Cognitive Load and Self-Determination Theories Applied to E-Learning: Impact on Students' Participation and Academic Performance

Background

Emergency clerkships expose students to a stressful environment that require multiple tasks, which may have a direct impact on cognitive load and motivation for learning. To address this challenge, Cognitive Load Theory and Self Determination Theory provided the conceptual frameworks to the development of a Moodle-based online Emergency Medicine course, inspired by real clinical cases.

Methods

Three consecutive classes (2013–2015) of sixth-year medical students (n = 304) participated in the course, during a curricular and essentially practical emergency rotation. “Virtual Rounds” provided weekly virtual patients in narrative format and meaningful schemata to chief complaints, in order to simulate real rounds at Emergency Unit. Additional activities such as Extreme Decisions, Emergency Quiz and Electrocardiographic challenge offered different views of emergency care. Authors assessed student´s participation and its correlation with their academic performance. A survey evaluated students´ opinions. Students graduating in 2015 answered an online questionnaire to investigate cognitive load and motivation.

Results

Each student produced 1965 pageviews and spent 72 hours logged on. Although Clinical Emergency rotation has two months long, students accessed the online course during an average of 5.3 months. Virtual Rounds was the most accessed activity, and there was positive correlations between the number of hours logged on the platform and final grades on Emergency Medicine. Over 90% of students felt an improvement in their clinical reasoning and considered themselves better prepared for rendering Emergency care. Considering a Likert scale from 1 (minimum load) to 7 (maximum load), the scores for total cognitive load were 4.79±2.2 for Virtual Rounds and 5.56±1.96 for real medical rounds(p<0,01).

Conclusions

A real-world inspired online course, based on cognitive and motivational conceptual frameworks, seems to be a strong tool to engage students in learning. It may support them to manage the cognitive challenges involved in clinical care and increase their motivation for learning.     

Intraocular Pressure Changes during Accommodation in Progressing Myopes,Stable Myopes and Emmetropes

Purpose

To investigate the changes of intraocular pressure (IOP) induced by 3-diopter (3 D) accommodation in progressing myopes, stable myopes and emmetropes.

Design

Cross-sectional study.

Participants

318 subjects including 270 myopes and 48 emmetropes.

Methods

195 progressing myopes, 75 stable myopes and 48 emmetropes participated in this study. All subjects had their IOP measured using iCare rebound tonometer while accommodative stimuli of 0 D and 3 D were presented.

Main Outcome Measures

IOP values without accommodation and with 3 D accommodation were measured in all subjects. Baseline IOPs and IOP changes were compared within and between groups.

Results

There was no significant difference in IOPs between progressing myopes, stable myopes and emmetropes when no accommodation was induced (17.47±3.46, 16.62±2.98 and 16.80±3.62 respectively, p>0.05). IOP experienced an insignificantly slight decrease after 3 D accommodation in three groups (mean change -0.19±2.16, -0.03±1.68 and -0.39±2.65 respectively, p>0.05). Subgroup analysis showed in progressing myopic group, IOP of children (<18 years old) declined with accommodation while IOP of adults (≥18 years) increased, and the difference was statistically significant (p = 0.008). However, after excluding the age factor, accommodation induced IOP changes of high progressing myopes (≤-6 D), low, moderate and non-myopes (>-6 D) was not significantly different after Bonferroni correction (p = 0.838).

Conclusions

Although no difference was detected between the baseline IOPs and accommodation induced IOP changes in progressing myopes, stable myopes and emmetropes, this study found accommodation could cause transient IOP elevation in adult progressing myopes.     

Hypoglycemia and Medical Expenses in Patients with Type 2 Diabetes Mellitus: An Analysis Based on the Korea National Diabetes Program Cohort

Background and Aims

Hypoglycemia is one of the most important adverse events in individuals with type 2 diabetes mellitus (T2DM). However, hypoglycemia-related events are usually overlooked and have been documented less in clinical practice.

Materials and Methods

We evaluated the incidence, clinical characteristics, and medical expenses of hypoglycemia related events in T2DM patients based on the Korea National Diabetes Program (KNDP), which is the largest multi-center, prospective cohort in Korea (n = 4,350). For accurate outcomes, the KNDP data were merged with claims data from the Health Insurance Review and Assessment Service (HIRA) of Korea.

