Search

An estimated 59 000 persons die annually of infection with the rabies virus worldwide, and dog bites are responsible for 95% of these deaths. Haiti has the highest rate of animal and human rabies in the Western Hemisphere. This study describes the status of animal welfare, animal vaccination, human bite treatment, and canine morbidity and mortality in Haiti in order to identify barriers to rabies prevention and control. An epidemiologic survey was used for data collection among dog owners during government-sponsored vaccination clinics at fourteen randomly selected sites from July 2014 to April 2015. A total of 2005 surveys were collected and data were analysed using parametric methods. Over 50% of owned dogs were allowed to roam freely, a factor associated with rabies transmission. More than 80% of dog owners reported experiencing barriers to accessing rabies vaccination for their dogs. Nearly one-third of the dog population evaluated in this study died in the year preceding the survey (32%) and 18% of these deaths were clinically consistent with rabies. Dog bites were commonly reported, with more than 3% of the study population bitten within the year preceding the survey. The incidence of canine rabies in Haiti is high and is exacerbated by low access to veterinary care, free-roaming dog populations and substandard animal welfare practices. Programmes to better understand the dog ecology and development of methods to improve access to vaccines are needed. Rabies deaths are at historical lows in the Western Hemisphere, but Haiti and the remaining canine rabies endemic countries still present a significant challenge to the goal of rabies elimination in the region.

The Third Edition of the ACEI Global Guidelines Assessment (GGA) was evaluated for its effectiveness as an international assessment tool for use by early childhood educators to develop, assess, and improve program quality worldwide. This expanded study was conducted in nine countries [People’s Republic of China (2 sites), Guatemala, India, Italy, Mexico (2 sites), Peru (2 sites), Taiwan, Thailand, United States] to continue the investigation of the psychometric properties of the GGA. A total of 346 programs and 678 early care and education professionals participated in this study. Results primarily confirmed the findings of the previous study, (Hardin et al. in Early Child Educ J 41(2): 91–101, 2013), indicating that the GGA showed strong to moderate internal consistency and interrater reliability for subscale ratings across this larger number of countries and programs. The congruence of item ratings and written evidence to support ratings was acceptable, although some programs had lower participation in providing evidence. To test concurrent validity of ratings, external raters also evaluated a subset of programs (n = 44 from Peru and United States) on both the GGA and the Early Childhood Environment Rating Scale-Revised that showed moderate positive correlations. Patterns of program practices were also identified within and across the participating sites and countries. Results suggest that the GGA can be used as an onsite evaluation method that can help stakeholder participants (teachers and administrators) increase their awareness of program quality standards and serve as an assessment method for their own programs. In particular, the results suggest the GGA is a reliable and useful instrument that can be used effectively by early childhood stakeholders for assessing and improving program quality worldwide (Bergen and Hardin in Child Educ 91(4): 259–264, 2015).

Dogs harbor numerous zoonotic pathogens, many of which are controlled through vaccination programs. The delivery of these programs can be difficult where resources are limited. We developed a dynamic model to estimate vaccination coverage and cost-per-dog vaccinated. The model considers the main factors that affect vaccination programs: dog demographics, effectiveness of strategies, efficacy of interventions and cost. The model was evaluated on data from 18 vaccination programs representing eight countries. Sensitivity analysis was performed for dog confinement and vaccination strategies. The average difference between modelled vaccination coverage and field data was 3.8% (2.3%–5.3%). Central point vaccination was the most cost-effective vaccination strategy when >88% of the dog population was confined. More active methods of vaccination, such as door-to-door or capture-vaccinate-release, achieved higher vaccination coverage in free-roaming dog populations but were more costly. This open-access tool can aid in planning more efficient vaccination campaigns in countries with limited resources.

Background Severely obese patients considering bariatric surgery face a difficult decision given the tradeoff between the benefits and risks of surgery. The objectives of this study was to study the forces driving this decision and improve our understanding of the decision-making process. Methods A 64-item survey was developed to assess factors in the decision-making process for bariatric surgery. The survey included the decisional conflict scale, decision self-efficacy scale, EuroQol 5D, and the standard gamble. Patients were recruited from a regularly scheduled bariatric surgery interest group meeting associated with a large, university-based bariatric practice and administered a survey at the conclusion of the interest group. Logistic regression models were used to predict who pursued or still planned to pursue surgery at 12 months. Results 200 patients were recruited over an 8-month period. Mean age was 45 years; mean BMI was 48 kg/m 2 , and 77% were female. The 12-month follow-up rate was 95%. At 12 months, 33 patients (17.6%) had surgery and 30 (16.0%) still planned to have surgery. There was no association between age, gender, or obesity-associated conditions and surgery or plan to have surgery. Patients having surgery or still planning to have surgery had significantly worse scores for quality of life and better scores for decisional conflict (indicating readiness to make a decision). Conclusion The decision to have bariatric surgery is strongly associated with patientsʼ perceptions of their current quality of life. In addition, lower decisional conflict and higher self-efficacy are predictive of surgery. Interestingly, factors that clinicians might consider important, such as gender, age, and the presence of obesity-associated co-morbidities did not influence patientsʼ decisions.

BACKGROUND: Omitting extensive lymph node dissection could reduce esophagectomy morbidity in patients without lymph node metastases. Sentinel node biopsy may identify abdominal or thoracic lymph node metastases, thereby differentiating treatment. Feasibility of this approach was investigated in Western European esophageal cancer patients with advanced disease, without lymph node metastases at diagnostic work-up. METHODS: The sentinel node biopsy was performed in eight esophageal cancer patients with cT1-3N0 disease. One day pre-operatively, Tc-99m-labeled nanocolloid was endoscopically injected around the tumor. Lymphoscintigraphy was performed 1 and 3 h after injection. All patients underwent robotic thoracolaparoscopic esophagectomy with two-field lymph node dissection. Intraoperatively, sentinel nodes were detected by gamma probe. The resection specimen was analyzed for remaining activity by scintigraphy and gamma probe. RESULTS: Visualization rates of lymphoscintigraphy 1 and 3 h after tracer injection were 88 and 100 %, respectively. Intraoperative identification rate was 38 %. Postoperative identification was possible in all patients using the gamma probe to analyze the resection specimen. In 5/8 patients, lymph node metastases were found at histopathology, none of which was detected by the sentinel node biopsy. No adverse events related to the sentinel node biopsy were observed. CONCLUSIONS: In our advanced esophageal cancer patients who underwent thoracolaparoscopic esophagectomy, the sentinel node biopsy did not predict lymph node status. Probably the real sentinel node could not be identified due to localization adjacent to the primary tumor or bypassing due to metastatic tumor involvement. Therefore, we consider the sentinel node biopsy not feasible in advanced esophageal cancer.

