Identification of lysyl oxidase as an adipocyte-secreted mediator that promotes a partial mesenchymal-to-epithelial transition in MDA-MB-231 cells.

Aim: Breast cancer (BC) is the most common cancer in women worldwide, where adiposity has been linked to BC morbidity. In general, obese premenopausal women diagnosed with triple-negative BC (TNBC) tend to have larger tumours with more metastases, particularly to the bone marrow, and worse prognosis. Previous work using a 3-dimensional (3D) co-culture system consisting of TNBC cells, adipocytes and the laminin-rich extracellular matrix (ECM) trademarked as Matrigel, demonstrated that adipocytes and adipocyte-derived conditioned media (CM) caused a partial mesenchymal-to-epithelial transition (MET). Given that MET has been associated with secondary tumour formation, this study sought to identify molecular mediators responsible for this phenotypic change. Methods: Adipocytes were cultured with and without Matrigel, where semi-quantitative proteomics was used to identify proteins whose presence in the CM was induced or enhanced by Matrigel, which were referred to as adipocyte-secreted ECM-induced proteins (AEPs). The AEPs identified were assessed for association with prognosis in published proteomic datasets and prior literature. Of these, 4 were evaluated by the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA), followed by a functional and MET marker analysis of 1 AEP on MDA-MB-231 cells grown on Matrigel or as monolayers. Results: The 4 AEPs showed a positive correlation between protein expression and poor prognosis. RT-qPCR analysis reported no significant change in AEPs mRNA expression. However, lysyl oxidase (LOX) was increased in CM of ECM-exposed adipocytes. Recombinant LOX (rLOX) caused the mesenchymal MDA-MB-231 TNBC cells to form less branched 3D structures and reduced the expression of vimentin. Conclusions: The data suggest that adipocyte-secreted LOX changes the mesenchymal phenotype of BC cells in a manner that could promote secondary tumour formation, particularly at sites high in adipocytes such as the bone marrow. Future efforts should focus on determining whether targeting LOX could reduce BC metastasis in obese individuals.

Assessment of Adverse Childhood Experiences, Adverse Professional Experiences, Depression, and Burnout in US Physicians.

OBJECTIVE: To assess associations of adverse childhood experiences (ACEs) and adverse occupational experiences (AOEs) with depression and burnout in US physicians. PARTICIPANTS AND METHODS: We performed a secondary analysis of data from a representative sample survey of US physicians conducted between November 20, 2020, and March 23, 2021, and from a probability-based sample of other US workers. The ACEs, AOEs, burnout, and depression were assessed using previously published measures. RESULTS: Analyses included data from 1125 of the 3671 physicians (30.6%) who received a mailed survey and 6235 of 90,000 physicians (6.9%) who received an electronic survey. The proportion of physicians age 29-65 who had lived with a family member with substance misuse during childhood (673 of 5039[13.4%]) was marginally lower (P <.001) than that of workers in other professions (448 of 2505 [17.9%]). The proportion of physicians age 29-65 who experienced childhood emotional abuse (823 of 5038 [16.3%]) was similar to that of workers in other professions (406 of 2508 [16.2%]). The average physician depression T-score was 49.60 (raw score ± SD, 6.48±3.15), similar to the normed US average. The AOEs were associated with mild to severe depression, including making a recent significant medical error (odds ratio [OR], 1.64; 95% CI, 1.33 to 2.02, P<.001), being named in a malpractice suit (OR, 1.30; 95% CI, 1.07 to 1.59, P=.008), and experiencing one or more coronavirus disease 2019-related AOEs (OR, 1.76; 95% CI, 1.56 to 1.99, P<.001). Having one or more ACEs was associated with mild to severe depression (OR, 1.58; 95% CI, 1.38 to 1.79, P<.001). The ACEs, coronavirus disease 2019-related AOEs, and medical errors were also associated with burnout. CONCLUSION: Assessing ACEs and AOEs and implementing selective primary prevention interventions may improve population health efforts to mitigate depression and burnout in physicians.

IMPACT: Evaluation of a Controlled Organizational Intervention Using Influential Peers to Promote Professional Fulfillment.