Results

During a median follow-up period of 3.23 years (95% CI: 3.14, 3.19), 88 subjects (2.02%) were newly diagnosed with hypoglycemia, and the incidence of hypoglycemia was 6.44 cases per 1,000 person-years (PY). Individuals with hypoglycemia were significantly older (59.7±10.7 vs. 53.3±10.4 years, p < 0.001), had more hospital visits (121.94±126.88 days/PY, p < 0.001), had a longer hospital stays (16.13±29.21 days/PY, p < 0.001), and incurred greater medical costs ($2,447.56±4,056.38 vs. $1,336.37±3,403.39 /PY, p < 0.001) than subjects without hypoglycemia.

Conclusion

Hypoglycemia-related events were infrequently identified among the medical records of T2DM subjects. However, they were associated significantly with poor clinical outcomes, and thus, hypoglycemia could have a substantial burden on the Korean national healthcare system.     

Outcomes and Treatment of Lumbosacral Spinal Tuberculosis: A Retrospective Study of 53 Patients

Study Strategy

A retrospective clinic study.

Purpose

To evaluate the efficacy of conservative and surgical treatment for lumbosacral tuberculosis.

Methods

This study retrospectively reviewed 53 patients with lumbosacral tuberculosis who were treated in our institution between January 2005 and January 2011. There were 29 males and 24 females with average ages of 37.53 ± 17.28 years (range 6–72 years). 11 patients were given only anti-TB drugs; the remainder underwent anterior debridement, interbody fusion with and without instrumentation, or one-stage anterior debridement combined with posterior instrumentation. Outcome data for these patients included neurologic status, lumbosacral angle, erythrocyte sedimentation rate value(ESR) and C-reactive protein value(CRP) were assessed before and after treatment.

Results

The mean lumbosacral angles were 23.00°± 2.90°in the conservatively treated patients and 22.36°± 3.92o in the surgically treated patients. At the final follow-up, this had improved to 24.10o ± 2.96°in the conservatively treated patients and 28.13° ± 1.93°in the surgically treated patients (all P < 0.05). There were statistically significant differences before and after treatment in terms of ESR and CRP (all P < 0.05). All patients achieved bone fusion. The mean follow-up period was 32.34 ± 8.13 months (range 18 to 55 months). The neurological deficit did not worsen in any of the patients.

Conclusions

It has been proven that conservative and surgical treatments are safe and effective and produce good clinical outcomes for patients with lumbosacral tuberculosis. The advantages of operation include thoroughness of debridement, decompression of the spinal cord, and adequate spinal stabilization.     

Prediabetes Phenotype Influences Improvements in Glucose Homeostasis with Resistance Training

Purpose

To determine if prediabetes phenotype influences improvements in glucose homeostasis with resistance training (RT).

Methods

Older, overweight individuals with prediabetes (n = 159; aged 60±5 yrs; BMI 33±4 kg/m²) completed a supervised RT program twice per week for 12 weeks. Body weight and composition, strength, fasting plasma glucose, 2-hr oral glucose tolerance, and Matsuda-Defronza estimated insulin sensitivity index (ISI) were assessed before and after the intervention. Participants were categorized according to their baseline prediabetes phenotype as impaired fasting glucose only (IFG) (n = 73), impaired glucose tolerance only (IGT) (n = 21), or combined IFG and IGT (IFG/IGT) (n = 65).

Results

Chest press and leg press strength increased 27% and 18%, respectively, following the 12-week RT program (both p<0.05). Waist circumference (-1.0%; pre 109.3±10.3 cm, post 108.2±10.6 cm) and body fat (-0.6%; pre 43.7±6.8%, post 43.1±6.8%) declined, and lean body mass (+1.3%; pre 52.0±10.4 kg, post 52.7±10.7 kg) increased following the intervention. Fasting glucose concentrations did not change (p>0.05) following the intervention. However, 2-hr oral glucose tolerance improved in those with IGT (pre 8.94±0.72 mmol/l, post 7.83±1.11 mmol/l, p<0.05) and IFG/IGT (pre 9.66±1.11mmol/l, post 8.60±2.00 mmol/l) but not in those with IFG (pre 6.27±1.28mmol/l, post 6.33± 1.55 mmol/l). There were no significant changes in ISI or glucose area under the curve following the RT program.