The aim of this study was to evaluate the worldwide trends in surgical techniques for esophageal cancer surgery by comparing it to our survey from 2007. In addition, new questions were added for gastroesophageal junction (GEJ) cancer. An international survey on surgery of esophageal and GEJ cancer was performed among surgical members of the International Society for Diseases of the Esophagus, the World Organization for Specialized Studies on Disease of the Esophagus, the International Gastric Cancer Association. Also, surgeons from personal networks were contacted. The participants filled out a web based questionnaire about surgical strategies for esophageal and gastroesophageal cancer. The overall response rate was 478/1147 (42%). The respondents represented 49 different countries and 6 different continents. The annual cumulative number of esophageal and gastric resections per surgeon was low (≤11) in 11%, medium (11-21) in 17%, and high (≥21) in 72% of respondents. In a subgroup analysis of esophageal surgeons the number of high volume surgeons increased from 45 to 54% over the past 7 years. The preferred lymph node dissection was two-field in 86%. A gastric conduit was the preferred method of reconstruction in 95%. In 2014, the preferred approach to esophagectomy was minimally invasive transthoracic in 43%, compared with 14% in 2007. In minimally invasive transthoracic esophagectomy the cervical anastomosis was favored in 54% of respondents in 2014 compared with 87% in 2007. The preferred technique of construction of the cervical anastomosis was hand-sewn in 64% and stapled in 36%, whereas the thoracic anastomosis was stapled in 77% and hand-sewn in 23%. The preferred surgical approach for Siewert type 1 tumors (5-1 cm proximal of the GEJ) was esophagectomy in 93% of respondents, whereas 6% favored gastrectomy and 3% combined a distal esophagectomy with a proximal gastrectomy. For Siewert type 2 tumors (1-2 cm from the GEJ) an extended gastrectomy was favored by 66% of respondents, followed by esophagectomy in 27% and total gastrectomy in 7%. Siewert type 3 tumors (2-5 cm distal of the GEJ) were preferably treated with gastrectomy in 90% of respondents, esophagectomy in 6%, and extended gastrectomy in 4%. The preferred curative surgical treatment of esophageal cancer is minimally invasive transthoracic esophagectomy with a two-field lymph node dissection and gastric conduit reconstruction. A strong worldwide trend toward minimally invasive surgery is observed. The preferred surgical treatment of GEJ tumors is esophagectomy for Siewert type 1 tumors and gastrectomy for Siewert type 3 tumors. The majority of surgeons favor an extended gastrectomy for Siewert type 2 tumors.

Group B streptococcal phosphoglycerate kinase (GBS-PGK), a glycolytic enzyme, has previously been identified on the surface of group B streptococcus (GBS). To identify genes involved in surface expression of GBS-PGK, we performed Tn917 mutagenesis followed by quantification of PGK expressed on the GBS surface. Tn917 mutagenesis identified 4 genes (sag0966, sag0979, sag0980, and sag1003) that when disrupted, alter expression of GBS-PGK on the bacterial surface. Three of the identified genes were localized to a region of the GBS genome containing genes (sag0973–sag0977) predicted to be involved in resistance to antimicrobial peptides. One mutant isolate, designated NCS13sag1003::Tn917, was found to have increased sensitivity to the antimicrobial peptides bacitracin and nisin. In addition, all of the mutant strains assayed were found to have decreased β-hemolysis. In conclusion, we have identified genes involved in surface expression of GBS-PGK. These genes also appear to be involved in antimicrobial peptide resistance and regulate expression of the β-hemolysin.

The glycolytic enzyme, phosphoglycerate kinase (PGK) of group B streptococci (GBS), has previously been identified as expressed on the GBS cell surface. The data presented describes the ability of group B streptococcal phosphoglycerate kinase (GBS-PGK) to bind to plasminogen and to bind actin. GBS-PGK binding to plasminogen was inhibited by the lysine analogue, 6-aminocaproic acid, suggesting plasminogen binding is achieved through GBS-PGK lysine residues. In addition to GBS-PGK surface expression, GBS-PGK was also found to be released from the bacterial cell suggesting GBS-PGK may affect its environment independent of GBS. To determine the effect of GBS-PGK on the actin cytoskeleton within a host cell, GBS-PGK attached to green fluorescent protein was transfected into and expressed in HeLa cells. Transfected GBS-PGK disrupted the actin cytoskeleton resulting in a compact or ovoid shaped HeLa cell rather than a typical epithelioid appearance. In conclusion, we have shown GBS-PGK binds to plasminogen and actin. We have also shown that GBS-PGK can be released from the bacterial cell and that transfected GBS-PGK can alter the epithelial cell cytoskeleton.

Background Thoracoscopic oesophagectomy was introduced to reduce the morbidity of transthoracic oesophagectomy. The aim was to assess the short- and mid-term results of robot-assisted thoracoscopic oesophagectomy for oesophageal cancer. Methods Between October 2003 and May 2007, 47 patients with resectable oesophageal cancer underwent robot-assisted thoracoscopic oesophagectomy. Clinical data were collected prospectively. Results Conversion to thoracotomy was necessary in seven patients. Median operating time was 450 min and median blood loss 625 ml. Median postoperative ventilation time was 1 day, intensive care stay 3 days and hospital stay 18 days. Twenty-one of 47 patients had pulmonary complications. Three patients died in hospital. A median of 29 (range 8–68) lymph nodes was dissected and R0 resection was achieved in 36 patients. Twenty-three patients had stage IVa disease. After a median follow-up of 35 months, median disease-free survival was 15 (95 per cent confidence interval 12 to 18) months. Conclusion Robot-assisted thoracoscopic oesophagectomy was oncologically acceptable. Operating time, blood loss and pulmonary complications might decrease with further experience.

In patients with esophageal cancer, radical surgical resection of the esophagus and surrounding lymph nodes is the only curative treatment option. Nevertheless, no standard surgical procedure exists. The aims of the present study were to gain insight into the frequencies of the various surgical techniques in esophageal cancer surgery as applied by surgeons throughout the world and to identify intercontinental differences regarding surgical techniques. Surgeons with particular interest in esophageal surgery, including members of the International Society for Diseases of the Esophagus, the European Society of Esophagology Group d'Etude Européen des Maladies de l'Oesophage and the OESO, were invited to participate in an online questionnaire. Questions were asked regarding approach to esophagectomy, extent of lymphadenectomy (LND), type of reconstruction, and anastomotic techniques. Subanalyses were performed for the surgeons' case volume per year, years of experience in esophageal cancer surgery, and continent. Of 567 invited surgeons, 269 participated, resulting in an overall response rate of 47%. The responders currently performing esophagectomies (n= 250; 44%), represented 41 countries across the six continents. Fifty-two percent of responders favor open transthoracic esophagectomy (TTE) over transhiatal esophagectomy (THE) or minimally invasive esophagectomy (MIE). THE is preferred by 26%, whereas MIE is favored by 14%. Eight percent have no preference for one approach to esophagectomy over the other. The extent of LND is most frequently the 2-field, routinely performed by 73% of surgeons. The continuity of the digestive tract is most frequently restored with a gastric conduit (85%). In open TTE, the anastomosis is routinely created in the neck by 56% of responders and in the chest by 40%. Cervical anastomoses are routinely fashioned by means of a handsewn technique by 65% of responders, while 35% favor the stapled technique. The cervical incision is predominantly performed vertically on the left side of the neck (routinely by 66%). A horizontal neck incision is routinely carried out by 19% of responders and a vertical right-sided incision by 11%. Significant differences in surgical techniques could be detected between low- and high-volume surgeons, between surgeons withor=10 versusor=21 years of experience, and between surgeons from different continents. In conclusion, currently the most commonly applied surgical procedure is the open right-sided transthoracic approach with a two-field lymphadenectomy, using a gastric tube anastomosed at the left side of the neck by means of a handsewn, end-to-side technique. The results of this survey provide baseline data for future research and for the development of international guidelines.

