Leaning in and moving forward: a call to action and review of diversity initiatives in SAGES.

BACKGROUND: Diversity, equity, and inclusion have been an intentional focus for SAGES well before the COVID-19 pandemic and the coincident societal recognition of social injustices and racism. Longstanding inequities within our society, healthcare, and the surgery profession have come to light in the aftermath of events that rose to attention around the time of Covid. In so doing, they have brought into focus disparities, injustices, and inequalities that have long been present in the field of surgery, selectively affecting the most vulnerable. METHODS: This White paper examines the current state of diversity within the field of surgery and SAGES (Society of American Gastrointestinal and Endoscopic Surgeons) approach and effort to pave the way forward to meaningful change. We delineate the imperative for diversity, equity, and inclusion for all. By all, we mean to be inclusive of the diversity of gender and sexual orientation, race, ethnicity, geography, sex, and disability in the field of surgery. RESULTS: SAGES is an organization that lives at the intersection of education and innovation. It has a vital role in assisting the surgical profession in addressing these issues and needs and being a force alongside others for sustained and necessary change. SAGES can only realize these goals through a commitment across all aspects of the organization to embed diversity, equity, and inclusion into our very fabric. CONCLUSION: True diversity, equity, and inclusion within a surgical organization is vital for its longevity, growth, relevance, and impact. Unfortunately, the absence of DEI limits opportunity, robs the organization of collective intelligence in an environment in which its presence is critical, contributes to health inequities, and impoverishes all within the society and its value to all with whom it interfaces. SAGES is an organization that lives at the intersection of education and innovation. It has a vital role in assisting the surgical profession in addressing these issues and needs and being a force alongside others for sustained and necessary change. SAGES can only realize these goals through a commitment across all aspects of the organization to embed diversity, equity, and inclusion into our very fabric. Strategies like those highlighted in this White Paper, may be within our grasp and we can learn yet more if we remain in a place of humility and teachability in the future.

Chimeric antigen receptor signaling: Functional consequences and design implications.

Chimeric antigen receptor (CAR) T cell therapy has transformed the care of refractory B cell malignancies and holds tremendous promise for many aggressive tumors. Despite overwhelming scientific, clinical, and public interest in this rapidly expanding field, fundamental inquiries into CAR T cell mechanistic functioning are still in their infancy. Because CAR T cells are manufactured from donor T lymphocytes, and because CARs incorporate well-characterized T cell signaling components, it has largely been assumed that CARs signal analogously to canonical T cell receptors (TCRs). However, recent studies demonstrate that many aspects of CAR signaling are unique, distinct from endogenous TCR signaling, and potentially even distinct among various CAR constructs. Thus, rigorous and comprehensive proteomic investigations are required for rational engineering of improved CARs. Here, we review what is known about proximal CAR signaling in T cells, compare it to conventional TCR signaling, and outline unmet challenges to improving CAR T cell therapy.

Validation of transcutaneous bilirubinometry during phototherapy for detection and monitoring of neonatal jaundice in a low-income setting.

Background: Severe neonatal jaundice (SNJ) and the associated long-term health sequelae are a significant problem in low-income countries (LIC) where measurement of total serum bilirubin (TSB) is often unavailable. Transcutaneous bilirubinometry (TcB) provides the opportunity for non-invasive, point-of-care monitoring. Few studies have evaluated its agreement with TSB levels during phototherapy in LIC.Aim: To determine agreement between TcB and TSB during phototherapy in a Haitian newborn population and to establish whether TcB can be safely used to guide treatment during phototherapy when TSB is unavailable.Methods: A single-centre prospective study (February to May 2017) in Cap Haïtien, northern Haiti was undertaken. Newborns <7 days of age with clinically detected jaundice were eligible for inclusion. A TcB device (JM-103) was used to screen for newborn jaundice along with a parallel TSB. A strip of black tape was placed across the sternum during phototherapy and uncovered for subsequent TcB measurements. Decisions about phototherapy treatment were based upon UK National Institute of Clinical Excellence (NICE) threshold criteria. Paired TSB and TcB measurements were compared using Bland-Altman methods.Results: The final analysis included 70 parallel TSB/TcB measurements from 35 infants within the first 5 days of life. Nineteen (54.3%) were male and 12 (34.3%) were <35 weeks. Thirty-two (91.4%) were receiving phototherapy. There was good agreement between TSB and TcB. Compared with TSB, TcB tended to over-estimate bilirubin (mean difference 11.1 µmol/L, 95% CI -10.2-32.5 µmol/L). However, at higher bilirubin levels (>250 µmol/L), TcB tended to under-estimate bilirubin compared with TSB and the difference increased.Conclusion: In an LIC setting in which serum bilirubin testing is not commonly available, TcB demonstrates good agreement with TSB and can be safely used to guide jaundice treatment during phototherapy but can lead to over-treatment at lower bilirubin levels and are more inaccurate at higher levels. For TcB levels >250 µmol, confirmation with serum bilirubin should be performed, if available, to avoid under-estimation.Abbreviations: LIC: low income countries; LMIC: low and middle income countries; TcB: transcutaneous bilirubinometry; TSB: transcutaneous serum biliubin.

