tumor uptake of ^99mTc-duramycin was validated ex vivo using γ-counting. Treatment response was further validated by cleaved caspase-3 (CC3) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL). Another four groups were treated parallelly under the same conditions to observe treatment response by tumor volume changes.

RESULTS

After 24 h treatment, ^99mTc-duramycin uptake in the NPC tumor models were significantly higher in group 1 than in group 2 (P < 0.05), group 3 (P < 0.05), or group 4 (P < 0.05); the uptake also increased notably in comparison with baseline values (P < 0.05). Compared with group 4, group 2 and group 3 both showed significant ^99mTc-duramycin uptake in the tumors (P < 0.05). Although the ^99mTc-duramycin uptake of group 2 was moderately higher than group 3, there were no significant differences between these two groups (P >0.05). There was a strong positive correlation between tumor ^99mTc-duramycin uptake and CC3 (r = 0.893, p < 0.0001) and TUNEL (r = 0.918, P < 0.0001). Tumor volume decreased remarkably in the RT in combination with CTX group on day 5, in the RT alone group on day 7, and was inhibited on day 8 in the CTX alone group, whereas the tumors grew continuously in the control group.

CONCLUSIONS

We demonstrated that RT in combination with CTX treatment significantly improved disease control in a NPC xenograft model compared with monotherapy with either. ^99mTc-duramycin imaging might be able to reliably identify response to RT in combination with CTX as early as 24 h after therapy initiation in NPC xenograft models. This might help to isolate non-responding patients in a timely manner and avoid unnecessary side effects in the clinic in the future.

Abstract P1-17-05: The impact of clinical risk assessment versus PAM-50 ROR score on prognosis and therapeutic decision making in patients with hormone-receptor positive early stage breast cancer

Background: Therapeutic recommendations for adjuvant treatment of hormone-receptor positive breast cancer patients depend on the individual recurrence risk. A number of genomic assays introduced to achieve this goal, but it's still questioned if they actually offer superior risk assessment compared to traditional risk evaluation by experienced clinicians. This study was designed to compare the prognostic accuracy of PAM-50 to clinical judgment.

Methods: Based on the real data of a large adjuvant trial cohort (ABCSG-8, postmenopausal HR positive breast cancer patients), we created online-questionnaires including demographic, histological, and local-therapy details, with and without results of PAM50 ROR score. Out of 14 international breast cancer experts asked for individual patient's risk evaluation (low, intermediate, high) and therapy recommendations, 9 completed the questionnaire.

Patient data were described by Kaplan-Meier estimates of distant disease free survival (DDFS) stratified by risk group. Cox regression models were compared using the Akaike Information Criterion (AIC).

Results: 10 years DDFS and hazard ratios for distant recurrences stratified by risk-group as estimated giving in Table 1:

10 years DDFS and hazard ratios for distant recurrences stratified by risk-group as estimated Low riskIntermediate riskHigh risk n (%)10y DDFS,%(95%CI)n (%)10y DDFS,%(95%CI)n (%)10y DDFS, %(95%CI)  HR(95% CI) HR(95% CI) HR(95% CI)Clinical only: AIC 817.6269 (43)93.0(89.8-96.2)289 (46)89.7(85.9-93.5)73 (11)76.6(66.1-87.1)  0.68(0.39,1.20) 1 2.57(1.41,4.65)PAM50 ROR: AIC 804.8241 (34)96.5(93.1-99.1)210 (33)89.2(84.7-93.7)207 (33)82.5(76.9-88.2)  0.27(0.11,0.62) 1 1.66(0.99,2.78)Combined: AIC 813.4232 (37)95.7(93.0-98.5)282 (45)87.8(83.7-92.0)117 (18)81.7(74.2-89.2)  0.42(0.22,0.84) 1 1.90(1.11,3.24)

Adding genomic information to clinical risk factors leads to escalation of therapeutic recommendations (i.e. additional chemotherapy, extended adjuvant endocrine) in 20% of patients, and de-escalation in 13% of patients.

Conclusions: Clinical judgment accurately identified the patients at high risk of relapse, but was clearly inferior to multi-genomic testing using the PAM-50 ROR score in differentiating low from intermediate risk. Particularly when avoiding unnecessary escalated therapy is the strategic goal, the addition of PAM-50 testing to clinical judgment offers improved accuracy in predicting low vs. intermediate risk of breast cancer recurrence.

Citation Format: Devyatko Y, Filipits M, Greil R, Balic M, Bago-Horvath Z, Singer C, Fitzal F, Steger G, Gray B, Ferree S, Fesl C, Soelkner L, von Minckwitz G, Gnant M. The impact of clinical risk assessment versus PAM-50 ROR score on prognosis and therapeutic decision making in patients with hormone-receptor positive early stage 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 P1-17-05.

