Oiling of American white pelicans, common loons, and northern gannets in the winter following the Deepwater Horizon (MC252) oil spill.

The Natural Resource Damage Assessment and Restoration Trustees for the Deepwater Horizon oil spill assessed the external oiling of migratory bird species dependent on open water in the Gulf of Mexico following the aforementioned spill. The assessment was designed to evaluate birds that use open water during the winter within 40 km of the Gulf shoreline. We focused on the American white pelican (Pelecanus erythrorhynchos), common loon (Gavia immer), and northern gannet (Morus bassanus). Point counts (pelican, loon) or strip transects (gannet) were used and each target species was assessed for oiling (unoiled, trace, light, moderate, or heavy amounts) and photographed. Due to distance at sighting and/or poor visibility, not all visible birds were assessed. The percentage of birds oiled varied by species, with the common loon being the highest (23.6%), followed by American white pelican (16.9%), and northern gannet (6.9%). Most of the American white pelicans and common loons had trace (83% and 72%, respectively) or light levels (11% and 24%, respectively) of oiling. The northern gannet had just trace levels of oiling. Some pelicans (6%) and loons (4%) had moderate amounts of oiling. Based on expert derived-mortality estimates and our estimates of oil exposure, we used Monte Carlo simulations to predict expected decreases of 2.5%, 4%, and 11% in the observed population for the northern gannet, American white pelican, and common loon, respectively. While these values are underestimates of the true values given the long time lag (10-12 months) between the oil spill and the assessment, these data represent some of the few estimates of exposure for these species and describe minimum risk estimates to these species.

Changes in functional connectivity of the amygdala during cognitive reappraisal predict symptom reduction during trauma-focused cognitive-behavioral therapy among adolescent girls with post-traumatic stress disorder.

BACKGROUND: While trauma-focused cognitive-behavioral therapy (TF-CBT) is the 'gold standard' treatment for pediatric post-traumatic stress disorder (PTSD), little is known about the neural mechanisms by which TF-CBT produces clinical benefit. Here, we test the hypothesis that PTSD symptom reduction during TF-CBT among adolescent girls with PTSD is associated with changes in patterns of brain functional connectivity (FC) with the amygdala during cognitive reappraisal. METHOD: Adolescent girls with PTSD related to physical or sexual assault (n = 34) were enrolled in TF-CBT, delivered in an approximately 12-session format, in an open trial. Before and after treatment, they were engaged in a cognitive reappraisal task, probing neural mechanisms of explicit emotion regulation, during 3 T functional magnetic resonance imaging. RESULTS: Among adolescent girls completing TF-CBT with usable pre- and post-treatment scans (n = 20), improvements in self-reported emotion from pre- to post-treatment were positively related to improvements in PTSD symptoms. Adolescent girls with greater post-treatment symptom reduction were also able to suppress amygdala-insula FC while re-appraising, which was not evident in girls with less symptom reduction. Pre- to post-treatment changes in right amygdala to left insula FC that scaled with PTSD symptom reduction also scaled with improvements in emotion regulation. CONCLUSIONS: These preliminary results suggest the neurocircuitry mechanisms through which TF-CBT produces clinical outcomes, providing putative brain targets for augmenting TF-CBT response.

Variable ultrasound echogenicity in flowing blood.

Real-time ultrasound imaging of large abdominal veins revealed bloodstream echogenicity of variable intensity. This variability is largely due to the entrance and persistance of tributary blood currents that show different echogenicity. Red cell aggregation is probably an important cause of bloodstream echoes and their variable intensity.

Effect of blood flow reversal in liver autotransplants upon the site of hepatocyte regeneration.