Neoadjuvant chemotherapy may improve the outcome of esophageal cancer after esophagectomy, but is accompanied by considerable toxicity by collateral destruction of normal cells. Such side effects may be avoided by developing therapies that specifically target molecular characteristics of tumors. The aim of the present study was to determine the proportion of esophageal squamous cell carcinoma (ESCC) patients that could possibly benefit from (a combination of) currently available targeted therapies, by assessing the frequency of immunohistochemical expression of their target molecular markers in ESCC tissues. Sections from a validated tissue microarray comprising 108 ESCCs were immunohistochemically stained for Bcl-2, c-KIT, cyclo-oxygenase-2 (COX-2), cyclin D1, estrogen receptor (ER), epidermal growth factor receptor (EGFR), Her-2/neu, progesterone receptor (PR), and vascular endothelial growth factor (VEGF). VEGF, cyclin D1, EGFR, and COX-2 could be detected in 55, 42, 40, and 40%, respectively. Her-2/neu, Bcl-2, and c-KIT were detected in 12, 11, and 10% of the tumors, respectively. No nuclear expression of ER or PR was noticed. Concurrent expression of two markers was noticed in 28% of ESCCs, whereas 25% of ESCCs showed concurrent expression of three markers. The concurrent expression of two of the most frequently expressed markers (VEGF, cyclin D1, EGFR, and COX-2) ranged from 11 (COX-2 and EGFR) to 26% (cyclin D1 and VEGF). The expression of all of these four markers was seen in 5% of ESCCs. Promising targets for molecular therapy in ESCC appear to be COX-2, VEGF, EGFR, and cyclin D1, as they are frequently overexpressed. Phase II clinical studies on these molecular markers may therefore be warranted. The role for targeted therapy against ER, PR, Her-2/neu, c-KIT, or Bcl-2 in ESCC seems limited.

Tissue microarray (TMA) technology has been developed to facilitate high-throughput immunohistochemical and in situ hybridization analysis of tissues by inserting small tissue biopsy cores into a single paraffin block. Several studies have revealed novel prognostic biomarkers in esophageal squamous cell carcinoma (ESCC) by means of TMA technology, although this technique has not yet been validated for these tumors. Because representativeness of the donor tissue cores may be a disadvantage compared to full sections, the aim of this study was to assess if TMA technology provides representative immunohistochemical results in ESCC. A TMA was constructed containing triplicate cores of 108 formalin-fixed, paraffin-embedded squamous cell carcinomas of the esophagus. The agreement in the differentiation grade and immunohistochemical staining scores of CK5/6, CK14, E-cadherin, Ki-67, and p53 between TMA cores and a subset of 64 randomly selected donor paraffin blocks was determined using kappa statistics. The concurrence between TMA cores and donor blocks was moderate for Ki-67 (kappa = 0.42) and E-cadherin (kappa = 0.47), substantial for differentiation grade (kappa = 0.65) and CK14 (kappa = 0.71), and almost perfect for p53 (kappa = 0.86) and CK5/6 (kappa = 0.93). TMA technology appears to be a valid method for immunohistochemical analysis of molecular markers in ESCC provided that the staining pattern in the tumor is homogeneous.

This paper presents the structural response of a full-scale composite strut and a hybrid strut/ship connection. The strut is comprised of a pultruded E-glass/epoxy core, a filament wound carbon/epoxy structural section, and an E-glass/vinyl ester outer wrap used to protect the strut from the sea environment. The connection of the strut to the ship is made using an adhesively bonded aluminum boot that acts as the ship interface. A summary of the strut design, the experimental setup, and instrumentation details, is presented. Testing includes studies of the low-level cyclic flexural response about the weak axis, flexure about the strong axis, and combined weak axis flexure and torsion. A test to peak load was conducted about the strong axis and a high-displacement amplitude test was conducted about the weak axis. The predominant failure mode during the high-level strong axis test consisted of failure in the aluminum material at the base of the test article and failure in the aluminum flanges that mounted the boot to the test frame. No signs of distress were observed in the composite material, either visually or using the instrumentation. The peak load about the strong axis exceeds the design moment by a factor of 3.6. A finite element analysis of the strut is also provided along with a comparison to the test results and shows that the rotational stiffness of the hybrid connection considerably influences the overall response.

The Objective Structured Clinical Examination (OSCE) is becoming more widely used for performance assessment in dentistry. The department of pediatric dentistry at Baylor College of Dentistry (BCD) began incorporating the OSCE into its curriculum in 1995. This article describes the evolution of the department's use of the OSCE and its impact on teaching and the curriculum. The discussion focuses on logistics and station design, curricular content and order, student anxiety, writing and scoring exams, and curriculum assessment. BCD has found that using an OSCE-based testing format is time-consuming and labor-intensive, but provides unprecedented feedback about students' understanding and pinpoints areas of confusion. The demands of an OSCE-based testing format reveal that students can master, to the level of competency, only a finite amount of information in a given time period. The timed, interactive aspects of the OSCE create high levels of student anxiety that must be addressed. Writing and scoring OSCE items are different from traditional test items. The OSCE is a valuable mechanism to assess the students' progress toward competency. This review of the process of incorporating OSCEs into a curriculum is the foundation for future assessment of the OSCE and its use for curricular improvement.

The purpose of this study was to examine preservice elementary teachers’ understanding of the concepts of photosynthesis and inheritance, to explore their self-efficacy beliefs in the teaching of science, and to investigate the relationship between these two issues. Data was gathered through the use of a misconception instrument and science teaching efficacy beliefs instruments. Seventy-nine preservice elementary teachers participated in this study. The results showed that participants held alternative conceptions regarding photosynthesis and inheritance and have generally positive self-efficacy beliefs regarding science teaching. The results also suggested that those participants with fewer alternative conceptions regarding photosynthesis had relatively high personal science teaching efficacy. Teachers are clearly a central component for student success in learning science; however, in 1983, Feistritzer and Boyer reported that among elementary teachers, understanding science concepts was at a low level. Previous studies have shown that elementary teachers often have negative attitudes toward science (Shrigley, 1974), have science anxiety (Czerniak & Chiarelott, 1990), have low science interest (Tilgner, 1990), and do not have confidence in their ability to teach science (DeTure, Gregory, & Ramsey, 1990). Studies also have found that elementary teachers generally possess a low level of knowledge regarding the concepts, facts, and skills concerning science (Stevens & Wenner, 1996; Victor, 1962; Wenner, 1993). A number of studies have documented that both preservice and inservice elementary teachers frequently hold alternative conceptions (or misconceptions) for a variety of science concepts and harbor misunderstandings (Atwood & Atwood, 1996; Schoon, 1993; Schoon & Boone, 1998). This often causes elementary teachers to avoid teaching science to children (Czerniak & Chiarelott, 1990; Westerback, 1982) or to spend less time teaching science in comparison to other subjects (Westerback, 1982).