Conclusions

RT without dietary intervention improves 2-hr oral glucose tolerance in individuals with prediabetes. However, the improvements in glucose homeostasis with RT appear limited to those with IGT or combined IFG and IGT.

Trial Registration

ClinicalTrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT01112709","term_id":"NCT01112709"}}NCT01112709     

A Randomized Study of the Effects of Additional Fruit and Nuts Consumption on Hepatic Fat Content,Cardiovascular Risk Factors and Basal Metabolic Rate

Background

Fruit has since long been advocated as a healthy source of many nutrients, however, the high content of sugars in fruit might be a concern.

Objectives

To study effects of an increased fruit intake compared with similar amount of extra calories from nuts in humans.

Methods

Thirty healthy non-obese participants were randomized to either supplement the diet with fruits or nuts, each at +7 kcal/kg bodyweight/day for two months. Major endpoints were change of hepatic fat content (HFC, by magnetic resonance imaging, MRI), basal metabolic rate (BMR, with indirect calorimetry) and cardiovascular risk markers.

Results

Weight gain was numerically similar in both groups although only statistically significant in the group randomized to nuts (fruit: from 22.15±1.61 kg/m² to 22.30±1.7 kg/m², p = 0.24 nuts: from 22.54±2.26 kg/m² to 22.73±2.28 kg/m², p = 0.045). On the other hand BMR increased in the nut group only (p = 0.028). Only the nut group reported a net increase of calories (from 2519±721 kcal/day to 2763±595 kcal/day, p = 0.035) according to 3-day food registrations. Despite an almost three-fold reported increased fructose-intake in the fruit group (from 9.1±6.0 gram/day to 25.6±9.6 gram/day, p<0.0001, nuts: from 12.4±5.7 gram/day to 6.5±5.3 gram/day, p = 0.007) there was no change of HFC. The numerical increase in fasting insulin was statistical significant only in the fruit group (from 7.73±3.1 pmol/l to 8.81±2.9 pmol/l, p = 0.018, nuts: from 7.29±2.9 pmol/l to 8.62±3.0 pmol/l, p = 0.14). Levels of vitamin C increased in both groups while α-tocopherol/cholesterol-ratio increased only in the fruit group.

Conclusions

Although BMR increased in the nut-group only this was not linked with differences in weight gain between groups which potentially could be explained by the lack of reported net caloric increase in the fruit group. In healthy non-obese individuals an increased fruit intake seems safe from cardiovascular risk perspective, including measurement of HFC by MRI.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT02227511","term_id":"NCT02227511"}}NCT02227511     

The Effect of Neutral Peritoneal Dialysis Solution with Low Glucose-Degradation-Product on the Fluid Status and Body Composition – A Randomized Control Trial

Background

Previous studies report conflicting results on the benefit of peritoneal dialysis (PD) patients treated with low glucose degradation product (GDP) solution. The effects of low GDP solution on body fluid status and arterial pulse wave velocity (PWV) have not been studied.

Methods

We randomly assigned 68 incident PD patients to low GDP (Intervention Group) or conventional solutions (Control Group); 4 dropped off before they received the assigned treatment. Patients were followed for 52 weeks for changes in ultrafiltration, residual renal function, body fluid status and arterial PWV.

Result

After 52 weeks, Intervention Group had higher overhydration (3.1 ± 2.6 vs 1.9 ± 2.2 L, p = 0.045) and extracellular water volume (17.7 ± 3.9 vs 15.8 ± 3.1 L, p = 0.034) than Control Group. There was no significant difference in PWV between groups. There was no significant difference in residual renal function between the Groups. Intervention Group had lower ultrafiltration volume than Control Group at 4 weeks (0.45 ± .0.61 vs 0.90 ± 0.79 L/day, p = 0.013), but the difference became insignificant at later time points. Intervention Group had lower serum CRP levels than Control Group (4.17 ± 0.77 vs 4.91 ± 0.95 mg/dL, p < 0.0001).

Conclusion

Incident PD patients treated with low GDP solution have less severe systemic inflammation but trends of less ultrafiltration, and more fluid accumulation. However, the effects on ultrafiltration and fluid accumulation disappear with time. The long term effect of low GDP solution requires further study.

