Detection of Diphtheritic Polyneuropathy by Acute Flaccid Paralysis Surveillance,India

Diphtheritic polyneuropathy is a vaccine-preventable illness caused by exotoxin-producing strains of Corynebacterium diphtheriae. We present a retrospective convenience case series of 15 children (6 girls) <15 years of age (mean age 5.2 years, case-fatality rate 53%, and 1 additional case-patient who was ventilator dependent at the time of last follow-up; median follow-up period 60 days) with signs and symptoms suggestive of diphtheritic polyneuropathy. All cases were identified through national acute flaccid paralysis surveillance, which was designed to detect poliomyelitis in India during 2002–2008. We also report data on detection of diphtheritic polyneuropathy compared with other causes of acute flaccid paralysis identified by this surveillance system.     

Feasibility of the 3D RCA catheter to engage the brachiocephalic vessels during carotid angiography and stenting

Background : Engagement of the brachiocephalic vessels during carotid angiography is performed using a JR‐4, Vitek, or other catheters with variable success. These catheters require additional training for safe manipulation. In this study, we evaluated the feasibility of using the 3D RCA catheter which requires less manipulation in the aorta, and less training, to engage the brachiocephalic vessels. Methods : We prospectively studied consecutive high‐risk patients undergoing carotid angiography and stenting from August 2005 to March 2009 at our institution. A baseline aortogram was performed to define the arch type in all patients. Engagement of the brachiocephalic vessels was initially attempted using the 3D RCA catheter using the following approach: The 3D RCA catheter is positioned in the ascending aorta beyond the brachiocephalic vessels take off. The natural curve of the catheter usually makes it point cephalad spontaneously in most patients and as it is gently withdrawn it engages the aortic arch vessels without much manipulation. Clinical follow‐up with a neurological exam was performed at one month and six months. Results : A total of 52 patients were enrolled in this study. Baseline demographics and aortic arch types encountered are listed in Table I . The 3D RCA catheter readily engaged the brachiocephalic vessels in 50/52 patients (96.0 %) in our cohort of patients undergoing carotid angiography. Of the 52 patients, 43 subsequently underwent carotid stenting and shuttle sheath placement was facilitated by initial engagement of the relevant common carotid artery with the 3D RCA catheter. There was one transient neurologic complication that resolved by 5 days in a patient that underwent carotid stenting. Conclusions : The 3D RCA catheter can be used with a high success rate to engage the brachiocephalic vessels in all 3 arch types, including a bovine arch during carotid angiography and facilitates shuttle sheath placement for carotid stenting. It requires less manipulation and therefore may be a more operator friendly approach. © 2010 Wiley‐Liss, Inc.     

Clinically suspected fibrocartilaginous embolism: clinical characteristics,treatments, and outcomes

Objective: To study the frequency, demographics, clinical characteristics, and outcomes of patients with an antemortem diagnosis of fibrocartilaginous embolism (FCE), a rare cause of spinal cord and cerebral infarction because of the presumed embolization of nucleus pulposus material into the vascular circulation. Methods: We retrospectively reviewed the institutional experience of patients who received an antemortem diagnosis of FCE by their treating physician at the Mayo Clinic (Rochester, MN, USA) from 1997 to 2009. All patients underwent laboratory, radiological, and clinical exclusion of other possible and related diagnoses. Results: Of 164 patients with acute spinal cord infarction seen during the study timeframe, 9 (5.5%; 95% CI 2.5, 10.2%) met inclusion criteria for high likelihood of FCE (6 men, 3 women; median age 46 years old, range 21–64). All patients were severely affected (median modified Rankin Scale 4, median Barthel index 45; mean time to evaluation 57 days). One patient (1/9) experienced concomitant cerebral infarction. No patients had noticeable improvement from steroid treatment. Conclusion: The diagnosis of FCE in life is common at this referral center, accounting for 5.5% of all cases of acute spinal cord infarction seen. Although FCE is a postmortem diagnosis, we propose clinical criteria for FCE in life to better characterize the relatively high number of patients with unexplained ischaemic myelopathy.     

Fe2+ binds iron responsive element-RNA, selectively changing protein-binding affinities and regulating mRNA repression and activation

Iron increases synthesis rates of proteins encoded in iron-responsive element (IRE)-mRNAs; metabolic iron (“free,” “labile”) is Fe²⁺. The noncoding IRE-RNA structure, approximately 30 nt, folds into a stem loop to control synthesis of proteins in iron trafficking, cell cycling, and nervous system function. IRE-RNA riboregulators bind specifically to iron-regulatory proteins (IRP) proteins, inhibiting ribosome binding. Deletion of the IRE-RNA from an mRNA decreases both IRP binding and IRP-independent protein synthesis, indicating effects of other “factors.” Current models of IRE-mRNA regulation, emphasizing iron-dependent degradation/modification of IRP, lack answers about how iron increases IRE-RNA/IRP protein dissociation or how IRE-RNA, after IRP dissociation, influences protein synthesis rates. However, we observed Fe²⁺ (anaerobic) or Mn²⁺ selectively increase the IRE-RNA/IRP K_D. Here we show: (i) Fe²⁺ binds to the IRE-RNA, altering its conformation (by 2-aminopurine fluorescence and ethidium bromide displacement); (ii) metal ions increase translation of IRE-mRNA in vitro; (iii) eukaryotic initiation factor (eIF)4F binds specifically with high affinity to IRE-RNA; (iv) Fe²⁺ increased eIF4F/IRE-RNA binding, which outcompetes IRP binding; (v) exogenous eIF4F rescued metal-dependent IRE-RNA translation in eIF4F-depeleted extracts. The regulation by metabolic iron binding to IRE-RNA to decrease inhibitor protein (IRP) binding and increase activator protein (eIF4F) binding identifies IRE-RNA as a riboregulator.