Careful measurements of knowledge, attitude, and psychomotor and communication skills are necessary components of testing in a competency-based approach to education in dentistry. In an effort to address these requirements, Baylor College of Dentistry (BCD), Dallas, Texas, has applied Purposeful Assessment Techniques (PAT) to the Objective Structured Clinical Examination (OSCE) currently in use. PAT are those techniques that allow one to work toward development of linear measurement scales that are "person-free" and "item-free." Person-free measurement means that useful data are produced regardless of the group being measured and item-free measurement means that it does not matter which mix of items is completed over the course of an assessment. The Rasch probabilistic model and a guiding definition of Objective Measurement were used in an effort to implement PAT for the BCD OSCE. A Rasch analysis of a BCD-administered OSCE produced an item map that demonstrated the range of difficulty of items by student performance. This item map can be used to determine which items can be repeated on subsequent tests to allow for linear measurement of students9 progression through the curriculum. The movement toward PAT described in this paper demonstrates how careful and evolving measurement in dental education can be of great benefit to faculty, staff, students, and the public.

We examined the effects of slash-and-burn of a tropical dry forest (TDF) and pasture establishment on fine root (≤1 mm) biomass and productivity. We also determined the seasonal changes of fine roots. The study was conducted in the coast of Jalisco, Mexico where the dominant vegetation is tropical dry forest. Two 33 m×100 m experimental plots with undisturbed TDF were slashed-and-burned by local farmers. Two adjacent plots with TDF were established as control sites. After slash-and-burning of the experimental plots, these were seeded with three pasture grasses along with two local maize varieties. Root sampling was initiated in March 1993 and roots were collected monthly until February 1994. Eight soil samples were collected randomly in each plot at each sampling date to a depth of 10 cm with a soil corer. Each soil core was divided in three depths: 0–2, 2.1–5, and 5–10 cm. Roots were separated in two size categories: fine (≤1.0 mm) and small (1.1–5 mm). Fine roots were separated into live and dead. Productivity of fine roots for each depth was estimated from the biomass data. Live fine root biomass in the 0–10 cm profile decreased due to burning but 47% of the fine root mass loss was at the 0–2 cm depth. Dead fine root biomass diminished significantly only at this depth. Total fine root productivity and mortality was 42–45% higher in TDF than in pasture in the first 5 cm of soil. About 86 and 76% of the fine root productivity in TDF and pasture, respectively, occurred in the first 5 cm of soil. Fine root turnover rates were high and similar in both ecosystems. Live fine root biomass in TDF and pasture increased in response to rainfall, particularly in the first 5 cm of soil. Mean annual live fine root biomass was significantly greater in TDF than in pasture only at the 0–2 cm depth. Mean biomass per cm of soil was greater in the first 2 cm of the profile in both TDF and pasture and it represented one-third of the fine root biomass in the 0–10 cm profile. There were no significant differences of small roots (1.1–5.0 mm in diameter) due to treatment, seasonality or dynamics. Based on root turnover and root production, our results indicate that the relative importance of belowground processes for C supply to the soil in this TDF is greater than the aboveground return.

Spontaneous dissection of the coronary arteries is quite rare. It is usually a catastrophic event with fatal outcome. We report two interesting cases of spontaneous dissection whose presentations exemplify the variable course the disorder may take. The first is the only report to our knowledge associated with aerobic exercise; the second is the only reported attempt at treatment with intracoronary thrombolysis.

The Centers for Disease Control and Prevention (CDC) was delegated authority to conduct the studies mandated in the Clinical Laboratory Improvement Amendments of 1988 (CLIA). Since that time, the CDC has been planning and implementing a research program, Evaluation of Quality of Laboratory Practices and Standards (EQLPS), aimed at demonstrating a clear linkage between patient outcome and laboratory practices and standards such as proficiency testing, quality assurance, and personnel standards. The goal of EQLPS is to improve the quality of laboratory medicine by providing a scientific and technical basis for laboratory practices and standards. In October 1995, the CDC will sponsor an Institute entitled "Frontiers in Laboratory Practice Research," during which strategies for conducting laboratory practice research will be discussed. The Institute should help identify research strategies that will eventually provide the information necessary to develop appropriate practice guidelines for laboratory medicine.

Ankle arthrodesis is commonly used in the treatment of ankle arthritis. The present study compared mesenchymal stem cell (MSC) bone allografts and proximal tibia autografts as adjuncts in performing ankle arthrodesis. A total of 109 consecutive ankle fusions performed from 2002 to 2008 were evaluated retrospectively. Of the 109 fusions, 24 were excluded from the present study, leaving 85 patients who had undergone ankle arthrodesis. Of the 85 patients, 41 had received a proximal tibia autograft and 44, an MSC bone allograft. These 2 groups were reviewed and compared retrospectively at least 2 years postoperatively for the overall fusion rate, interval to radiographic fusion, and interval to clinical fusion. A modified and adjusted American College of Foot and Ankle Surgeons ankle scale was used to measure patient satisfaction. The overall fusion rate was 84.1% in the MSC bone allograft group and 95.1% in the proximal tibia autograft group (p = .158). The corresponding mean intervals to radiographic fusion were 13.0 ± 2.5 weeks and 11.3 ± 2.8 weeks (p ≤ .001). The interval to clinical fusion was 13.1 ± 2.1 weeks and 11.0 ± 1.5 weeks (p ≤ .001) in the MSC bone allograft and proximal tibia autograft group, respectively. No statistically significant difference was found in the fusion rates between the MSC bone allograft and proximal tibia autograft groups. Also, no statistically significant difference was found between the preoperative and postoperative scores using a modified and adjusted American College of Foot and Ankle Surgeons ankle scale between the 2 groups (p = .41 and p = .44, respectively). A statistically significant delay to radiographic and clinical fusion was present in the MSC bone allograft group compared with the proximal tibia autograft group; however, no difference was found in patient satisfaction.

As the esophagus has a unique longitudinal lymphatic drainage system in the submucosal layer, lymph node metastases of esophageal cancer can occur along the entire esophagus from the cervical to the abdominal part. The optimal treatment for esophageal cancer, therefore, consists of transthoracic en bloc esophagectomy (TTE) with an extensive mediastinal and abdominal lymph node dissection (LND). This approach through thoracotomy is accompanied by signifi cant morbidity, which is predominantly due to cardiopulmonary complications. To reduce the surgical trauma and thus the morbidity of open TTE, less-invasive surgical techniques such as transhiatal esophagectomy (THE) were introduced. A randomized controlled trial on TTE vs. THE has shown the latter to carry a lower complication rate. However, since with THE the esophagus is stripped out of the mediastinum, only a limited LND can be carried out without dissection of the upper mediastinal lymph nodes. Consequently, a trend toward a better survival for TTE over THE was detected. Statistical signifi cance was not reached, but this was most probably a result of the fact that the study was underpowered. Minimally invasive esophagectomy (MIE) was introduced to further reduce morbidity. With regard to MIE, the world’s largest series on thoracolaparoscopic esophagectomy has shown a signifi cantly lower blood loss and morbidity compared to open TTE. However, the survival after this procedure was worse than after open TTE (3-year overall survival rate for Stage II patients of 20 vs. 50%, respectively). This could be explained by the fact that a less extensive en bloc resection was preformed due to the disadvantages of “conventional” scopic surgery, such as a 2D vision, disturbed eye-hand coordination, and fewer degrees of freedom. 8 Robot-Assisted Thoracolaparoscopic Esophagectomy