Effect of injection site on alfaxalone-induced sedation in ball pythons (Python regius).

OBJECTIVES: To evaluate the sedative and cardiorespiratory effects of alfaxalone in ball pythons following subcutaneous administration in the cranial versus caudal third of the body. MATERIALS AND METHODS: In a prospective, randomised, blinded, complete crossover study, eight ball pythons ( Python regius ) received alfaxalone in the cranial or caudal third of the body. Sedative and cardiorespiratory parameters were recorded. RESULTS: Administration of alfaxalone in the cranial third of the body resulted in significantly deeper and longer sedation compared with administration in the caudal third of the body. Righting reflex was lost in five of eight snakes following cranial injection compared with one of eight snakes after caudal injection. Jaw tone was lost in all snakes following cranial injection and intubation was successfully performed in seven. In contrast, snakes did not lose jaw tone and intubation was not possible following caudal injection. Heart rate and respiratory rate were significantly decreased following administration of alfaxalone in the cranial third of the body. CLINICAL SIGNIFICANCE: Administration of drugs that undergo hepatic metabolism or excretion should not be performed in the caudal third of the body in snakes, because it can result in significantly reduced drug efficacy. A hepatic first-pass effect is assumed to be the most likely underlying cause for the observed effect because part of the venous return from the caudal body flows directly to the liver.

A technique for re-utilizing catheter insertion sites in children with difficult central venous access.

Maintenance of central venous access in patients with chronic medical conditions such as short bowel syndrome demands forethought and ingenuity. We describe an innovative technique for re-utilizing central venous access sites in patients who have chronic central venous access needs. Records of patients undergoing this technique were reviewed between August 2012 and December 2015. The technique involves "cutting-down" to the sterile fibrous tunnel that naturally forms around tunneled catheters. The fibrous sheath is then isolated and controlled much as would be done for a venous "cut-down." A separate exit site is then created for the new catheter and it is tunneled to the "cut-down" site per routine. The non-functioning catheter is then removed from the surgical field. The proximal fibrous sheath is finally cannulated either directly with the new catheter or with a wire/dilator system. This technique effectively re-uses the same venous access point while allowing for a complete change of the physical line and external site. Twenty attempts at this technique were made in twelve patients; six patients underwent the site re-utilization procedure multiple times. Re-using the fibrous tunnel to re-cycle the internal catheter site was successful in seventeen of twenty attempts. All patients had chronic conditions leading to difficult long-term central venous access [short bowel syndrome (6), hemophilia (2), cystic fibrosis (1), chronic need for central IV access (3)]. Indications for catheter replacement included catheter occlusion/mechanical failure/breakage (9), dislodgement (6), infection (1), and inadequate catheter length due to patient growth (4). Broviac/Hickman catheter sites were most commonly re-used (13; one failure); re-using a portcath site was successful in 5 of 7 attempts. There were no short term infections or mechanical complications. We describe a novel technique for salvaging tunneled central venous catheter access sites. This technique is well suited for patients with difficult and long-term central venous access needs, particularly those with chronic conditions such as intestinal failure. It is specifically useful when tunneled lines are broken, precipitated or clotted and unamenable to wiring.

Reactivation of coccidioidomycosis: a prosthetic joint infection in Spain.

