To determine if lymphatic channels and sentinel lymph nodes (SLNs) with and without metastases can be detected with lymphatic ultrasonography (US) after peritumoral injection of a US contrast agent ...and to determine if lymphatic US can be used to assess SLNs for the presence of metastatic infiltration.
Six swine with 17 melanomas were evaluated. Conventional gray-scale, color flow, and gray-scale phase-inversion harmonic US examinations were performed. A US contrast agent was administered in four sites around each melanoma (1-mL total dose). Lymphoscintigraphy was followed by injection of a blue dye and then dissection. SLNs identified at lymphatic US were characterized by two readers in consensus as normal or as having metastases; results were compared with histologic findings. Statistical analyses included the sign test and the kappa statistic.
Lymphatic US depicted 28 SLNs, while lymphoscintigraphy depicted 27 "hot spots" suspected of representing SLNs (including two false-positive findings). Dissection after blue dye injection helped identify 31 SLNs. There were no false-positive US findings for SLN detection. Five of six nodes not seen with lymphoscintigraphy were detected with lymphatic US. The accuracy of SLN detection was 90% (28 of 31) for lymphatic US and 81% (25 of 31) for lymphoscintigraphy (P =.29). Lymphatic US correctly depicted metastases in 19 of 20 SLNs, and five of the eight normal SLNs were correctly characterized, with an accuracy of 86% (kappa = 0.62).
Detection of SLNs with lymphatic US compared favorably with that at lymphoscintigraphy. Lymphatic US can depict metastases within the SLN, which was not possible with lymphoscintigraphy.
Crystalline silicon (c-Si) photovoltaics are robust, manufacturable, and Earth-abundant. However, barriers exist for c-Si modules to reach US$0.50-0.75/W sub(p) fabrication costs necessary for ...subsidy-free utility-scale adoption. We evaluate the potential of c-Si photovoltaics to reach this goal by developing a bottom-up cost model for c-Si wafer, cell, and module manufacturing; performing a sensitivity analysis to determine research domains that provide the greatest impact on cost; and evaluating the cost-reduction potential of line-of-sight manufacturing innovation and scale, as well as advanced technology innovation. We identify research domains with large cost reduction potential, including improving efficiencies, improving silicon utilization, and streamlining manufacturing processes and equipment, and briefly review ongoing research and development activities that impact these research domains. We conclude that multiple technology pathways exist to enable US$0.50/W sub(p) module manufacturing in the United States with silicon absorbers. More broadly, this work presents a user-targeted research and development framework that prioritizes research needs based on market impact.
Laparoscopic adjustable gastric banded plication (LAGBP) is a novel technique for weight loss surgery. This study evaluates the safety and short-term efficacy of LAGBP in a U.S. population. The ...setting was an academic medical center in the United States.
Patients who underwent LAGBP between 2012 and 2013 were reviewed retrospectively. Demographic characteristics, pre and perioperative details, body mass index (BMI), and percent excess weight loss (%EWL) were analyzed and compared to case-matched cohorts that had laparoscopic adjustable gastric banding (LAGB) or laparoscopic sleeve gastrectomy (LSG) during the same time period.
Seventeen patients (14 females) underwent LAGBP during the study period and were case-matched based on age, sex, race, and preoperative BMI with patients having LAGB and LSG. Mean age and preoperative BMI for LAGBP cohort were 42.5±11.6 years and 47.7±6.5 kg/m2, respectively. Mean operative time and estimated blood loss were 72±16 minutes and 23±23 mL, respectively, compared to 49±16 minutes (P=.002) and 15±23 mL for LAGB, and 66±18 minutes and 36±22 mL for LSG. There were no perioperative deaths. Hospital length of stay was 1.1±.3 days for LAGBP, versus .7±.3 days (P=.004) for LAGB, and 2.7±1.4 days (P<.001) for LSG. At 12-month follow-up, patients in the LAGBP and LAGB groups had undergone similar number of band adjustments (4.7 versus 5.1; P=.68). The %EWL was 46.1±14.8% for the LAGBP cohort, compared to 38.9±20.6% for LAGB, and 57.7±16% for LSG.
LAGBP is technically feasible and safe, and offers weight loss results positioned between LAGB and LSG at 1 year. To date, this is the largest U.S. series to compare this novel technique to more traditional weight loss procedures.
