The action of lipoprotein lipase on triglyceride-rich lipoproteins generates fatty acids that are either transported into tissues or mix with circulating free fatty acids (FFAs) via a process known as spillover. In the present study, arterial, portal vein, and hepatic vein sampling catheters were surgically placed in nine mongrel dogs. The animals were subsequently studied after a 42-h fast during infusion of [14C]oleate and a lipid emulsion containing [3H]triolein; the emulsion was used as a surrogate for the study of chylomicron metabolism. More than one-half of splanchnic [3H]triglyceride uptake occurred in the liver, and substantial fractional spillover of [3H]oleate was observed in both liver and nonhepatic tissues (∼50% each). There was a significant correlation between FFA release from nonhepatic tissues (presumably visceral fat) and nonhepatic fractional spillover (R = 0.81, P < 0.01), consistent with a model in which the rate of intracellular lipolysis influences spillover by determining the direction of net fatty acid flow between the cell and the interstitium. There was a significant correlation between “true” and “net” splanchnic spillover (R = 0.84, P < 0.005), the latter representing calculation of spillover between arterial and hepatic venous blood without portal venous data. Metabolism of chylomicron triglycerides in visceral fat may be an important source of portal venous FFAs.
Serial Biomarker Measurements in Ambulatory Patients With Chronic Heart Failure
Background— Cardiac troponin T (cTnT) and B-type natriuretic peptide (BNP) have been used to estimate prognosis in heart failure; however, most studies have evaluated decompensated patients with single measurements. To determine if there are advantages to serial measurements, we evaluated stable chronic heart failure patients every 3 months for 2 years. Methods and Results— A cohort of 190 New York Heart Association class III–IV heart failure patients was prospectively enrolled from June 2001 to January 2004. Primary end points were death, cardiac transplantation, or hospitalization. At study enrollment cTnT was <0.01 ng/mL in 87 (45.8%) patients, 0.01 to 0.03 ng/mL in 50 (26.3%) patients, and >0.03 ng/mL in 53 (27.9%) patients. An increase in cTnT above normal (<0.01 ng/mL) carried a 3.4-fold increased risk ( P =0.019). Further increases (≥20%) from an elevated level worsened the overall risk (hazard ratio, 5.09; P <0.001). BNP was elevated (>95th percentile for age and gender normal population) in 122 (64.2%) patients. An elevation of BNP from normal at any time during the study was associated with a poor outcome, but, once elevated, further changes in BNP (increases or decreases) remained associated with the same risk (hazard ratio, 5.09; P <0.001). Combined elevations of cTnT (>0.03 ng/mL) and BNP defined the highest risk group (hazard ratio, 8.58; P <0.001). Conclusions— Elevations of cTnT or BNP from normal detected at any time during clinical follow-up in ambulatory patients with chronic heart failure are highly associated with an increased risk of events. Further increases in cTnT contribute to additional risk. Combined elevations of cTnT and BNP contribute the highest risk. The ability to monitor changes by serial measurements adds substantially to the assessment of risk in this patient population.
Optimal Management of Abdominal Aortic Aneurysms and Urologic Malignancies: Benefits of Simultaneous Surgical Treatment
The coexistence of urologic malignancy (UM) and abdominal aortic aneurysm (AAA) is rare. Simultaneous treatment may increase morbidity, whereas staged operations delay necessary treatment. We reviewed our experience to develop guidelines for evaluation and management. Clinical data of all patients diagnosed between 1980 and 1998 with both AAA and UM, who also had staged or simultaneous surgical treatment were reviewed. Four thousand forty-seven patients underwent AAA repair during the study period at our institution. Of these, 18 (0.44%) patients, 16 men and two women (mean age: 74 years, range: 61 to 92) had UM. UM was discovered incidentally in nine patients with AAA with computed tomography (CT) scan (7) and ultrasonography (2). In one patient with AAA, hematuria raised the suspicion of UM. Eight patients were diagnosed with AAA during evaluation of UM by CT scan or ultrasound (7) or during laparotomy (1). Initial signs and symptoms included abdominal pain (33%), gross hematuria (33%), and urinary tract infections (17%), although 33% were asymptomatic. The AAA was symptomatic at first examination in three (17%) patients, 14 (78%) patients had hypertension, and two (11%) had renal insufficiency (overall mean serum creatinine: 1.6, range: 0.8 to 3.7). Mean AAA diameter was 5.8 cm (range: 3.8 to 8 cm). Aortography documented significant contralateral renal artery disease in two patients. Twelve patients underwent simultaneous AAA repair and resection of UM; the operations were staged in six (AAA repair first in 2, nephrectomy first in 4). One patient required emergent repair of a ruptured AAA three days after nephrectomy. UM was treated with nephrectomy in 17 patients, and with bilateral ureterectomy and cystectomy in one. A straight aortic graft was implanted in seven patients, a bifurcated graft in ten, and one had extra-anatomic reconstruction. Two patients required reconstruction of the contralateral renal artery. The 30-day mortality rate was 0% after staged and 6% after simultaneous repair (p= >0.1). Major perioperative complications occurred more frequently after simultaneous (42%) than after staged repair (33%), although the difference was not significant (p= >0.1). Two patients developed postoperative renal failure. Seventeen patients were followed for an average of 3.9 years (14 days to 10.8 years). Three (17%) patients died of recurrent cancer at 1, 10.7, and 10.8 years after surgery. Patients with resectable UM have satisfactory long-term survival, which justifies aggressive treatment of concomitant AAA. Aortography in these patients is suggested to exclude contralateral renal artery disease. Complications were frequent, but simultaneous repair did not increase morbidity or mortality significantly. The risk of AAA rupture after nephrectomy, need to correct contralateral renal artery disease at the time of nephrectomy, and disadvantage of delaying treatment of UM are compelling reasons to favor simultaneous treatment of AAA and UM.
