Superior shoulder suspensory complex fracture dislocation case report.

BACKGROUND: Acromioclavicular joint dislocation can be more complex than it first appears. The presented case had an unusual combination of injuries to the superior shoulder suspensory complex, which yielded some interesting learning points. CASE SUMMARY: The injuries were sustained after a fall from a push bike and included acromioclavicular dislocation with coracoid process, clavicle and acromion process fractures. These were identified on the initial X-ray examination, which was followed by computed tomography for surgical planning. The injuries were successfully treated by internal fixation. CONCLUSION: The unexpected complexity of the injuries could have led to subtle but important findings being overlooked. This case highlights the importance of a thorough search strategy, consideration of injury biomechanics and knowledge of associated injuries.

Twelve tips on how to survive PBL as a medical student.

BACKGROUND: Starting medical school can be both exciting and daunting. This is particularly the case when the style of learning is different from that which has been experienced previously. For many students, their first experience of learning through a problem-based learning (PBL) approach is when they commence their medical student programme. AIM: This article provides 12 tips on how to survive PBL as a medical student. METHODS: The tips have been based on the authors' experience of PBL and the current literature evidence base. A chronological order was used for the tips to guide the reader, whether student or PBL facilitator, through tips for the various stages of the PBL process. RESULTS: These 12 tips provide students and PBL facilitators with 12 practical tips to help them to realise the learning process and rationale for PBL. The tips commence with surviving the initial PBL sessions and continue through the process, finishing with the use of PBL in the clinical setting where the written scenarios are replaced by patient case histories. CONCLUSION: Using a PBL approach facilitates the learning of clinical and science knowledge in context through clinical scenarios, whilst working and learning together as a group. It is envisaged that these tips will be beneficial for PBL facilitators working with students that are new to PBL, and for the PBL students themselves.

Diurnal variation in the responsiveness of the hypothalamic-pituitary-adrenal axis of the male rat to noise stress.

Basal activity of the rat hypothalamic-pituitary-adrenal (HPA) axis is highly dynamic and displays both circadian and ultradian rhythmicity in corticosterone secretion. This study investigated the relationship between basal corticosterone pulsatility and the corticosterone response to noise during the early light phase when there are no endogenous corticosterone pulses and during the early dark phase when there are hourly pulses of corticosterone. An automated blood sampling system was used to collect blood in conscious male rats at 5-min intervals before, during and after exposure to 10-min periods of white noise (104 dB). Behavioural responses to noise were also monitored during these periods. During the early light phase (morning), there was a consistent corticosteroid response to noise with corticosterone concentrations rising rapidly and reaching peak values 10-15 min after the noise had ceased, following which circulating concentrations declined at a rate comparable to the hormones half-life. A second noise stress, 80 min later, resulted in adaptation of the corticosterone response. During the early dark phase (evening), the corticosterone response to the noise was similar to that seen in the morning, although there was no adaptation to a second stimulus. During the evening, the inhibition of endogenous HPA activity after the sound was limited to 40 min following stress.

Gonadectomy reverses the sexually diergic patterns of circadian and stress-induced hypothalamic-pituitary-adrenal axis activity in male and female rats.

Enhanced corticosterone release by female compared to male rats under basal and stress conditions is well documented. The demonstration that gonadectomy enhances stress-induced corticosterone secretion in male rats, but reduces such levels in female rats, suggests a causal association between gonadal steroids and corticosterone release. The present study examined the corticosterone profile of sham gonadectomized and gonadectomized female and male rats under basal and stress conditions. An automated sampling system collected blood from each freely moving, unanaesthetized rat every 10 min (i) over a 24-h period; (ii) following noise stress; and (iii) following an immune-mediated stress (lipopolysaccharide, LPS). Plasma was analysed for corticosterone content using radioimmunoassay. Castration resulted in a significant increase in basal corticosterone release compared to the sham-castrated male rats. Pulsar analysis revealed a significant two-fold increase in the number of corticosterone pulses over 24 h. Corticosterone increases in response to noise stress and to LPS injection were enhanced following castration. Conversely, ovariectomy resulted in a two-fold reduction in the number of corticosterone pulses as well as the stress response compared to sham-ovariectomized female rats. Arginine vasopressin (AVP), corticotrophin-releasing hormone (CRH) and glucocorticoid receptor mRNAs in the paraventricular nucleus and pro-opiomelanocortin (POMC) mRNA in the anterior pituitary were analysed post-LPS administration by in situ hybridization. Significantly higher values were found for AVP, CRH and POMC mRNAs examined for sham females and castrated males compared to sham males and ovariectomized females. This study confirms previous reports concerning the influence of gonadal factors in regulating HPA axis activity and stress responsiveness. The present results extend these observations to the regulation of the dynamic pattern of corticosterone release under basal conditions and suggests that this alteration in pulsatility is important for the differences in stress responsiveness when comparing males and females.