Actions of the 5‐HT4 serotonergic receptor partial agonist, tegaserod, were investigated on mucosal secretion in the guinea‐pig and human small intestine and on electrophysiological behaviour of ...secretomotor neurons in the guinea‐pig small intestinal submucosal plexus. Expression of 5‐HT4 receptor protein and immunohistochemical localization of the 5‐HT4 receptor in the submucosal plexus in relation to expression and localization of choline acetyltransferase and the vesicular acetylcholine (ACh) transporter were determined for the enteric nervous system of human and guinea‐pig small intestine. Immunoreactivity for the 5‐HT4 receptor was expressed as ring‐like fluorescence surrounding the perimeter of the neuronal cell bodies and co‐localized with the vesicular ACh transporter. Exposure of mucosal/submucosal preparations to tegaserod in Ussing chambers evoked increases in mucosal secretion reflected by stimulation of short‐circuit current. Stimulation of secretion had a relative high EC50 of 28.1 ± 1.3 μmol L−1, was resistant to neural blockade and appeared to be a direct action on the secretory epithelium. Tegaserod acted at presynaptic 5‐HT4 receptors to facilitate the release of ACh at nicotinic synapses on secretomotor neurons in the submucosal plexus. The 5‐HT2B receptor subtype was not involved in actions at nicotinic synapses or stimulation of secretion.
Lead is a confirmed neurotoxin, but questions remain about lead-associated intellectual deficits at blood lead levels < 10 μg/dL and whether lower exposures are, for a given change in exposure, ...associated with greater deficits. The objective of this study was to examine the association of intelligence test scores and blood lead concentration, especially for children who had maximal measured blood lead levels < 10 μg/dL. We examined data collected from 1,333 children who participated in seven international population-based longitudinal cohort studies, followed from birth or infancy until 5-10 years of age. The full-scale IQ score was the primary outcome measure. The geometric mean blood lead concentration of the children peaked at 17.8 μg/dL and declined to 9.4 μg/dL by 5-7 years of age; 244 (18%) children had a maximal blood lead concentration < 10 μg/dL, and 103 (8%) had a maximal blood lead concentration < 7.5 μg/dL. After adjustment for covariates, we found an inverse relationship between blood lead concentration and IQ score. Using a log-linear model, we found a 6.9 IQ point decrement 95% confidence interval (CI), 4.2-9.4 associated with an increase in concurrent blood lead levels from 2.4 to 30 μg/dL. The estimated IQ point decrements associated with an increase in blood lead from 2.4 to 10 μg/dL, 10 to 20 μg/dL, and 20 to 30 μg/dL were 3.9 (95% CI, 2.4-5.3), 1.9 (95% CI, 1.2-2.6), and 1.1 (95% CI, 0.7-1.5), respectively. For a given increase in blood lead, the lead-associated intellectual decrement for children with a maximal blood lead level < 7.5 μg/dL was significantly greater than that observed for those with a maximal blood lead level ≥ 7.5 μg/dL (p = 0.015). We conclude that environmental lead exposure in children who have maximal blood lead levels < 7.5 μg/dL is associated with intellectual deficits.
Within the last decade safe and practical ultrasound contrast agents have been introduced. Most of these are based on gasfilled microbubbles, which markedly enhance Doppler signals and, in some ...cases, also gray-scale images. The clinical improvements expected from ultrasound contrast is reviewed. Tissue-specific contrast agents constitute another area of potential clinical significance. One particular agent is taken up by the reticulo-endothelial system and produces so-called acoustic emission signals when imaged. An introduction to the unique clinical applications of acoustic emission is given. Harmonic imaging is a new contrast-specific imaging modality, which utilizes the nonlinear properties of some agents in an attempt to alleviate current limitations of ultrasound contrast studies. Examples of harmonic images are presented.
Motivated by a model of the response of vertically aligned carbon nanotube （VACNT） pillars in uniaxial compression, we consider the deformation of a class of compressible elastic-viscoplastic solids ...with a hardeningsoftening-hardening variation of flow strength with plastic strain. In previous work （Hutchens et al. 2011） a constitutive relation was presented and used to model the response of VACNT pillars in axisymmetric compression. Subsequently, it was found that due to a programming error the constitutive relation presented in the paper （Hutchens et al. 2011） was not the one actually implemented. In particular, the plastic flow rule actually used did not satisfy plastic normality. Here, we present the constitutive formulation actually implemented in the previous work （Hutchens et al. 2011）. Dynamic, finite deformation, finite element calculations are carried out for uniaxial compression, uniaxial tension and for indentation of a ＂half-space＂ by a conical indenter tip. A sequential buckling-like deformation mode is found in compression when there is plastic non-normality and hardening- softening-hardening. The same material characterization gives rise to a Lfiders band-like deformation mode in ten- sion. When there is a deformation mode with a sharp front along mesh boundaries, the overall stress-strain response contains high frequency oscillations that are a mesh artifact. The responses of non-softening solids are also analyzed and their overall stress-strain behavior and deformation modes are compared with those of hardening-softening- hardening solids. We find that indentation with a sharp indenter tip gives a qualitatively equivalent response for hardening and hardening-softening-hardening solids.