OBJECTIVE: To determine the effects of a popular opinion leader (POL)-led organizational intervention targeting all physicians and advanced practice providers (APPs) working within clinic groups on professional fulfillment (primary outcome), gratitude, burnout, self-valuation, and turnover intent. PATIENTS AND METHODS: All 20 Stanford University HealthCare Alliance clinics with ≥5 physicians-APPs were matched by size and baseline gratitude scores and randomly assigned to immediate or delayed intervention (control). Between July 10, 2018, and March 15, 2019, trained POLs and a physician-PhD study investigator facilitated 4 interactive breakfast or lunch workshops at intervention clinics, where colleagues were invited to discuss and experience one evidence-based practice (gratitude, mindfulness, cognitive, and behavioral strategies). Participants in both groups completed incentivized annual assessments of professional fulfillment, workplace gratitude, burnout, self-valuation, and intent to leave as part of ongoing organizational program evaluation. RESULTS: Eighty-four (75%) physicians-APPs at intervention clinics attended at least 1 workshop. Of all physicians-APPs, 236 of 251 (94%) completed assessments in 2018 and 254 of 263 (97%) in 2019. Of 264 physicians-APPs with 2018 or 2019 assessment data, 222 (84%) had completed 2017 assessments. Modal characteristics were 60% female, 46% White, 49% aged 40 to 59 years, 44% practicing family-internal medicine, 78% living with partners, and 53% with children. Change in professional fulfillment by 2019 relative to average 2017 to 2018 levels was more favorable (0.63 points; effect size = 0.35; P=.001) as were changes in gratitude and intent to leave among clinicians practicing at intervention clinics. CONCLUSION: Interventions led by respected physicians-APPs can achieve high participation rates and have potential to promote well-being among their colleagues.

Thiamine-responsive megaloblastic anaemia.

We report a 26-year-old girl who was diagnosed with diabetes mellitus in her childhood and was treated with insulin. With a history of visual disturbances during her childhood and anaemia, which was partially evaluated; the possibility of syndromic diabetes was considered. Genetic analysis was done and revealed a mutation in the SLC19A2 gene, confirming the diagnosis of thiamine-responsive megaloblastic anaemia. She was supplemented with thiamine, which dramatically improved her haemoglobin levels and glucose control. However, her vision could not be salvaged as the rod-cone dystrophy is a permanent damage.

Three-Dimensional Co-Culture Method for Studying Interactions Between Adipocytes, Extracellular Matrix, and Cancer Cells.

Three-dimensional (D) culture models are increasingly becoming the model of choice for studying different biological phenomena such as cell-cell interaction, drug resistance, and gene expression. These models include extracellular matrix (ECM) proteins that better model the in vivo conditions as it allows cells to have both cell-cell and cell-ECM contacts. In the context of the tumor microenvironment, there are additional types of cells present in addition to the ECM. Thus, an intermediate between 2D cell culture and in vivo mouse models can be desired to interrogate the interactions between multiple cell types under the influence of the ECM. Here we describe a 3D co-culture technique for studying breast cancer-adipocyte interactions. This technique could easily be modified to analyze interactions between other cancer cell types and different fibroblast-like cells.

Performance Nutrition for Physician Trainees Working Overnight Shifts: A Randomized Controlled Trial.

PURPOSE: To compare acute effects of 2 dietary interventions with usual dietary habits on physician trainees' alertness during overnight shifts. METHOD: This registered, controlled, block randomized crossover trial (NCT03698123) was conducted between October 2018 and May 2019 at Stanford Medicine. Physician trainees working at least 3 overnight shifts during a 1-week period were recruited. During the first night, participants followed their usual dietary habits. During the intervention nights (low carbohydrate-to-protein ratio and high carbohydrate-to-protein ratio interventions), participants received healthy dinners, snacks, water, and, upon request, caffeinated beverages, at the beginning of their shifts and were instructed to eat meals before 10 pm. The sequence of interventions on the second and third nights were block randomized across study weeks. Outcome measures (a priori) were overnight changes in validated measures of specific neurobehavioral dimensions: psychomotor vigilance, sensory-motor speed, working memory, and risk decision making, as well as self-reported sleepiness and work exhaustion. RESULTS: Sixty-one physician trainees participated in this study. Compared with usual dietary habits, overnight changes in psychomotor vigilance scores (scale 0-1,000) improved by 51.02 points (95% CI: 12.08, 89.96) and sleepiness (scale 1-7) improved by 0.69 points (95% CI: 0.33, 1.05) under the low carbohydrate-to-protein ratio intervention. Compared with usual dietary habits, overnight changes in sleepiness (scale 1-7) improved by 0.61 points (95% CI: 0.25, 0.96) under the high carbohydrate-to-protein ratio intervention. Neither intervention had beneficial effects relative to usual dietary habits with respect to sensory-motor speed, working memory, risk decision making, or work exhaustion. There were no differences in outcomes between low carbohydrate-to-protein ratio and high carbohydrate-to-protein ratio interventions. CONCLUSIONS: Dietary interventions may mitigate negative effects of physician trainee sleep deprivation during overnight shifts. Future studies are warranted to further examine the effectiveness of nutritional strategies on physician alertness during overnight shifts.