Intraoperative Duplex Ultrasound During Carotid Endarterectomy
The purpose of this study was to examine the technical aspects of intraoperative duplex ultrasound (DUS) following carotid endarterectomy (CEA), suggest criteria to differentiate significant lesions requiring immediate surgical revision from normal or benign defects, and evaluate how frequently intraoperative DUS provides useful or unsuspected information. A retrospective study was performed on all patients who had both CEA and intraoperative carotid DUS between January 1,1990. and January 1,1995. A total of 155 DUS examinations were performed in 149 patients. Findings were grouped into three categories: normal; minor/insignificant lesions; and hemodynamically significant lesions based on the presence or absence of elevated peak systolic velocities, visible stenosis/thrombus, or intimal flap/dissection. Postoperative status was correlated with intraoperative DUS findings. Ninety-one (59%) examinations performed on 87 patients produced normal findings. Forty-seven (30%) examinations performed on 45 patients showed minor abnormalities consisting of insignificant residual plaque, residual external carotid artery stenoses, small intimal flaps, elevated velocities with no associated anatomic lesion, or an arterial kink. Fourteen patients (9%) had significant findings requiring immediate surgical revision. These consisted of large intimal flaps or dissection in six patients, marked residual plaque and significant stenosis in five patients, thrombus in two patients, and a kink in one patient. Three additional patients ( 2 %) had significant findings but were not revised for various reasons. No significant difference was identified in morbidity or mortality rates between those patients with normal findings, those patients with minor technical defects, and those patients with significant abnormalities undergoing immediate surgical revision. However, two of three patients who had significant abnormalities within the common carotid artery that were not revised suffered perioperative ipsilateral strokes. Intraoperative DUS is a safe and accurate method to assess the technical adequacy of CEA. Intraoperative DUS showed significant lesions in 11% of patients. Identification and immediate repair of significant technical defects may decrease perioperative complication rate and long-term restenosis rate.
Transoral laser microsurgery for carcinoma of the supraglottic larynx
Gemcitabine, Cisplatin, and Radiotherapy for Patients With Locally Advanced Pancreatic Adenocarcinoma: Results of the North Central Cancer Treatment Group Phase II Study N9942
Purpose A phase II study was conducted to determine the efficacy and toxicity of radiotherapy with concomitant gemcitabine and cisplatin for patients with locally advanced pancreatic adenocarcinoma. Patients and Methods Forty-eight patients with locally advanced pancreatic adenocarcinoma received gemcitabine (30 mg/m2) and cisplatin (10 mg/m2) twice weekly during the first 3 weeks of radiotherapy. The radiation dose to the primary tumor and regional nodes was 45 Gy in 25 fractions, and the gross tumor volume received an additional 5.4 Gy in three fractions. Four weeks after radiotherapy, patients received gemcitabine (1,000 mg/m2) once weekly every 3 of 4 weeks for a 12-week period. The primary end point was survival at 12 months. Secondary end points were time to progression, toxicity, and quality of life. Results Survival at 1 year was 40% for 47 eligible patients. The median survival was 10.2 months. Confirmed responses were observed for 8.5% (two partial, two complete), and median time to progression was 7.3 months. Grade 4 or higher toxicity was observed for 31% and consisted primarily of hematologic and GI toxicity. There was a trend toward improved overall quality of life, measured by the Symptom Distress Scale (P = .06), with significant improvements in domains of insomnia, pain, and outlook. Conclusion The combination of radiotherapy, gemcitabine, and cisplatin was well tolerated. Survival results were similar to those achieved with other treatment regimens for patients with locally advanced pancreatic cancer but did not meet our predefined criteria for additional evaluation of this regimen.
High Sensitivity of In Vivo Detection of Gold Nanorods Using a Laser Optoacoustic Imaging System
Background: Reliable measurement of subfascial pressures represents an essential part of compartment syndrome management. To date, there is neither consensus on the number or location of foot compartments, nor a standardized protocol for needle placement. The purpose of this study was to devise a new system using 3-Tesla MRI that assesses the number and location of these compartments. Methods: To document the specific location of foot compartments, high resolution 3-Tesla MRI (General Electric, Milwaukee, WI) was coupled with a dedicated transmit-receive high signal-to-noise foot/ankle coil (IGC-Medical Advances, Milwaukee, WI). Individual compartments were highlighted and mapped to T1-weighted MRI. Three-dimensional image analysis allowed standardized needle placement recommendations. Results: Six feet from healthy volunteers were imaged. From these, ten compartments were described: (1) medial, (2) central superficial, (3) central deep (adductor), (4) lateral, (5–8) interossei, (9) calcaneal, and (10) skin. Optimal needle placement and depth were identified. Conclusions: The proposed system allowed us to assess the number and location of foot compartments. Computer image analysis enabled us to define exact points for needle insertion and depth of penetration for accurate pressure monitoring.
P‐020: Regional gray matter reductions in Alzheimer's dementia and amnestic mild cognitive impairment: Preliminary findings from the Alzheimer's disease neuroimaging initiative using voxel‐based morphometry