257 Comparing Practice Testing to Restudying in the Dissecting Room: An Experimental Study

Aim

Medical students employ many strategies for learning, most commonly restudying. However, evidence suggests that restudying is not as effective as other strategies, namely practice testing. Different studies have compared restudying to practice testing on a variety of subjects. Few studies have assessed the effect of practice testing in anatomy courses. To the best of the authors' knowledge, no studies have investigated practice testing in the dissecting room (DR). In this study, we aim to measure the effect of practice testing in a DR setting, as compared to restudying.

Method

Second-year medical students learning the cardiovascular system were included in the study. Two groups were randomly selected to participate in practice tests taken at the end of DR sessions. The other two groups were asked to restudy the material. At the end of the four-week course, all students took a 15 points multiple-choice exam on learned material. Authors of practice tests were blind to the final exam content and vice versa.

Results

One hundred eight students participated in the study. Fifty-three students were in the practice testing group, and 55 were in the restudying group. The practice testing group performed significantly better than the restudying group (p = .008), with a mean of 8.57 +/- 2.3 for the practice testing group and 7.27 +/- 2.6 for the restudying group.

Conclusions

Practice testing significantly improved retention of Anatomy. We recommend that practice testing is implemented regularly at the end of DR sessions to enhance the learning experience.

259 Effect of Telegram Videos on Anatomy Education Among 2nd Year Medical Students, University of Khartoum, 2021

Aim

COVID-19 had major effect on the health and medical education. In order to oblige with the social distancing and quarantine, universities shifted to online learning. This study aimed to assess the effect of online education on anatomy DR (dissection room) teaching by the use of telegram software.

Method

This was a cross-sectional, prospective interventional study, which was carried out among 2nd year medical students in University of Khartoum. Students undertook initial tests on the heart and anterior abdominal wall modules. Telegram videos, prepared by the author, on the anatomy of the heart and the anterior abdominal wall were distributed to students. Students took a second test after watching the videos. A total number of 41 students attended heart sessions and 40 students attended the anterior abdominal wall sessions were included.

Results

The pre-test mean score for the heart and abdomen modules were 4.56 ± 2.335 and 6.15 ± 2.94, respectively. The post-tests means were 9.98 ± 2.877 and 8.95 ± 3.14, respectively. 90% and 75% of the students were satisfied with these videos, respectively.

Conclusions

This study revealed that Telegram videos as a method of online teaching had a positive effect on the students' performance, which was evidenced by the significant improvement in student's scores after watching the videos. Additionally, most of the students were satisfied with the videos and give positive feedback.

Effect of the renin angiotensin system inhibitors on inflammatory markers: a systematic review and meta-analysis of 32 randomized controlled trials

Background

Inflammation plays a critical role in the etiology of cardiovascular disease (CVD). The renin-angiotensin system inhibitors including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) have been shown to be effective in reducing elevated blood pressure. However, the information on their potential effect on inflammatory markers including C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) is still lacking.

Purpose

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to synthesize evidence about effect of ACEIs and ARBs on selected inflammatory markers.

Methods

PubMed, Scopus, and Embase were searched from inception until February 15, 2021. We included RCTs that assessed the effect of ACEIs or ARBs, compared with placebo, on any of the following markers: CRP, IL-6, or TNF-α. Mean changes in the relevant markers levels were pooled as a standardized mean difference (SMD) with a 95% confidence interval (CI) under the random-effects model. Heterogeneity was assessed using I2 and χ2 tests.