Evaluation of HiCrome KPC Agar for the Screening of Carbapenem-Resistant Enterobacterales Colonization in the ICU Setting of a Tertiary Care Hospital.

Background Spread of carbapenem-resistant Enterobacterales (CRE) is a significant concern in intensive care unit (ICU) settings. Approaches to routine screening for CRE colonization in all ICU patients vary depending on institutional epidemiology and resources. The present study was aimed to evaluate the performance of HiCrome Klebsiella pneumoniae carbapenemase (KPC) agar for the detection of CRE colonization in ICU settings taking the Centers for Disease Control and Prevention (CDC) recommended method as reference. Methods Two-hundred and eighty rectal swabs (duplicate) from 140 patients were subjected to CRE detection in HiCrome KPC agar and MacConkey agar (CDC criteria). Results Using CDC method, total 41 CRE isolates were recovered comprising of 29 Escherichia coli , 11 Klebsiella, and 1 Enterobacter spp. On the other hand, 49 isolates of CRE recovered from 140 rectal swabs using HiCrome KPC agar, out of which 33 were E. coli , 15 Klebsiella, and 1 Enterobacter sp. Statistical Analysis Sensitivity, specificity, negative, and positive predictive values of CRE screening by HiCrome KPC agar were found to be 100% (91.4-100), 91.9% (84.8-95.8), 83.6% (70.9-91.4), and 100% (95.9-100), respectively, taking the CDC recommended method as reference. Conclusion HiCrome KPC agar has high sensitivity in screening CRE colonization. Further studies are needed to establish its applicability for detecting the predominant circulating carbapenemases in the Indian setting.

Assessment of Physician Sleep and Wellness, Burnout, and Clinically Significant Medical Errors.

Importance: Sleep-related impairment in physicians is an occupational hazard associated with long and sometimes unpredictable work hours and may contribute to burnout and self-reported clinically significant medical error. Objective: To assess the associations between sleep-related impairment and occupational wellness indicators in physicians practicing at academic-affiliated medical centers and the association of sleep-related impairment with self-reported clinically significant medical errors, before and after adjusting for burnout. Design, Setting, and Participants: This cross-sectional study used physician wellness survey data collected from 11 academic-affiliated medical centers between November 2016 and October 2018. Analysis was completed in January 2020. A total of 19 384 attending physicians and 7257 house staff physicians at participating institutions were invited to complete a wellness survey. The sample of responders was used for this study. Exposures: Sleep-related impairment. Main Outcomes and Measures: Association between sleep-related impairment and occupational wellness indicators (ie, work exhaustion, interpersonal disengagement, overall burnout, and professional fulfillment) was hypothesized before data collection. Assessment of the associations of sleep-related impairment and burnout with self-reported clinically significant medical errors (ie, error within the last year resulting in patient harm) was planned after data collection. Results: Of all physicians invited to participate in the survey, 7700 of 19 384 attending physicians (40%) and 3695 of 7257 house staff physicians (51%) completed sleep-related impairment items, including 5279 women (46%), 5187 men (46%), and 929 (8%) who self-identified as other gender or elected not to answer. Because of institutional variation in survey domain inclusion, self-reported medical error responses from 7538 physicians were available for analyses. Spearman correlations of sleep-related impairment with interpersonal disengagement (r = 0.51; P < .001), work exhaustion (r = 0.58; P < .001), and overall burnout (r = 0.59; P < .001) were large. Sleep-related impairment correlation with professional fulfillment (r = -0.40; P < .001) was moderate. In a multivariate model adjusted for gender, training status, medical specialty, and burnout level, compared with low sleep-related impairment levels, moderate, high, and very high levels were associated with increased odds of self-reported clinically significant medical error, by 53% (odds ratio, 1.53; 95% CI, 1.12-2.09), 96% (odds ratio, 1.96; 95% CI, 1.46-2.63), and 97% (odds ratio, 1.97; 95% CI, 1.45-2.69), respectively. Conclusions and Relevance: In this study, sleep-related impairment was associated with increased burnout, decreased professional fulfillment, and increased self-reported clinically significant medical error. Interventions to mitigate sleep-related impairment in physicians are warranted.