Detection of prohibited substances in equine hair by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry - application to doping control samples

The detection of drugs in human hair samples has been performed by laboratories around the world for many years and the matrix is popular in disciplines, such as workplace drug testing. To date, however, hair has not become a routinely utilised matrix in sports drug detection. The analysis of hair samples offers several potential advantages to doping control laboratories, not least of which are the greatly extended detection window and the ease of sample collection and storage. This article describes the development, validation, and utilisation of a sensitive ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC-MS/MS) method for the detection of 50 compounds. This provides significantly improved coverage for those analytes which would be of particular interest if detected in hair, such as anabolic steroid esters and selective androgen receptor modulators (SARMs). Qualitative validation of the method resulted in estimated limits of detection as low as 0.1 pg/mg for the majority of compounds, with all being detected at 2 pg/mg or below. The suitability of the method for the detection of prohibited substances in incurred material was demonstrated by the successful detection of several compounds, such as stanozolol, boldenone undecylenate, clenbuterol, and GW-501516, in genuine equine hair samples. Estimated concentrations of the detected substances ranged from 0.27 to 8.6 pg/mg. The method has been shown to be fit-for-purpose for routine screening of equine hair samples by the analysis of over 400 genuine hair samples.

The in vitro detection of botulinum neurotoxin-cleaved endogenous VAMP is epitope-dependent

The in vitro potency of botulinum neurotoxin (BoNT) serotypes is often measured by monitoring cleavage of their soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein substrates. A frequently used method is Western blot, whereby the full-length protein and cleaved form migrate at different molecular weights. Until now, it has been extremely difficult to detect the cleaved cellular form of the SNARE protein vesicle associated membrane protein 1, 2 or 3 (VAMP1, 2 or 3) by Western blot. These VAMP isoforms are the substrates of BoNT serotypes BoNT/B, D, F and G as well as tetanus neurotoxin. Using custom made anti-VAMP antibodies against epitopes either side of the cleavage sites for BoNT/B, BoNT/D and BoNT/F, we have successfully detected the cleaved C-terminal VAMP fragment in cortical neurons. These new antibodies enable quantitative assessment of the potency of VAMP-cleaving neurotoxins by a gain of signal Western blot assay.

Site-selective spectroscopy with depth resolution using resonant x-ray reflectometry

Combining dissimilar transition metal oxides (TMOs) into artificial heterostructures enables to create electronic interface systems with new electronic properties that do not exist in bulk. A detailed understanding of how such interfaces can be used to tailor physical properties requires characterization techniques capable to yield interface sensitive spectroscopic information with monolayer resolution. In this regard resonant x-ray reflectivity (RXR) provides a unique experimental tool to achieve exactly this. It yields the element specific electronic depth profiles in a non-destructive manner. Here, using a YBa₂Cu₃O_7−δ (YBCO) thin film, we demonstrate that RXR is further capable to deliver site selectivity. By applying a new analysis scheme to RXR, which takes the atomic structure of the material into account, together with information of the local charge anisotropy of the resonant ions, we obtained spectroscopic information from the different Cu sites (e.g., chain and plane) throughout the film profile. While most of the film behaves bulk-like, we observe that the Cu-chains at the surface show characteristics of electron doping, whereas the Cu-planes closest to the surface exhibit an orbital reconstruction similar to that observed at La_1−xCa_xMnO₃/YBCO interfaces.

FGF2 and EGF Are Required for Self-Renewal and Organoid Formation of Canine Normal and Tumor Breast Stem Cells

Recent studies suggest that human tumors are generated from cancer cells with stem cell (SC) properties. Spontaneously occurring cancers in dogs contain a diversity of cells that like for human tumors suggest that certain canine tumors are also generated from cancer stem cells (CSCs). CSCs, like normal SCs, have the capacity for self-renewal as mammospheres in suspension cultures. To understand how cells with SC properties contribute to canine mammary gland tumor development and progression, comparative analysis between normal SCs and CSCs, obtained from the same individual, is essential. We have utilized the property of sphere formation to develop culture conditions for propagating stem/progenitor cells from canine normal and tumor tissue. We show that cells from dissociated mammospheres retain sphere reformation capacity for several serial passages and have the capacity to generate organoid structures ex situ. Utilizing various culture conditions for passaging SCs and CSCs, fibroblast growth factor 2 (FGF2) and epidermal growth factor (EGF) were found to positively or negatively regulate mammosphere regeneration, organoid formation, and multi-lineage differentiation potential. The response of FGF2 and EGF on SCs and CSCs was different, with increased FGF2 and EGF self-renewal promoted in SCs and repressed in CSCs. Our protocol for propagating SCs from normal and tumor canine breast tissue will provide new opportunities in comparative mammary gland stem cell analysis between species and anticancer treatment and therapies for dogs. J. Cell. Biochem. 118: 570-584, 2017. © 2016 Wiley Periodicals, Inc.

Endovascular Management of Unusual Aneurysms of the Axillary and Subclavian Arteries

Purpose:

Aneurysms of the upper extremity arteries are uncommon and may be difficult to manage with standard surgical techniques. We report the exclusion of three axillary-subclavian aneurysms with covered stents.

Methods and Results:

Palmaz stents were covered with either polytetrafluoroethylene (2 cases) or brachial vein and deployed to exclude pseudoaneurysms in 1 axillary (ruptured) and 2 left subclavian arteries. Two of the patients had advanced cancer and died within 52 days and 3 months of treatment, but their aneurysms were occluded at the time of their death. The repair in the third patient is patent at 9 months.