Trial Registration

ClinicalTrials.gov NCT00966615     

Effect of Acute Intermittent CPAP Depressurization during Sleep in Obese Patients

Background

Obstructive Sleep Apnea (OSA) describes intermittent collapse of the airway during sleep, for which continuous positive airway pressure (CPAP) is often prescribed for treatment. Prior studies suggest that discontinuation of CPAP leads to a gradual, rather than immediate return of baseline severity of OSA. The objective of this study was to determine the extent of OSA recurrence during short intervals of CPAP depressurization during sleep.

Methods

Nine obese (BMI = 40.4 ± 3.5) subjects with severe OSA (AHI = 88.9 ± 6.8) adherent to CPAP were studied during one night in the sleep laboratory. Nasal CPAP was delivered at therapeutic (11.1 ± 0.6 cm H₂0) or atmospheric pressure, in alternating fashion for 1-hour periods during the night. We compared sleep architecture and metrics of OSA during CPAP-on and CPAP-off periods.

Results

8/9 subjects tolerated CPAP withdrawal. The average AHI during CPAP-on and CPAP-off periods was 3.6 ± 0.6 and 15.8 ± 3.6 respectively (p<0.05). The average 3% ODI during CPAP-on and CPAP-off was 4.7 ± 2 and 20.4 ± 4.7 respectively (p<0.05). CPAP depressurization also induced more awake (p<0.05) and stage N1 (p<0.01) sleep, and less stage REM (p<0.05) with a trend towards decreased stage N3 (p = 0.064).

Conclusion

Acute intermittent depressurization of CPAP during sleep led to deterioration of sleep architecture but only partial re-emergence of OSA. These observations suggest carryover effects of CPAP.     

Oocyte Scoring Enhances Embryo-Scoring in Predicting Pregnancy Chances with IVF Where It Counts Most

Context

Our center’s quality improvement optimization process on many occasions anecdotally suggested that oocyte assessments might enhance embryo assessment in predicting pregnancy chances with in vitro fertilization (IVF).

Objective

To prospectively compare a morphologic oocyte grading system to standard day-3 morphologic embryo assessment.

Design, Setting, Patients

We prospectively investigated in a private academically-affiliated infertility center 94 consecutive IVF cycles based on 6 criteria for oocyte quality: morphology, cytoplasm, perivitelline space (PVS), zona pellucida (ZP), polar body (PB) and oocyte size, each assigned a value of -1 (worst), 0 (average) or +1 (best), so establishing an average total oocyte score (TOS). Embryo assessment utilized grade and cell numbers of each embryo on day-3 after oocyte retrieval. Clinical pregnancy was defined by presence of at least one intrauterine gestational sac.

Interventions

Standard IVF cycles in infertile women.

Main Outcome Measures

Predictability of pregnancy based on oocyte and embryo-grading systems.

Results

Average age for all patients was 36.5 ± 7.3 years; mean oocyte yield was 7.97± 5.76; Patient specific total oocyte score (PTOS) was -1.05 ± 2.24. PTOS, adjusted for patient age, was directly related to odds of increased embryo cell numbers (OR 1.12, P = 0.025), embryo grade (OR 1.19, P < 0.001) and clinical pregnancy [OR 1.58 (95%CI 1.23 to 2.02), P < 0.001]. Restricting the analysis to day three embryos of high quality (8-cell/ good grades), TOS was still predictive of clinical pregnancy (OR 2.08 (95%CI 1.26 to 3.44, P = 0.004). Among the 69 patients with embryos of Grade 4 or better available for transfer 23 achieved Clinical Pregnancy. When the analysis was restricted to the 69 transfers with good quality embryos (≥ Grade 4) the Oocyte Scoring System (TOS) (AUC±SE 0.863±0.044, oocyte score) provided significantly greater predictive value for clinical pregnancy compared to the embryo grade alone (AUC 0.646 ± 0.072, embryo grade) p = 0.015.

Conclusions

Oocyte-scoring, thus, provides useful clinical information especially in good prognosis patients with large numbers of high quality embryos. This finding appears of particular importance at a time when many IVF centers are committing sizable investments to closed incubation systems with time-lapse photography, which are exclusively meant to define embryo morphology.     

Venous Thromboembolism and Cerebrovascular Events in Patients with Giant Cell Arteritis: A Population-Based Retrospective Cohort Study

Objective

To investigate the incidence of venous thromboembolism (VTE) and cerebrovascular events in a community-based incidence cohort of patients with giant cell arteritis (GCA) compared to the general population.