A resident of Spain was found to have a prosthetic knee infection due to coccidioidomycosis. He had a history of having pneumonia which resolved while living in an area of California endemic for Coccidioides in 1957-1961. The patient left California in 1961 returned to Spain and never left Spain thereafter. In 2006, a total knee replacement was done. In 2013, a prosthetic knee infection was documented due to coccidioidomycosis. By molecular DNA analysis, Coccidioides immitis was identified from the knee tissue, a species most commonly found in California. This represents reactivation of a Coccidioides infection 56 years after leaving the endemic area.

Arm versus forearm tourniquet for carpal tunnel decompression - Which is better? A randomized controlled trial.

UNLABELLED: Tourniquet pain is a common source of complaint for patients undergoing carpal tunnel decompression and practice varies as to the tourniquet position used. There is little evidence to suggest benefit of one position over another. Our aim was to compare patient and surgeon experience of forearm and arm tourniquets. Following a power calculation, 100 patients undergoing open carpal tunnel decompression under local anaesthetic were randomized to either an arm or a forearm tourniquet. Measurements of blood pressure, heart rate and pain were taken at 2.5 min intervals. The operating surgeon also provided a visual analogue scale rating for the extent of bloodless field achieved and for any obstruction caused by the tourniquet. There was no statistically significant inter-group difference in patient pain or physiological response, tourniquet time, bloodless field or length of procedure. The degree of obstruction caused by the tourniquet was significantly higher in the forearm group. LEVEL OF EVIDENCE: I. Prospective Randomized Controlled Trial.

A reliable surgical treatment for digital mucous cysts.

There is no clear consensus about the best operative technique for the treatment of digital mucous cysts. We carried out a retrospective review of all patients who underwent excision of a digital mucous cyst using a local advancement skin flap over a 10-year period. A total of 69 patients were included and were reviewed at an average of 38 months (minimum 6 months) post-operatively. No patients were lost to follow-up. There was only one case of cyst recurrence. Of these 67 patients were happy with the scar and 63 patients said they would have the procedure again; 36 patients had a pre-operative nail deformity and 21 reported that the deformity grew out after the procedure.

Expanding the BP1-BP2 15q11.2 Microdeletion Phenotype: Tracheoesophageal Fistula and Congenital Cataracts.

The proximal q arm of chromosome 15 contains breakpoint regions BP1-BP5 with the classic deletion of BP1-BP3 best known to be associated with Prader-Willi and Angelman syndromes. The region is approximately 500 kb and microdeletions within the BP1-BP2 region have been reported in patients with developmental delay, behavioral abnormalities, and motor apraxia as well as dysmorphic features including hypertelorism, cleft or narrow palate, ear abnormalities, and recurrent upper airway infections. We report two patients with unique, never-before-reported 15q11.2 BP1-2 microdeletion syndrome findings, one with proximal esophageal atresia and distal tracheoesophageal fistula (type C) and one with congenital cataracts. Cataracts have been described in Prader-Willi syndrome but we could not find any description of cataracts in Angelman syndrome. Esophageal atresia and tracheoesophageal fistula have not been reported to our knowledge in either syndrome. A chance exists that both cases are sporadic birth defects; however, the findings of the concomitant microdeletion cannot be overlooked as a possible cause. Based on our review of the literature and the presentation of our patients, we recommend that esophageal atresia and distal tracheoesophageal fistula as well as congenital cataracts be included in the phenotypic spectrum of 15q11.2 BP1-2 microdeletion syndrome.

Delta-opioid receptor activation prolongs respiratory motor output during oxygen-glucose deprivation in neonatal rat spinal cord in vitro.

