Dosimetry of the cone beam computed tomography Veraviewepocs 3D compared with the 3D Accuitomo in different fields of view

OBJECTIVES: This study compares tissue-absorbed and effective doses of the cone beam CT (CBCT) units, the Veraviewepocs 3D and the 3D Accuitomo, in different protocols. METHODS: The absorbed organ doses were measured using an anthropomorphic phantom loaded with thermoluminescent dosemeters (TLDs) in 16 sensitive organ sites. Both CBCT units were deployed with different fields of view (FOVs): 3D Accuitomo using two protocols (anterior 4 x 4 cm scan and anterior 6 x 6 cm scan) and Veraviewepocs 3D using three protocols (anterior 4 x 4 cm scan, anterior 8 x 4 cm scan and panoramic + anterior 4 x 4 cm). Equivalent and effective doses were then calculated, the latter based on the International Commission on Radiological Protection's (ICRP) 2005 recommendations. RESULTS: The lowest effective dose was observed for the 3D Accuitomo 4 x 4 cm (20.02 microSv), the highest for the 3D Accuitomo 6 x 6 cm (43.27 microSv). The effective dose recorded for Veraviewepocs 3D was 39.92 microSv for the 8 x 4 cm scan, 30.92 microSv for the 4 x 4 cm scan and 29.78 microSv for the panoramic + 4 x 4 cm scan protocol. CONCLUSIONS: The radiation doses delivered by both machines were in comparable ranges when using 4 x 4 cm FOV. A smaller FOV should be used for dental images, whereas a larger FOV should be restricted to cases in which a wider view is required.     

NGAL is an early predictive biomarker of contrast-induced nephropathy in children

We hypothesized that neutrophil gelatinase-associated lipocalin (NGAL) is an early predictive biomarker of contrast-induced nephropathy (CIN). We prospectively enrolled 91 children (age 0–18 years) with congenital heart disease undergoing elective cardiac catheterization and angiography with contrast administration (CC; Ioversol). Serial urine and plasma samples were analyzed in a double-blind fashion by NGAL enzyme-linked immunosorbent assay (ELISA). CIN, defined as a 50% increase in serum creatinine from baseline, was found in 11 subjects (12%), but detection using increase in serum creatinine was only possible 6–24 h after CC. In contrast, significant elevation of NGAL concentrations in urine (135 ± 32 vs. 11.6 ± 2 ng/ml without CIN, p < 0.001) and plasma (151 ± 34 vs. 36 ± 4 without CIN, p < 0.001) were noted within 2 h after CC in those subjects. Using a cutoff value of 100 ng/ml, sensitivity, specificity, and area under the receiver-operating characteristic (ROC) curve for prediction of CIN were excellent for the 2-h urine NGAL (73%, 100%, and 0.92, respectively) and 2-h plasma NGAL (73%, 100%, and 0.91, respectively). By multivariate analysis, the 2-h NGAL concentrations in the urine (R ² = 0.52, p < 0.0001) and plasma (R ² = 0.72, p < 0.0001) were found to be powerful independent predictors of CIN. Patient demographics and contrast volume were not predictive of CIN.     

Neural responses associated with positive and negative emotion processing in patients with left versus right temporal lobe epilepsy

Studies on emotion processing in patients with temporal lobe epilepsy have dealt mainly with the processing of negative emotions. To further understand the neural basis of emotional disorders in temporal lobe epilepsy, we studied patterns of brain activation induced by implicit processing of negative and positive emotions perceived through facial expressions and emotionally salient stimuli in candidates for surgical treatment of intractable epilepsy. Using functional MRI, we compared, in patients with mesial temporal lobe epilepsy and healthy subjects, the patterns of brain activation elicited by the implicit processing of fearful, sad, and happy faces and pleasant and unpleasant scenes. The results revealed different patterns of activation in patients with left and right mesial temporal lobe epilepsy, compared with healthy subjects, suggesting that the left and right mesial temporal regions are involved differently in emotion processing, which could be related to different contributions in emotional arousal.     

