Characteristics of International Medical Graduates in Academic Plastic Surgery.

BACKGROUND: International medical graduates play a significant role in meeting U.S. health care needs, and contribute to a more diverse provider workforce. This study aimed to determine the prevalence, characteristics, and academic productivity of plastic surgery international medical graduate faculty. METHODS: A cross-sectional study was conducted to compare characteristics of international medical graduates against domestic medical graduates including demographics, trainings, academic ranks, leadership positions, number of publications and citations, and Hirsch index. RESULTS: International medical graduates represent 10.3 percent of all 918 academic plastic surgeons in the United States, with the majority having graduated from India (16.8 percent), Brazil (8.4 percent), and the United Kingdom (8.4 percent). International medical graduates were more likely to have graduated from independent programs (OR, 5.7; p < 0.0001) and to have completed research fellowship (OR, 2.1; p = 0.0001) and burn fellowship (OR, 6.5; p < 0.0001). Programs led by international medical graduate chairs employed more international medical graduate faculty (21 percent versus 9 percent; p < 0.0001). International medical graduates had comparable Hirsch indices, number of publications, and citations, but received less National Institutes of Health funding ($32,020 versus $223,365). International medical graduates also had comparable rates of attaining leadership positions such as fellowship director and chair but required fewer years of experience to become residency director (8.3 years versus 17.3 years). CONCLUSIONS: The contribution of international medical graduates in academic plastic surgery was evident based on research productivity, academic ranks, and leadership positions. International medical graduates are more likely to be employed in programs led by international medical graduate chairs. This study may help guide aspiring international medical graduate academics and aid in hiring decisions at academic institutions.

The Role of Schlemm's Canal Endothelium Cellular Connectivity in Giant Vacuole Formation: A 3D Electron Microscopy Study.

Purpose: We investigated whether cellular connectivity between Schlemm's canal (SC) inner wall (IW) endothelium, and juxtacanalicular connective tissue (JCT), and between IW endothelial cells, plays a role in giant vacuole (GV) and pore formation by comparing perfusion- and immersion-fixed eyes. Methods: Normal human donor eyes (n = 4) were either immersion-fixed (0 mm Hg) or perfusion-fixed (15 mm Hg). Trabecular meshwork near SC was imaged using serial block-face scanning electron microscopy. A total of 12 IW cells from each group were 3D-reconstructed from ∼7040 electron micrographs and compared. In each cell, connections between IW cells and JCT cells/matrix were quantified; IW/IW connectivity was measured by cell border overlap length. GV volume, density, shape, and intracellular and paracellular pores were analyzed. Results: The mean number of IW/JCT cell-cell connections per cell significantly decreased (P < 0.01) while the summed GV volume per cell significantly increased (P < 0.01) in perfusion-fixed eyes compared to immersion-fixed eyes. Intracellular pores were observed in 14.6% of GVs in perfusion-fixed eyes and not observed in immersion-fixed eyes. The mean IW/IW overlap length per cell decreased (P < 0.01), and paracellular pores were found only in regions where IW/IW connectivity was minimal (overlap length = 0 µm) in perfusion-fixed eyes and not observed in immersion-fixed eyes. Conclusions: Our data suggest that changes in IW/JCT connectivity may be an important factor in the formation of larger GVs, and decreased IW/IW connectivity may promote paracellular pore formation. Targeting the IW/JCT and IW/IW connectivity may therefore be a potential strategy to regulate outflow resistance and IOP. .

Shorter scleral spur in eyes with primary open-angle glaucoma.

PURPOSE: We determined whether the scleral spur is shorter in primary open-angle glaucoma (POAG) eyes compared to age-matched normal eyes and whether the collapse of Schlemm's canal (SC) is more prevalent in eyes with a shorter scleral spur. METHODS: The anterior segments of normal (n = 20) and POAG eyes (n = 20) were fixed and processed for light microscopy. The scleral spur length, ratio of posterior trabecular meshwork (TM) insertion into the scleral spur to the posterior TM height, and the percentage of SC collapse were measured. Analysis using an existing mathematical model was conducted to estimate the distances that the scleral spur theoretically would move in vivo and to determine if these distances would be sufficient to keep SC open in POAG compared to normal eyes. RESULTS: The mean scleral spur length was significantly shorter in POAG eyes compared to normal eyes (P < 0.0001). A higher mean percentage of SC collapse was found in POAG eyes than in normal eyes (P < 0.0001). Estimated posterior movement of scleral spur in POAG eyes was less than sufficient to prevent the collapse of SC. A significant negative correlation was found between the posterior scleral spur movement and percent collapse of SC (P < 0.0001). CONCLUSIONS: A shorter scleral spur found in POAG eyes was associated with a higher percent of SC collapse. Our data suggest that a shorter scleral spur may be a risk factor in the development of POAG by being insufficient to hold SC open.

Finite element analysis of the pressure-induced deformation of Schlemm's canal endothelial cells.

The endothelial cells lining the inner wall of Schlemm's canal (SC) in the eye are relatively unique in that they support a basal-to-apical pressure gradient that causes these cells to deform, creating giant vacuoles and transendothelial pores through which the aqueous humor flows. Glaucoma is associated with an increased resistance to this flow. We used finite element modeling and estimates of cell modulus made using atomic force microscopy to characterize the pressure-induced deformation of SC cells and to estimate the maximum pressure drop that SC cells can support. We examined the effects of cell geometry, cell stiffness, and the contribution of the cell cortex to support the pressure-generated load. We found that the maximum strain generated by this loading occurs at the points of cell-substrate attachment and that the cortex of the cells bears nearly all of this load. The ability of these cells to support a significant transcellular pressure drop is extremely limited (on the order of 5 mmHg or less) unless these cells either stiffen very considerably with increasing deformation or have substantial attachments to their substratum away from their periphery. This puts limits on the flow resistance that this layer can generate, which has implications regarding the site where the bulk of the flow resistance is generated in healthy and glaucomatous eyes.

Reliability of the 12-step ascend and descend test and its correlation with motor function in people with chronic stroke.

OBJECTIVE: To investigate: (i) the intra-rater, inter-rater and test-retest reliability of the 12-step stair test; (ii) its correlation with other stroke-specific impairments; and (iii) the cut-off scores that best discriminate patients with stroke from healthy elderly subjects. DESIGN: Cross-sectional study. SETTING: University-based rehabilitation centre. SUBJECTS: Thirty-five subjects with chronic stroke and 29 healthy elderly subjects. METHODS: The 12-step ascend and descend test was administered along with the Fugl-Meyer Motor Assessment for the lower extremities (FMA-LE), hand-held dynamometer measurements of hip abductor and knee extensor muscle strength, the Five Times Sit to Stand Test (FTSTST), assessment using the Berg Balance Scale (BBS), activities-specific balance confidence scale (ABC) assessment, the 10-metre walk test, and the Timed "Up and Go" (TUG) test. RESULTS: The 12-step ascend and descend test showed excellent intra-rater, inter-rater and test-retest reliability. The test was positively correlated with FTSTST times, gait velocity, and TUG times, and negatively correlated with FMA-LE scores and BBS scores. A test performance of 15.22 seconds or less was shown reliably to discriminate healthy elderly subjects from stroke survivors. CONCLUSION: The 12-step ascend and descend test is a reliable clinical test that is inexpensive and easy to implement, and is useful for assessing the stair-walking ability of patients with chronic stroke.