Results

Thirty-two RCTs (n=3,403 patients) were included in the analysis. Overall pooled analysis suggested that ACEIs significantly reduced plasma levels of CRP (SMD: −1.08 [95% CI: −1.57 to −0.59]; I2: 95%), IL-6 (SMD: −0.75 [95% CI: −1.41 to −0.09]; I2: 81%), and TNF-α (SMD: −1.77 [95% CI: −2.82 to −0.73]; I2: 95%). This lowering effect remained statistically significant by perindopril in terms of all relevant markers, by quinapril and ramipril in terms of IL-6 and by enalapril in terms of TNF-α. As for the ARBs as a class, they showed a statistically significant reduction only in terms of CRP (SMD: −0.14 [95% CI: −0.28 to −0.01]; I2: 0%) and did not significantly affect any of the other markers. Moreover, the ARBs individual drugs did not show any significant effect on any of the relevant markers except for valsartan that significantly reduced plasma levels of IL-6 (SMD: −0.42 [95% CI: −0.80 to −0.04]; I2: 0%).

Conclusions

Based on the results of this meta-analysis, ACEIs showed a beneficial lowering effect on CRP, IL-6, and TNF-α, while ARBs were effective as a class only in terms of CRP reduction. Further larger RCTs are warranted to confirm these results particularly in case of individual drugs and to assess the significance of these reductions in terms of CVD prevention.

Funding Acknowledgement

Type of funding sources: None.

Association of statin use in older people primary prevention group with risk of cardiovascular events and mortality: a systematic review and meta-analysis of observational studies

Background

Current evidence from randomized controlled trials on statins for primary prevention of cardiovascular disease (CVD) in older people, especially those aged >75 years, is still lacking.

Purpose

We conducted a systematic review and meta-analysis of observational studies to extend the current evidence about association of statin use in older people primary prevention group with risk of CVD and mortality.

Methods

PubMed, Scopus, and Embase were searched from inception until March 18, 2021. We included observational studies (cohort or nested case-control) that compared statin use vs non-use for primary prevention of CVD in older people aged ≥65 years; provided that each of them reported the risk estimate on at least one of the following primary outcomes: all cause-mortality, CVD death, myocardial infarction (MI), and stroke. Risk estimates of each relevant outcome were pooled as a hazard ratio (HR) with a 95% confidence interval (CI) using the random-effects meta-analysis model.

Results

Ten observational studies (9 cohort and one case-control study; n=872,845) fulfilled our criteria. The overall combined estimate suggested that statin therapy was associated with a significantly lower risk of all-cause mortality (HR: 0.86 [95% CI: 0.79 to 0.93]), CVD death (HR: 0.80 [95% CI: 0.78 to 0.81]), and stroke (HR: 0.85 [95% CI: 0.76 to 0.94]) and a non-significant association with risk of MI (HR: 0.74 [95% CI: 0.53 to 1.02]). The beneficial association of statins with the risk of all-cause mortality remained significant even at higher ages (>75 years old; HR: 0.88 [95% CI: 0.81 to 0.96]) and in both men (HR: 0.75 [95% CI: 0.74 to 0.76]) and women (HR: 0.85 [95% CI: 0.72 to 0.99]). However, this association with the risk of all-cause mortality remained significant only in those with DM (HR: 0.82 [95% CI: 0.68 to 0.98]) but not in those without DM.

Conclusions

Statin therapy in older people (aged ≥65 years) without CVD was associated with a 14%, 20% and 15% lower risk of all-cause mortality, CVD death and stroke, respectively. The beneficial association with the risk of all-cause mortality remained significant even at higher ages (>75 years old), in both men and women, and in individuals with DM, but not in those without DM. These observational findings support the need for trials to test benefits of statins in those above 75 years of age.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Results of the meta-analysis

Long-term outcome of JJ stent insertion for primary obstructive megaureter in children

BACKGROUND/AIM

Endoscopic stenting is an accepted treatment option for children with symptomatic or progressive primary obstructive megaureter (PROM). Here, long-term outcomes with endoscopic stenting are reviewed.

METHODS

Patients with PROM treated surgically over a 12-year period were identified using a prospectively maintained departmental database. Data were analysed using Microsoft Excel 2013 and unpaired t-tests through GraphPad Software QuickCalcs.