The middle radioulnar joint and triarticular forearm complex

The forearm is composed of the radial and ulnar shafts, which are linked by the interosseous membrane and intercalated between the elbow and wrist. The radius and ulna are connected by three joints, the proximal, middle, and distal radioulnar joints. The forearm ensures pronation/supination and longitudinal load transfer. The biomechanical and clinical relevance of the proximal and distal radioulnar joints is well established. In contrast, the middle radioulnar joint was considered relatively unimportant until studies published in the last decade showed that it fulfils crucial biomechanical functions and is of considerable clinical significance. We believe the conventional concept in which the forearm is viewed as part of either the elbow or the wrist is outdated and that a more relevant concept describes the forearm as a triarticular complex that functions as a full-fledged entity. In this concept, the three forearm radioulnar joints (proximal, middle, distal) work together to provide stability, mobility and load transfer. Here, we will argue for the relevance of the triarticular complex concept based on published data about forearm biomechanics and pathological conditions.     

Preoperative prediction of prolonged mechanical ventilation following coronary artery bypass grafting.

OBJECTIVE: Few studies have attempted to evaluate who would require prolonged mechanical ventilation following heart surgery. The objectives of this study were to identify predictors of prolonged ventilation in a large group of coronary artery bypass grafting (CABG) patients from a single institution. METHODS: One thousand, eight hundred and twenty-nine consecutive patients undergoing CABG were reviewed retrospectively and evaluated for preoperative predictors of prolonged ventilation which included: age, gender, ejection fraction (EF), renal function, diabetes, angina status, New York Heart Association Class, number of diseased vessels, urgency of the procedure, re-operation, chronic lung disease (COPD) and intraoperative variables such as IABP, inotropes, stroke and myocardial infarction. Prolonged ventilation was defined as > or = 24 h. Stepwise logistic regression analysis was performed. RESULTS: Patients were on average 65.4+/-10.6 years of age, 30% were diabetic, 80% had triple vessel disease and 93% were of functional class III/IV. The mean ejection fraction was 60+/-16 percent. Overall peri-operative mortality was 2.7%. There were 157 patients that required prolonged ventilation with a peri-operative mortality of 18.5% (P < 0.001). Preoperative independent predictors of prolonged ventilation were found to be: unstable angina (OR 5.6), EF < 50 (OR 2.3), COPD (OR 2.0), preop. renal failure (OR 1.9), female gender (OR 1.8) and age > 70 (OR 1.7). Based on these predictors, a model was created to estimate of the risk of prolonged ventilation in individual patients following CABG with results ranging from < or = 3% in patients without any risk factors to > or = 32% in patients with five or more independent risk factors.Certain intraoperative variables were strong predictors of prolonged ventilation and included: stroke (OR 12.3), re-operation for bleeding (OR 6.9) and perioperative MI (OR 5.8). CONCLUSION: We were able to create a stable model where several preoperative and intra-operative variables were shown to be predictive of prolonged ventilation after CABG surgery. The ability to identify patients at increased risk for prolonged ventilation may allow the development of pre-emptive strategies and more effective resource allocation.     

The differential effect of BMI on prosthetic versus autogenous breast reconstruction: A multivariate analysis of 12,986 patients

