Is there a problem with the problems in problem‐based learning?

OBJECTIVE: To determine the balance between acute and chronic medical problems in the PBL cases at 2 Australian medical schools. METHODS: Analysis of 162 PBL cases. RESULTS: Cases concentrate on acute problems in young people and neglect chronic disease in the old. CONCLUSION: This imbalance may contribute to negative attitudes towards elderly patients and people with chronic disease.     

Ventricular septal defect complicated by infective endocarditis of the aortic valve causing severe aortic regurgitation: the role of aortic valve repair

BACKGROUND AND AIMS OF THE STUDY: Children with ventricular septal defect (VSD) who develop severe aortic regurgitation following infective endocarditis (IE) require aortic valve replacement in most cases. Few reports exist of repair of the aortic valve under such circumstances. Here, we report details from two patients in whom aortic valve repair resulted in a good outcome. METHODS: Two children (aged 4 and 3 years) with either perimembranous or doubly committed subarterial VSD presented with congestive cardiac failure (NYHA class IV) following IE. The aortic valve in both children, and the pulmonary valve in one child, were severely damaged with vegetation, leading to severe (grade IV) aortic regurgitation. The second patient had bilateral bronchiectasis with respiratory infection and severe anemia. In addition to VSD closure, partial cuspal replacement using glutaraldehyde-tanned pericardium was performed successfully in both cases to restore geometry. RESULTS: Both children showed a dramatic improvement following surgery and during follow up of 36 and 11 months, respectively. Both remained asymptomatic, with good growth, good left ventricular function and the presence of only trivial aortic regurgitation. CONCLUSION: In selected patients with suitable anatomy, repair of the aortic valve with pericardial cusp replacement may be the procedure of choice. An additional benefit is the avoidance of long-term anticoagulation.     

A functional neuroanatomical investigation of the role of the medial preoptic area in neural circuits regulating maternal behavior

The medial preoptic area (MPOA) is essential for normal maternal behavior in the rat. Hormone stimulation of the MPOA facilitates the behavior and lesions of the MPOA and the adjoining ventral part of the bed nucleus of the stria terminalis (vBST) disrupt the behavior. The MPOA/vBST also show increases in Fos protein expression during maternal behavior. The present study examines the larger neural circuitry within which the MPOA/vBST might operate to influence maternal behavior. Combining Fos immunocytochemistry with unilateral excitotoxic amino acid lesions or lateral knife cuts of the MPOA/vBST, we sought to identify brain regions which might be under the influence of Fos expressing neurons in the MPOA/vBST. Two brain regions, the shell of the nucleus accumbens (NAs), and the intermediate part of the lateral septum (LSi) were identified. Both the NAs and LSi exhibited elevated Fos expression during maternal behavior, while unilateral MPOA/vBST damage resulted in an ipsilateral reduction of maternal behavior-induced Fos expression in each area, suggesting that MPOA/vBST neurons modulate Fos expression and associated neural activity in both of these structures during maternal behavior. Importantly, these unilateral preoptic lesions also depressed maternal behavior-induced Fos expression in the ipsilateral MPOA and vBST. The effects of these lesions on Fos expression in the periaqueductal gray (PAG) and other brain regions are also presented.     

Radiation exposure impairs luteinizing hormone signal transduction and steroidogenesis in cultured human leydig cells.

Therapeutic, accidental, and experimental radiation exposures decreased serum testosterone in males, leading to various sexual problems. Since testicular Leydig cells are the predominant source of circulating testosterone, findings on the direct effects of radiation on Leydig cell steroidogenesis and the mechanism behind such effects would be of greater importance to the use of safer radiation doses in cancer therapy and to adopt preventive or therapeutic measures to alleviate postirradiation lesions, respectively. Therefore, this study was undertaken to explore the same using cultured human Leydig cells. Testicles removed from advanced prostatic carcinoma patients were used for isolation and purification of Leydig cells. Purified Leydig cells were cultured and then exposed to different doses (2, 4, 6, 8, and 10 Gy) of fractioned gamma radiation. Normal and irradiated cells were used for luteinizing hormone (LH) receptor quantification or total RNA isolation to study LH receptor mRNA expression or LH/cyclic AMP (cAMP) stimulation test. While LH-stimulated cells were used for cAMP assay, LH- and cAMP-stimulated cells were used for the estimation of steroidogenic enzymes, testosterone and estradiol production. Radiation exposure caused adverse effects on Leydig cell steroidogenesis in a dose-dependent manner. While lower doses (2 and 4 Gy) were ineffective, higher doses (6 Gy and above) drastically decreased LH receptor, basal and LH-stimulated cAMP generation, and basal, LH-, and cAMP-stimulated steroidogenesis. While 2 Gy of radiation exposure increased the LH receptor mRNA level, other doses did not induce any significant change. Therefore, it is concluded that higher doses of radiation impair Leydig cell steroidogenesis by affecting LH signal transduction at the level of both pre- and post-cAMP generation. Decreased level of LH receptors following higher doses of radiation exposure is not coupled with impaired expression of its mRNA.     

Psammomatous extra-calvarial meningioma of the neck

A case of Primary extraraniul meningioma of the parapharyngcal space arising simulitueouly as two distinct tumour masses from two sepurae cranial nerves is reported. The paucity of reported eases is the evidence for its rarily.     

Neuroleptic malignant syndrome occurring in a suspected case of systemic lupus erythematosus

The case of a 40 year old female patient of SLE who developed fatal neuroleptic malignant syndrome following administration of serenase (haloperidol) is reported. Relevant literature has been reviewed.     

Multifocal synchronous osteosarcoma: The Scottish bone tumour registry experience

We report 3 cases of multifocal synchronous osteosarcoma constituting 1% of osteosarcoma cases in the Scottish Bone Tumour Registry over 30 years. All were children and had a median age of 10 years. They all presented with multiple bony lesions in the absence of demonstrable pulmonary metastases. Treatment was with palliative radiotherapy in two and combination chemotherapy and radiotherapy in the most recent case. Survival was poor in all cases, with a median of 7 months. A proposal is made for genetic studies in future cases to help elucidate the origin of these tumours. The multicentric and metastatic hypotheses are discussed. © 1993 Wiley-Liss, Inc.