SUMMARY The outcome of esophagectomy could be improved by optimal diagnostic strategies leading to adequate preoperative patient selection. Neoadjuvant therapy could improve outcome by increasing the number of radical resections and by controlling metastatic disease. The purposes of this study were to gain insight into the current worldwide practice of staging modalities and neoadjuvant therapy in esophageal cancer, and to detect intercontinental differences. Surgeons with particular interest in esophageal surgery, including members of the International Society for Diseases of the Esophagus, the European Society of Esophagology – Group d'Etude Europeen des Maladies de l'Oesophage, and the OESO, were invited to participate in an online questionnaire. Questions were asked regarding staging modalities, neoadjuvant therapy, and response evaluation applied in esophageal cancer patients. Of 567 invited surgeons, 269 participated resulting in a response rate of 47%. The responders currently performing esophagectomies (n= 250; 44%) represented 41 countries across the six continents. Esophagogastroscopy with biopsy and computed tomography (CT) scanning were routinely performed by 98% of responders for diagnosing and staging esophageal cancer, while endoscopic ultrasound (EUS) and barium esophagography were routinely applied by 58% and 51%, respectively. Neoadjuvant therapy is routinely administered by 33% and occasionally by 63% of responders. Of the responders that administer identical neoadjuvant regimens to esophageal adenocarcinoma (AC) and squamous cell carcinoma, 54% favor chemoradiotherapy. For AC, chemotherapy is preferred by 31% of the responders that administer neoadjuvant therapy, whereas for squamous cell carcinoma, the majority of responders (38%) prefer chemoradiotherapy. Response to neoadjuvant therapy is predominantly assessed by CT scanning of the chest and abdomen (86%). Barium esophagography, EUS, and combined CT/PET scan are requested for response monitoring in equal frequency (25%). Substantial differences in applied staging modalities and neoadjuvant regimens were detected between surgeons from different continents. In conclusion, currently the most commonly applied diagnostic modalities for staging and restaging esophageal cancer are CT scanning of the chest and abdomen, gastroscopy, barium esophagography and EUS. Neoadjuvant therapy is routinely applied by one third of the responders. Intercontinental differences have been detected in the diagnostic modalities applied in esophageal cancer staging and in the administration of neoadjuvant therapy. The results of this survey provide baseline data for future research and for the development of international guidelines.

Background: Water-soluble contrast swallow examination is routinely carried out after oesophagectomy to detect leakage of the cervical oesophagogastric anastomosis. This study evaluated the diagnostic accuracy and clinical value. Methods: Patients with oesophageal carcinoma who underwent oesophagectomy with gastric conduit formation and a hand-sewn cervical anastomosis between 1989 and 2003 were reviewed on outcome of routine aqueous contrast swallow examination (RACSE) and appearance of clinical anastomotic leakage. Results: An RACSE was carried out in 207 (82%) of 252 patients on postoperative day 8 (range 3–15). In 45 patients, no RACSE was executed, mainly because of a prolonged stay in intensive care unit. In 18 (9%) of 207 cases, the RACSE could not be interpreted by the radiologist. In 19 (53%) of 36 patients who developed a clinical leakage, the leak had already manifested clinically before the routine contrast examination was planned. Taken together, the false-positive rate was 8%, the false-negative rate 48%, sensitivity 52%, specificity 92%, positive predictive value 46% and negative predictive value 93%. No significant differences were found between the accuracy of RACSE in end-to-end or end-to-side cervical anastomoses. Conclusion: Given the very low sensitivity and low positive predictive value and given the fact that in 53% of patients with a clinical leak, the leakage had appeared clinically before the contrast swallow examination was routinely planned, we propose to abandon the routine contrast swallow examination after oesophagectomy to detect cervical anastomotic leakage. Alternatively, anastomotic integrity can be tested by drinking small amounts of water with simultaneous observation of the cervical wound.

This is the first report of a thoracoscopic esophagectomy for a giant leiomyoma of the upper esophagus aided by a robotic system. A 37-year-old man presented with progressive dysphagia and nocturnal aspiration. Endoscopic ultrasound and CT scan of the chest revealed an upper esophageal tumor of 9 x 4 cm arising from the muscularis mucosae. A fine needle aspiration showed clustering of mesenchymal cells, confirming the diagnosis of a stromal cell tumor. A mesenchymal malignancy was suspected because the tumor was located in the upper esophagus and was arising from the muscularis mucosae, both uncommon for a leiomyoma. Moreover, tumor size, an indicator of potential malignancy if >3 cm, was 9 cm. Therefore, an esophagectomy was performed thoracoscopically with the formation of a gastric conduit via laparotomy and a hand-sewn end-to-side cervical anastomosis. The thoracoscopic phase was performed with support of the da Vincitrade mark robotic system, which allowed for an excellent 3-dimensional view and a precise dissection of the esophagus along the vital mediastinal structures. The duration of the thoracoscopic part was 115 min and that of the total procedure was 270 min. Blood loss during the thoracoscopic phase was 50 mL; total blood loss was 200 mL. The patient was ventilated for 1 day; his total intensive care stay was 2 days. He left the hospital in good condition on the 11th postoperative day. Histopathological examination combined with immunohistochemistry revealed a leiomyoma of 9.0 x 5.0 x 2.5 cm. After 3 years of follow-up, the patient is in good health.

Aims: The mammalian target of rapamycin (mTOR), an important regulator of protein translation and cell proliferation, is activated in various malignancies. In a randomised controlled trial of advanced renal cell carcinoma patients, targeted therapy to mTOR by means of rapamycin analogues has been shown to significantly improve survival. An in vitro study has revealed that mTOR is activated in oesophageal squamous cell carcinoma (OSCC) cell lines and that mTOR expression is inhibited by rapamycin. The objectives of this histological study were to determine the proportion of OSCC tissues with activated mTOR (p-mTOR) expression, thereby assessing the percentage of patients with OSCC that would possibly benefit from neoadjuvant rapamycin therapy, and to identify the clinicopathological features of these potentially rapamycin-sensitive tumours. Methods: The expression of p-mTOR (Ser2448) was immunohistochemically assessed in a validated tissue microarray comprising triplicate tissue biopsy cores of 108 formalin-fixed, paraffin-embedded OSCCs. Staining results were correlated with clinicopathological data. Results: Normal oesophageal epithelium was negative for p-mTOR. Activated mTOR expression was located in the cytoplasm of oesophageal tumour cells. 26 (25%) of 105 assessable OSCCs showed tumour cells with positive staining for activated mTOR. Activated mTOR expression was associated with a lesser degree of differentiation only (p = 0.024). No correlation was detected between p-mTOR and the proliferation marker Ki-67. Conclusions: Activated mTOR can be detected in one-quarter of OSCCs. Since this subset of patients may potentially benefit from mTOR inhibiting therapy, a phase II clinical trial of neoadjuvant mTOR-inhibiting therapy in patients with OSCC may be considered.