BackgroundThe comparative safety of breast reconstruction in obese patients remains to be clearly defined. This study utilized multi-institutional data to characterize the effect of body mass index (BMI) on breast reconstruction outcomes.MethodsUtilizing Current Procedural Terminology (CPT) codes, patients undergoing tissue expander, pedicled transverse rectus abdominis myocutaneous (TRAM) flap, latissimus dorsi flap, and free flap breast reconstruction were identified in the National Surgical Quality Improvement Program (NSQIP) database. Patients were stratified as obese (BMI ≥ 30) and non-obese (BMI < 30). Overall postoperative morbidity, flap complications, non-flap complications, and reoperation rates were compared among the groups.ResultsOf 12,986 patients who underwent breast reconstruction, 3636 (28.0%) were obese. Overall morbidity was significantly elevated in obese patients across all forms of reconstruction (p < 0.05). BMI was correlated with increased surgical complications for tissue expander, pedicled TRAM, and free flap reconstructions (OR = 1.09, OR = 1.05, OR = 1.10, respectively; p < 0.05). Medical complications were higher in obese patients undergoing tissue expander and pedicled TRAM reconstructions (p = 0.001 and p < 0.001), but no significant difference was observed in latissimus and free flap reconstruction patients. Compared with obese tissue expander recipients, obese patients reconstructed using autologous tissue had higher rates of reoperations (12.8% versus 9.1%), overall morbidity (18.0% versus 9.5%), surgical (12.7% versus 8.3%), and medical complications (9.0% versus 2.2%).ConclusionsThe NSQIP database allows for evaluation and comparison of reconstructive outcomes in the obese population. Increased BMI was associated with higher morbidity in autologous reconstruction than tissue expander reconstruction. Among autologous procedures, latissimus flaps experienced the lowest captured 30 day morbidity.     

Frozen red blood cells in combat casualty care: clinical and logistical considerations

OBJECTIVE: To test the hypothesis that a supply of frozen red blood cells and a system for processing pyrogen-free crystalloid solution would meet the needs of an echelon 3 medical treatment facility in the U.S. military, caring for casualties during the initial phase of a military medical operation. DATA SOURCES: Blood requirements for potential combat casualties were estimated from transfusion data on: (1) patients admitted to Boston City Hospital following trauma, utilizing a computerized data base, (2) patients admitted to the Naval Support Hospital-Da Nang during the Vietnam War, from 1966 to 1970, from published and unpublished material, and (3) casualties estimated by Department of Defense expert panels for specific conflicts. The procedure for processing frozen red blood cells was evaluated at the Naval Blood Research Laboratory. Estimates of wounded in action were provided by the Department of Defense. DATA SYNTHESIS: Computer modeling using standard spreadsheet software on a personal computer. CONCLUSIONS: Under military conditions, a frozen red blood cell bank and a system for processing pyrogen-free resuscitative fluid could be used to prepare 96 units of red cells and 960 1 of crystalloid solution per day. This would be adequate to treat approximately 180 casualties, the number projected for a 5-day battle with heavy casualties (6 wounded in action/1,000 soldiers/day). It was concluded that a frozen blood bank system and system for processing pyrogen-free resuscitative fluid could successfully meet the needs of an echelon 3 medical facility in the initial phase of a military medical operation.     

Lymphokine-induced phagocytosis in angiocentric immunoproliferative lesions (AIL) and malignant lymphoma arising in AIL

A factor that augmented the phagocytosis of IgG-coated ox red blood cells by the human monocyte/macrophage line U937 was identified in cell culture supernatants from two of two patients with angiocentric peripheral T cell lymphomas, three of three patients with angiocentric immunoproliferative lesions that were not frankly malignant, and one of two patients with T lymphoblastic malignancies. The factor was not present in supernatants derived from 14 nonangiocentric peripheral T cell lymphomas of other histologic types nor in ten cases of B cell lymphoma and two cases of Hodgkin's disease. A similar factor was present in the supernatants of concanavalin A (Con A)-stimulated normal peripheral blood mononuclear cells and in the supernatants of IL-2- dependent T cell lines derived from normal peripheral blood. The factor had an apparent mol wt of greater than 50,000 daltons, was heat labile (100 degrees C for two minutes), and stable at pH 2.0. Its stimulation of phagocytosis was independent of any increase in number of Fc receptors. Thus, this factor is probably not gamma-interferon. This factor may play a pathogenetic role in the hemophagocytic syndromes associated with certain T cell malignancies and immunodeficient states.