Association of Physician Burnout With Suicidal Ideation and Medical Errors.

Importance: Addressing physician suicide requires understanding its association with possible risk factors such as burnout and depression. Objective: To assess the association between burnout and suicidal ideation after adjusting for depression and the association of burnout and depression with self-reported medical errors. Design, Setting, and Participants: This cross-sectional study was conducted from November 12, 2018, to February 15, 2019. Attending and postgraduate trainee physicians randomly sampled from the American Medical Association Physician Masterfile were emailed invitations to complete an online survey in waves until a convenience sample of more than 1200 practicing physicians agreed to participate. Main Outcomes and Measures: The primary outcome was the association of burnout with suicidal ideation after adjustment for depression. The secondary outcome was the association of burnout and depression with self-reported medical errors. Burnout, depression, suicidal ideation, and medical errors were measured using subscales of the Stanford Professional Fulfillment Index, Maslach Burnout Inventory-Human Services Survey for Medical Personnel, and Mini-Z burnout survey and the Patient-Reported Outcomes Measurement Information System depression Short Form. Associations were evaluated using multivariable regression models. Results: Of the 1354 respondents, 893 (66.0%) were White, 1268 (93.6%) were non-Hispanic, 762 (56.3%) were men, 912 (67.4%) were non-primary care physicians, 934 (69.0%) were attending physicians, and 824 (60.9%) were younger than 45 years. Each SD-unit increase in burnout was associated with 85% increased odds of suicidal ideation (odds ratio [OR], 1.85; 95% CI, 1.47-2.31). After adjusting for depression, there was no longer an association (OR, 0.85; 95% CI, 0.63-1.17). In the adjusted model, each SD-unit increase in depression was associated with 202% increased odds of suicidal ideation (OR, 3.02; 95% CI, 2.30-3.95). In the adjusted model for self-reported medical errors, each SD-unit increase in burnout was associated with an increase in self-reported medical errors (OR, 1.48; 95% CI, 1.28-1.71), whereas depression was not associated with self-reported medical errors (OR, 1.01; 95% CI, 0.88-1.16). Conclusions and Relevance: The results of this cross-sectional study suggest that depression but not physician burnout is directly associated with suicidal ideation. Burnout was associated with self-reported medical errors. Future investigation might examine whether burnout represents an upstream intervention target to prevent suicidal ideation by preventing depression.

Adipose Tissue from Lean and Obese Mice Induces a Mesenchymal to Epithelial Transition-Like Effect in Triple Negative Breast Cancers Cells Grown in 3-Dimensional Culture.

Breast cancer is the second leading cause of cancer-related mortality among women globally with obesity being one risk factor. Obese breast cancer patients have at least a 30% increased risk of death from breast cancer compared to non-obese breast cancer patients because they present with larger tumors and generally have increased rates of metastasis. Moreover, obese breast cancer patients respond more poorly to treatment compared to non-obese patients, particularly pre-menopausal women diagnosed with triple negative breast cancer (TNBC). To help understand the molecular mechanisms underlying the increased metastasis associated with obesity, we previously established a three-dimensional culture system that permits the co-culture of adipocytes and TNBC cells in a manner that mimics an in vivo milieu. Using this system, we demonstrate that white adipose tissue from both lean and obese mice can induce a partial mesenchymal-to-epithelial transition (MET). Triple negative breast cancer cells adopt an epithelial morphology and have an increased expression of some epithelial markers, but they maintain the expression of mesenchymal markers, furnishing the breast cancer cells with hybrid properties that are associated with more aggressive tumors. Thus, these data suggest that adipose tissue has the potential to promote secondary tumor formation in lean and obese women. Further work is needed to determine if targeting the partial MET induced by adipose tissue could reduce metastasis.