Dear Editor, With interest we read the article by Galvani and co-authors in which they describe their initial experience with laparoscopic transhiatal esophagectomy partly aided by a robotic system [1]. Their series consists of 18 selected patients with Barrett’s esophagus and high-grade dysplasia (n = 9), adenocarcinoma in situ (n = 2), superficial adenocarcinoma (n = 5) or T2–3 esophageal adenocarcinoma (n = 2) without clinical evidence of lymph node metastases. Since robot-assisted laparoscopic esophagectomy in these patients was accompanied by low blood loss, low cardiopulmonary complication rate, and no in-hospital mortality, the authors conclude their surgical technique to be a safe and effective alternative for the treatment of esophageal adenocarcinoma. We agree with the authors that this procedure may be safe and effective for the treatment of high-grade dysplasia or in situ carcinoma; however, for esophageal cancer some remarks have to be made regarding its oncological effectiveness. The mean number of 14 lymph nodes dissected is fewer than in the open transhiatal (mean 16) and transthoracic (mean 31) approach [2]. The authors fail to describe the location of these lymph nodes, retrieved either abdominally (e.g. left gastric artery nodes) or mediastinally. Most probably the mediastinal lymphadenectomy was limited to the perioesophageal and the carinal stations. Several studies however, have shown that distal esophageal adenocarcinomas frequently metastasize to lymph nodes located in the upper mediastinum [3,4]. When performing the hybrid robot-assisted transhiatal approach, these potential metastatic lymph nodes will be left in situ. Recently, two series of robot-assisted thoracolaparoscopic esophagolymphadenectomies have been published describing a technique where a proper mediastinal lymph node dissection is performed including the bilateral paratracheal and aortopulmonary window nodes [5, 6]. This may be the reason for the relatively high rate of tumor recurrence in the Galvani series [1]. After a mean follow-up of 22 months, two (11%) patients had died and three (17%) had recurrence in a patient population with 50% of patients diagnosed with high-grade dysplasia and 50% with superficial adenocarcinoma with neither lymph node metastases nor tumor involvement in the resection margins. The technique described by Galvani et al. may therefore not be suitable for esophageal cancer, but rather for high-grade dysplasia.

Definition of improved therapeutic regimens of interferon-alpha (IFN-alpha) for the treatment of Kaposi's sarcoma (KS) would be useful since currently recommended doses are sometimes associated with unacceptable toxicity. IFN concentrations were measured in serum samples from men with AIDS-associated KS who were enrolled in a trial of IFN-alpha alone (16 patients) or a trial of IFN-alpha combined with zidovudine (25 patients). Analyses were done to examine the relationship between the dose of IFN-alpha, blood level of IFN, and the patient's clinical response to treatment. There was no correlation between dose of zidovudine given and response. As expected, there was a high correlation between dose of IFN-alpha and blood level in both studies (p less than 0.001). Furthermore, we found relationships between clinical response and both dose of IFN-alpha and blood level achieved. In the two studies combined, among men with greater than 200 CD4+ cells/mm3 of blood at baseline on average daily doses of greater than or equal to 10 million international units (MIU) of IFN-alpha, 13/19 (68%) responded compared to 6/17 (35%) on less than MIU (p = 0.05). Similarly, of men with IFN blood levels greater than or equal to 100 IU/mL 12/16 (75%) responded compared to 7/20 (35%) of those with blood levels less than 100 IU/mL (p = 0.02). The dose and blood levels of IFN achieved and maintained may be important factors in determining responses of KS. Additional clinical trials of IFN-alpha treatment of KS at doses about 10 MIU/day appear warranted.

The transient response of a vertical fracture, uniformly pressurized by a fluid, is analyzed. The fracture extends over the full height of an horizontal poroelastic layer bounded by two semi-infinite impermeable elastic regions. The study focuses on the calculation of the fracture volume Af(t), given an arbitrary pressurization history pf(t). The first step in solving this general problem is to reduce it to a superposition of two modal responses, corresponding to the sudden application of a constant normal stress and a constant pore pressure in the fracture. In a second step, the transient variation of the fracture volume (response function) for each of the loading modes is determined numerically using a finite-element formulation. These modal response functions are first calculated for the particular case where the drained elastic coefficients of the permeable layer are the same as those of the impermeable bounding barriers. The results are then extended to the more general case characterized by a contrast of elastic properties between the permeable and impermeable layers. The factors influencing the fracture response are examined, with special attention being given to the role of the poroelastic constants, and the stiffness ratio between the layers. This work is applicable to the PKN model for hydraulically-driven fracture propagation. It is concluded that poroelastic effects related to this model can be both greater than previous estimates would suggest and occur more rapidly if the permeable layer of rock is bounded by stiffer layers.

We studied the relationship between early human immunodeficiency virus type 1 (HIV-1) specific immune responses and pathogenesis of infection in participants enrolled in the multicenter AIDS cohort study (MACS). Sera collected at 6-month intervals for 2 years (visit 1-5) from 39 persons who seroconverted by enzyme-linked immunosorbent assay (ELISA) 6 months (visit 2) after enrollment were examined for isotype-specific Western blot reactivity, neutralizing antibodies (NA) against two divergent strains of HIV-1 (HIV-1IIIB and HIV-1RF), and for antibodies capable of participating in antibody-dependent, cell-mediated cytotoxicity (ADCC). These results were compared with changes in CD4+ cell number and episodes of lymphadenopathy. Twenty-five subjects had antibodies of at least one isotype reactive to at least one HIV-1 protein by Western blot at visit 1, before they became ELISA positive. NA reactive with HIV-1IIIB were detected before those reactive with HIV-1RF. NA were first observed in 11 sera at visit 2, in 22 sera at visit 3, and in 3 sera at visit 4; sera from three patients remained nonneutralizing through visit 5. In most cases, NA were detected after a decline in CD4+ cell numbers. The data are consistent with the interpretation that NA develop after about 16 to 18 months of declining CD4+ cell numbers, following which the rate of decline in CD4+ cell numbers slows. In contrast, HIV-1 envelope antigen-specific ADCC responses were first observed in 11 subjects at visit 1 when all 39 were NA and ELISA negative, in 12 subjects at visit 2, in 13 subjects at visit 3, and 1 subject at visit 4. Early ADCC responses were associated with high mean % CD4+ cell numbers and absence of lymphadenopathy throughout the 2-year observation period. Not all subjects who developed ADCC developed NA. In some subjects, ADCC and NA were detectable for the first time at the same visit, for others ADCC was detectable prior to NA, and for a few NA was detectable prior to ADCC. These findings suggest that ADCC and neutralization are mediated by different antibody populations, that they may partially inhibit the progress of HIV-1 infection, and that the late appearance of NA may relate to the failure of immunity to effect recovery from this infection.