We studied the role of the direction of intrahepatic blood flow upon the location of hepatocyte formation in regenerating liver. Single liver lobes in the dog were autotransplanted to the region of the neck with the blood supply reestablished in a manner to perfuse the hepatic lobule from portal tract to central vein or, in a reverse direction, from central vein to portal tract. Partial resection of the nontransplanted liver was later performed to induce regeneration in the grafts by humoral means. Tritiated thymidine was administered, and radioautographs were prepared from excised graft and nontransplanted liver. In the "straight" blood flow grafts, as well as in all nontransplanted livers, labeled hepatocytes indicating DNA synthesis were found predominantly in the vicinity of the portal tracts. In the "reverse" blood flow grafts, labeled hepatocytes were more prevalent about the central veins. Thus, the localization of hepatocyte formation in the lobule during active liver regeneration cannot be attributed to an inherently greater capacity of periportal liver cells to divide but is probably related to their preferential exposure to blood constituent changes (humoral mechanisms). Hepatocyte regeneration in the presence of abnormal directional circulation might lead to lobular disorganization resulting in consequent biochemical aberrations despite the formation of new cells.

Operative ultrasonography for lung cancer surgery.

During 60 operations for lung cancer, high-resolution (7.5 MHz) operative ultrasonography was performed to evaluate direct cardiovascular invasion of tumor (24 operations), lymph node metastasis (30 operations), liver metastasis (13 operations). Immediately after thoracotomy or sternotomy but before tissue dissection, operative scanning enabled delineation and evaluation of the evaluation of the vessels and heart (atrium) behind or within the tumor and detection of regional lymph nodes. The accuracy of operative ultrasound in diagnosing the presence or the extent of cardiovascular invasion was 91.7% (22 of 24 operations), which was significantly (p less than 0.02) higher than preoperative studies (62.5%), including computed tomography and angiography. Of the 24 surgical procedures, 23 were consistent with operations proposed on the basis of operative ultrasound findings, whereas only 16 were consistent with preoperatively proposed (p less than 0.01). Operative ultrasound provided the capability of depicting lymph nodes as small as 3 mm. More lymph nodes (8.0 +/- 1.84 nodes per cancer) were detected with operative ultrasound than with computed tomography (4.8 +/- 1.56 nodes) (p less than 0.001); however, the sensitivity and specificity of operative ultrasound in determining lymph node metastasis were 82.4% and 67.3%, respectively. No liver metastasis was identified. The information provided by operative ultrasound regarding cardiovascular invasion and lymph node and liver metastasis was considered helpful in selecting the type of surgical procedure an in avoiding unnecessary tissue dissection.

Ultrasonic detection of red cell aggregation immediately preceding blood clotting.

High-resolution ultrasonic imaging of circulating blood was used to study the relation between red cell aggregation and blood clotting in vitro. A reversible increase in echogenicity produced by red cell aggregation occurred in moving heparinized blood as shear rate was decreased. We induced clotting of the heparinized blood by administration of protamine. At both low (1.6 sec-1) and moderate (22.6 sec-1) mean shear rates, transient homogenous increased echogenicity indicative of red cell aggregation preceded blood clotting. In separate experiments, we established that protamine can cause increased echogenicity due to red cell aggregation which can be reversed by adding heparin to circulating suspended red cells in the absence of clotting factors. Presumably, these effects of protamine and heparin are due to electrostatic bonding involving red cell surfaces. We conclude from these studies that red cell aggregation precedes clotting of heparinized blood by protamine at low and moderate shear rates.

Effect of plasma proteins and temperature on echogenicity of blood.

An explanation is proposed for the echogenicity to ultrasound scanning at 5 mHz and above of unclotted blood under conditions of stasis. In vitro experiments using blood from normal subjects and from patients with myeloma revealed that: 1) lysis of red cells prevented echogenicity, 2) echogenicity increased with increasing hematocrit, fibrinogen and other macromolecules, and temperature, and 3) blood from myeloma patients showed increased echogenicity and rouleau formation, a form of aggregation seen on peripheral smears. From these experiments it was concluded that red cell aggregation is a major cause of echogenicity of unclotted blood, requiring both intact red cells and conditions which are known to enhance red cell aggregation, such as the presence of macromolecules and increased temperature.