Methods

A population-based inception cohort of patients with incident GCA between January 1, 1950 and December 31, 2009 in Olmsted County, Minnesota and a cohort of non-GCA subjects from the same population were assembled and followed until December 31, 2013. Confirmed VTE and cerebrovascular events were identified through direct medical record review.

Results

The study population included 244 patients with GCA with a mean ± SD age at diagnosis of 76.2 ± 8.2 years (79% women) and an average length of follow-up of 10.2 ± 6.8 years. Compared to non-GCA subjects of similar age and sex, patients diagnosed with GCA had a higher incidence (%) of amaurosis fugax (cumulative incidence ± SE: 2.1 ± 0.9 versus 0, respectively; p = 0.014) but similar rates of stroke, transient ischemic attack (TIA), and VTE. Among patients with GCA, neither baseline characteristics nor laboratory parameters at diagnosis reliably predicted risk of VTE or cerebrovascular events.

Conclusion

In this population-based study, the incidence of VTE, stroke and TIA was similar in patients with GCA compared to non-GCA subjects.     

Reliability of the Actigraph GT3X+ Accelerometer in Adults under Free-Living Conditions

Background

Reliability of the Actigraph GT3X+ accelerometer has not been determined under normal wear time criteria in a large sample of subjects and accelerometer units. The aim of this study was to assess contralateral hip difference and inter-instrument reliability of the Actigraph GT3X+ monitor in adults under long-term free-living conditions.

Methods

Eighty-seven adult subjects (28 men; mean (standard deviation) age 31.3 (12.2) years; body mass index 23.7 (3.1) kg/m²) concurrently wore two GT3X+ accelerometers (174 units in total) attached to contralateral hips for 21 days. Reliability was assessed using Bland-Altman plots, mixed model regression analyses and absolute measures of agreement for different lengths of data accumulation (single-day-, 7-day- and 21-day periods).

Results

There were no significant differences between contralateral hips (effect size ≤0.042; p ≥.213). Inter-instrument reliability increased with increased length of data-accumulation. For a 7-day measurement period (n = 232 weeks), limits of agreement were ±68 cpm (vertical axis) and ±81.3 cpm (vector magnitude) for overall physical activity (PA) level, ±51 min for sedentary time, ±18.2 min for light PA, ±6.3 min for moderate PA, ±3.5 min for vigorous PA, and ±6.7 min for moderate-to-vigorous PA.

Conclusions

The Actigraph GT3X+ accelerometer is a reliable tool for measuring PA in adults under free-living conditions using normal data-reduction criteria. Contralateral hip differences are very small. We suggest accelerometers be attached to the right hip and data to be accumulated over several days of measurement.     

Sense of Coherence among Older Adult Residents of Long-Term Care Facilities in Taiwan: A Cross-Sectional Analysis

Background

Growing evidence shows that sense of coherence (SOC) is related to health promotion. Knowledge of SOC among older adults in Taiwan is limited. The present study aimed to investigate SOC status and its relationship to personal and environmental factors among older adult residents of long-term care facilities (LTCFs) in northeastern Taiwan.

Methods

This cross-sectional study was performed in Yilan, Taiwan. With face-to-face interviews, we obtained data from 104 LTCF residents (aged 65 years and older) using the Chinese version of Antonovsky''s short 13-item SOC scale. We also collected the information on personal characteristics, physical and social environmental resources. Multiple linear regression was used to analyze factors potentially influencing SOC.

Results

Of the participants, the mean score (±standard deviation) of SOC was 58.3 (±8.8), while scores on SOC subscales (comprehensibility, manageability, and meaningfulness) were 23.4 ±4.5, 17.9 ±3.8, and 17.0 ±3.2, respectively. Education level, activities of daily living and number of LTCF staff were found to be independently associated with SOC status after adjusting for demographic characteristics, health status, and environmental resources. In addition, interactions between personal and environmental factors had a crucial influence on SOC status.

Conclusions

Participants in this study had relatively low SOC scores compared to their counterparts in Western countries. In addition to personal factors, environmental factors can play a significant role in SOC status among older adult LTCF residents. Comprehensive evaluation of SOC status should consider person-environment interaction effects.     