Our objective was to determine the efficacy of computer-assisted robotic laparoscopic Heller myotomy.
A 76-year-old woman with a significant history of achalasia was evaluated for laparoscopic Heller ...myotomy. The daVinci surgical system was used throughout the procedure.
Computer assistance allowed scaling of hand motions from a range of 2:1 to 5:1. Successful dissection of the esophageal musculature was accomplished, and a Toupet-type fundoplication was performed. The patient was discharged from the hospital the day after surgery with five port incisions, each <1 cm.
Telemanipulator computer-assisted surgical devices may have applications in procedures that require advanced and finely tuned motions, such as Heller myotomy. The benefits of extra magnification and three-dimensional imaging can help prevent esophageal perforation and identify residual circular muscle fibers.
To assess the feasibility and usefulness of contrast-enhanced sonography for tumor detection and guidance of liver VX2 tumor ablation and to evaluate post radiofrequency ablation effectiveness.
VX2 ...tumors were implanted into the livers of 6 rabbits. Both conventional and harmonic gray scale and power Doppler imaging were performed with a commercially available scanner to evaluate the liver tumors before and after intravenous injection of a sonographic contrast agent before and after radiofrequency ablation. Contrast-enhanced imaging was used to detect the tumors before ablation, to guide needle insertion, and to measure the ablation sites after radiofrequency ablation. Pathologic examination was performed for comparison.
Three tumors were seen without contrast enhancement, whereas 10 tumors (<1 cm) were detected with contrast enhancement. Intentionally, 2 tumors were completely ablated and 5 tumors were partially ablated. In 3 cases, incompletely ablated tumors could only be identified on contrast-enhanced Doppler imaging by enhancing the detection of residual tumor vascularity. There was excellent concordance between sonographic imaging and gross pathologic findings.
Contrast-enhanced sonographic imaging appears useful for detection of liver tumors and for guiding and monitoring tumor ablation therapies.
Background
Intraoperative cholangiography (IOC) is the current gold standard for biliary imaging during laparoscopic cholecystectomy (LC). However, utilization of IOC remains low. Near-infrared ...fluorescence cholangiography (NIRF-C) is a novel, noninvasive method for real-time, intraoperative biliary mapping. Our aims were to assess the safety and efficacy of NIRF-C for identification of biliary anatomy during LC.
Methods
Patients were administered indocyanine green (ICG) prior to surgery. NIRF-C was used to identify extrahepatic biliary structures before and after partial and complete dissection of Calot’s triangle. Routine IOC was performed in each case. Identification of biliary structures using NIRF-C and IOC, and time required to complete each procedure were collected.
Results
Eighty-two patients underwent elective LC with NIRF-C and IOC. Mean age and body mass index (BMI) were 42.6 ± 13.7 years and 31.5 ± 8.2 kg/m
2
, respectively. ICG was administered 73.8 ± 26.4 min prior to incision. NIRF-C was significantly faster than IOC (1.9 ± 1.7 vs. 11.8 ± 5.3 min,
p
< 0.001). IOC was unobtainable in 20 (24.4 %) patients while NIRF-C did not visualize biliary structures in 4 (4.9 %) patients. After complete dissection, the rates of visualization of the cystic duct, common bile duct, and common hepatic duct using NIRF-C were 95.1, 76.8, and 69.5 %, respectively, compared to 72.0, 75.6, and 74.3 % for IOC. In 20 patients where IOC could not be obtained, NIRF-C successfully identified biliary structures in 80 % of the cases. Higher BMI was not a deterrent to visualization of anatomy with NIRF-C. No adverse events were observed with NIRF-C.
Conclusions
NIRF-C is a safe and effective alternative to IOC for imaging extrahepatic biliary structures during LC. This technique should be evaluated further under a variety of acute and chronic gallbladder inflammatory conditions to determine its usefulness in biliary ductal identification.
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