RESULTS

Fifty-seven patients with PROM were surgically managed in the study centre from 2005 to 2017. Twenty-nine of fifty-seven patients had the stent as the primary procedure, whereas the remainder had ureterostomy, re-implantation or nephrectomy. Six patients had bilateral PROM, giving a total of 35 renal units that were fully analysed. There was 7:1 male predominance, and 20 of 29 patients (69%) were diagnosed antenatally. The median age at stent insertion was 8 months (40 days-10 years); the median prestent ureteric diameter was 19 mm and the median pre-operative function on MAG3 was 44%. Cystoscopic stent insertion was feasible in all patients. The stent was left for a median of 183 days. In 9 of 35 (26%) renal units, the JJ stent was a successful sole long-term treatment, with median follow-up of 5 years and 8 months. The success rate was not different in children aged <1 year (8/22; 36%) in comparison to children aged >1 year (1/13; 8%), P = 0.1. The remaining 26 renal units required further surgical intervention: ureteric re-implantation in 25 and nephrectomy in one. Indications for further surgery were stent complications in 11 renal units and stent failure in 15 (Table 1). Complications related to the stent were noted in 14 renal units (41%), half being stent migration. Other complications included UTIs, stent encrustation and recurrent haematuria. There was no identifiable prestent parameter, whether clinical or radiological, that could predict which patients were likely to be successfully managed solely by stent insertion. Stent insertion was never successful as a definitive procedure when the distal ureteric diameter was >12 mm on the ultrasound after stent removal.

DISCUSSION

Success rates with primary stenting as a sole treatment for PROM was 26%, which is less than that seen in other reports (50-66%). This may be attributed to the long-term follow-up in this study, together with the strict criteria for success.

CONCLUSION

In the authors' experience, cystoscopically inserted JJ stents are of limited success as the sole treatment for PROM. In infants aged <1 year, stent insertion remains a reasonable temporising measure until the infant is old enough for a definitive procedure.

Thyroid Cancer Profile: Experience of Liga Contra El Cancer Honduras 2014-2017

Background: In recent years we have observed increase in thyroid carcinoma TC incidence at cancer centers in Honduras. TC is linked to exposure to ionizing radiation. Other risks factors described in literature are obesity, diabetes, nitrites and nitrates in diet and alcohol. DNA rupture, activation of oncogenes, and secretion of inflammatory cytokines are initial events that derive in mutations and malignant transformation. Papillar, follicular and undifferentiated carcinoma are the histologic types. Little is known about TC in the population, and there are no efficient models for prevention and early detection to date. Aim: Describe the clinical and demographic profile of patients diagnosed with TC at La Liga Contra el Cancer Hospital LCC from 2014-2017, with intention to identify patterns that allow approaches to pathogenicity and prevention. Methods: We revised 103 medical records of all TC patients treated at LCC from Jan 2014-December 2017 to obtain information about geographical origin, age, gender, localization of tumor, identifiable risk factor, treatment and outcomes. A digital database was in Microsoft Office Excel and exported to SPSS. Patient information was deidentified before data extraction. Results: 91.3% patients were female. Median age 49.3 ± 15.6 years (95% CI, 46.05-52.2). Patients went from 11/18 departments (political division), 74% gathered in the northern zone of the country. Histology type: papillary 91.3%; follicular 4.9%, anaplasic 1.9%; medullary 1.0%. Papillary TC, 37% of patients were in fifth decade, 22.9% in patients 31-40 yo, 17.3% in patients 41-50 yo, 9.7% were under 30s. Clinical stage at diagnosis: I I (n = 24) 23.6%, II (n = 13), 12.6%. III (n = 18), 17.5%. IV (n = 14), 15.6%; not suitable for staging 5.8%, the rest had no precise information for staging. 12.6% of patients reported family history of cancer (any type), 33% of patients reported comorbidities. Conclusion: Thyroid carcinoma has increased in the last years, from our experience we can identify that women are mostly affected, with papillary type being the most common. Ages affected are between 41-60 years old. One third of patients had comorbidities as hypothyroidism, diabetes and arterial hypertension. 74% reside in the northern zone of Honduras, there is need to elucidate if it is a matter of geographical location of the LCC. No emerging risk factors were identified in this cohort. More research is needed to profile thyroid carcinoma in our region.

