Effectiveness of spaced repetition for clinical problem solving amongst undergraduate medical students studying paediatrics in Pakistan.

BACKGROUND: Studies using spaced repetition for teaching and learning in undergraduate clinical rotations such as paediatrics are limited, even more so in the South Asian region. Therefore, this study aimed to identify the effectiveness of utilizing spaced repetition compared to traditional learning methods among undergraduate medical students during their paediatric rotation at a medical university in Pakistan. METHODS: Bahria University Medical and Dental College (BUMDC) conducted quasii-experimental research in Karachi. Four topics were identified from the Year 5 Pediatrics curriculum to be used in the study, using which the study content was developed along with 50 multiple choice questions (MCQs) for assessment. All BUMDC Year 5 medical students rotating in Pediatrics were included and randomly allocated to the control or intervention group. In the control group, they provided the students with traditional study methods consisting of books and lectures to learn topics. In the intervention group, we created an Anki flashcard deck of the same topics to enable learning via spaced repetition. The researchers conducted a pretest and post test assessment of the 50 MCQs in both groups at the beginning and after the four-week study interval. The data were analysed using SPSS 19. RESULTS: A total of 115 BUMDC medical students agreed to participate in the study; 70 (59.1%) were in the intervention group, and 45 (41.7%) were in the control group. The pretest mean score of the control group was 27.96 ± 3.70, and the posttest mean score was 27.22 ± 5.02, with no statistically significant difference at the 95% confidence level. The mean score of the pretest for the intervention group was 27.93 ± 4.53, and that of the posttest was 30.8 ± 4.56, with a statistically significant difference at the 95% confidence level. The intervention showed a significant effect size of 0.8. CONCLUSION: The use of spaced repetitions resulted in significantly greater scores for medical students studying paediatrics than for those using more traditional methods of learning, compromising medical books and lectures. Considering that medical students need to retain a vast amount of information, using spaced repetition through flashcards can be a more effective learning tool that is more cost-efficient and time-efficient than traditional learning methods.

Unveiling the sweetness: evaluating yield and quality attributes of early generation sweet corn (Zea mays subsp. sachharata) inbred lines through morphological, biochemical and marker-based approaches.

BACKGROUND: Sweet corn is gaining tremendous demand worldwide due to urbanization and changing consumer preferences. However, genetic improvement in this crop is being limited by narrow genetic base and other undesirable agronomic traits that hinder the development of superior cultivars. The main requirement in this direction is the development of potentially promising parental lines. One of the most important strategies in this direction is to develop such lines from hybrid-oriented source germplasm which may provide diverse base material with desirable biochemical and agro-morphological attributes. METHODS AND RESULTS: The study was undertaken to carry out morphological and biochemical evaluation of 80 early generation inbred lines (S2) of sweet corn that were developed from a cross between two single cross sweet corn hybrids (Mithas and Sugar-75). Moreover, validation of favourable recessive alleles for sugar content was carried out using SSR markers. The 80 sweet corn inbreds evaluated for phenotypic characterization showed wide range of variability with respect to different traits studied. The highest content of total carotenoids was found in the inbred S27 (34 µg g-1) followed by the inbred S65 (31.1 µg g-1). The highest content for total sugars was found in S60 (8.54%) followed by S14 (8.34%). Molecular characterization of 80 inbred lines led to the identification of seven inbreds viz., S21, S28, S47, S48, S49, S53, and S54, carrying the alleles specific to the sugary gene (su1) with respect to the markers umc2061 and bnlg1937. Comparing the results of scatter plot for biochemical and morphological traits, it was revealed that inbreds S9, S23, S27 and S36 contain high levels of total sugars and total carotenoids along with moderate values for amylose and yield attributing traits. CONCLUSION: The inbred lines identified with desirable biochemical and agro-morphological attributes in the study could be utilized as source of favourable alleles in sweet corn breeding programmes after further validation for disease resistance and other agronomic traits. Consequently, the study will not only enhance the genetic base of sweet corn germplasm but also has the potential to develop high-yielding hybrids with improved quality. The inbreds possessing su1 gene on the basis of umc2061 and bnlg1937 markers were also found to possess high sugar content. This indicates the potential of these lines as desirable candidates for breeding programs aimed at improving sweet corn yield and quality. These findings also demonstrate the effectiveness of the molecular markers in facilitating marker-assisted selection for important traits in sweet corn breeding.