Purpose: Segmentation quality can affect quantitative image feature analysis. The objective of this study is to examine the relationship between computed tomography (CT) image quality, segmentation performance, and quantitative image feature analysis. Methods: A total of 90 pathology proven breast lesions in 87 dedicated breast CT images were considered. An iterative image reconstruction (IIR) algorithm was used to obtain CT images with different quality. With different combinations of 4 variables in the algorithm, this study obtained a total of 28 different qualities of CT images. Two imaging tasks/objectives were considered: 1) segmentation and 2) classification of the lesion as benign or malignant. Twenty-three image features were extracted after segmentation using a semi-automated algorithm and 5 of them were selected via a feature selection technique. Logistic regression was trained and tested using leave-one-out-cross-validation and its area under the ROC curve (AUC) was recorded. The standard deviation of a homogeneous portion and the gradient of a parenchymal portion of an example breast were used as an estimate of image noise and sharpness. The DICE coefficient was computed using a radiologist’s drawing on the lesion. Mean DICE and AUC were used as performance metrics for each of the 28 reconstructions. The relationship between segmentation and classification performance under different reconstructions were compared. Distributions (median, 95% confidence interval) of DICE and AUC for each reconstruction were also compared. Results: Moderate correlation (Pearson’s rho = 0.43, p-value = 0.02) between DICE and AUC values was found. However, the variation between DICE and AUC values for each reconstruction increased as the image sharpness increased. There was a combination of IIR parameters that resulted in the best segmentation with the worst classification performance. Conclusion: There are certain images that yield better segmentation or classification performance. The best segmentation Result does not necessarily lead to the best classification Result. This work has been supported in part by grants from the NIH R21-EB015053. R Nishikawa is receives royalties form Hologic, Inc.

Transthoracic esophagectomy with extended lymph node dissection is associated with higher morbidity rates than transhiatal esophagectomy. This morbidity rate could be reduced by the use of minimally invasive techniques. The feasibility of robot-assisted thoracoscopic esophagectomy (RTE) with mediastinal lymphadenectomy was assessed prospectively.This study investigated 21 consecutive patients with esophageal cancer who underwent RTE using the Da Vinci robotic system. Continuity was restored with a gastric conduit and a cervical anastomosis.A total of 18 (86%) procedures were completed thoracoscopically. The operating time for the thoracoscopic phase was 180 min (range, 120-240 min), and the median blood loss was 400 ml (range, 150-700 ml). A median of 20 (range, 9-30) lymph nodes were retrieved. The median intensive care unit stay was 4 days (range, 1-129 days), and the hospital stay was 18 days (range, 11-182 days). Pulmonary complications occurred in 10 patients (48%), and one patient (5%) died of a tracheoneoesophageal fistula.In this initial experience, robot-assisted thoracoscopic esophagectomy was found to be feasible, providing an effective lymphadenectomy with low blood loss. Standardization of the technique and increased experience should reduce the complication rate, which is in the range of the rate for open transthoracic dissection.

BACKGROUND: Apple allergy is dominated by IgE antibodies against Mal d 1 in areas where birch pollen is endemic. Apples with significantly decreased levels of Mal d 1 would allow most patients in these areas to eat apples without allergic reactions. OBJECTIVE: The aim of this study was to inhibit the expression of Mal d 1 in apple plants by RNA interference. METHODS: In vitro -grown apple plantlets were transformed with a construct coding for an intron-spliced hairpin RNA containing a Mal d 1-specific inverted repeat sequence separated by a Mal d 1-specific intron sequence. The presence of the construct in transformants was checked by PCR. Expression of Mal d 1 in leaves was monitored by prick-to-prick skin testing in 3 patients allergic to apples and by immunoblotting with a Mal d 1-reactive mAb and with IgE antibodies against Mal d 1. RESULTS: After transformation, plantlets were selected on the basis of having a normal phenotype and growth rate. With PCR, in 6 of 9 selected plantlets, the presence of the gene-silencing construct was demonstrated. By skin prick test it was shown that a wild-type plantlet had significantly ( P < .05) higher allergenicity than 5 of the transformants. Reduction of expression of Mal d 1 was confirmed by immunoblotting. In wild-type and unsuccessful transformants, a strong band was detected with Mal d 1-reactive mAb 5H8 at the expected apparent M r of 17 kDa. This band was virtually absent in the transformants that carried the gene-silencing construct. With human IgE antibodies, the same observations were made. CONCLUSIONS: Mal d 1 expression was successfully reduced by RNA interference. This translated into significantly reduced in vivo allergenicity. These observations support the feasibility of the production by gene silencing of apples hypoallergenic for Mal d 1

Many endodontic sealers contain constituents that have been shown to inhibit the polymerization of resin cements. This may be important when prefabricated posts are cemented at the same appointment as root canal obturation. This study evaluated the effects of cementing posts with a resin cement immediately or at a delayed time period after obturation using Roth's 801 Elite Grade or AH26 sealer cements. The contribution of mechanical post-space preparation was also assessed as a critical variable. One hundred twenty extracted canines were randomly divided into eight experimental groups. The variables evaluated were the order of post preparation (either before or after obturation), the type of sealer used, and the time of post cementation. All teeth received a stainless steel #6 Parapost XP cemented with a resin cement, Panavia 21. Each experimental group underwent tensile testing for retention using an Instron universal testing machine. For both sealers posts cemented in teeth in which the canal was obturated before post-space preparation and thus had sealer-contaminated dentin removed by the space preparation procedure had significantly higher retentive values than those obturated after post-space preparation in which contaminated dentin might remain. Sealer used and time of cementation had no specific effect on retention. Achieving a clean, “freshened” den-tinal surface during mechanical post-space preparation seems to be a critical variable for post retention when a resin cement is used.

With interest we read the article by Sutherland et al. [1] in which they reported their initial experience with transhiatal robot-assisted total esophagectomy in 36 patients with esophageal cancer. Seven (19.4%) patients had postoperative incarcerated hiatal hernias and of those seven patients one died due to complications of the hernia repair. According to the authors, because the mediastinal dissection is done via laparoscopy, the hiatus is extensively dilated by the angles of the robotic arms, thereby increasing the risk of postoperative hiatal hernia. They therefore recommend performing a primary closure and reinforcement with mesh sutured to the gastric wall. In 2009 we published the largest series of robot-assisted thoracolaparoscopic esophagectomies (RTE) [2]. We have performed this procedure in more than 140 patients. Minimally invasive esophagectomy substantially reduces blood loss and postoperative hospital and intensive care stay compared to open esophagectomy [3]. We adhere to the combined thoracic and abdominal approach to provide optimal oncological clearance. To date, the largest study that compares transhiatal with transthoracic surgery showed an important trend toward improved survival after transthoracic esophagectomy [4]. The survival benefit is attributed to a more extensive lymphadenectomy in the mediastinum. Furthermore, studies have shown that distal esophageal carcinomas frequently metastasize to lymph nodes in the upper mediastinum [2, 5] We have not experienced any postoperative hiatal hernias in our patients so far. In our opinion, this is the result of performing the mediastinal dissection of the esophagus and surrounding lymph nodes through thoracoscopy instead of through the diaphragm. During the laparoscopic phase of RTE, the stomach is mobilized, regional abdominal lymph nodes are dissected, and the esophagus is pulled out of the mediastinum. By performing the mediastinal dissection thoracoscopically, the integrity of the hiatus is preserved and no incarcerated hiatal hernias will be encountered postoperatively. In this way, the above-mentioned recommendation of the authors can be abandoned. We would encourage Sutherland et al. to continue performing robot-assisted esophagectomies and to experience the many advantages of the robot-assisted thoracoscopic approach.

