Predicting recovery from deep neuromuscular block by rocuronium in the elderly

STUDY OBJECTIVE:To determine the influence of aging on the relationship between posttetanic count (PTC) and train-of-four (TOF) response during intense neuromuscular blockade caused by rocuronium. DESIGN: Prospective, observational, clinical comparison study. SETTING: Operating room of a university hospital. PATIENTS: 42 ASA physical status I and II patients, 20 of whom were elderly (ages 65 to 80 yrs) and 22 younger control patients (ages 18 to 40 yrs), who were scheduled for elective orthopedic surgery and ear, nose, and throat surgery with a planned duration of 2 hours. INTERVENTIONS: Neuromuscular blockade was evaluated with accelerometry of the thumb, using posttetanic twitch (PTT) and TOF stimulation of the ulnar nerve, in patients who received rocuronium 1 mg x kg(-1). MEASUREMENTS AND MAIN RESULTS: The first responses to posttetanic nerve stimulation were seen at mean times of 38.5 and 35.2 minutes after the injection of rocuronium in the elderly and in the young, respectively (NS). The average interval between the appearance of a posttetanic response and the first response to TOF stimulation (T1) was longer in the elderly than the young (22.3 +/- 8.1 (SD) vs.14.8 +/- 4.2 min, p < 0.05). There was a significant correlation between PTC and the time to first response to TOF nerve stimulation both in the elderly and in the young (r = -0.73, p < 0.0001 and r = -0.87, p < 0.0001, respectively). CONCLUSIONS: Posttetanic twitch stimulation is a useful method of monitoring intense neuromuscular blockade caused by rocuronium in both age groups. The interval between the earliest appearance of a posttetanic response and the first response to TOF stimulation (T1) is greater in the elderly than in the young.     

A painful squat test provides limited diagnostic utility in CAM-type femoroacetabular impingement

Purpose

The purpose of this study is to determine the relationship between a symptomatic maximal squat and the presence of radiographic CAM-type femoroacetabular impingement (FAI) on magnetic resonance imaging (MRI) and to determine the sensitivity and specificity of a maximal squat test for the presence of radiographic CAM-type femoral deformity in an adult population.

Methods

In this pilot study, 76 consecutive patients were recruited from an outpatient clinic at McMaster University. All patients presented with pre-arthritic hip pain and were asked to perform a maximal squat. The results of this test were compared to magnetic resonance imaging and magnetic resonance angiographic (MRI and MRA) findings evaluating and characterizing CAM-type FAI deformity.

Results

The sensitivity and specificity of the maximal squat test were 75 % (56.6–88.5 %) and 41 % (27.0–56.8 %), respectively, for CAM-type FAI deformity. The positive and negative likelihood ratios were modest at 1.3 (0.9–1.7) and 0.6 (0.3–1.2), respectively. This means that a 30 % pre-test probability is improved to 36 % following a positive squat test and reduced to 20 % with a negative squat test.

Conclusion

The maximal squat test was found to have marginal incremental diagnostic ability for CAM-type FAI. Its utility in the diagnostic evaluation of FAI remains limited. This survey elucidates areas of research for future studies relevant to the clinical diagnosis of FAI.

Level of evidence

III.     

Susceptibility to discoloration of dental restorative materials containing dimethacrylate resin after bleaching

Odontology - The aim of this study is to compare the susceptibility to discoloration of dental restorative materials containing dimethacrylate resin after bleaching. In this study, resin-modified...     

Do the neurologists recognize autoimmune epilepsy well enough? What is the effect of the pandemic on this matter?

Neurological Sciences - The concept of “autoimmune epilepsy” (AE) has been emphasized more frequently through the recent increase in recognition of various autoantibodies specific to...     

Head Cooling Prior to Exercise in the Heat Does Not Improve Cognitive Performance

