علیرضا صدقی

During vision process, the information produced by rod and cone photoreceptors is compressed in retina and then is transmitted by three separated pathways of ganglion cells, Magno, Parvo and Konio, to the upper level processing centers. There are electrophysiological and psychophysical evidences that these three pathways show characteristic patterns of malfunction in multiple sclerosis (MS) patients. Although fMRI can provide accurate localization of the neural activities in these pathways, there is no fMRI study on malfunctions of these pathwyas in MS yet. So by employing the differences in structure and function of these cells, we generated three different visual stimuli with different spatial and temporal frequencies to stimulate each pathway separately. These stimuli were shown to the subject inside MRI scanner by a calibrated projector located outside of scanner room. The fMRI data were acquired from two groups of normal and MS subjects (each including 5 subjects) by using a standard protocol. Finally, the activation results in visual lobe and LGN were analyzed in within-group and between-group levels. Results showed patterns of malfunctions in visual cortex and LGN in MS group. Also, among Magno, Parvo, and Konio cellular pathways in LGN, just the activation of Magno cellular pathway showed significant malfunction in MS group.

Severe arterial injuries in the hand can be hazardous to the limbs and even life- threatening. The aim of this study was to investigate the management methods in the patients with acute injuries of the ulnar or radial artery in the emergency department. This cross-sectional prospective study was conducted in the emergency department of Sina Hospital in Tehran, from 2012 to 2013. Stable vital signs, wrist and forearm laceration with jumper or active bleeding, radial or ulnar artery injury; one or both were among our inclusion criteria. Vital signs, level of consciousness, coincident injuries were assessed and physical examination was performed in all patients. We recorded time of patient arrival, primary and secondary treatment, and consultation and follow up visits in emergency department or ward. 50 patients (3 females and 47 males) with a mean age of 30.34y ± 9.69y were enrolled. The first step was to examine and pack up bleeding. The most common injury was due to sharp instruments (84%) and the most common injured artery was radial artery (68%).The mean duration of the first treatment was 1.24 ± 0.93 min. 37 patients (74%) were treated by ligation in the emergency room and the remaining 13 patients (26%) were sent to the operating room for repair and vascular anastomosis by our vascular surgeon. Mean values of duration for ligation were 16.72 ± 13.83 min and 117.76 ± 114 min in emergency medicine and vascular surgery groups, respectively that showed a significant difference between the two groups (p= 0.0001). The overall duration of hospitalization for the patients was 69.04 ± 82.74 hour (5- 311 hours). We can conclude that the radial or ulnar artery ligation considering its indications or contraindications, in emergency room can play an important role in the recovery of patient's hemodynamic status and speed up of the next step of patient’s treatment.