Exposure to high fructose corn syrup during adolescence in the mouse alters hepatic metabolism and the microbiome in a sex-specific manner.

KEY POINTS: The prevalence of obesity and non-alcoholic fatty liver disease in children is dramatically increasing at the same time as consumption of foods with a high sugar content. Intake of high fructose corn syrup (HFCS) is a possible aetiology as it is thought to be more lipogenic than glucose. In a mouse model, HFCS intake during adolescence increased fat mass and hepatic lipid levels in male and female mice. However, only males showed impaired glucose tolerance. Multiple metabolites including lipids, bile acids, carbohydrates and amino acids were altered in liver in a sex-specific manner at 6 weeks of age. Some of these changes were also present in adulthood even though HFCS exposure ended at 6 weeks. HFCS significantly altered the gut microbiome, which was associated with changes in key microbial metabolites. These results suggest that HFCS intake during adolescence has profound metabolic changes that are linked to changes in the microbiome and these changes are sex-specific. ABSTRACT: The rapid increase in obesity, diabetes and fatty liver disease in children over the past 20 years has been linked to increased consumption of high fructose corn syrup (HFCS), making it essential to determine the short- and long-term effects of HFCS during this vulnerable developmental window. We hypothesized that HFCS exposure during adolescence significantly impairs hepatic metabolic signalling pathways and alters gut microbial composition, contributing to changes in energy metabolism with sex-specific effects. C57bl/6J mice with free access to HFCS during adolescence (3-6 weeks of age) underwent glucose tolerance and body composition testing and hepatic metabolomics, gene expression and triglyceride content analysis at 6 and 30 weeks of age (n = 6-8 per sex). At 6 weeks HFCS-exposed mice had significant increases in fat mass, glucose intolerance, hepatic triglycerides (females) and de novo lipogenesis gene expression (ACC, DGAT, FAS, ChREBP, SCD, SREBP, CPT and PPARα) with sex-specific effects. At 30 weeks, HFCS-exposed mice also had abnormalities in glucose tolerance (males) and fat mass (females). HFCS exposure enriched carbohydrate, amino acid, long chain fatty acid and secondary bile acid metabolism at 6 weeks with changes in secondary bile metabolism at 6 and 30 weeks. Microbiome studies performed immediately before and after HFCS exposure identified profound shifts of microbial species in male mice only. In summary, short-term HFCS exposure during adolescence induces fatty liver, alters important metabolic pathways, some of which continue to be altered in adulthood, and changes the microbiome in a sex-specific manner.

Outcomes of Cataract Surgery Complicated by Retained Lens Fragments Requiring Pars Plana Vitrectomy.

OBJECTIVE: To analyze outcomes and complications related to cataract surgery complicated by retained lens fragment (RLF) requiring pars plana vitrectomy (PPV) in a county hospital where procedures are performed by trainees. METHODS: Retrospective study of consecutive patients who met inclusion criteria and underwent PPV for RLF in the vitreous cavity at an urban teaching hospital between January 2010 and January 2016 (N=20). MAIN OUTCOMES/MEASURES: Visual acuity was recorded pre- and post-operatively over a follow-up period of 3 to 12 months. Complications and patient factors contributing to outcomes were assessed using paired and unpaired t-tests and multiple linear regression. RESULTS: The average rate of cataract surgery with RLF requiring PPV was 0.75%. Twenty patients met inclusion criteria. Mean pre-operative visual acuity (VA) was logMAR 1.7 (Snellen 20/1000). Nearly half (8/20) had nuclear cataracts grade 3+ or higher. The majority (14/20) had factors predisposing them to cataract surgery complications. Most patients underwent PPV within 1 week (median 6.5 days). At 12-month follow-up, significant (p=0.001) visual acuity (VA) improvement from initial VA was observed, with final mean logMAR 0.6 (± 0.75; Snellen 20/80) and median logMAR 0.35 (Snellen 20/45). Nearly half of the patients had a final Snellen VA ≥20/40. Factors associated with less VA improvement were older age and greater proportion of lens dropped (p<0.01). Complications following PPV included hypotony (5 patients), corneal edema (4), elevated intraocular pressure (IOP) (3), and cystoid macular edema (3). CONCLUSIONS/RELEVANCE: Despite patients with advanced pathology and trainee surgeons, rates of cataract surgery-associated RLF requiring PPV at a large tertiary care teaching hospital are similar to reported rates in the literature.

