Medical students as future clinicians will apply their anatomy knowledge in medical imaging. There are various radiological resources available for the medical students to learn anatomy and ...contextualise it to the clinical setting. Ultrasound is a safe and non- invasive imaging procedure commonly used in clinical practice. This study aimed to use portable ultrasound and evaluate its impact as an adjunct to cadaveric anatomy teaching together with cross sectional anatomy images and line diagrams.
Ultrasound teaching was incorporated into upper limb and lower limb anatomy practical dissecting room sessions. The number of medical students who participated was 121 students from the year 2008 - 2009 and 94 students from the year 2009- 2010. The students were divided into groups of 15-20. Initially ultrasound demonstration was carried out on a volunteer and then the students were given the opportunity to use the ultrasound and identify normal anatomical structures visualized on images. For the students in the year 2009- 2010, ultrasound teaching was supplemented with cross sectional anatomy images and line diagrams. Questionnaires were distributed with seven questions rated using four point Likert scale and free text. Qualitative data was analysed using 2- proportion Z test and Fischer's exact test.
The number of students in the 2009-2010 year group who were confident in interpreting ultrasound images increased significantly when compared to the 2008-2009 year group of students. The majority of students were able to identify structures like bone, muscles and blood vessels on ultrasound images. There was a significant increase in the number of students who found the ultrasound teaching useful and also those who regarded ultrasound to have improved understanding of anatomy considerably.
Ultrasound acts as a useful adjunct to teach anatomy in a clinical context to medical students. The use of cross sectional anatomy images and line diagrams together can aid ultrasound image orientation of structures during these sessions. Early exposure to this imaging technology may prime students for later encounters with ultrasound during clinical practice.
Remodeling of uterine spiral arteries is critical for the continuation of a successful pregnancy. Uterine natural killer (uNK) cells are the predominant leukocyte population in the early pregnant ...decidua, and a role for these cells in spiral artery remodeling in pregnancy has been suggested. Angiogenic growth factors were measured in isolated uNK and total (unseparated) decidual cells (8-10 or 12-14 weeks gestation, n=5 each gestational age) after culture for 48 h. Angiopoietin (Ang)1, placental growth factor, transforming growth factor-beta1 (TGF-beta1), and vascular endothelial growth factor (VEGF)-C were measured by enzyme-linked immunosorbent assay. Angiogenin, Ang2, fibroblast growth factor basic, intercellular adhesion molecule (ICAM)-1, keratinocyte growth factor (KGF), platelet-derived growth factor-BB, and VEGF-A were measured using a FASTQuant angiogenic growth factor multiplex protein assay. Levels of Ang2, ICAM-1, and KGF, secreted by the total decidual fraction, decreased with increasing gestational age. uNK levels of Ang2 and VEGF-C also decreased with increasing gestational age. At 8-10 weeks gestation, there was no difference in the level of Ang1, Ang2, TGF-beta1, and VEGF-C secreted by uNK cells and the total decidual fraction. At 12-14 weeks, uNK cells secreted significantly lower levels of VEGF-C than the total decidual fraction. Early pregnancy decidua is a major source of angiogenic growth factors whose levels decrease with increasing gestational age, suggesting that they may play a role in spiral artery remodeling. uNK cells appear to be a prominent source of Ang1, Ang2, TGF-beta1, and VEGF-C within the placental bed.