Ultrasonography of blood during stasis and coagulation.

A series of in vitro and animal experiments were performed to determine ultrasonic features of blood during stasis and coagulation. Liquid whole blood became echogenic within a few seconds to 3 minutes following the onset of stasis. This occurred in citrated human blood allowed to stand and in occluded segments of vena cava and aorta of dogs. Mechanical agitation of the blood in stasis caused a disappearance of echoes. This echogenicity occurred with gray-scale and real-time ultrasonography using 7.5-mHz transducers, but was not observed with 3.5-mHz transducer used in real-time scanning. Whole blood clot was echogenic both with 7.5- and 3.5-mHz scanning. Fibrin clot was sonolucent. Echogenicity with stasis did not occur with plasma, serum, or packed erythrocytes. The development of echogenicity required the presence of fibrinogen or its products plus erythrocytes. The echogenicity of blood during stasis detectable by high-frequency ultrasonography probably was related to physical layering of blood products. The disappearance of reflective echoes following agitation suggested that the layering could be readily disrupted.

Detection of experimental arterial defects by portable and serial biplanar operative arteriography.

The accuracy of arteriography in detecting vascular defects similar to those encountered during vascular surgery was evaluated experimentally. Intimal flaps, thrombi, and strictures were created in dog aortas and studied under circumstances resembling operating room conditions by single-view portable and serial biplanar contrast arteriography. The specificity of both types of arteriography was comparable and high for detecting vascular defects. The sensitivity for diagnosing strictures was also comparable and high. However, both radiographic techniques were relatively insensitive in the detection of small intimal flaps and thrombi. In the detection of these two types of defects, serial biplanar arteriography was significantly more sensitive than portable arteriography. The degree of the superiority of serial bi-plane and the possible clinical insignificance of small defects indicates that portable arteriography in the operating room may still be an adequate methodology.

Comparative accuracy of operative ultrasonography and cholangiography in detecting common duct calculi.

Operative ultrasonography and operative radiographic cholangiography were compared for diagnostic effectiveness with regard to their ability to screen the common bile duct for the presence of calculi. We performed real-time B-mode ultrasonography and cholangiography using two injections of contrast material. In 350 patients, 349 ultrasonic and 285 cholangiographic examinations were performed with technically satisfactory results. The sensitivity, specificity, efficiency, and predictability of a negative test were at a high and comparable level for the two diagnostic procedures. However, the predictability of a positive test for ultrasonography of 91.8% was significantly greater (P less than 0.02) than the predictability of 73.2% for cholangiography. Since predictability of a positive test is based on common duct exploration rather than presumptive evidence of a clinical course, this test may be more valid than the other measures to determine diagnostic effectiveness. The advantages of ultrasonography, which are superior accuracy, favorable image qualities, reduced invasiveness, increased safety, avoidance of contrast material, and lower cost, were contrasted with the problems of ultrasonography, which included a slow learning curve for performance and interpretation of the technique and the limited availability of dedicated ultrasound equipment for surgical operations. We concluded that the advantages outweighed the problems and that operative ultrasonography of the common duct warrants wider application in clinical surgery.

Localization of an occult insulinoma by intraoperative ultrasonography.

Intraoperative ultrasonography has not been used previously to locate an insulinoma that was not surgically palpable or that could not be seen by selective arteriography. In this report we described a patient with an insulinoma localized to the pancreatic head identified by transhepatic portal venous sampling but not by selective arteriography or palpation. At operation intraoperative ultrasonography demonstrated an 8 mm tumor in the pancreatic head and guided the successful enucleation.

Sterile, portable radiation shield for the operating room.

A sterile, portable radiation shield has been developed to protect the surgeon who must remain in the operative field during radiation exposure. The shield is simple to construct and to use. There is no undue prolongation of operating time. The shield effectively reduces exposure to radiation.