Dear Editor, With great interest we read the article by Schroder et al. to be published in a forthcoming issue of the Journal of Gastrointestinal Surgery in which they investigated the potential value of resecting the azygos vein in transthoracic esophagectomy for esophageal cancer. During (robot-assisted) thoracoscopic esophagectomy, the trunk of the azygos vein is often preserved as the scopic ligation of the numerous intercostal veins is technically difficult and time-consuming. One may postulate that this may negatively affect the extent of lymph node harvesting or the circumferential radical (R0) resection rate. Schroder et al. have, therefore, performed a prospective evaluation on the amount of lymph nodes surrounding the azygos vein in 92 patients with esophageal cancer having undergone open transthoracic esophagectomy with two-field lymphadenectomy. Lymph nodes near the azygos vein were identified in 65% of patients and metastases in these lymph nodes were found in 8%. They, therefore, conclude that the dissection of the azygos vein should not be abandoned, irrespective of the surgical approach. A comment should be made on the design of the study. As clearly shown in Figure 2 of their article, they dissected the azygos vein with the surrounding tissues sharply from the esophagus, which is not representative for (robot-assisted) thoracoscopic esophagectomy. In (robot-assisted) thoracoscopic esophagectomy, subsequent to the ligation of the azygos arch, the mediastinal dissection of the esophagus and surrounding tissues is performed sharply along the azygos trunk. In this way, the fatty tissue in between the esophagus and the azygos vein (including the lymph nodes of stations 108 and 110) as well as the thoracic duct are included in the esophageal resected specimen and are not left in situ when the trunk of the azygos vein is preserved. The number of lymph nodes that will be left in situ with (robot-assisted) thoracoscopic esophagectomy will, therefore, be much less than stated in this article. Indeed, in our recently published cadaveric study in which we investigated an identical research question, a mean amount of only 0.67 lymph nodes were identified around the azygos vein using the thoracoscopic dissection method. Using this approach, in 60% of cadavers, no lymph nodes near the azygos vein were detected at all. With regard to the possible effect of azygos vein preservation on the radical resection rate, we can refer to our first report on 21 esophageal cancer patients having undergone robot-assisted thoracoscopic esophagectomy. The R0 resection rate of 76% in that series is similar to that of open transthoracic esophagectomy. In our opinion, it is, therefore, justified to preserve the azygos trunk during (minimally invasive) transthoracic esophagectomy.

With interest we read the article by Kernstine and colleagues, describing their initial experience with totally robot-assisted thoracolaparoscopic esophagolymphadenectomy [1]. Their series consisted of three consecutive groups, each combining the robot-assisted thoracoscopic procedure with either open abdominal surgery, laparoscopy, or robot-assisted laparoscopy. These groups represent the learning curve followed by the authors. Indeed, we followed a similar strategy with our first 21 cases of robot-assisted thoracolaparoscopic esophagolymph-adenectomy, published in this journal in 2006 [2]. We experienced a steep learning curve and found a reduction of the pulmonary complication rate only after we had introduced the laparoscopic abdominal phase. This is consistent with previous reports of conventional thoracolaparoscopic esophagectomy [3]. Before introducing the procedure in our clinic, we tested the port position and the position of the robotic system extensively in a cadaveric study and came to a thoracic position similar to that presented by Kernstine et al. [1]. The position of the robotic system in our setup, however, is more dorsocranial [2, 4]. In our experience, the Da Vinci robotic system (Intuitive Surgical, Inc, Sunnyvale, CA, USA) has been very beneficial during the thoracoscopic phase of esophageal resection and lymph node dissection, allowing for a very precise dissection along the vital mediastinal structures. Yet, we have found the robotic system less suitable for the abdominal phase, requiring maneuvers with large amplitude leading to collisions of the robotic arms. Especially during the dissection along the greater curvature of the stomach, a large area of various positions must be covered. We therefore perform the abdominal phase by conventional laparoscopy using an ultrasonic dissector device. Selective use of the robot can save operating time. The median operating time for robot-assisted thoracoscopy with conventional laparoscopy is 7.5 h [2], compared with 11.2 h in case of the totally robotic procedure [1]. The authors do not describe any benefit from use of the robotic system during the abdominal phase. The median number of lymph nodes dissected in the current series was less than in our series (18 [1] vs 20 [2]), eventhough the authors denominate their procedure a three-field lymph node dissection. A formal cervical lymph node dissection was not performed in this series, so actually a two-field lymphadenectomy was performed [5]. With regard to the azygos vein, we agree with the authors that the trunk of this vein can be preserved during robot-assisted thoracoscopic esophagolymphadenectomy. We have recently shown in a cadaveric study that preservation of the azygos vein during thoracic esophagolymphadenectomy did not substantially affect the extent of mediastinal lymph node harvesting [6].

contralateral pleura make necessary a clinical study. We showed the feasibiliy of VAM dissection in resecting the paratracheal mesothelial cysts. Our cases showed the interest of using VAM for left-sided BPF. The dissection of the trachea through its natural route enables tracheal mobilization. The mediastinal shift is not a contraindication for VAM but represents a risk for contralateral pleural opening during transpericardial sternotomy or the modified Abruzzini technique. Previous mediastinoscopy is not a contraindication inasmuch as the morbidity is not increased and there is a low risk of contamination. Our 2 cases showed good technical results. The first patient is still alive 2 years after the procedure. Unfortunately, the second patient died of severe sepsis. Perhaps all types of surgery in the presence of severe sepsis are risky. In conclusion, each patient must be treated individually. The best method of closure must be based on the unique set of circumstances. Direct surgical repair can be achieved in most patients. The VAM technique is our choice for a long (at least 10 mm) bronchial stump on the left side because its specific morbidity is minimal compared with transpericardial sternotomy or a transthoracic approach.

We read with great interest the article by Choi and colleagues reporting the effects of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) on oxygenation and intrapulmonary shunting during one-lung ventilation in robot-assisted thoracoscopic esophagectomy (RTE) with the patient in the prone position [1]. Because the results of their randomized clinical study indicate that PVC provides no advantage over VCV, the authors conclude that both ventilation techniques can be applied safely during RTE with the patient in the prone position. Although this is an interesting study providing new insights into this specific field of anaesthesiology, some remarks need to be made. First, the study population was randomly divided into two groups, yet the authors omitted an overview of the baseline characteristics of both study groups. This raises the question whether there were statistically significant differences between the two groups. Second, the authors failed to describe intraoperative data such as total surgery time and blood loss that may have influenced the end points of this study. Additionally, the primary outcomes were limited to hemodynamic and respiratory variables. It would have been of greater clinical interest if the authors had analyzed the effect of the different ventilation strategies on postoperative outcomes, such as intensive care unit stay and postoperative pulmonary morbidity (e.g., pneumonia, atelectasis, and adult respiratory distress syndrome). In 2006, we extensively described our surgical technique of RTE with the patient in the left lateral decubitus position [2]. Our short- and midterm results for 47 esophageal cancer patients who underwent RTE have shown this technique to be very promising [3]. Regrettably, Choi and colleagues did not describe the surgical technique of RTE with the patient in the prone position. We look forward to a new publication of this research group on this topic.