Clinical characteristics and role of early cardiac magnetic resonance imaging in patients with suspected ST-elevation myocardial infarction and normal coronary arteries

A variety of conditions other than acute myocardial infarction may cause ST-elevation. Our objective was to evaluate the impact of cardiac magnetic resonance (CMR) on differential diagnosis from a prospective series of patients with suspected ST-elevation myocardial infarction (STEMI) and completely normal coronary arteries. Among 1,145 patients with suspected STEMI, 49 patients had completely normal coronary arteries and entered a prospective registry. CMR was done within 24 h, if possible, and included function analyses, T2-weighted imaging (T2 ratio), T1-weighted imaging before and after gadolineum administration (global relative enhancement; gRE), and late gadolineum enhancement (LGE). All patients were asked for a follow-up CMR after approximately 3 months. The incidence of patients with suspected STEMI and normal coronary arteries was 4.3% and mean age was 45 ± 14 years (STEMI group 64 ± 13 years; P < 0.001). 55% had a recent history of infection. Cardiac biomarkers showed a moderate elevation on admission. There was a significant change from baseline to follow-up for LV end-diastolic volumes (EDV) (P < 0.001), LV mass (P < 0.05), mean T2 ratio (P < 0.05), and LGE volume (P < 0.05). Major diagnostic groups were myocarditis (29%), pericarditis (27%), and takotsubo cardiomyopathy (10%). 18% were regarded as non-diagnostic. The study showed an incidence of 4.3% of patients with suspected STEMI and completely normal coronary arteries. Early CMR was valuable in the evaluation of the differential diagnoses and to exclude myocardial abnormalities in patients with uncertain aetiology. Further studies are needed for the assessment of long-term outcome.     

Learning basic surgical skills with mental imagery: using the simulation centre in the mind

Context  Although surgeons and athletes frequently use mental imagery in preparing to perform, mental imagery has not been extensively researched as a learning technique in medical education.
Objective  A mental imagery rehearsal technique was experimentally compared with textbook study to determine the effects of each on the learning of basic surgical skills.
Methods  Sixty-four Year 2 medical students were randomly assigned to 2 treatment groups in which they undertook either mental imagery or textbook study. Both groups received the usual skills course of didactic lectures, demonstrations, physical practice with pigs' feet and a live animal laboratory. One group received additional training in mental imagery and the other group was given textbook study. Performance was assessed at 3 different time-points using a reliable rating scale.
Results  Analysis of variance on student performance in live rabbit surgery revealed a significant interaction favouring the imagery group over the textbook study group.
Conclusions  The mental imagery technique appeared to transfer learning from practice to actual surgery better than textbook study.     

Clinical evaluation of brushing time and plaque removal potential of two manual toothbrushes

Abstract: Aim: To compare plaque removal efficacy of Oral‐B CrossAction (CA) used for 1 min with an American Dental Association (ADA) manual toothbrush used for 2 or 5 min in an examiner‐blind, three‐treatment, six‐period crossover study. Materials and methods: After refraining from all oral hygiene procedures for 23–25 h, subjects were randomly assigned to one of nine possible six‐period (visit) treatment sequences. Plaque was assessed at baseline (Rustogi Modified Navy Plaque Index). Post‐brushing scores were recorded after brushing with a marketed dentifrice and the assigned toothbrush for the specified duration. The same procedure was followed at each of six subsequent visits. Clinical measurements were carried out by the same examiner. Results: Forty subjects completed the study. All three treatments effectively removed plaque from the whole mouth, along the gingival margin and from approximal surfaces. Whole mouth and gingival margin plaque removal scores with CA for 1 min did not differ significantly from scores with the ADA toothbrush used for 2 min. The ADA brush used for 5 min showed significantly greater whole mouth (P < 0.001) and gingival margin (P < 0.001) plaque reduction than the two other treatments. Approximal plaque removal scores did not differ between the three treatments. Conclusions: Efficient plaque removal can be achieved after 1 min of brushing with CA. The amount of plaque removed did not differ significantly from that achieved with the ADA brush after 2 min of brushing. Greater whole mouth and gingival margin plaque removal scores were seen with the ADA brush after 5 min.     

白蛋白微球作为肝靶向给药载体的研究

用均匀设计方法和计算机技术筛选了乳化化学交联法制备白蛋白微球的六个因素,十二个水平。优化出最佳制备工艺,制备了平均粒径0.41～0.47μm的白蛋白微球。将此工艺制备的¹²⁵I-白蛋白微球做动物体内研究,结果表明微球iv后主要浓集在肝脏,可达注入总剂量的68%,此微球在靶组织肝脏的变化规律可用二室模型契合。     

Gizzard erosions as a cause of mortality in white leghorn chickens

Increased mortality connected with gizzard erosions has been observed in several flocks of White Leghorn chicks in Sweden. Bacterial infection of the gizzard wall was a common finding in chicks that had died from the disease. Infection with Clostridium perfringens is supposed to be the main cause of mortality, but the primary cause of the gizzard lesions has not been established.