Band keratopathy in children previously treated with diode laser for type 1 retinopathy of prematurity.

Band keratopathy is a corneal degeneration caused by chronic inflammation, systemic abnormalities, or, rarely, a primary biallelic SLC4A4 mutation leading to calcium hydroxyapatite deposition in Bowman's layer. We report a series of 16 eyes of 10 children with a remote history of diode laser treated retinopathy of prematurity who developed late-onset band keratopathy without evidence of other prior risk factors. The majority of patients developed band keratopathy bilaterally. Five eyes had visually significant central band keratopathy that required treatment with disodium ethylenediaminetetracetic acid (EDTA) chelation or phototherapeutic keratectomy. Band keratopathy may be an underreported late ophthalmic complication of diode-laser treated retinopathy of prematurity.

Etiology and treatment outcomes of persistent postoperative inflammation in primary resident-performed cataract surgeries at a large tertiary care public hospital.

PURPOSE: To determine the risk factors, intraoperative and postoperative complications, therapeutic interventions, and visual outcomes for persistent postoperative inflammation in primary resident-performed cataract surgeries. SETTING: Ben Taub General Hospital, Houston, Texas, USA. DESIGN: Retrospective case series. METHODS: Primary resident-performed cataract surgeries from January 2012 to June 2015 were analyzed for persistent postoperative inflammation, defined as persistent anterior chamber inflammatory reaction after a standard 1-month topical corticosteroid and nonsteroidal antiinflammatory drug (NSAID) drops taper. Preoperative characteristics, operative complications, therapeutic modalities, and duration of therapy were analyzed. The primary outcome measures were duration of corticosteroid and NSAID therapy, treatment modalities, and postoperative visual outcomes at the 1-month postoperative visit. RESULTS: The study assessed 1290 primary resident-performed cataract surgeries. Persistent postoperative inflammation occurred in 82 eyes (6.6%). The presumed etiology was classified as idiopathic persistent postoperative inflammation, nonadherence to topical therapy, and complicated cataract surgery. Patients with persistent postoperative inflammation were more likely of African American descent, had hypertension, or used aspirin, anticoagulants, or prostaglandins (P = .019, P = .027, P = .028, P = .020, respectively). The complicated cataract subgroup required a longer duration of therapy (P = .021) and was the only subgroup to require injections or systemic corticosteroids. There was no significant difference in postoperative corrected distance visual acuity (CDVA) when comparing patients with persistent postoperative inflammation with those without inflammation or between the subgroups. CONCLUSIONS: The idiopathic and nonadherent subgroups were successfully treated with topical antiinflammatory therapy; the complicated subgroup required longer duration and multiple modalities of treatment. Visual outcomes were comparable to the general cataract population with no differences in postoperative CDVA.

Outcomes and complication rates of primary resident-performed cataract surgeries at a large tertiary-care county hospital.

PURPOSE: To identify the preoperative risk factors, intraoperative events, and postoperative complications increasing the risk for poor visual outcomes in resident-performed cataract surgeries at a tertiary-care county hospital. SETTING: Ben Taub General Hospital, Houston, Texas, USA. DESIGN: Retrospective case series. METHODS: Resident-performed cataract surgeries were analyzed for risk factors, comorbidities, and intraoperative and postoperative complications. The main outcome measures were preoperative and postoperative uncorrected distance visual acuity and corrected distance visual acuity (CDVA), which were correlated with preoperative demographics, intraoperative and postoperative events, and resident training level. The data were subdivided into cases without events and cases with events to determine which complications led to poor visual outcomes. RESULTS: The study analyzed 1290 resident-performed cataract surgeries. The mean visual acuity improved significantly after surgery in all patients (P < .001), with 80.5% of patients without complications and 70.7% with complications attaining a CDVA of 20/40 or better (P < .002). Poor visual outcomes were associated with α-antagonist use (P = .043) and pseudoexfoliation syndrome (P = .001). The most common intraoperative complications were vitreous loss (6.7%) and posterior capsule tear (7.0%). The mean postoperative visual acuity did not vary by trainee year, and the rate of dropped nucleus during surgery declined as residents progressed in training (P < .05). All other complication rates were similar between levels of training. CONCLUSION: Despite more complicated cataracts and advanced comorbidities, primary resident-performed cataract surgery in a tertiary-care county hospital system achieved visual outcomes and complication rates similar to those found in other training hospitals.