Alterations in the balance of leucocyte populations in uterine decidua may lead to the generation of an unfavourable cytokine environment that is associated with unsuccessful pregnancy. Single and ...double immunohistochemical labelling was used to examine leucocyte populations in decidua from normal third trimester, foetal growth-restricted and pre-eclamptic pregnancies. Placental bed biopsies from 12 women undergoing elective Caesarean section with no hypertension or foetal growth restriction (FGR), 8 women with FGR without maternal hypertension and 12 women with pre-eclampsia (PE) were used to quantify decidual CD56+ uterine NK cells, CD14+ macrophages, CD3+T-lymphocytes and CD8+ lymphocytes. CD3+CD56+, CD8+CD56+ and CD161+CD3+ double-labelled cells in decidua were compared in PE and control decidua. Decidual CD3+T-lymphocytes (P<0.01), CD8+ cytotoxic T-lymphocytes (P<0.05), CD14+ macrophages (P<0.0001) and CD56+ uterine natural killer (uNK) cells (P=0.01) were decreased in placental bed biopsies from women with PE compared with control third trimester decidua. By contrast, only CD56+ uNK cells were decreased in FGR decidua (P<0.05). Double-positive CD8+CD56+ cells were also decreased in PE compared with control third trimester decidua (P<0.05). The reduction in specific leucocyte subset numbers in PE and uNK cells in FGR suggests that altered local cytokine balance may be important in defective trophoblast invasion and spiral artery transformation in these pathological pregnancies.
BACKGROUND Extravillous trophoblast (EVT) cell invasion of uterine decidua and the inner third of myometrium is critical for successful pregnancy. Many decidual factors are likely to play a role in ...regulating this process. We have previously shown that cytokines, known to be produced by uterine natural killer (uNK) cells, such as TNF-α, TGF-β1 and IFN-γ inhibit EVT invasion. We therefore hypothesized that supernatants from purified uNK cells would inhibit EVT invasion. METHODS AND RESULTS Total unfractionated decidual cell supernatants from 8 to 10 weeks gestation increased EVT invasion from placental villous explants, although uNK cell supernatants from 8 to 10 weeks gestation had no effect. In contrast, both total decidual and uNK cell supernatants from 12 to 14 weeks gestation stimulated EVT invasion. MMP-2, uPA, PAI-1 and PAI-2 levels did not differ under any of the conditions tested, whereas MMP-9 levels were increased in the presence of both total decidual and uNK cell supernatants from both gestational age groups. There was a decrease in the level of EVT apoptosis in the presence of uNK cell supernatant from 12 to 14 weeks, but not 8–10 weeks, gestation. CONCLUSIONS Decidual uNK cell supernatants from 12 to 14 weeks gestational age stimulated EVT invasion, potentially by increasing MMP9 levels and reducing apoptosis. Total decidual cell isolates stimulated EVT invasion at both gestational ages investigated, potentially reflecting the complex nature of these cell culture supernatants.
BACKGROUND Invasion by extravillous trophoblast into uterine decidua and myometrium with remodeling of spiral arteries is essential for normal human pregnancy and is tightly regulated. Uterine ...natural killer (uNK) cells appear to be a major maternal regulator of placentation through the secretion of growth factors, cytokines and proteinases. METHOD Matrix metalloproteinase (MMP)-2 and MMP-9 activity in placental bed biopsies was studied using in situ gelatin zymography. Expression by uNK cells of MMP-2, MMP-9 and their tissue inhibitors, TIMP-1, TIMP-2 and TIMP-3, was localized in the placental bed by immunohistochemistry. Levels of MMP-2, MMP-9, TIMP-1, TIMP-2 and TIMP-3 secreted into 24 h cell culture supernatants of isolated uNK and unseparated (total) decidual cells (8–10 and 12–14 weeks gestation, n = 10 each group) were determined by gelatin gel zymography or western blot as appropriate. RESULTS: Gelatinase activity in situ appeared greater in decidua than myometrium. uNK cells showed strong immunostaining for MMP-2 and TIMP-2. MMP-9 activity was lower in uNK cells than total decidual supernatants (8–10 weeks: P = 0.0003; 12–14 weeks: P = 0.0012). In contrast, there was no difference in MMP-2 secreted by either uNK cell or total decidual cultures. CONCLUSIONS uNK cells from early human pregnancy decidua possess innate protease activity, especially MMP-2, providing further evidence for a role for these cells in regulation of trophoblast invasion and spiral artery remodeling in early placentation.