Association of Occupational Distress and Sleep-Related Impairment in Physicians With Unsolicited Patient Complaints.

OBJECTIVE: To study the relationship between occupational distress and sleep-related impairment in physicians and unsolicited patient complaints. PARTICIPANTS AND METHODS: We used deidentified data from an academic medical center's physician survey administered in April and May of 2013 to perform a retrospective cohort study. Third-party stewards of the identifiable information regarding unsolicited patient complaints from January 1, 2013, through December 31, 2016, matched these data with corresponding physicians' occupational distress data. Unsolicited patient complaints were used to calculate the Patient Advocacy Reporting System (PARS) score, a validated predictor of malpractice litigation risk and clinical outcomes. Physicians were grouped into 1 of 3 PARS risk categories based on previously defined thresholds: low risk (score of 0), intermediate risk (score of 1-12), or high risk (score ≥13). RESULTS: Each 1-point increase in burnout and sleep-related impairment, on a 5-point scale, was associated with a 69% (odds ratio [OR], 1.69; 95% CI, 1.12-2.54) and 49% (OR, 1.49; 95% CI, 1.08-2.05) increased odds of being in the next higher PARS risk category, respectively, averaged across all 4 years. Professional fulfillment was a protective factor, associated with fewer unsolicited patient complaints. Each 1-point decrease in professional fulfillment was associated with a 68% (OR, 1.68; 95% CI, 1.16-2.44) increased odds of being in the next higher PARS risk category. The effect of depression on PARS risk category was not significant (OR, 1.33; 95% CI, 0.84-2.10). CONCLUSION: Findings from this research suggest that occupational distress and sleep-related impairment in physicians are associated with unsolicited patient complaints.

Adipocytes in the Tumour Microenvironment.

Adipose tissue contribution to body mass ranges from 6% in male athletes to over 25% in obese men and over 30% in obese women. Crosstalk between adipocytes and cancer cells that exist in close proximity can lead to changes in the function and phenotype of both cell types. These interactions actively alter the tumour microenvironment (TME). Obesity is one of the major risk factors for multiple types of cancer, including breast cancer. In obesity, the increase in both size and number of adipocytes leads to instability of the TME, as well as increased hypoxia within the TME, which further enhances tumour invasion and metastasis. In this chapter, we will discuss the diverse aspects of adipocytes and adipocyte-derived factors that affect the TME as well as tumour progression and metastasis. In addition, we discuss how obesity affects the TME. We focus primarily on breast cancer but discuss what is known in other cancer types when relevant. We finish by discussing the studies needed to further understand these complex interactions.

TOXIC POSTERIOR SEGMENT SYNDROME AFTER DROPLESS CATARACT SURGERY WITH COMPOUNDED TRIAMCINOLONE-MOXIFLOXACIN.

PURPOSE: To report toxic posterior segment syndrome after dropless cataract surgery using locally compounded triamcinolone-moxifloxacin. METHODS: A retrospective case review of 7 patients presenting with a decrease in visual acuity after dropless cataract surgery. RESULTS: All patients experienced significant reductions in best-corrected visual acuity of the postoperative eye ranging from 20/40 to count finger at 4 feet (average best-corrected visual acuity 20/220) immediately after surgery. The presenting symptoms included flashes, floaters, photophobia, glare, halos, visual distortions, and problems assessing colors. In three cases, foveal retinal pigment epithelium changes were noted on dilated fundus exam (DFE). Ellipsoid zone loss was noted on ocular coherence tomography in five of the seven affected eyes. Electrophysiology testing in five of the seven affected eyes demonstrated large decreases in full-field electroretinogram amplitude, oscillatory potentials, multifocal electroretinogram, and visual evoked potential, along with a negative electroretinogram. One patient was treated with a dexamethasone implant, but no improvement in visual acuity was noted. CONCLUSION: This is the first case series of toxic posterior segment syndrome occurring secondary to intracameral compounded triamcinolone-moxifloxacin in dropless cataract surgery. The FDA has attributed the toxicity to abnormally high levels of the binding agent poloxamer 407 in the compounded medication. Clinicians should be aware of this phenomenon and exhibit caution when using compounded medications.

