Regional myocardial dysfunction: evaluation of patients with prior myocardial infarction with fast CT

A prototype ultrafast cine computed tomographic (CT) scanner, designed specifically for cardiac imaging, was used to evaluate a preliminary series of patients with prior myocardial infarction (n = 21) and a control group without coronary artery disease (n = 5). Multilevel 50-msec CT scan exposures were obtained during peripheral intravenous bolus injections of contrast medium. A comparison was made between cine-CT scans and standard left ventriculographic images in assessing segmental left ventricular motion. Results indicate that cine CT, performed at sufficiently rapid speeds (20 scans per second) to allow useful analysis of regional ventricular wall motion, can provide adequate image quality. Analysis of 110 segments revealed a good correlation (90.9%) between the two techniques in characterizing normal from abnormal regional wall motion. Cine CT, based on this initial study, demonstrates considerable potential for evaluating not only cardiac chamber dimensions but also segmental wall dynamics.     

Gelatin matrix treatment of complex renal injuries in a porcine model

PURPOSE: We developed a complex porcine renal laceration model at our laboratory to test the efficacy of an abbreviated, sutureless treatment regimen using FloSeal gelatin matrix hemostatic sealant (Baxter Healthcare Corp., Fremont, California). We evaluated the influence of preliminary renal arterial occlusion on hemostatic efficacy and assessed the risk of delayed hematoma or urinoma formation after treatment. MATERIALS AND METHODS: A total of 21 commercial swine underwent celiotomy with creation of a complex upper pole renal injury using a 4 x 4 cm cruciate press instrument. The injury was uniformly produced at the caudal extent of the upper third portion of the left kidney. Subjects were prospectively randomized into 3 treatment groups. Experimental animals were treated with the application of gelatin matrix with (7 in group 1) or without (7 in group 2) preliminary renal arterial occlusion. Control subjects (7 in group 3) were treated with conventional horizontal mattress sutured gelatin sponge bolsters over the capsular injury. Operative blood loss, time to hemostasis and volume of gelatin matrix required for hemostasis were compared among the groups. Abdominal computerized tomography with intravenous contrast medium was performed in each animal 7 days postoperatively. RESULTS: Gelatin matrix use resulted in significantly less mean blood loss (80.7 and 99.0 ml in groups 1 and 2, respectively) vs conventional suture treatment (191.8 ml in group 3, p = 0.036). Time to hemostasis was similarly decreased (1.1, 2 to 2.5 and 5.8 minutes in groups 1 to 3, respectively, p = 0.009). Followup abdominal computerized tomography with contrast medium revealed no clinically significant perinephric fluid collections (greater than 2 cm). CONCLUSIONS: FloSeal gelatin matrix hemostatic sealant provided effective hemostasis after complex renal injury with and without preliminary vascular control. No delayed bleeding or clinically significant urinoma formation was noted. These findings suggest a possible increased role for FloSeal gelatin matrix in renal salvage surgery.     

Ferromagnetic materials in patients: detection before MR imaging

A number of surgical clips and other metallic materials embedded within patients have ferromagnetic properties that present a potential hazard when in the strong fields associated with magnetic resonance imaging. Several types of magnetometers and metal detectors were investigated as possible pre-imaging screening devices. The sensitivities and costs of these devices are given.     

Cardiac tamponade and pulmonary compression due to volvulus of oesophageal coloplasty

We describe an unusual case of cardiac tamponade and pulmonary compression due to acute volvulus of colon interposition occuring late after oesophagectomy. Clinical signs were suggestive of cardiac tamponade but there was no evidence of pericardial effusion by transthoracic echocardiography. Thoracic-CT provided the diagnostic clue in revealing the extrapericardial nature (a major dilatation of the colonic transplant) of the tamponade. This diagnosis should be considered in case of acute cardiopulmonary distress occuring early or late after oesophagectomy.     

Epidural haematoma after evacuation of contralateral subdural haematoma

Background Sequentially evolving intracranial bilateral haematomas, where the second haematoma develops after the surgical removal of the first one is rarely reported. Aim To report a patient who developed an epidural haematoma after evacuation of a contralateral subdural haematoma. Methods A 49-year-old male was admitted to our department after head injury. A brain computerized tomography (CT) scan revealed an acute subdural haematoma in the right temporal area which was evacuated. During his stay in the intensive care unit, he was submitted to intracranial pressure monitoring, which soon rose. Results A new CT scan showed an acute epidural haematoma in the contralateral parietal area that was also evacuated. Conclusions While rising intracranial pressure after the evacuation of a traumatic haematoma is usually attributed to brain oedema or recurrent haematoma at the craniotomy site, the development of a contralateral epidural haematoma requiring surgical treatment should not be overlooked.     

Heterologous expression and functional analysis of rat Nav1.8 (SNS) voltage-gated sodium channels in the dorsal root ganglion neuroblastoma cell line ND7-23

The voltage-gated sodium channel NaV1.8 (SNS, PN3) is thought to be a molecular correlate of the dorsal root ganglion (DRG) tetrodotoxin resistant (TTX-R) Na+ current. TTX-R/NaV1.8 is an attractive therapeutic drug target for inflammatory and neuropathic pain on the basis of its specific distribution in sensory neurones and its modulation by inflammatory mediators. However, detailed analysis of recombinant NaV1.8 has been hampered by difficulties in stably expressing the functional protein in mammalian cells. Here, we show stable expression and functional analysis of rat NaV1.8 (rNaV1.8) in the rat DRG/mouse N18Tg2 neuroblastoma hybridoma cell line ND7-23. Rat NaV1.8 Na+ currents were recorded (789 +/- 89 pA, n=62, over 20-cell passages) that qualitatively resembled DRG TTX-R in terms of gating kinetics and voltage-dependence of activation and inactivation. The local anaesthetic drug tetracaine produced tonic inhibition of rNaV1.8 (mean IC50 value 12.5 microM) and in repeated gating paradigms (2-10 Hz) also showed frequency-dependent block. There was a correlation between the ability of several analogues of the anticonvulsant/analgesic compound lamotrigine to inhibit TTX-R and rNaV1.8 (r=0.72, P<0.001). RT-PCR analysis of wild type ND7-23 cells revealed endogenous expression of the beta1 and beta3 accessory Na+ channel subunits-the possibility that the presence of these subunits assists and stabilises expression of rNaV1.8 is discussed. We conclude that the neuroblastoma ND7-23 cell line is a suitable heterologous expression system for rNaV1.8 Na+ channels in that it allows stable expression of a channel with biophysical properties that closely resemble the native TTX-R currents in DRG neurones. This reagent will prove useful in the search for pharmacological inhibitors of rNaV1.8 as novel analgesics.