Ultrasonic imaging during vascular surgery.

Real-time B-mode ultrasound scanning was used during arterial reconstruction surgery to supplement the information of preoperative arteriography and to detect vascular defects immediately after restoration of blood flow. At 55 operations, 100 sites were examined. At three operations, ultrasound provided new information that, in two patients, directly affected the choice of operation. Intraoperative postreconstruction scanning detected vascular defects in over 20% of the patients. Intimal flaps were the commonest defects observed. In most instances in which defects were seen, the vessels were not reentered because the defects were considered to be too small or located in a nonstrategic site or both. One relatively large intimal flap in a common carotid artery prompted reentry. Ultrasound during vascular operations proved to be a highly sensitive diagnostic tool to supplement preoperative arteriography and to detect vascular defects resulting from reconstructive surgery.

Type of compression for reducing venous stasis. A study of lower extremities during inactive recumbency.

Determination of the optimal compression to reduce venous stasis was studied in terms of the amount of pressure and manner of application (graded or uniform pressure). Both lower extremities of seven inactive recumbent subjects were tested using transcutaneous Doppler ultrasonic measurement of femoral vein blood flow velocity. Optimal compression was defined as the externally applied pressure that produced the greatest increase in femoral vein flow velocity consistent with safety and the practicality of hospital use of elastic stockings. Optimal compression for elastic stockings to be used by hospitalized patients who spend substantial time in bed should be 18 to 8 mm Hg (ankle to midthigh). At this compression, average femoral vein blood flow velocity is increased to 138.4% of base line. Gradient compression at this level was found to produce a greater femoral vein flow velocity than the same amount of compression distributed uniformly over the lower extremity.

Risk assessment of pulmonary embolism by multivariate analysis.

A prospective study of 6,527 hospitalized patients was performed to evaluate the effectiveness of multivariate analysis of risk factors to correctly designate risk for pulmonary embolism. History of previous pulmonary embolism was the single most important factor. In patients without prior history, five factors emerged: inactivity, congestive heart failure, Doppler ultrasound evidence of deep-vein occlusion, female sex, and black race. Used together, these factors permitted a discrimination of risk such that 68.7% of pulmonary embolization was found to occur in 32.2% of the population designated as showing increased risk. Multivariate analysis of clinical factors improved assessment of risk, compared to the use of lower extremity findings alone, and proved to be useful in identifying individuals at increased risk for pulmonary embolism.

Detection of pancreatic tumors by ultrasound during surgery.

Real-time B-mode ultrasonic scanning was performed during 14 operations for pancreatic tumors. All operations were for adenocarcinoma, except in one patient with a Zollinger-Ellison tumor. The ultrasonic tissue appearance of pancreatic carcinoma was not specific. However, ultrasonic signs of pancreatic duct dilation, striction or invasion of the superior mesenteric veins, and common bile duct involvement may help to establish the diagnosis of malignancy. A triad of ultrasound signs indicative of malignant obstruction of the common bile duct consisted of (1) dilation, (2) absence of biliary stones, and (3) a distinctive termination pattern of the duct. Operative ultrasound was used to guide a biopsy needle to obtain pancreatic tissue samples. The Zollinger-Ellison tumor of the pancreas produced a sonolucent appearance that clearly distinguished it from the surrounding tissue.

Ultrasonic assistance during surgery for pancreatic inflammatory disease.

Real-time B-mode ultrasound scanning was used during 35 operations for inflammatory disease of the pancreas. In 21, ultrasonography was considered helpful in operative management of pancreatic pseudocysts, abscesses, and chronic pancreatitis. Assistance consisted of establishing a diagnosis not made during preoperative testing, more precisely localizing pancreatic abnormalities, and excluding the presence of pseudocyst, abscess cavities, and dilated ducts. Operative ultrasound is a safe and simple technique that may reduce the use of tissue dissection, contrast material injections, and radiation.

