Occult anterograde flow is an under-recognized but crucial predictor of early recanalization with intravenous tissue-type plasminogen activator.

BACKGROUND AND PURPOSE: Thrombolysis depends on the ability of blood and thrombolytic agents to permeate thrombus. We devised a novel technique to quantify blood permeating through thrombi and determine whether this parameter predicts early recanalization with intravenous tissue-type plasminogen activator. METHODS: Intravenous tissue-type plasminogen activator-treated patients with stroke and complete occlusion on computed tomographic angiography were analyzed using perfusion computed tomography and a delay insensitive algorithm. We generated maps that measure delay in arrival time of contrast within the intracranial arterial tree (T0 maps). A positive sloped regression line of T0 values measured along artery silhouette distal to thrombus was defined as marker of permeable thrombus (occult anterograde flow). Median T0 values at proximal and distal thrombus interface were measured. Early recanalization was assessed on first angiography of subsequent intra-arterial procedure or on a 4-hour computed tomographic angiography. RESULTS: Of 66 patients, occult anterograde flow was detected in 17 (25.8%). Early recanalization was more in patients with occult anterograde flow versus not (66.7 versus 29.7%; P=0.031). Median T0 value (in s) at distal thrombus interface (1.5 versus 3.8; P=0.006) and difference in median T0 value between proximal and distal thrombus interface (1.3 versus 3.7; P=0.014) were less in early recanalizers versus in nonrecanalizers. In multivariable analysis, patients with occult anterograde flow and T0 value difference between proximal and distal thrombus interface ≤2 s recanalized most (71.4%; odds ratio, 12.15; 95% confidence interval, 2.05-71.91), whereas patients with retrograde flow and T0 value difference >2 s recanalized least (25.9%; odds ratio, 1). CONCLUSIONS: Occult anterograde flow through thrombus can be assessed by perfusion computed tomography T0 maps and predicts early recanalization with intravenous tissue-type plasminogen activator robustly.

Syndrome of inappropriate antidiuretic hormone secretion in patients with olfactory neuroblastoma.

OBJECTIVE: The syndrome of inappropriate antidiuretic hormone secretion (SIADH) has been reported as a paraneoplastic syndrome in many different types of malignancies. Several case reports of SIADH have been reported in patients with olfactory neuroblastoma (ONB), but the exact incidence is unknown. The purpose of this study was to review our experience with olfactory neuroblastoma and to identify all patients who had a history of SIADH prior to the diagnosis of ONB. STUDY DESIGN: Case series and chart review. SETTING: Tertiary care university-affiliated medical center. SUBJECTS AND METHODS: A total of 21 patients presented to our institution with ONB between 1997 and 2009. All records were reviewed for a history of preoperative hyponatremia or SIADH. RESULTS: Three patients were identified who had a history of SIADH prior to the diagnosis of ONB. Immunohistochemical staining of the tumor specimens from the 3 patients with SIADH was positive for arginine vasopressin. SIADH resolved in all 3 patients after successful treatment of ONB. CONCLUSION: Although uncommon, SIADH can be the presenting symptom of ONB and should be considered during the workup for idiopathic SIADH.

Influence of scale deposition on cathodic-protection performance in desalination plant conditions.

This paper describes an investigation into the interrelationships between the performance of an impressed current cathodic protection (CP) system and the deposition of scale compounds in a seawater pipe system. Some experiments were conducted on a laboratory set-up but the emphasis was on tests on a 0.25 m diameter steel pipe fed by seawater flowing to a thermal desalination plant. The experimental approach involved monitoring the CP current as a function of time at various set potentials and correlating this data with evidence from visual inspection of the pipe-wall surfaces and small probe specimens. The influences of control potential and seawater flow rate at temperatures of 25-35 degrees C were studied. Selected scale samples were subjected to examination by scanning electron microscopy and X-ray diffraction. The overall findings are discussed in terms of fundamental scale/CP-operation interactions and aspects relevant to practical operation of CP systems on seawater pipe installations.