Comparison of corneal power, astigmatism, and wavefront aberration measurements obtained by a point-source color light-emitting diode-based topographer, a Placido-disk topographer, and a combined Placido and dual Scheimpflug device.

PURPOSE: To evaluate and compare the performance of a point-source color light-emitting diode (LED)-based topographer (color-LED) in measuring anterior corneal power and aberrations with that of a Placido-disk topographer and a combined Placido and dual Scheimpflug device. SETTING: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas USA. DESIGN: Retrospective observational case series. METHODS: Normal eyes and post-refractive-surgery eyes were consecutively measured using color-LED, Placido, and dual-Scheimpflug devices. The main outcome measures were anterior corneal power, astigmatism, and higher-order aberrations (HOAs) (6.0 mm pupil), which were compared using the t test. RESULTS: There were no statistically significant differences in corneal power measurements in normal and post-refractive surgery eyes and in astigmatism magnitude in post-refractive surgery eyes between the color-LED device and Placido or dual Scheimpflug devices (all P > .05). In normal eyes, there were no statistically significant differences in 3rd-order coma and 4th-order spherical aberration between the color-LED and Placido devices and in HOA root mean square, 3rd-order coma, 3rd-order trefoil, 4th-order spherical aberration, and 4th-order secondary astigmatism between the color-LED and dual Scheimpflug devices (all P > .05). In post-refractive surgery eyes, the color-LED device agreed with the Placido and dual-Scheimpflug devices regarding 3rd-order coma and 4th-order spherical aberration (all P > .05). CONCLUSIONS: In normal and post-refractive surgery eyes, all 3 devices were comparable with respect to corneal power. The agreement in corneal aberrations varied. FINANCIAL DISCLOSURE: Drs. Wang, Koch, and Weikert are consultants to Ziemer Ophthalmic Systems AG. Dr. Koch is a consultant to Abbott Medical Optics, Inc., Alcon Surgical, Inc., and i-Optics Corp.

Contribution of posterior corneal astigmatism to total corneal astigmatism.

PURPOSE: To determine the contribution of posterior corneal astigmatism to total corneal astigmatism and the error in estimating total corneal astigmatism from anterior corneal measurements only using a dual-Scheimpflug analyzer. SETTING: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. DESIGN: Case series. METHODS: Total corneal astigmatism was calculated using ray tracing, corneal astigmatism from simulated keratometry, anterior corneal astigmatism, and posterior corneal astigmatism, and the changes with age were analyzed. Vector analysis was used to assess the error produced by estimating total corneal astigmatism from anterior corneal measurements only. RESULTS: The study analyzed 715 corneas of 435 consecutive patients. The mean magnitude of posterior corneal astigmatism was -0.30 diopter (D). The steep corneal meridian was aligned vertically (60 to 120 degrees) in 51.9% of eyes for the anterior surface and in 86.6% for the posterior surface. With increasing age, the steep anterior corneal meridian tended to change from vertical to horizontal, while the steep posterior corneal meridian did not change. The magnitudes of anterior and posterior corneal astigmatism were correlated when the steeper anterior meridian was aligned vertically but not when it was aligned horizontally. Anterior corneal measurements underestimated total corneal astigmatism by 0.22 @ 180 and exceeded 0.50 D in 5% of eyes. CONCLUSIONS: Ignoring posterior corneal astigmatism may yield incorrect estimation of total corneal astigmatism. Selecting toric intraocular lenses based on anterior corneal measurements could lead to overcorrection in eyes that have with-the-rule astigmatism and undercorrection in eyes that have against-the-rule astigmatism. FINANCIAL DISCLOSURE: The authors received research support from Ziemer Group. In addition, Dr. Koch has a financial interest with Alcon Laboratories, Inc., Abbott Medical Optics, Inc., Calhoun Vision, Inc., NuLens, and Optimedica Corp.

TNFα protects cardiac mitochondria independently of its cell surface receptors.