Self-valuation: Attending to the Most Important Instrument in the Practice of Medicine.

OBJECTIVE: To measure self-valuation, involving constructive prioritization of personal well-being and a growth mindset perspective that seeks to learn and improve as the primary response to errors, in physicians and evaluate its relationship with burnout and sleep-related impairment. METHODS: We analyzed cross-sectional survey data collected between July 1, 2016, and October 31, 2017, from 5 academic medical centers in the United States. All faculty and medical-staff physicians at participating organizations were invited to participate. The self-valuation scale included 4 items measured on a 5-point (0-4) Likert scale (summative score range, 0-16). The self-valuation scale was developed and pilot tested in a sample of 250 physicians before inclusion in the multisite wellness survey, which also included validated measures of burnout and sleep-related impairment. RESULTS: Of the 6189 physicians invited to participate, 3899 responded (response rate, 63.0%). Each 1-point score increase in self-valuation was associated with -1.10 point lower burnout score (95% CI, -1.16 to -1.05; standardized ß=-0.53; P<.001) and 0.81 point lower sleep-related impairment score (95% CI, -0.85 to -0.76; standardized ß=-0.47; P<.001), adjusting for sex and medical specialty. Women had lower self-valuation (Cohen d=0.30) and higher burnout (Cohen d=0.22) than men. Lower self-valuation scores in women accounted for most of the sex difference in burnout. CONCLUSION: Low self-valuation among physicians is associated with burnout and sleep-related impairment. Further research is warranted to develop and test interventions that increase self-valuation as a mechanism to improve physician well-being.

A Novel 3-Dimensional Co-culture Method Reveals a Partial Mesenchymal to Epithelial Transition in Breast Cancer Cells Induced by Adipocytes.

Cancer metastases are accountable for almost 90% of all human cancer related deaths including from breast cancer (BC). Adipocytes can alter the tumor microenvironment, which can promote metastasis by inducing an epithelial-to-mesenchymal transition (EMT) in BC cells. However, the role of adipocytes during the mesenchymal-to-epithelial transition (MET), that can be important in metastasis, is not clear. To understand the effect of adipocytes on the BC progression, there is a requirement for a better in vitro 3-dimensional (3D) co-culture system that mimics the breast tissue and allows for more accurate analysis of EMT and MET. We developed a co-culture system to analyze the relationship of BC cells grown in a 3D culture with adipocytes. We found that adipocytes and adipocyte-derived conditioned media, but not pre-adipocytes, caused the mesenchymal MDA-MB-231 and Hs578t cells to form significantly more epithelial-like structures when compared to the typical stellate colonies formed in control 3D cultures. SUM159 cells and MCF7 cells had a less dramatic shift as they normally have more epithelial-like structure in 3D culture. Biomarker expression analysis revealed that adipocytes only induced a partial MET with proliferation unaffected. In addition, adipocytes had reduced lipid droplet size when co-cultured with BC cells. Thus, we found that physical interaction with adipocytes and ECM changes the mesenchymal phenotype of BC cells in a manner that could promote secondary tumor formation.

CD24 is required for regulating gene expression, but not glucose uptake, during adipogenesis.

Adipose tissue dysfunction in obesity and lipodystrophy results in major health complications such as heart disease and stroke, and is associated with an increased risk of some cancers. We have previously found that the cell surface receptor CD24 regulates adipogenesis as measured by lipid accumulation and gene expression in mature adipocytes. How CD24 regulates these processes remains unknown. To begin answering this question, we first determined that CD24 does not affect glucose uptake in differentiating adipocytes in vitro. We then examined changes in global gene expression via DNA microarray in 3T3-L1 adipocytes with siRNA-mediated knock-down of CD24 expression. We found that CD24 expression is necessary for upregulation of up to 134 genes. We validated the CD24-mediated regulation of 4 of these genes during in vitro adipogenesis of 3T3-L1 and primary cells isolated from the inguinal white adipose tissue depots of CD24 knockout mice. Surprisingly, we found that only 1 of these genes was also regulated by CD24 in cells from the epididymal depot. Overall, these data suggest that CD24 is necessary for select gene expression in a depot-specific manner during adipogenesis in vitro. These findings could help elucidate the mechanisms regulating lipid accumulation in adipocytes thereby aiding in the development of novel treatment strategies for obesity and lipodystophy.