Identification of a parathyroid adenoma by operative ultrasonography.

During surgery, real-time ultrasound scanning accurately localized a parathyroid adenoma posterior to be the superior pole of the right thyroid lobe. This was made feasible because of the ultrasound features of parathyroid tissue and current developments in ultrasound instrumentation.

Laparoscopic ultrasonography versus operative cholangiography during laparoscopic cholecystectomy: review of the literature and a comparison with open intraoperative ultrasonography.

BACKGROUND: Laparoscopic ultrasonography (LUS) has been used increasingly over the last several years as a new imaging modality. To define the role of LUS during laparoscopic cholecystectomy, we evaluated LUS by prospectively comparing it with operative cholangiography (OC), by reviewing the literature on LUS, and by retrospectively comparing it with intraoperative ultrasonography performed during open cholecystectomy. STUDY DESIGN: LUS and OC were compared prospectively in 100 consecutive patients during laparoscopic cholecystectomy. The success rate of examination, the time required, the accuracy in diagnosing bile duct calculi, and the delineation of biliary anatomy were evaluated. RESULTS: The success rate of examination was 95% for LUS and 92% for OC. The main reason for unsatisfactory LUS was incomplete visualization of the distal common bile duct. The time required was 8.2 minutes for LUS and 15.9 minutes for OC (p<0.0001). Nine patients had bile duct calculi. LUS had one false-negative result and OC had two false-positives and one false-negative. The accuracies of LUS and OC were comparable except for a slightly better positive predictive value of LUS (100% versus 77.8%; p>0.1). In a literature review, 12 recent prospective studies comparing LUS and OC and three studies on open intraoperative ultrasonography were reviewed. Twelve studies of LUS with a total of 2,059 patients demonstrated results similar to the present study. The success rate was 88% to 100% for both tests. The time for LUS was approximately 7 minutes, about half of the time needed for OC. Overall, LUS was associated with fewer false-positive results than OC; the positive predictive value and specificity of LUS were better, while the sensitivity and negative predictive value of LUS and OC were comparable. OC detected ductal variations or anomalies more distinctly than LUS. Compared with open intraoperative ultrasonography, LUS had a slightly lower success rate and required a slightly longer time because it was technically more demanding, but the two procedures had a similar accuracy for diagnosing bile duct calculi. CONCLUSIONS: Because of their different advantages and disadvantages, LUS and OC can be used in a complementary manner. There is a learning curve for LUS because of its technical difficulty. Once learned, however, LUS can be used as the primary screening procedure for bile duct calculi because of its safety, speed, and cost-effectiveness. OC can be used selectively, particularly when ductal anatomic variations or anomalies or bile duct injuries are suspected.

Role of red cells in preventing the growth of platelet aggregation.

Using high-resolution real-time two-dimensional ultrasound, we have investigated the role of red cells in the growth of already established platelet aggregates under controlled flow conditions. Platelet rich plasma (PRP) was circulated in vitro in horizontally and vertically arranged tubing at mean shear rate ranging from 60 to 0 sec-1, and adenosine diphosphate (ADP) was used to induce platelet aggregation. ADP-induced platelet aggregates grew in size and tended to sediment as shear rate decreased, in particular, below 10 sec-1. At 0 sec-1 (stasis), large clusters of platelet aggregates formed. The addition of washed red cells to produce a hematocrit of only 2% significantly interfered with the growth and sedimentation of platelet aggregates as shear rate was reduced. Formaldehyde-hardened erythrocytes had a similar effect in preventing the growth of platelet aggregates, suggesting that mechanical collision of red cells with platelet aggregates may be the cause of growth inhibition. Therefore, the thrombotic process may be enhanced in red cell poor zones in circulation resulting from flow disturbances associated with vascular stenosis or within artificial organs and extracorporeal systems. The present study also suggested that red cell free PRP should be carefully administered therapeutically.