Dendroaspis natriuretic peptide regulates the cardiac L-type Ca2+ channel activity by the phosphorylation of alpha1c proteins

Dendroaspis natriuretic peptide (DNP), a new member of the natriuretic peptide family, is structurally similar to atrial, brain, and C-type natriuretic peptides. However, the effects of DNP on the cardiac function are poorly defined. In the present study, we examined the effect of DNP on the cardiac L-type Ca2+ channels in rabbit ventricular myocytes. DNP inhibited the L-type Ca2+ current (ICa,L) in a concentration dependent manner with a IC50 of 25.5 nM, which was blocked by an inhibitor of protein kinase G (PKG), KT5823 (1 microM). DNP did not affect the voltage dependence of activation and inactivation of ICa,L. The alpha1c subunit of cardiac L-type Ca2+ channel proteins was phosphorylated by the treatment of DNP (1 microM), which was completely blocked by KT5823 (1 microM). Finally, DNP also caused the shortening of action potential duration in rabbit ventricular tissue by 22.3 +/- 4.2% of the control (n = 6), which was completely blocked by KT5823 (1 microM). These results clearly indicate that DNP inhibits the L-type Ca2+ channel activity by phosphorylating the Ca2+ channel protein via PKG activation.

Reliability and Validity of the Modified Emergency Severity Index-2 as a Triage Tool

PURPOSE: We measured the inter-rater reliability and validity of the modified Emergency Severity Index-2 ((m)ESI-2) as a triage tool in the emergency department (ED). METHODS: We applied (m)ESI-2 to 2,724 patients who visited three EDs. In each ED, emergency medicine residents, interns, and nurses independently evaluated the severity of the patient with (m)ESI-2. Data on the triage result, the patient disposition, and the length of stay in the ED were collected prospectively. For patients who were admitted or who stayed more than 24 hours in the ED, the APACHE II score was calculated. RESULTS: The weighted kappa value was 0.602 between residents and interns, 0.541 between residents and nurses, and 0.451 between interns and nurses. Hospitalization (ED death, admission, transfer) rates were 100% in category 1 and 82.4%, 53.8%, 17.2%, 6.2% in categories 2 through 5, respectively. The mean length of stay was longest in category 3 (687 min) and shortest in category 5 (150 min). The mean APACHE II score was highest in category 1 (10.8) and 8.6, 6.2, 5.2, 2.9 in categories 2 through 5, respectively. CONCLUSION: The (m)ESI-2 demonstrated good to fair interrater reliability among residents, interns, and nurses, and the resultant categories were related with the hospitalization rates, the length of stay in the ED, and the APACHE II score. With further modification and refinement, (m)ESI-2 can be a reliable and a valid triage tool in the ED.

Primary Pulmonary Leiomyosarcoma: A Case Report / 대한흉부외과학회지

The incidence of pulmonary leiomyosarcoma as primary lung tumor is very rare. Most of the primary leiomyosarcomas originate in the hilar region in relation to the main bronchus or pulmonary vessels and only a few originate more peripherally. This rare tumor can mimic bronchial carcinoma and present with local or systemic symptoms, or it may be discovered as an incidental finding on a routine chest X-ray. We report with review of literature, a case of incidental primary pulmonary leiomyosarcoma which originated peripherally. Huge mass was found on the left lung of a 61-year-old man on the chest X-ray peripherally. He underwent the surgical resection of the left pneumonectomy and the postoperative course was uneventful.

Characteristics of Motor Evoked Potentials by Pyramidal and Extrapyramidal Systems in Rats / 대한정형외과연구학회지

PURPOSE: Electrophysiologically assess conduction pathways of the pyramidal and extrapyramidal systems in rats and predict the pathways involved in spinal cord injuries. METHOD: The motor area of the cerebral cortex, medullary reticular nucleus, lateral vestibular nucleus, and red nucleus of adult Sprague-Dawley rats were stimulated with microelectrodes. Laminectomies were performed at the C6, T10 and L2 cord level. Field potentials evoked by stimulation of the cerebral cortex and the three motor nuclei were recorded with a glass microelectrode of 1.5~2.5 Mohm filled with 0.2M NaCl. To construct a cross-sectional map of field potentials, recording was made in 7 tracks equally spaced across the spinal cord. In each track, field potentials were recorded at seven equally spaced points from the ventral to dorsal cord. RESULT: Stimulation of the cerebral motor cortex evoked 5 wanes, such as P1, P2, P3, P4, P5. P1 was monitored mainly in the bilateral dorsal half of the spinal cord and other wades mainly in the ventral half of the spinal cord. With lateral vestibular nucleus stimulation, 1 or 2 short duration biphasic waves followed by a longer duration positive wave were monitored mainly in the ipsilateral ventrolateral funiculus of the cord. Field potentials produced by stimulating the medullary reticular nucleus were shown mainly in the ventromedial funiculus, and their latencies were longer than those from the vestibular nucleus stimulation. Field potentials generated by the stimulation of the red nucleus were monitored mainly in the dorsolateral funiculus. CONCLUSION: motor evoked potential is clinically useful to evaluate the descending pathways of the spinal cord.

Spared Corticospinal Tract Projections Through Lateral Funiculi after Dorsal Section of the Rat Mid-thoracic Spinal Cord / 대한정형외과연구학회지

In the rat lumbar spinal cord, the pathways and distribution of corticospinal tract (CST) axons were investigated using retrograde transport of Fast Blue(FB) and Fluoro-Gold(FG). The purpose of this study was, therefore, to fond the extent of CST projections in the lateral funiculus in the rat. Total of twelve female rats were used in this study. The laminectomy was performed at the 78 cord level to expose the spinal cord. Using a radiofrequency lesioning device, the CST, including the dorsal columns, were lesioned bilaterally. Three to seven days after lesioning, two laminectomies were performed at C6-8 and L3-5 to expose the spinal cord for dye injections. Retrograde tracing of fast blue(FB) and fluoro-gold(FG) were used to quantitate the number of cerebral cortex neurons projecting to the lumbar cord through tracts other than the CST in the dorsal column. New findings of the this study are : (1) a small number of CST axons projected to lumbosacral spinal cord bilaterally in the dorsolateral funiculi. (2) some axons projecting to the lumbar cord through the dorsolateral funiculi are collateral of neuron that project to the cervical spinal cord. Our results suggest that there are a larger number of CSTs than previously thought projecting to the lumbar spinal cord through the lateral funiculi. These residual tracts may play a role in the functional recovery of the affected limbs.