Delta opioid receptor (DOR) activation protects the adult mammalian brain during oxygen-glucose deprivation (OGD), but it is not known whether neonatal spinal motor circuits are also protected. Also, it is unclear whether the timing of spinal DOR activation relative to spinal OGD is important for neuroprotection. Thus, a split-bath in vitro neonatal rat brainstem/spinal cord preparation was used to record spontaneous respiratory motor output from cervical (C4-C5) and thoracic (T5-T6) ventral spinal roots while exposing only the spinal cord to OGD solution (0 mM glucose, bubbled with 95% N(2)/5% CO(2)) or DOR agonist drugs (DADLE, DPDPE). Spinal OGD solution application caused respiratory motor output frequency and amplitude to decrease until all activity was abolished (i.e. end-point times) after 25.9±1.4 min (cervical) and 25.2±1.4 min (thoracic). Spinal DOR activation via DPDPE (1.0 µM) prior-to and during spinal OGD increased cervical and thoracic end-point times to 35-48 min. Spinal DADLE or DPDPE (1.0 µM) application 15 min following spinal OGD onset increased cervical and thoracic end-point times to 36-45 min. Brief spinal DPDPE (1.0 µM) application for 10 min at 25 min before spinal OGD onset increased cervical and thoracic end-point times to 41-46 min. Overall, the selective DOR agonist, DPDPE, was more effective at increasing end-point times than DADLE. Naltrindole (DOR antagonist; 10 µM) pretreatment blocked DPDPE-dependent increase in end-point times, suggesting that DOR activation was required. Spinal naloxone (1.0 µM) application before and during spinal OGD also increased end-point times to 31-33 min, but end-point times were not altered by Mu opioid receptor (MOR) activation or DOR activation/MOR blockade, indicating that there are complex interactions between OGD and opioid signaling pathways. These data suggest DOR activation before, during, and after spinal OGD protects central motor networks and may provide neuroprotection during unpredictable perinatal ischemic events.

Single incision Nuss procedure for pectus excavatum.

PURPOSE: To describe a unique single incision modification of the Nuss procedure and compare results to a historical cohort of standard Nuss patients. METHODS: A retrospective review of 32 patients who underwent the Nuss procedure at a tertiary academic medical center over a 4-year period (2007-2010). Fourteen consecutive patients who underwent the modified technique (MN) were compared to the previous 18 patients who underwent the standard procedure (SN). We evaluated for differences between group demographics, operative variables, and postoperative course. The major technical modification was performing the entire procedure through a single right lateral thoracic incision. The dissection for bar placement on the left side of the chest was performed in a subcutaneous, pre-sternal and pre-muscular plane from the right-sided incision. The bar was placed from the right side and positioned in the standard fashion. Thoracoscopy was preformed via the same incision using a 45-degree thoracoscope and multiple trocar positions. The bar was anchored to the chest wall with a unilateral bar stabilizer. RESULTS: There were no statistically significant differences between the study groups in any of the patient, operative or postoperative care parameters. CONCLUSION: The single incision modified Nuss procedure is as safe and efficacious as the standard technique.

Changes in ventral respiratory column GABAaR ε- and δ-subunits during hibernation mediate resistance to depression by EtOH and pentobarbital.

During hibernation in the 13-lined ground squirrel, Ictidomys tridecemlineatus, the cerebral cortex is electrically silent, yet the brainstem continues to regulate cardiorespiratory function. Previous work showed that neurons in slices through the medullary ventral respiratory column (VRC) but not the cortex are insensitive to high doses of pentobarbital during hibernation, leading to the hypothesis that GABA(A) receptors (GABA(A)R) in the VRC undergo a seasonal modification in subunit composition. To test whether alteration of GABA(A)R subunits are responsible for hibernation-associated pentobarbital insensitivity, we examined an array of subunits using RT-PCR and Western blots and identified changes in ε- and δ-subunits in the medulla but not the cortex. Using immunohistochemistry, we confirmed that during hibernation, the expression of ε-subunit-containing GABA(A)Rs nearly doubles in the VRC. We also identified a population of δ-subunit-containing GABA(A)Rs adjacent to the VRC that were differentially expressed during hibernation. As δ-subunit-containing GABA(A)Rs are particularly sensitive to ethanol (EtOH), multichannel electrodes were inserted in slices of medulla and cortex from hibernating squirrels and EtOH was applied. EtOH, which normally inhibits neuronal activity, excited VRC but not cortical neurons during hibernation. This excitation was prevented by bicuculline pretreatment, indicating the involvement of GABA(A)Rs. We propose that neuronal activity in the VRC during hibernation is unaffected by pentobarbital due to upregulation of ε-subunit-containing GABA(A)Rs on VRC neurons. Synaptic input from adjacent inhibitory interneurons that express δ-subunit-containing GABA(A)Rs is responsible for the excitatory effects of EtOH on VRC neurons during hibernation.

Somatic p16(INK4a) loss accelerates melanomagenesis.