BACKGROUND
Uterine natural killer (uNK) cells are a major source of cytokines and angiogenic growth factors (AGFs), with AGF levels decreasing and cytokine levels increasing with gestational age. The ...factors that regulate AGF and cytokine secretion are unclear but may involve interactions between uNK cells and extravillous trophoblast (EVT) cells. We hypothesize that uNK cell interaction with EVT cells alters their cytokine and AGF secretion.
METHODS
Ex vivo co-cultures of uNK cells with either EVT (irradiated or fresh) or villous cytotrophoblast (CTB; control cell type) cells isolated from the same patients at 8–10 or 12–14 weeks gestational age (n = 10 each group) were established. Co-cultures were established with either direct contact between the different cell types or with the cells separated by a 0.4 µm filter. AGFs and cytokines were measured in cell culture supernatants using multiplex analysis (FAST Quant) or ELISA.
RESULTS
Secretion of angiopoietin-1 (P< 0.006) and vascular endothelial growth factor-C (P< 0.001) by uNK cells was lower when these cells were co-cultured, either directly or indirectly, with both trophoblast cell types at both gestational ages tested compared with when cultured alone. In contrast, interleukin (IL)-6 (P < 0.0001), IL-8 (P < 0.0001) and transforming growth factor-β1 (P < 0.002) were decreased only in direct uNK/EVT and uNK/CTB co-culture conditions at 8–10 and 12–14 weeks gestational age.
CONCLUSIONS
AGF and cytokine secretion was reduced after co-culture of uNK cells and both EVT and CTB cells. It remains unclear whether uNK cell AGF and cytokine production was reduced after co-culture with trophoblast cells (EVT or CTB) or whether trophoblast cell (EVT or CTB) AGF and cytokine production was reduced after co-culture with uNK cells. Local production of AGFs and cytokines in the placental bed may be lowered when uNK cells come in direct contact with EVT cells.
Invasion of extravillous trophoblast cells into the uterus in human pregnancy is tightly regulated. The transforming growth factor-beta (TGFB) family has been suggested to play a role in controlling ...this process. We hypothesized that TGFB1, 2, and 3 would inhibit the invasive capacity of extravillous trophoblast cells. We also studied trophoblast apoptosis and proliferation and secreted protease levels as potential mechanisms by which these cytokines may act. Inhibition of endogenous TGFB1, 2, and 3 with neutralizing antibodies increased the invasive capacity of extravillous trophoblast cells derived from placental explants. Similarly, addition of exogenous TGFB1, 2, and 3 inhibited the invasive capacity of these cells in a dose-dependent manner. Proliferation of trophoblast in the placental explants did not alter in response to any of the cytokines tested. Apoptosis of villous and extravillous trophoblast did not alter in response to TGFB1, 2, and 3. There was a reduction in secreted levels of matrix metalloproteinase (MMP) 9 and urokinase plasminogen activator in response to all three cytokines. MMP2 and tissue inhibitor of metalloproteinase 1 and 3 levels were not altered. These results suggest that TGFB1, 2, and 3 inhibit trophoblast invasion by a mechanism dependent on reduced protease activity.
Background Feedback is a vital component of the learning process; however, great variation exists in the quality, quantity, and method of delivery. Video feedback is not commonly used in the teaching ...of surgical skills. The aim of this trial was to evaluate the benefit of 2 types of video feedback—individualized video feedback (IVF), with the student reviewing their performance with an expert tutor, and unsupervised video-enhanced feedback (UVF), where the student reviews their own performance together with an expert teaching video—to determine if these improve performance when compared with a standard lecture feedback. Methods A prospective blinded randomized control trial comparing lecture feedback with IVF and UVF was carried out. Students were scored by 2 experts directly observing the performance and 2 blinded experts using a validated pro forma. Participants were recorded on video when performing a suturing task. They then received their feedback via any of the 3 methods before being invited to repeat the task. Results A total of 32 students were recruited between the 3 groups. There was no significant difference in suturing skill performance scores given by those directly observing the students and those blinded to the participant. There was no statistically significant difference between the 2 video feedback groups (p = 1.000), but there was significant improvement between standard lecture feedback and UVF (p = 0.047) and IVF (p = 0.001). Conclusion Video feedback can facilitate greater learning of clinical skills. Students can attain a similar level of surgical skills improvement with UVF as with teacher-intensive IVF.