High Intensity Exercise in Multiple Sclerosis: Effects on Muscle Contractile Characteristics and Exercise Capacity,a Randomised Controlled Trial

Introduction

Low-to-moderate intensity exercise improves muscle contractile properties and endurance capacity in multiple sclerosis (MS). The impact of high intensity exercise remains unknown.

Methods

Thirty-four MS patients were randomized into a sedentary control group (SED, n = 11) and 2 exercise groups that performed 12 weeks of a high intensity interval (H_ITR, n = 12) or high intensity continuous cardiovascular training (H_CTR, n = 11), both in combination with resistance training. M.vastus lateralis fiber cross sectional area (CSA) and proportion, knee-flexor/extensor strength, body composition, maximal endurance capacity and self-reported physical activity levels were assessed before and after 12 weeks.

Results

Compared to SED, 12 weeks of high intensity exercise increased mean fiber CSA (H_ITR: +21±7%, H_CTR: +23±5%). Furthermore, fiber type I CSA increased in H_CTR (+29±6%), whereas type II (+23±7%) and IIa (+23±6%,) CSA increased in H_ITR. Muscle strength improved in H_ITR and H_CTR (between +13±7% and +45±20%) and body fat percentage tended to decrease (H_ITR: -3.9±2.0% and H_CTR: -2.5±1.2%). Furthermore, endurance capacity (W_max +21±4%, time to exhaustion +24±5%, VO_2max +17±5%) and lean tissue mass (+1.4±0.5%) only increased in H_ITR. Finally self-reported physical activity levels increased 73±19% and 86±27% in H_CTR and H_ITR, respectively.

Conclusion

High intensity cardiovascular exercise combined with resistance training was safe, well tolerated and improved muscle contractile characteristics and endurance capacity in MS.

Trial Registration

ClinicalTrials.gov NCT01845896     

Dexmedetomidine Reduces Shivering during Mild Hypothermia in Waking Subjects

Background and Purpose

Reducing body temperature can prolong tolerance to ischemic injury such as stroke or myocardial infarction, but is difficult and uncomfortable in awake patients because of shivering. We tested the efficacy and safety of the alpha-2-adrenergic agonist dexmedetomidine for suppressing shivering induced by a rapid infusion of cold intravenous fluids.

Methods

Ten subjects received a rapid intravenous infusion of two liters of cold (4°C) isotonic saline on two separate test days, and we measured their core body temperature, shivering, hemodynamics and sedation for two hours. On one test day, fluid infusion was preceded by placebo infusion. On the other test day, fluid infusion was preceded by 1.0 μg/kg bolus of dexmedetomidine over 10 minutes.

Results

All ten subjects experienced shivering on placebo days, with shivering beginning at a mean (SD) temperature of 36.6 (0.3)°C. The mean lowest temperature after placebo was 36.0 (0.3)°C (range 35.7-36.5°C). Only 3/10 subjects shivered on dexmedetomidine days, and the mean lowest temperature was 35.7 (0.4)°C (range 35.0-36.3°C). Temperature remained below 36°C for the full two hours in 6/10 subjects. After dexmedetomidine, subjects had moderate sedation and a mean 26 (13) mmHg reduction in blood pressure that resolved within 90 minutes. Heart rate declined a mean 23 (11) bpm after both placebo and dexmedetomidine. Dexmedetomidine produced no respiratory depression.

Conclusion

Dexmedetomidine decreases shivering in normal volunteers. This effect is associated with decreased systolic blood pressure and sedation, but no respiratory depression.     

Identifying the Functional Flexion-extension Axis of the Knee: An In-Vivo Kinematics Study

Purpose

This study aimed to calculate the flexion-extension axis (FEA) of the knee through in-vivo knee kinematics data, and then compare it with two major anatomical axes of the femoral condyles: the transepicondylar axis (TEA) defined by connecting the medial sulcus and lateral prominence, and the cylinder axis (CA) defined by connecting the centers of posterior condyles.

Methods

The knee kinematics data of 20 healthy subjects were acquired under weight-bearing condition using bi-planar x-ray imaging and 3D-2D registration techniques. By tracking the vertical coordinate change of all points on the surface of femur during knee flexion, the FEA was determined as the line connecting the points with the least vertical shift in the medial and lateral condyles respectively. Angular deviation and distance among the TEA, CA and FEA were measured.