Loss of p16(INK4a)-RB and ARF-p53 tumor suppressor pathways, as well as activation of RAS-RAF signaling, is seen in a majority of human melanomas. Although heterozygous germline mutations of p16(INK4a) are associated with familial melanoma, most melanomas result from somatic genetic events: often p16(INK4a) loss and N-RAS or B-RAF mutational activation, with a minority possessing alternative genetic alterations such as activating mutations in K-RAS and/or p53 inactivation. To generate a murine model of melanoma featuring some of these somatic genetic events, we engineered a novel conditional p16(INK4a)-null allele and combined this allele with a melanocyte-specific, inducible CRE recombinase strain, a conditional p53-null allele and a loxP-stop-loxP activatable oncogenic K-Ras allele. We found potent synergy between melanocyte-specific activation of K-Ras and loss of p16(INK4a) and/or p53 in melanomagenesis. Mice harboring melanocyte-specific activated K-Ras and loss of p16(INK4a) and/or p53 developed invasive, unpigmented and nonmetastatic melanomas with short latency and high penetrance. In addition, the capacity of these somatic genetic events to rapidly induce melanomas in adult mice suggests that melanocytes remain susceptible to transformation throughout adulthood.

Bicarbonate-regulated soluble adenylyl cyclase (sAC) mRNA expression and activity in peripheral chemoreceptors.

UNLABELLED: Peripheral arterial chemoreceptors in the carotid body (CB) are modulated by pH/CO(2). Soluble adenylyl cyclase (sAC) is directly stimulated by bicarbonate ions (HCO(3)). Because CO(2)/HCO(3) mediates depolarization in chemoreceptors, we hypothesized that sAC mRNA would be expressed in the CB, and its expression and function would be regulated by CO(2)/HCO(3).Sprague-Dawley rats at postnatal days 16-17 were used to compare sAC mRNA gene expression between CB and non-chemosensitive tissues: superior cervical (SCG), petrosal (PG) and nodose ganglia (NG) by quantitative real time-PCR. Rat sAC gene expression was standardized to the expression of GAPDH (housekeeping gene) and the data were analyzed with the Pfaffl method. Gene and protein expression, and sAC regulation in the testis was used as a positive control. To determine the regulation of sAC mRNA expression and activity, all tissues were exposed to increasing concentrations of bicarbonate (0, 24, 44 mM, titrated with CO(2) and maintained a constant pH of 7.40). RESULTS: sAC mRNA expression was between 2-11% of CB expression in the SCG, PG and NG. Furthermore, only in the CB did HCO(3) upregulate sAC gene expression and increase cAMP levels. CONCLUSION: sAC mRNA and protein expression is present in peripheral arterial chemoreceptors and non-chemoreceptors. In the CB, CO(2)/HCO(3) not only activated sAC but also regulated its expression, suggesting that sAC may be involved in the regulation of cAMP levels in response to hyper/hypocapnia.

Multilayer PDMS microfluidic chamber for controlling brain slice microenvironment.

A novel three-layer microfluidic polydimethylsiloxane (PDMS) device was constructed with two fluid chambers that holds a brain slice in place with microposts while maintaining laminar perfusate flow above and below the slice. Our fabrication technique permits rapid production of PDMS layers that can be applied to brain slices of different shapes and sizes. In this study, the device was designed to fit the shape and thickness (530-700 microm) of a medullary brain slice taken from P0-P4 neonatal rats. Medullary slices in this chamber spontaneously produced rhythmic, respiratory-related motor output for up to 3 h, thereby demonstrating that brain slice viability was maintained for prolonged periods. This design is unique in that it achieves independent control of fluids through multiple channels in two separate fluid chambers. The laminar flow exhibited by the microfluidic chamber allows controlled solutions to target specific areas of the brain slice based on the input flow rates. To demonstrate this capability, a stream of Na(+)-free solution was focused on one half of a medullary slice to abolish spontaneous neural activity in only that half of the brain slice, while the other half remained active. We also demonstrated that flow of different solutions can be focused over the midline of the brain slice. The multilayer brain slice chamber design can integrate several traditional types of electrophysiology tools that are commonly used to measure neurophysiological properties of brain slices. Thus, this new microfluidic chamber is advantageous for experiments that involve controlled drug or solution delivery at high spatiotemporal resolution.

