OCT-4 expression in follicular and luteal phase endometrium: a pilot study

<p>Abstract</p> <p>Background</p> <p>The stem cell marker Octamer-4 (OCT-4) is expressed in human endometrium. Menstrual cycle-dependency of OCT-4 expression has not been investigated to date.</p> <p>Methods</p> <p>In a prospective, single center cohort study of 98 women undergoing hysteroscopy during the follicular (n = 49) and the luteal (n = 40) phases of the menstrual cycle, we obtained endometrial samples. Specimens were investigated for OCT-4 expression on the mRNA and protein levels using reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. Expression of OCT-4 was correlated to menstrual cycle phase.</p> <p>Results</p> <p>Of 89 women sampled, 49 were in the follicular phase and 40 were in the luteal phase. OCT-4 mRNA was detected in all samples. Increased OCT-4 mRNA levels in the follicular and luteal phases was found in 35/49 (71%) and 27/40 (68%) of women, respectively (p = 0.9). Increased expression of OCT-4 protein was identified in 56/89 (63%) samples. Increased expression of OCT-4 protein in the follicular and luteal phases was found in 33/49 (67%) and 23/40 (58%) of women, respectively (p = 0.5).</p> <p>Conclusions</p> <p>On the mRNA and protein levels, OCT-4 is not differentially expressed during the menstrual cycle. Endometrial OCT-4 is not involved in or modulated by hormone-induced cyclical changes of the endometrium.</p

A randomized comparison of video demonstration versus hands-on training of medical students for vacuum delivery using Objective Structured Assessment of Technical Skills (OSATS)

$\textbf {Background:}$ To compare medical students’ skills for vaginal operative delivery by vacuum extraction (VE) after hands-on training versus video demonstration. $\textbf {Methods:}$ We randomized medical students to an expert demonstration (group 1) or a hands-on (group 2) training using a standardized VE algorithm on a pelvic training model. Students were tested with a 40-item Objective Structured Assessment of Technical Skills (OSATS) scoring system after training and 4 days later. OSATS scores were the primary outcome. Performance time, self-assessment, confidence, and global rating scale were secondary outcomes. We assessed the constructive validity of OSATS in this VE model comparing metric scores of experts and students. $\textbf {Results:}$ In all, 137 students were randomized. OSATS scores were higher in group 2 (n=63) compared with group 1 (n=74) (32.89$\pm$6.39 vs 27.51$\pm$10.27, respectively; P<0.0001). Global rating scale (1.49$\pm$0.76 vs 2.33$\pm$0.94, respectively; P<0.0001), confidence (2.22$\pm$0.75 vs 3.26$\pm$0.94, respectively; P=0.04), self-assessment (2.03$\pm$0.62 vs 2.51$\pm$0.77, respectively; P<0.0001), and performance time (38.81$\pm$11.58seconds vs 47.23$\pm$17.35 seconds, respectively; P=0.001) also favored group 2. After 4 days, this effect persisted with OSATS scores still being significantly higher in group 2 (30.00$\pm$6.50 vs 25.59$\pm$6.09, respectively; P=0.001). The assessed OSATS scores showed constructive validity. In a multiple linear regression analysis, group assignment independently influenced OSATS scores, whereas sex, handedness, sports activities, and type of curriculum were not independently associated with OSATS scores. $\textbf {Conclusions:}$ Hands-on training is superior to video demonstration for teaching VE on a pelvic model. $\textbf {Abbreviations:}$ CON = confidence, GRS = global rating scale, OSATS = Objective Structured Assessment of Technical Skills, PT = performance time, SA = self-assessment, VE = vacuum extraction