Results

The TEA-FEA angular deviation was significantly larger than that of the CA-FEA in 3D and transverse plane (3.45° vs. 1.98°, p < 0.001; 2.72° vs. 1.19°, p = 0.002), but not in the coronal plane (1.61° vs. 0.83°, p = 0.076). The TEA-FEA distance was significantly greater than that of the CA-FEA in the medial side (6.7 mm vs. 1.9 mm, p < 0.001), but not in the lateral side (3.2 mm vs. 2.0 mm, p = 0.16).

Conclusion

The CA is closer to the FEA compared with the TEA; it can better serve as an anatomical surrogate for the functional knee axis.     

Patients Lacking Sustainable Long-Term Weight Loss after Gastric Bypass Surgery Show Signs of Decreased Inhibitory Control of Prepotent Responses

Background

A considerable number of bariatric patients report poor long-term weight loss after Roux-en-Y gastric bypass (RYGB) surgery. One possibility for an underlying cause is an impairment of cognitive control that impedes this patient group’s dietary efforts.

Objective

To investigate if patients having either poor or good weight loss response, ~12 years after RYGB-surgery, differ in their ability to inhibit prepotent responses when processing food cues during attentional operations—as measure of cognitive control.

Methods

In terms of weight loss following RYGB-surgery, 15 ‘poor responders’ and 15 ‘good responders’, matched for gender, age, education, preoperative body mass index, and years since surgery, were administered two tasks that measure sustained attention and response control: a go/no-go task and a Stroop interference task; both of which are associated with maladaptive eating behaviours.

Results

The poor responders (vs. good responders) needed significantly more time when conducting a go/no-go task (603±134 vs. 519±44 msec, p = 0.03), but the number of errors did not differ between groups. When conducting a Stroop interference task, poor responders read fewer inks than good responders (68±16 vs. 85±10 words, p = 0.002).

Conclusion

Patients lacking sustainable weight loss after RYGB-surgery showed poorer inhibitory control than patients that successfully lost weight. In the authors’ view, these results suggest that cognitive behavioral therapies post-RYGB-surgery may represent a promising behavioral adjuvant to achieve sustainable weight loss in patients undergoing this procedure. Future studies should examine whether these control deficits in poor responders are food-specific or not.     

Packed Red Blood Cells Are an Abundant and Proximate Potential Source of Nitric Oxide Synthase Inhibition

Objective

We determined, for packed red blood cells (PRBC) and fresh frozen plasma, the maximum content, and ability to release the endogenous nitric oxide synthase (NOS) inhibitors asymmetric dimethylarginine (ADMA) and monomethylarginine (LNMMA).

Background

ADMA and LNMMA are near equipotent NOS inhibitors forming blood’s total NOS inhibitory content. The balance between removal from, and addition to plasma determines their free concentrations. Removal from plasma is by well-characterized specific hydrolases while formation is restricted to posttranslational protein methylation. When released into plasma they can readily enter endothelial cells and inhibit NOS. Fresh rat and human whole blood contain substantial protein incorporated ADMA however; the maximum content of ADMA and LNMMA in PRBC and fresh frozen plasma has not been determined.

Methods

We measured total (free and protein incorporated) ADMA and LNMMA content in PRBCs and fresh frozen plasma, as well as their incubation induced release, using HPLC with fluorescence detection. We tested the hypothesis that PRBC and fresh frozen plasma contain substantial inhibitory methylarginines that can be released chemically by complete in vitro acid hydrolysis or physiologically at 37°C by enzymatic blood proteolysis.

Results

In vitro strong-acid-hydrolysis revealed a large PRBC reservoir of ADMA (54.5 ± 9.7 µM) and LNMMA (58.9 ± 28.9 μM) that persisted over 42-d at 6° or -80°C. In vitro 5h incubation at 37°C nearly doubled free ADMA and LNMMNA concentration from PRBCs while no change was detected in fresh frozen plasma.

Conclusion

The compelling physiological ramifications are that regardless of storage age, 1) PRBCs can rapidly release pathologically relevant quantities of ADMA and LNMMA when incubated and 2) PRBCs have a protein-incorporated inhibitory methylarginines reservoir 100 times that of normal free inhibitory methylarginines in blood and thus could represent a clinically relevant and proximate risk for iatrogenic NOS inhibition upon transfusion.     