This study investigated the effectiveness of head cooling on cognitive performance after 30 min and 60 min of running in the heat. Ten moderately-trained, non-heat-acclimated, male endurance athletes (mean age: 22 ± 6.6 y; height: 1.78 ± 0.10 m; body-mass: 75.7 ± 15.6 kg; VO_2peak: 51.6 ± 4.31 mL^-1>kg^-1>min) volunteered for this study. Participants performed two experimental trials: head cooling versus no-cooling (within-subjects factor with trial order randomized). For each trial, participants wore a head-cooling cap for 15 min with the cap either cooled to 0°C (HC) or not cooled (22°C; CON). Participants then completed 2 × 30 min running efforts on a treadmill at 70% VO_2peak in hot conditions (35°C, 70% relative humidity), with a 10 min rest between efforts. Working memory was assessed using an operation span (OSPAN) task immediately prior to the 15 min cooling/no-cooling period (22°C, 35% RH) and again after 30 min and 60 min of running in the heat. Numerous physiological variables, including gastrointestinal core temperature (T_c) were assessed over the protocol. Scores for OSPAN were similar between trials, with no interaction effect or main effects for time and trial found (p = 0.58, p = 0.67, p = 0.54, respectively). Forehead temperature following precooling was lower in HC (32.4 ± 1.6°C) compared with CON (34.5 ± 1.1°C) (p = 0.01), however, no differences were seen in T_c, skin temperature, heart rate and ratings of perceived exertion between HC and CON trials at any time point assessed (p > 0.05). In conclusion, despite HC reducing forehead temperature prior to exercise, it did not significantly improve cognitive performance during (half-time break) or after subsequent exercise in hot environmental conditions, compared to a no cooling control.Key points

• Wearing a cooling cap for 15 min significantly reduced forehead temperature compared to baseline, as well as compared to a no-cooling control.
• Despite forehead temperature being significantly lower after cooling, forehead temperatures were similar between the cooling and no-cooling trials during exercise in a hot environmental chamber.
• Cooling the forehead prior to exercise in the heat did not improve subsequent cognitive performance assessed midway and after exercise.

Key words: Running, precooling, thermoregulation, cognitive execution     

Proposing novel MDM2 inhibitors: Combined physics‐driven high‐throughput virtual screening and in vitro studies

The mouse double minute 2 (MDM2) protein acts as a negative regulator of the p53 tumor suppressor. It directly binds to the N terminus of p53 and promotes p53 ubiquitination and degradation. Since the most common p53‐suppressing mechanisms involve the MDM2, proposing novel inhibitors has been the focus of many in silico and also experimental studies. Thus, here we screened around 500,000 small organic molecules from Enamine database at the binding pocket of this oncogenic target. The screening was achieved systematically with starting from the high‐throughput virtual screening method followed by more sophisticated docking approaches. The initial high number of screened molecules was reduced to 100 hits which then were studied extensively for their therapeutic activity and pharmacokinetic properties using binary QSAR models. The structural and dynamical profiles of the selected molecules at the binding pocket of the target were studied thoroughly by all‐atom molecular dynamics simulations. The free energy of the binding of the hit molecules was estimated by the MM/GBSA method. Based on docking simulations, binary QSAR model results, and free energy calculations, 11 compounds ( E1 – E11 ) were selected for in vitro studies. HUVEC vascular endothelium, colon cancer, and breast cancer cell lines were used for testing the binding affinities of the identified hits and for further cellular effects on human cancer cell. Based on in vitro studies, six compounds ( E1 , E2 , E5 , E6 , E9 , and E11 ) in breast cancer cell lines and six compounds ( E1 , E2 , E5 , E6 , E8 , and E10 ) in colon cancer cell lines were found as active. Our results showed that these compounds inhibit proliferation and lead to apoptosis.     

Breast Cancer Knowledge and Screening Behaviors of the Female Teachers

Breast cancer is the most frequently occurring cancer in women. The objective of this study was to determine the level of knowledge about risk factors for breast cancer and screening behaviors among 468 female teachers who work in Sivas, Turkey. In this cross-sectional survey, a self-administered, structured questionnaire was used for data collection. Up to one-half (52.4%) of the teachers thought that they had enough knowledge about breast cancer. The sources of that information were television (59.0%), newspapers (48.9%), and health professionals (24.1%); 58.5% of the teachers had a sufficient knowledge level about breast cancer risk factors. The most frequently reported risk factor was family history of breast cancer (94.9%), followed by getting older, high fat diet and having a first child at a late age (68.6%, 51.7%, and 45.1%, respectively). No significant differences were found in knowledge by age groups, having breast-related complaints, teaching experience, or marital status. Among the teachers, 43.9% had performed breast self-examination; yet only 10.5% of them performed it monthly. Only 22.3% of the teachers reported having at least one clinical breast-examination. Among the 136 women over the age of forty years, only 37.5% had had at least one mammogram. A significant association was noted between level of knowledge about breast cancer risk factors and use of breast self-examination. Also, being married and having breast-related complaints were significantly related to practicing clinical breast-examination and mammography. This study revealed a relatively low awareness about the knowledge and practice of screening methods among teachers. The relatively low rates of breast self-examination, clinical breast-examination, and mammography practiced by this group of teachers are of concern and suggest that increased awareness of these methods, their value, and how they should be conducted is needed.