Collagen overlays can inhibit leptin and adiponectin secretion but not lipid accumulation in adipocytes.

BACKGROUND: White adipose tissue (WAT) is essential for energy storage as well as being an active endocrine organ. The secretion of adipokines by adipocytes can affect whole body metabolism, appetite, and contribute to overall health. WAT is comprised of lipid-laden mature adipocytes, as well as immune cells, endothelial cells, pre-adipocytes, and adipose-derived stem cells. In addition, the presence of extracellular matrix (ECM) proteins in WAT can actively influence adipocyte differentiation, growth, and function. Type I collagen is an abundant fibrous ECM protein in WAT that is secreted by developing adipocytes. However, the extent and overall effect of Type I collagen on adipokine secretion in mature adipocytes when added exogenously has not been established. METHODS: We characterized the effects of Type I collagen overlays prepared using two different buffers on adipocyte physiology and function when added at different times during differentiation. In addition, we compared the effect of collagen overlays when adipocytes were cultured on two different tissue culture plastics that have different adherent capabilities. Triglyceride accumulation was analyzed to measure adipocyte physiology, and leptin and adiponectin secretion was determined to analyze effects on adipokine secretion. RESULTS: We found that collagen overlays, particularly when added during the early differentiation stage, impaired adipokine secretion from mature adipocytes. Collagen prepared using PBS had a greater suppression of leptin than adiponectin while collagen prepared using HANKS buffer suppressed the secretion of both adipokines. The use of CellBind plates further suppressed leptin secretion. Triglyceride accumulation was not substantially impacted with any of the collagen overlays. DISCUSSION: Adipokine secretion can be selectively altered by collagen overlays. Thus, it is feasible to selectively manipulate the secretion of adipokines by adipocytes in vitro by altering the composition or timing of collagen overlays. The use of this technique could be applied to studies of adipokine function and secretion in vitro as well as having potential therapeutic implications to specifically alter adipocyte functionality in vivo.

Pain After Percutaneous Irreversible Electroporation of Renal Tumors Is Not Dependent on Tumor Location.

INTRODUCTION: Irreversible electroporation (IRE) is a non-thermal minimally invasive technique that is used to treat small renal masses (SRMs). Prior work has demonstrated greater narcotic requirements after radiofrequency ablation (RFA) for tumors that are closer to body-wall musculature. We hypothesized that pain after IRE is not dependent on tumor location due to the athermal mechanistic action. MATERIALS AND METHODS: A retrospective review of 50 consecutive percutaneous IRE and RFA cases was performed from 2013 to 2014. Eight patients were excluded from analysis due to incomplete anesthesia record and/or multiple ablations per session, leaving 21 patients in each group. Data collected included patient age, sex, body mass index, nephrometry score, shortest distance to the closest body-wall muscle, perioperative narcotic use, and patient-reported pain score. Pearson correlation test and multivariable linear regression were used to identify predictors of postoperative pain, with significance set at p = 0.05. RESULTS: There was no difference in the mean distance from tumor edge to the nearest body-wall muscle between IRE and RFA (2.6 cm vs 2.4 cm, p = 0.729, respectively). Total mean perioperative narcotic usage was 20.4 mg after IRE and 26.7 mg after RFA (p = 0.096). Mean postoperative pain score (scale 0-10) was slightly higher after RFA (4.3) compared with IRE (2.4), but this was not statistically significant (p = 0.088). Pearson correlation test identified tumor proximity to be significiantly associated with both pain score (p = 0.011) and postoperative narcotic use (p = 0.049) after RFA but not after IRE. On multivariable analysis, only tumor proximity to the body wall was significantly correlated to pain score (-1.4, p = 0.041) after RFA but was not found to be a factor for pain after IRE. CONCLUSIONS: Patients whose tumors lie close to their body-wall musculature do not have greater narcotic requirements or higher pain scores in the perioperative period after IRE. Percutaneous IRE may be preferred over RFA for SRMs that are close to the body wall to minimize pain.