Food deprivation and hypothalamic neuropeptide gene expression: effects of strain background and the diabetes mutation.

We have used a novel method to identify genes expressed in the hypothalamus which may be potentially involved in controlling food intake and energy metabolism. We assumed that food deprivation, a powerful stimulus of food intake, would stimulate the activity of neural pathways involved in feeding behavior which should be reflected in an increase in the synthesis of any relevant neuropeptide and its messenger RNA. A study of 5 neuropeptides in 5 strains of mice has identified neuropeptide Y (NPY) as a gene whose expression in the hypothalamus is controlled by nutritional status, suggesting that hypothalamic NPY neurons are a link in the neural network regulating feeding behavior and energy metabolism. In addition, we have studied the effect of the diabetes mutation on neuropeptide gene expression during fasting and refeeding. Our findings suggest that abnormal NPY and enkephalin gene expression in the hypothalamus may be two important determinants of the expression of the diabetes mutation.     

Magnetic resonance imaging confirmation of resolution of periodontoid pannus formation following C1/C2 posterior transarticular screw fixation.

Chronic odontoid fractures are considered unstable spinal lesions. Chronic instability in this region leads to the development of an inflammatory pannus, which can progress resulting in spinal cord compression radiographically and a myelopathy syndrome clinically. In this report we document three cases of reversal of pannus after C1/C2 transarticular screw fixation of an unstable odontoid fracture. Three patients were identified with chronic odontoid fractures and spinal cord compression due to periodontoid pannus formation. All patients presented with a progressive myelopathy syndrome. All patients underwent preoperative and postoperative magnetic resonance imaging (MRI) of the craniovertebral junction. C1/C2 transarticular screw fixation was performed for stabilization of C1/C2. Postoperatively there were no complications. Postoperative MRI at 6 months demonstrated resolution of the ventral pannus. Moreover, all patients exhibited improvement of preoperative neurological deficits. MRI is the imaging technique of choice for diagnosis and follow-up of patients with chronic odontoid fractures and ventral pannus. C1/C2 transarticular screw fixation provides a viable method for spinal stabilization in this region. In addition, stabilization can result in resolution of inflammatory pannus formation secondary to instability of the C1/C2 articulation.     

Spontaneous neuronal hyperactivity in the medial and intralaminar thalamic nuclei of patients with deafferentation pain

Electrical activity was recorded from single cells in the thalamus of 10 patients with chronic pain associated with deafferentation. Under local anesthesia, these patients underwent either electrode implantation or thalamotomy for treatment of their pain. In eight of the 10 patients, single units were identified as discharging spontaneously in high-frequency, often rhythmic, bursts. The discharges were of two types: short bursts comprised of two to six spikes with a burst frequency of one to four per second; and long trains of 30 to 80 spikes of similar frequency. Reconstruction of electrode trajectories indicated that recordings were made from the region corresponding to the lateral aspect of the mediodorsal thalamic nucleus, the central lateral nucleus, a small part of the central median nucleus, and the parafascicular nucleus. In the eight patients in whom spontaneous neuronal burst activity was exhibited, it was impossible to study activity evoked by natural cutaneous stimulation due to the continuous spontaneous neuronal discharges. Both animal and human studies have suggested that pain related to deafferentation is accompanied by spontaneous hyperactivity in the dorsal horn of the spinal cord and in the ventral posterior thalamic nuclei. The authors present evidence of spontaneous neuronal hyperactivity in the intralaminar thalamic nuclei of patients with pain related to deafferentation. The findings suggest that spontaneous neuronal discharge in patients with pain related to deafferentation is more widespread in the central nervous system than has been previously appreciated. The results have important implications for the surgical treatment of chronic pain.     

Central venous catheter-related Rhodotorula rubra fungemia

With the increased use of indwelling central venous catheters, increasing numbers of cases of Rhodotorula fungemia have been observed in patients with neoplasia and neutropenia. In most patients with catheter-related Rhodotorula fungemia, the condition has been treated with broadspectrum antibiotics. We report two cases of central venous catheter-related Rhodotorula rubra fungemia that occurred in patients with acute myeloblastic leukemia. Both patients were in a state of neutropenia. One patient was treated with amphotericin B and his central venous catheter was removed, but he died of Klebsiella pneumoniae bacteremia. The other patient was treated with amphotericin B and discharged, with a central venous catheter, after recovery from neutropenia. Although the management of catheter-related Rhodotorula fungemia infections remains controversial, resolution of the underlying disease is more important than catheter removal for recovery from Rhodotorula rubra fungemia. Received: August 22, 2001 / Accepted: October 8, 2001     

Quality in Clinical Practice

This paper reports the proceedings of the discussion panel assigned to look at clinical aspects of quality in emergency medicine. One of the seven stated objectives of the Academic Emergency Medicine consensus conference on quality in emergency medicine was to educate emergency physicians regarding quality measures and quality improvement as essential aspects of the practice of emergency medicine. Another topic of interest was a discussion of the value of information technology in facilitating quality care in the clinical practice of emergency medicine. It is important to note that this is not intended to be a comprehensive review of this extensive topic, but instead is designed to report the discussion that occurred at this session of the consensus conference.