Anatomy of the lymphovenous valve of the thoracic duct in humans

The majority of lymph generated in the body is returned to the blood circulation via the lymphovenous junction (LVJ) of the thoracic duct (TD). A lymphovenous valve (LVV) is thought to guard this junction by regulating the flow of lymph to the veins and preventing blood from entering the lymphatic system. Despite these important functions, the morphology and mechanism of this valve remains unclear. The aim of this study was to investigate the anatomy of the LVV of the TD. To do this, the TD and the great veins of the left side of the neck were harvested from 16 human cadavers. The LVJs from 12 cadavers were successfully identified and examined macroscopically, microscopically, and using microcomputed tomography. In many specimens, the TD branched before entering the veins. Thus, from 12 cadavers, 21 LVJs were examined. Valves were present at 71% of LVJs (15/21) and were absent in the remainder. The LVV, when present, was typically a bicuspid semilunar valve, although the relative size and position of its cusps were variable. Microscopically, the valve cusps comprised luminal extensions of endothelium with a thin core of collagenous extracellular matrix. This study clearly demonstrated the morphology of the human LVV. This valve may prevent blood from entering the lymphatic system, but its variability and frequent absence calls into question its utility. Further structural and functional studies are required to better define the role of the LVV in health and disease.     

Simultaneous determination of epinephrine and uric acid at a gold electrode modified by a 2-(2,3-dihydroxy phenyl)-1, 3-dithiane self-assembled monolayer

In the present paper, the use of a gold electrode modified by 2-(2,3-dihydroxy phenyl)-1,3-dithiane self-assembled monolayer (DPDSAM) for the determination of epinephrine (EP) and uric acid (UA) was described. Initially, cyclic voltammetry was used to investigate the redox properties of this modified electrode at various scan rates. The apparent charge transfer rate constant, k_s, and transfer coefficient, α, were calculated. Next, the mediated oxidation of EP at the modified electrode was described. At the optimum pH of 8.0, the oxidation of EP occurs at a potential about 155 mV less positive than that of an unmodified gold electrode. The values of electron transfer coefficients (α = 0.356), catalytic rate constant (k = 1.624 × 10⁴ M⁻¹ s⁻¹) and diffusion coefficient (D = 1.04 × 10⁻⁶ cm² s⁻¹) were calculated for EP, using electrochemical approaches. Based on differential pulse voltammetry, the oxidation of EP exhibited a dynamic range between 0.7 and 500.0 μM and a detection limit (3σ) of 0.51 μM. Furthermore, simultaneous determination of EP and UA at the modified electrode was described. Finally, this method was used for the determination of EP in EP ampoule.     

A review of the surface and internal anatomy of the caudal canal in children

The anatomy of the sacral hiatus and caudal canal is prone to significant variation, yet studies assessing this in the pediatric population remain limited. Awareness of the possible anatomical variations is critical to the safety and success of caudal epidural blocks, particularly when image guidance is not employed. This systematic review analyzes the available evidence on the clinical anatomy of the caudal canal in pediatric patients, emphasizing surface anatomy and internal anatomical variations. A literature search using three electronic databases and standard pediatric and anatomy reference texts was conducted yielding 24 primary and seven secondary English‐language sources. Appreciating that our current landmark‐guided approaches to the caudal canal are not well studied in the pediatric population is important for both clinicians and researchers.     

Integrating ultrasound into modern medical curricula

Ultrasonography is widely practiced in many disciplines. It is becoming increasingly important to design well‐structured curricula to introduce imaging to students during medical school. This review aims to analyze the literature for evidence of how ultrasonography has been incorporated into anatomy education in medical school curricula worldwide. A literature search was conducted using multiple databases with the keywords: “Ultrasound OR Ultrasonographic examination*” and “Medical student* OR Undergraduate teaching* OR Medical education*” and “Anatomy* OR Living anatomy* OR Real‐time anatomy.*” This review found that ultrasound curricula vary in stage of implementation, course length, number of sessions offered to students as well as staffing and additional course components. Most courses consisted of didactic lectures supplemented with demonstration sessions and/or hands‐on ultrasound scanning sessions. The stage of course implementation tended to depend on the aim of the course; introductory courses were offered earlier in a student's career. Most courses improved student confidence and exam performance, and more junior students tended to benefit more from learning anatomy with ultrasound guidance rather than learning clinical examination skills. Students tended to prefer smaller groups when learning ultrasound to get more access to using the machines themselves. Ultrasonography is an important skill, which should be taught to medical students early in their careers as it facilitates anatomical education and is clinically relevant, though further objective research required to support the use of ultrasound education as a tool to improve clinical examination skills in medical students. Clin. Anat. 30:452–460, 2017. © 2017 Wiley Periodicals, Inc.