Comparison of the Dynesys Dynamic Stabilization System and Posterior Lumbar Interbody Fusion for Lumbar Degenerative Disease

Background

There have been few studies comparing the clinical and radiographic outcomes between the Dynesys dynamic stabilization system and posterior lumbar interbody fusion (PLIF). The objective of this study is to compare the clinical and radiographic outcomes of Dynesys and PLIF for lumbar degenerative disease.

Methods

Of 96 patients with lumbar degenerative disease included in this retrospectively analysis, 46 were treated with the Dynesys system and 50 underwent PLIF from July 2008 to March 2011. Clinical and radiographic outcomes were evaluated. We also evaluated the occurrence of radiographic and symptomatic adjacent segment degeneration (ASD).

Results

The mean follow-up time in the Dynesys group was 53.6 ± 5.3 months, while that in the PLIF group was 55.2 ± 6.8 months. At the final follow-up, the Oswestry disability index and visual analogue scale score were significantly improved in both groups. The range of motion (ROM) of stabilized segments in Dynesys group decreased from 7.1 ± 2.2° to 4.9 ± 2.2° (P < 0.05), while that of in PLIF group decreased from 7.3 ± 2.3° to 0° (P < 0.05). The ROM of the upper segments increased significantly in both groups at the final follow-up, the ROM was higher in the PLIF group. There were significantly more radiographic ASDs in the PLIF group than in the Dynesys group. The incidence of complications was comparable between groups.

Conclusions

Both Dynesys and PLIF can improve the clinical outcomes for lumbar degenerative disease. Compared to PLIF, Dynesys stabilization partially preserves the ROM of the stabilized segments, limits hypermobility in the upper adjacent segment, and may prevent the occurrence of ASD.     

Pregnancy Requires Major Changes in the Quality of the Diet for Nutritional Adequacy: Simulations in the French and the United States Populations

Background

Maternal nutrition is critical to the health of both mother and offspring, but there is a paucity of data on the nutritional adequacy of diets during pregnancy.

Objective

Our objective was to identify to what extent pregnancy reduces the nutritional adequacy of the expecting mother’s diet and if this nutritional gap can be resolved by simple quantitative or qualitative changes in the diet.

Materials and Methods

We evaluated the observed overall nutritional adequacy of diets of French and American women of childbearing age participating in ENNS (n = 344) and NHANES (n = 563) using the probabilistic approach of the PANDiet system, resulting in a 100-point score. Then, we simulated the changes in the PANDiet scores of women of childbearing age who would remain on their diet during pregnancy. Finally, by either increasing the quantity of consumed foods or using eleven snacks recommended during pregnancy, we simulated the effect of a 150-kcal increase in the energy intake of French women.

Results

Observed PANDiet scores were equal to 59.3 ± 7.0 and 58.8 ± 9.3 points respectively in France and in the US. Simulation of pregnancy for women of childbearing age led to a decrease in nutritional adequacy for key nutrients during pregnancy and resulted in reducing PANDiet scores by 3.3 ± 0.1 and 3.7 ± 0.1 points in France and in the US. Simulated 150-kcal increases in energy intake proved to be only partially effective in filling the gap both when the quantity of food consumed was increased and when recommended snacks were used.

Conclusions

The decrease in nutritional adequacy induced by pregnancy cannot be addressed by simply following generic dietary guidelines.     

No Relation between Body Temperature and Arterial Recanalization at Three Days in Patients with Acute Ischaemic Stroke

Background

Recanalization of an occluded intracranial artery is influenced by temperature-dependent enzymes, including alteplase. We assessed the relation between body temperature on admission and recanalization.

Methods

We included 278 patients with acute ischaemic stroke within nine hours after symptom onset, who had an intracranial arterial occlusion on admission CT angiography, in 13 participating centres. We calculated the relation per every 0.1°Celsius increase in admission body temperature and recanalization at three days.

Results

Recanalization occurred in 80% of occluded arteries. There was no relation between body temperature and recanalization at three days after adjustments for age, NIHSS score on admission and treatment with alteplase (adjusted odds ratio per 0.1°Celsius, 0.99; 95% confidence interval, 0.94–1.05; p = 0.70). Results for patients treated or not treated with alteplase were essentially the same.

Conclusions

Our findings suggest that in patients with acute ischaemic stroke there is no relation between body temperature on admission and recanalization of an occluded intracranial artery three days later, irrespective of treatment with alteplase.