Background: Extravillous trophoblast cell (EVT) invasion of decidua and inner third of the myometrium is critical for a successful pregnancy. Many decidual factors are likely to play a role in ...regulating this process, including uterine natural killer (uNK) cell-derived cytokines. Hypotheses: 1) uNK cells are a major source of IFN gamma (IFN-γ) and 2) IFN-γ inhibits EVT invasion via an increase in EVT apoptosis and/or a decrease in active protease levels. Methods: Total decidual and uNK cells from 8-10 wk and 12-14 wk gestational age were cultured. IFN-γ mRNA (real-time RT-polymerase chain reaction) and protein levels (FastQuant multicytokine analysis) were determined. EVT invasion in the presence of IFN-γ or anti-IFN-γ-neutralizing antibodies was assessed. Trophoblast apoptosis and proliferation was assessed in explants by immunohistochemistry for M30 and Ki67. Substrate zymography was performed to determine levels of secreted MMP2, MMP9, and uPA. Results: mRNA and protein for IFN-γ was detected in both total decidual and uNK cell fractions. Trophoblast invasion was inhibited by IFN-γ. The level of M30-positive EVT was increased in the presence of IFN-γ whereas levels of secreted MMP2 were decreased. Conclusions: uNK cells are a source of IFN-γ within early human pregnancy decidua. Mechanisms of IFN-γ inhibition of EVT invasion include both increased EVT apoptosis and reduced levels of active proteases.--Lash, G. E., Otun, H. A., Innes, B. A., Kirkley, M., De Oliveira, L., Searle, R. F., Robson, S. C., Bulmer, J. N. Interferon-γ inhibits extravillous trophoblast cell invasion by a mechanism that involves both changes in apoptosis and protease levels.
Simulation training has potential in developing clinical skills in pre-clinical medical students, but there is little evidence on its effectiveness.
Twenty four first year graduate entry preclinical ...medical students participated in this crossover study. They were divided into two groups, one performed chest examination on each other and the other used SimMan. The groups then crossed over. A pretest, midtest and post-test was conducted in which the students answered the same questionnaire with ten questions on knowledge, and confidence levels rated using a 5 point Likert scale. They were assessed formatively using the OSCE marking scheme. At the end of the session, 23 students completed a feedback questionnaire. Data was analyzed using one-way ANOVA and independent t-test.
When the two groups were compared, there was no significant difference in the pretest and the post-test scores on knowledge questions whereas the midtest scores increased significantly (P< 0.001) with the group using SimMan initially scoring higher. A significant increase in the test scores was seen between the pre-test and the mid-test for this group (P=0.009). There was a similar albeit non significant trend between the midtest and the post-test for the group using peer examination initially.Mean confidence ratings increased from the pretest to midtest and then further in the post-test for both groups. Their confidence ratings increased significantly in differentiating between normal and abnormal signs Group starting with SimMan, between pretest and midtest (P= 0.01) and group starting with peer examination, between midtest and post-test (P=0.02). When the students' ability to perform examination on each other for both groups was compared, there was a significant increase in the scores of the group starting with SimMan (P=0.007).
This pilot study demonstrated a significant improvement in the students' knowledge and competence to perform chest examination after simulation with an increase in the student's perceived levels of confidence. Feedback from the students was extremely positive. SimMan acts as a useful adjunct to teach clinical skills to preclinical medical students by providing a simulated safe environment and thus aids in bridging the gap between the preclinical and clinical years in medical undergraduate education.
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