Ergonomic considerations for unique surgeon populations.

PURPOSE OF REVIEW: Surgeons are rapidly diversifying as a population, introducing new ergonomic challenges. This review describes the challenges that are experienced by special populations of surgeons including small-handed surgeons, pregnant surgeons, and trainees, and evidence-based solutions to overcome them. RECENT FINDINGS: Small-handed and female surgeons report more musculoskeletal complaints compared with their male counterparts. Pregnant surgeons frequently report development or worsening of musculoskeletal disorders such as carpal tunnel syndrome and low back pain. Trainees also report high rates of musculoskeletal complaints with minimal autonomy to alter their environment. Limited objective data exists regarding the ideal instruments currently available for special populations. Several small, randomized studies have proposed exercise regimens targeting the upper extremities and pregnancy-related pain syndromes with improvements in symptoms. Various methods of ergonomic education have been studied in trainees with improvements in operating room posture and performance. SUMMARY: Limited objective data is available to recommend specific surgical instruments for high-risk surgeon populations. Beneficial exercise regimens have been described for musculoskeletal disorders commonly plaguing surgeons but have yet to be studied explicitly in small-handed or pregnant surgeons and trainees.

Structural and biophysical characterization of the Burkholderia pseudomallei IspF inhibitor L-tryptophan hydroxamate.

The enzyme 2-methylerythritol 2,4-cyclodiphosphate synthase, IspF, is essential for the biosynthesis of isoprenoids in most bacteria, some eukaryotic parasites, and the plastids of plant cells. The development of inhibitors that target IspF may lead to novel classes of anti-infective agents or herbicides. Enantiomers of tryptophan hydroxamate were synthesized and evaluated for binding to Burkholderia pseudomallei (Bp) IspF. The L-isomer possessed the highest potency, binding BpIspF with a KD of 36 µM and inhibited BpIspF activity 55% at 120 µM. The high-resolution crystal structure of the L-tryptophan hydroxamate (3)/BpIspF complex revealed a non-traditional mode of hydroxamate binding where the ligand interacts with the active site zinc ion through the primary amine. In addition, two hydrogen bonds are formed with active site groups, and the indole group is buried within the hydrophobic pocket composed of side chains from the 60 s/70 s loop. Along with the co-crystal structure, STD NMR studies suggest the methylene group and indole ring are potential positions for optimization to enhance binding potency.

Xylem form and function under extreme nutrient limitation: an example from California's pygmy forest.

Xylem anatomy and function have large implications for plant growth as well as survival during drought, but the impact of nutrient limitation on xylem is not fully understood. This study examines the pygmy forest in California, a plant community that experiences negligible water stress but is severely stunted by low-nutrient and acidic soil, to investigate how nutrient limitation affects xylem function. Thirteen key anatomical and hydraulic traits of stems of four species were compared between pygmy forest plants and nearby conspecifics growing on richer soil. Resistance to cavitation (P50 ), a critical trait for predicting survival during drought, had highly species-specific responses: in one species, pygmy plants had a 26% decrease in cavitation resistance compared to higher-nutrient conspecifics, while in another species, pygmy plants had a 56% increase in cavitation resistance. Other traits responded to nutrient limitation more consistently: pygmy plants had smaller xylem conduits and higher leaf-specific conductivity (KL ) than conspecific controls. Edaphic stress, even in the absence of water stress, altered xylem structure and thus had substantial impacts on water transport. Importantly, nutrient limitation shifted cavitation resistance in a species-specific and unpredictable manner; this finding has implications for the assessment of cavitation resistance in other natural systems.