Conclusions:

Endovascular exclusion of axillary and subclavian aneurysms with covered stents may offer a useful alternative to operative repair, particularly in patients with significant comorbidities.

Early Prediction of Tumor Response to Treatment: Preclinical Validation of 99mTc-Duramycin

Noninvasive imaging of cell death can provide an early indication of the efficacy of tumor treatment, aiding clinicians in distinguishing responding patients from nonresponding patients early on. (99m)Tc-duramycin is a SPECT tracer for cell death imaging. In this study, our aim was to validate the use of (99m)Tc-duramycin for imaging the early response of tumors to treatment.

METHODS

An in vitro binding assay was performed on COLO205 cells treated with 5-fluorouracil (3.1, 31, or 310 μM) and oxaliplatin (0.7 or 7 μM) or radiation (2 or 4.5 Gy). (99m)Tc-duramycin cell binding and the levels of cell death were evaluated after treatment. In vivo imaging was performed on 4 groups of CD1-deficient mice bearing COLO205 human colorectal cancer tumors. Each group included 6 tumors. The first group was given irinotecan (100 mg/kg), the second oxaliplatin (5 mg/kg), the third irinotecan (80 mg/kg) plus oxaliplatin (5 mg/kg), and the fourth vehicle (0.9% NaCl and 5% glucose). For radiotherapy studies, COLO205 tumors received 4.5 Gy, 2 fractions of 4.5 Gy in a 24-h interval, pretreatment with an 80 mg/kg dose of irinotecan combined with 2 fractions of 4.5 Gy in a 24-h interval, or no treatment (n = 5-6/group). Therapy response was evaluated by (99m)Tc-duramycin SPECT 24 h after the last dose of therapy. Blocking was used to confirm tracer specificity. Radiotracer uptake in the tumors was validated ex vivo using γ-counting, cleaved caspase-3, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) histology.

RESULTS

Chemotherapy and radiotherapy increased (99m)Tc-duramycin binding to COLO205 cells in a concentration/dose- and time-dependent manner, which correlated well with cell death levels (P < 0.05) as analyzed by annexin V and caspase 3/7 activity. In vivo, (99m)Tc-duramycin uptake in COLO205 xenografts was increased 2.3- and 2.8-fold (P < 0.001) in mice treated with irinotecan and combination therapy, respectively. Blocking with unlabeled duramycin demonstrated specific binding of the radiotracer. After tumor irradiation with 4.5 Gy, (99m)Tc-duramycin uptake in tumors increased significantly (1.24 ± 0.07 vs. 0.57 ± 0.08 percentage injected dose per gram in the unirradiated tumors; P < 0.001). γ-counting of radioactivity in the tumors positively correlated with cleaved caspase-3 (r = 0.85, P < 0.001) and TUNEL (r = 0.81, P < 0.001) staining.

CONCLUSION

We demonstrated that (99m)Tc-duramycin can be used to image induction of cell death early after chemotherapy and radiotherapy. It holds potential to be translated into clinical use for early assessment of treatment response.

Neuroanatomical Tracing Techniques in the Ear: History, State of the Art, and Future Developments

The inner ear has long been at the cutting edge of tract tracing techniques that have shaped and reshaped our understanding of the ear's innervation patterns. This review provides a historical framework to understand the importance of these techniques for ear innervation and for development of tracing techniques in general; it is hoped that lessons learned will help to quickly adopt transformative novel techniques and their information and correct past beliefs based on technical limitations. The technical part of the review presents details of our protocol as developed over the last 30 years. We also include arguments as to why these recommendations work best to generate the desired outcome of distinct fiber and cell labeling, and generate reliable data for any investigation. We specifically focus on two tracing techniques, in part developed and/or championed for ear innervation analysis: the low molecular multicolor dextran amine tract tracing technique and the multicolor tract tracing technique with lipophilic dyes.

Culture and characterization of mammary cancer stem cells in mammospheres

Mammospheres (MMs) are a model for culturing and maintaining mammary gland stem cells (SCs) or cancer stem cells (CSCs) ex situ. As MMs recapitulate the micro-niche of the mammary gland or a tumor, MMs are a model for studying the properties of SCs or CSCs, and for mapping, isolating, and characterizing the SC/CSC generated lineages. Cancer stem cells share with normal SCs the properties of self-renewal and the capacity to generate all cell types and organ structures of the mammary gland. Analysis of human tumor samples suggests that CSCs are heterogeneous in terms of proliferation and differentiation potential. Mammospheres from CSCs likewise display heterogeneity. This heterogeneity makes analysis of CSC generated MMs challenging. To identify the unique and diverse properties of MM derived CSCs, comparative analysis with MMs obtained from normal SCs is required. Here we present protocols for identifying and enriching cells with SC features from a cancer cell line using the LA7CSCs as a model. A comprehensive and comparative approach for identifying, isolating, and characterizing MMs from SCs and CSCs from human breast is also introduced. In addition, we describe detailed procedures for identifying, isolating, and characterizing mammary gland specific cell types, generated during MM formation.