Effects of partial liquid ventilation with perfluorodecalin in the juvenile rabbit lung after saline injury

OBJECTIVE

To evaluate the feasibility of using the perfluorochemical, perfluorodecalin, for partial liquid ventilation (PLV) with respect to gas exchange and lung mechanics in normal and saline-injured lungs of juvenile rabbits.

DESIGN

Experimental, prospective, randomized, controlled study.

SETTING

Physiology laboratory at a university medical school.

SUBJECTS

Seventeen juvenile rabbits assigned to three groups.

INTERVENTIONS

The conventional mechanical ventilation (CMV)-injury group (n = 5) was treated with CMV after establishing a lung injury; the PLV-injury group (n = 6) was treated with PLV after lung injury; and the PLV-healthy group (n = 6) was supported with PLV without lung injury. Lung injury was created by repeated saline lung lavages. PLV-treated animals received a single dose of intratracheal perfluorodecalin at a volume equal to the measured preinjury gas functional residual capacity (functional residual capacity = 18.6+/-1.5 [SEM] mL/kg).

MEASUREMENTS AND MAIN RESULTS

Sequential measurements of total respiratory compliance and arterial blood chemistries were performed in all groups. Oxygenation index (OI) and ventilation efficiency index were calculated. After lung injury, there was a significant (p < .05) decrease in PaO2, total respiratory compliance, and ventilation efficiency index and an increase in OI and PaCO2. In the PLV-injury group, PLV significantly (p < .05) improved PaO2 (+60%) and OI (-33%) over time. Compliance was significantly (p < .05) higher (90%) than in the CMV-injury group over time.

CONCLUSIONS

These results demonstrate that PLV with perfluorodecalin improved oxygenation and increased respiratory compliance in the saline-injured rabbit lung. In addition, similar to the effects of several other perfluorochemical liquids on normal lungs, pulmonary administration of perfluorodecalin was associated with a small impairment in gas exchange and a significant decrease in lung compliance in the juvenile rabbit model.

Pharmacologic approaches for the management of systemic hypertension in pregnancy

Hypertension in pregnancy includes a group of distinct disorders that require special consideration in both prevention and pharmacologic treatment. In recent years, there have been few advances regarding the pathophysiology and prevention of preeclampsia, or in recommendations for first-line drug therapy of the hypertensive complications of preeclampsia. Similarly, the recommendations for pharmacologic treatment of women with chronic hypertension antedating pregnancy have changed little, primarily because first-line medications have the advantage of having been the subjects of extensive research experience. Recent clinical trials have demonstrated the efficacy and safety of various second-line drugs for treating hypertensive disorders of pregnancy; whether these therapies can eventually replace the standard recommended medications will require more extensive long-term investigation.

Generation of natural killer cells from both Fc gamma RII/III+ and Fc gamma RII/III- murine fetal liver progenitors

In vitro culture of day-15.5 murine fetal liver (FL) cells in the presence of recombinant interleukin-2 (IL-2) results in the expansion of Fc gamma RII/III+ CD3-Ti-NK1.1+ cells displaying both natural killer (NK) and antibody-dependent cell cytotoxicity (ADCC) cytolytic activities. These FL-derived NK cells express Fc gamma RIII (CD16) in association with an Fc epsilon RI gamma homodimer on their surface. In contrast, in vitro expansion of FL cells in the absence of IL-2 generates noncytotoxic cells belonging to the myelomonocytic lineage (Mac1+Gr1+NK1.1-). Hence, IL-2 appears to be critical for the proliferation and differentiation of NK cells from FL progenitors. Experiments in which FL cells were fractionated by density gradient centrifugation before in vitro expansion showed that NK progenitors are contained within a cell population with a density of 1.04 < d < 1.08 g/mL. Cells with d > 1.08 g/mL (representing > or = 40% of FL cells) have no such NK progenitor activity. In addition, after intrathymic injection into Ly5 congenic host animals, day-15.5 CD4-CD8- FL cells mature into CD4+CD8+ thymocytes within 12 days. Interestingly, this T-cell progenitor activity is restricted to subpopulations of FL cells that also contain NK progenitors, but is absent in high-density (d > 1.08 g/mL) FL cells. Finally, fractionation of FL cells according to surface expression of Fc gamma RII/III complexes shows that NK (and T-lymphocyte) progenitors are found in both Fc gamma RII/III+ and Fc gamma RII/III-FL subpopulations.