Our novel proposal is that TNFα exerts a direct effect on mitochondrial respiratory function in the heart, independently of its cell surface receptors. TNFα-induced cardioprotection is known to involve reactive oxygen species (ROS) and sphingolipids. We therefore further propose that this direct mitochondrial effect is mediated via ROS and sphingolipids. The protective concentration of TNFα (0.5 ng/ml) was added to isolated heart mitochondria from black 6 × 129 mice (WT) and double TNF receptor knockout mice (TNFR1&2(-/-)). Respiratory parameters and inner mitochondrial membrane potential were analyzed in the presence/absence of two antioxidants, N-acetyl-L: -cysteine or N-tert-butyl-α-(2-sulfophenyl)nitrone or two antagonists of the sphingolipid pathway, N-oleoylethanolamine (NOE) or imipramine. In WT, TNFα reduced State 3 respiration from 279.3 ± 3 to 119.3 ± 2 (nmol O2/mg protein/min), increased proton leak from 15.7 ± 0.6% (control) to 36.6 ± 4.4%, and decreased membrane potential by 20.5 ± 3.1% compared to control groups. In TNFR1&2(-/-) mice, TNFα reduced State 3 respiration from 205.2 ± 4 to 75.7 ± 1 (p < 0.05 vs. respective control). In WT mice, both antioxidants added with TNFα restored State 3 respiration to 269.2 ± 2 and 257.6 ± 2, respectively. Imipramine and NOE also restored State 3 respiration to 248.4 ± 2 and 249.0 ± 2, respectively (p < 0.01 vs. TNFα alone). Similarly, both antioxidant and inhibitors of the sphingolipid pathway restored the proton leak to pre-TNF values. TNFα-treated mitochondria or isolated cardiac muscle fibers showed an increase in respiration after anoxia-reoxygenation, but this effect was lost in the presence of an antioxidant or NOE. Similar data were obtained in TNFR1&2(-/-) mice. TNFα exerts a protective effect on respiratory function in isolated mitochondria subjected to an anoxia-reoxygenation insult. This effect appears to be independent of its cell surface receptors, but is likely to be mediated by ROS and sphingolipids.

Comparison of CT scan and colour flow Doppler ultrasound in detecting venous tumour thrombous in renal cell carcinoma.

BACKGROUND: Renal cell carcinoma has marked tendency to spread into renal vein, inferior vena cava and right side of heart. Extension of tumour thrombus into these veins will alter the surgical approach. We have compared the CT scan with Colour flow Doppler ultrasound in detecting venous tumour thrombus in renal vein and inferior vena cava. METHODS: This cross-sectional study included 30 adult patients presenting with renal tumour. Patients of either gender were included in the study. Non probability convenience sampling was used. All patients underwent colour flow Doppler ultrasound and CT scan with contrast to asses the renal vein and inferior vena cava. The results were confirmed by intra operative findings and histopathology. The data was analyzed using SPSS version 12. RESULTS: Out of 30 patients, 20 (66%) were males and 10 (34%) female. The tumour was predominantly on the right side (60%), as was renal venous tumour thrombus (44%). Inferior vena cava was involved in 4 cases predominantly due to right sided tumours. The sensitivity of Doppler ultrasound in detecting renal venous tumour thrombus (88% on right and 100% on left side) was higher than CT scan (63% on right and 60% on left side). Doppler ultrasound was also superior to CT scan in detecting vena caval thrombus. CONCLUSION: The overall sensitivity of Doppler sonography was higher than CT scan in detecting tumour extension into renal veins and inferior vena cava. Therefore, it can be used as a complementary tool in equivocal cases.

Chest radiography in children aged 2-59 months diagnosed with non-severe pneumonia as defined by World Health Organization: descriptive multicentre study in Pakistan.

OBJECTIVES: To evaluate the chest radiographs of children diagnosed with non-severe pneumonia on the basis of the current World Health Organization guidelines (fast breathing alone) for radiological evidence of pneumonia. DESIGN: Descriptive analysis. SETTING: Outpatient departments of six hospitals in four cities in Pakistan. PARTICIPANTS: 2000 children with non-severe pneumonia were enrolled; 1932 children were selected for chest radiography. INTERVENTIONS: Two consultant radiologists used standardised WHO definitions to evaluate chest radiographs; no clinical information was made available to them. If they disagreed, the radiographs were read by a third radiologist; the final classification was based on agreement between two of the three radiologists. MAIN OUTCOME MEASURES: Presence or absence of pneumonia on radiographs. RESULTS: Chest radiographs were reported normal in 1519 children (82%). Radiological evidence of pneumonia was reported in only 263 (14%) children, most of whom had interstitial pneumonitis. Lobar consolidation was present in only 26 children. The duration of illness did not correlate significantly with the presence of radiological changes (relative risk 1.17, 95% confidence interval 0.91 to 1.49). CONCLUSION: Most children diagnosed with non-severe pneumonia on the basis of the current WHO definition had normal chest radiographs.