Dietary sodium alters aldosterone's effect on renal sodium transporter expression and distal convoluted tubule remodelling.

Aldosterone is responsible for maintaining volume and potassium homeostasis. Although high salt consumption should suppress aldosterone production, individuals with hyperaldosteronism lose this regulation, leading to a state of high aldosterone despite dietary sodium consumption. The present study examines the effects of elevated aldosterone, with or without high salt consumption, on the expression of key Na+ transporters and remodelling in the distal nephron. Epithelial sodium channel (ENaC) α-subunit expression was increased with aldosterone regardless of Na+ intake. However, ENaC ß- and γ-subunits unexpectedly increased at both a transcript and protein level with aldosterone when high salt was present. Expression of total and phosphorylated Na+ Cl- cotransporter (NCC) significantly increased with aldosterone, in association with decreased blood [K+ ], but the addition of high salt markedly attenuated the aldosterone-dependent NCC increase, despite equally severe hypokalaemia. We hypothesized this was a result of differences in distal convoluted tubule length when salt was given with aldosterone. Imaging and measurement of the entire pNCC-positive tubule revealed that aldosterone alone caused a shortening of this segment, although the tubule had a larger cross-sectional diameter. This was not true when salt was given with aldosterone because the combination was associated with a lengthening of the tubule in addition to increased diameter, suggesting that differences in the pNCC-positive area are not responsible for differences in NCC expression. Together, our results suggest the actions of aldosterone, and the subsequent changes related to hypokalaemia, are altered in the presence of high dietary Na+ . KEY POINTS: Aldosterone regulates volume and potassium homeostasis through effects on transporters in the kidney; its production can be dysregulated, preventing its suppression by high dietary sodium intake. Here, we examined how chronic high sodium consumption affects aldosterone's regulation of sodium transporters in the distal nephron. Our results suggest that high sodium consumption with aldosterone is associated with increased expression of all three epithelial sodium channel subunits, rather than just the alpha subunit. Aldosterone and its associated decrease in blood [K+ ] lead to an increased expression of Na-Cl cotransporter (NCC); the addition of high sodium consumption with aldosterone partially attenuates this NCC expression, despite similarly low blood [K+ ]. Upstream kinase regulators and tubule remodelling do not explain these results.

The Impact of Fellowship Training in Academic Plastic Surgery.

BACKGROUND: The competitive nature of an academic plastic surgery career has contributed to an increase in sub-specialization. The aim of this study is to assess the benefits of subspecialty fellowship training to pursue a career in academic plastic surgery. METHODS: A cross-sectional study was conducted of all current academic plastic surgeons (APSs) participating in Accreditation Council for Graduate Medical Education-certified residency programs. Online faculty website listings were used to collect their demographics, training and practice characteristics, academic rank and leadership positions, and research productivity. RESULTS: A total of 927 APSs met the inclusion criteria, of which 70.2% had undergone fellowship training, with an overall significant increase in fellowship-trained surgeons within the last 10 years (odds ratio [OR], 1.66; P = 0.0005). Hand training was the most common fellowship (35.6%), followed by craniofacial (32.0%) and microsurgery (28.1%). Fellowship training was more prevalent among younger (48.7 vs 53.5 years, P < 0.0001), White (67.8%), and non-White (77.4%, P = 0.0058) APSs who had received either integrated (67.1%) or independent (81.8%, P < 0.0001) plastic surgery training and are currently working in a department (OR, 1.44; P = 0.028). Fellowship training was shown to influence academic rank (associate professor: OR, 1.68 [P = 0.0073]; full professor: OR, 0.58 [P = 0.0008]), leadership position (fellowship director OR, 10.09; P < 0.0001) and research productivity (publications: 26 vs 16.5; P = 0.0009). In addition, fellowship attainment did not correlate with the size of the employing academic program, population of the city of practice, or being a residency director or chair. CONCLUSION: The majority of APSs have undergone fellowship training, and there is very strong evidence supporting its impact in current entry and advancement in academic plastic surgery.

An Evaluation of Race Disparities in Academic Plastic Surgery.

BACKGROUND: Academic plastic surgery has a history of underrepresentation of ethnic and racial minority groups. Recent policy shifts by national medical groups and plastic surgery societies have focused on reversing these inequalities. This study seeks to measure ethnic and racial representation at academic and leadership positions following recent changes. METHODS: A cross-sectional study was conducted in June of 2018, measuring ethnic and racial diversity of U.S. academic plastic surgery faculty. Among faculty, career qualifications, years of experience, faculty positions, and leadership ethnicity were compared. RESULTS: A total of 930 academic plastic surgeons were included in the study. Classified collectively as nonwhite, this group graduated more recently than other academic plastic surgeons (2006 versus 2001; p < 0.0001) and had greater rates of clinical fellowship attainment (OR, 1.62; 95 percent CI, 1.16 to 2.26). Nonwhite individuals were less likely to be employed in the full professor position compared with their white colleagues (OR, 0.6; 95 percent CI, 0.42 to 0.88; p = 0.0077). However, after adjustment for differences in years of postresidency experience, this disparity was no longer significant (OR, 1.06; 95 percent CI, 0.62 to 1.83; p = 0.82), indicating the importance of current cohort experience differences. Assessment of program leadership found that nonwhite chairs employed significantly more nonwhite faculty (42.5 percent versus 20.9 percent; p < 0.0001). CONCLUSIONS: Academic plastic surgery continues to face disparities in representation of both ethnic and racial minorities. Current inequalities are most severe at senior academic positions and may be linked to cohort experience differences along with leadership and promotion biases.

Change Is Happening: An Evaluation of Gender Disparities in Academic Plastic Surgery.

BACKGROUND: Gender disparities in academic plastic surgery are known; however, recently, professional societies have endorsed a culture of gender diversification. This study aims to evaluate the effects of these changes at faculty and leadership positions. METHODS: A cross-sectional study was conducted in June of 2018 to evaluate gender representation among U.S. academic plastic surgery faculty, and compare career qualifications, years of experience, and faculty positions. RESULTS: A total of 938 academic plastic surgeons were identified, of which only 19.8 percent were women. Female surgeons graduated more recently than men (2009 versus 2004; p < 0.0001) and predominantly from integrated residency programs (OR, 2.72; 95 percent CI, 1.87 to 3.96), were more likely to be an assistant professor (OR, 2.19; 95 percent CI, 1.58 to 3.05), and were less likely to be a full professor (OR, 0.20; 95 percent CI, 0.11 to 0.35) or program chair (OR, 0.32; 95 percent CI, 0.16 to 0.65). After adjustment for differences in years of postresidency experience, only disparities at the full professor position remained significant (OR, 0.34; 95 percent CI, 0.16 to 0.17), indicating that experience-independent gender inequality is prominent at the full professor level and that current differences in cohort experience are a significant contributor to many of the observed positional disparities. Lastly, programs led by a female chair employed significantly more female faculty (32.5 percent versus 18.2 percent; p = 0.016). CONCLUSIONS: Gender diversity in academic plastic surgery remains a significant issue, but may see improvement as the disproportionately high number of junior female academics advance in their careers. However, leadership and promotion disparities between men and women still exist and must be addressed.