Fc gamma RII/III and CD2 expression mark distinct subpopulations of immature CD4-CD8- murine thymocytes: in vivo developmental kinetics and T cell receptor beta chain rearrangement status

We have recently identified a dominant wave of CD4-CD8- (double-negative [DN]) thymocytes in early murine fetal development that express low affinity Fc gamma receptors (Fc gamma RII/III) and contain precursors for Ti alpha/beta lineage T cells. Here we show that Fc gamma RII/III is expressed in very immature CD4low single-positive (SP) thymocytes and that Fc gamma RII/III expression is downregulated within the DN subpopulation and before the CD3-CD8low SP stage in T cell receptor (TCR)-alpha/beta lineage-committed thymocytes. DN Fc gamma RII/III+ thymocytes also contain a small fraction of TCR-gamma/delta lineage cells in addition to TCR-alpha/beta progenitors. Fetal day 15.5 DN TCR-alpha/beta lineage progenitors can be subdivided into three major subpopulations as characterized by cell surface expression of Fc gamma RII/III vs. CD2 (Fc gamma RII/III+CD2-, Fc gamma RII/III+CD2+, Fc gamma RII/III-CD2+). Phenotypic analysis during fetal development as well as adoptive transfer of isolated fetal thymocyte subpopulations derived from C57B1/6 (Ly5.1) mice into normal, nonirradiated Ly5.2 congenic recipient mice identifies one early differentiation sequence (Fc gamma RII/III+CD2(-)-->Fc gamma RII/III+CD2(+)-->Fc gamma RII/III-CD2+) that precedes the entry of DN thymocytes into the CD4+CD8+ double-positive (DP) TCRlow/- stage. Unseparated day 15.5 fetal thymocytes develop into DP thymocytes within 2.5 d and remain at the DP stage for > 48 h before being selected into either CD4+ or CD8+ SP thymocytes. In contrast, Fc gamma RII/III+CD2- DN thymocytes follow this same developmental pathway but are delayed by approximately 24 h before entering the DP compartment, while Fc gamma RII/III-CD2+ display accelerated development by approximately 24 h compared with total day 15.5 thymocytes. Fc gamma RII/III-CD2+ are also more developmentally advanced than Fc gamma RII/III+CD2- fetal thymocytes with respect to their TCR beta chain V(D)J rearrangement. At day 15.5 in gestation, beta chain V(D)J rearrangement is mostly, if not entirely, restricted to the Fc gamma RII/III-CD2+ subset of DN fetal thymocytes. Consistent with this analysis in fetal thymocytes, > 90% of adult thymocytes derived from mice carrying a disrupting mutation at the recombination-activating gene 2 locus (RAG-2-/-) on both alleles are developmentally arrested at the DN CD2- stage. In addition, there is a fivefold increase in the relative percentage of thymocytes expressing Fc gamma RII/III in TCR and immunoglobulin gene rearrangement-incompetent homozygous RAG-2-/- mice (15% Fc gamma RII/III+) versus rearrangement-competent heterozygous RAG-2+/- mice (< 3% Fc gamma RII/III+). Thus, Fc gamma RII/III expression defines an early DN stage preceding V beta(D beta)I beta rearrangement, which in turn is followed by surface expression of CD2. Loss of Fc gamma RII/III and acquisition of CD2 expression characterize a late DN stage immediately before the conversion into DP thymocytes.