Serotonin-induced in vitro long-term facilitation exhibits differential pattern sensitivity in cervical and thoracic inspiratory motor output.

Intermittent hypoxia induces 5-HT-dependent, pattern-sensitive long-term facilitation (LTF) of spinal respiratory motor output. We used a split-bath in vitro neonatal rat brainstem-spinal cord preparation to test whether: 1) intermittent spinal 5-HT exposure (without hypoxia) is sufficient to induce LTF in phrenic and intercostal inspiratory motor outputs; 2) LTF magnitude is greater in intercostal versus phrenic activity; and 3) phrenic and intercostal motor output exhibits differential pattern sensitivity to 5-HT application. With a barrier at spinal segment C1, 5-HT (5 muM) was applied episodically (3 min 5-HT, 5 min wash, x3) to the spinal cord (C2-L1) while recording inspiratory bursts in cervical (C4 or C5) and thoracic (T5 or T6) ventral roots. Episodic 5-HT application increased cervical and thoracic burst amplitudes to 136+/-22% and 150+/-22% of baseline, respectively, at 120 min post-drug (P<0.01). Continuous 5-HT application (5 muM, 9 min) had no effect on cervical burst amplitude at 120 min post-drug, but increased thoracic burst amplitude to 142+/-11% of baseline at 120 min post-drug (P<0.001). Methysergide pretreatment abolished both cervical and thoracic 5-HT-induced LTF. Quantitative reverse transcriptase-polymerase chain reaction and immunocytochemistry revealed that 5-HT(2A) and 5-HT(7) receptor subtypes (receptors known to influence LTF expression in adult rats) are expressed in ventral cervical and thoracic spinal cord with no differences in expression levels due to spinal segment or age. Thus, 5-HT is sufficient to induce spinal LTF in neonatal rats and differences in pattern sensitivity suggest heterogeneity in underlying mechanisms.

Influence of oestradiol and tamoxifen on oestrogen receptors-alpha and -beta protein degradation and non-genomic signalling pathways in uterine and breast carcinoma cells.

Tamoxifen acts as an oestrogen antagonist in the breast reducing cell proliferation, but in the uterus as an oestrogen agonist resulting in increased cell proliferation. Tamoxifen exerts its tissue-specific effects through the oestrogen receptors (ERalpha or ERbeta). The levels and functions of the two ERs affect the response of the target tissue to oestrogen and tamoxifen. We examined the control of ER stability in breast and uterine cell lines using western blotting and RT-PCR. In MCF-7 breast-derived cells, ERalpha and ERbeta proteins were rapidly degraded via the proteasome pathway in response to oestradiol; conversely tamoxifen stabilised both receptors. In Ishikawa uterine-derived cells, oestradiol and tamoxifen stabilised ERalpha but led to degradation of ERbeta by the proteasome pathway. Further investigations showed that oestradiol induced activation of the non-genomic ERalpha/Akt signalling pathway in MCF-7 cells. We have demonstrated that the alternative Erk signalling pathway is activated in Ishikawa cells following oestradiol treatment in the absence of an active proteasome pathway and therefore increased levels of ERbeta. In conclusion, our data have demonstrated tamoxifen or oestradiol control of ER subtype stability and that non-genomic activation of transcription pathways is cell specific.

Post-embryonic expression of C. elegans microRNAs belonging to the lin-4 and let-7 families in the hypodermis and the reproductive system.

MicroRNAs (miRNAs) are regulatory molecules that negatively control gene expression by binding to complementary sequences on target mRNAs. The most thoroughly characterized miRNAs, lin-4 and let-7, direct cell fate determination during the larval transitions in C. elegans and act as key regulators of temporal gene expression. lin-4 and let-7 are founding members of two distinct families of miRNA genes sharing strong sequence homology primarily in the 5' end of the mature miRNAs. In this report, we characterize the temporal and spatial expression patterns of lin-4 and let-7 family members using northern blot analysis and mir::gfp fusion studies. Our results show that lin-4 and let-7 homologues possess distinct temporal and spatial expression patterns during nematode development and that known heterochronic genes regulate their expression. We find that certain lin-4 and let-7 family members display overlapping expression patterns in the hypodermis and the reproductive system, suggesting that combinations of miRNAs from across families may control common developmental events.