RESUMEN
Pulmonary metastasectomy for sarcoma is surgery without proven benefit, and in the light of a randomized controlled trial examining pulmonary metastasectomy in colorectal cancer, it should be questioned.
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Neoplasias Colorrectales , Neoplasias Pulmonares , Metastasectomía , Sarcoma , Neoplasias de los Tejidos Blandos , Neoplasias Colorrectales/cirugía , Humanos , Neoplasias Pulmonares/cirugía , Neumonectomía , Sarcoma/cirugíaRESUMEN
AIM: The aim of this work was to examine the burden of further treatments in patients with colorectal cancer following a decision about lung metastasectomy. METHOD: Five teams participating in the Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) study provided details on subsequent local treatments for lung metastases, including the use of chemotherapy. For patients in three groups (no metastasectomy, one metastasectomy or multiple local interventions), baseline factors and selection criteria for additional treatments were examined. RESULTS: The five teams recruited 220 patients between October 2010 and January 2017. No lung metastasectomy was performed in 51 patients, 114 patients had one metastasectomy and 55 patients had multiple local interventions. Selection for initial metastasectomy was associated with nonelevated carcinoembryonic antigen, fewer metastases and no prior liver metastasectomy. These patients also had better Eastern Cooperative Oncology Group scores and lung function at baseline. Four sites provided information on chemotherapy in 139 patients: 79 (57%) had one to five courses of chemotherapy, to a total of 179 courses. The patterns of survival after one or multiple metastasectomy interventions showed evidence of guarantee-time bias contributing to an impression of benefit over no metastasectomy. After repeated metastasectomy, a significantly higher risk of death was observed, with no apparent reduction in chemotherapy usage. CONCLUSION: Repeated metastasectomy is associated with a higher risk of death without reducing the use of chemotherapy. Continued monitoring without surgery might reassure patients with indolent disease or allow response assessment during systemic treatment. Overall, the carefully collected information from the PulMICC study provides no indication of an important survival benefit from metastasectomy.
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Neoplasias Colorrectales , Neoplasias Pulmonares , Metastasectomía , Estudios de Cohortes , Neoplasias Colorrectales/terapia , Humanos , Neoplasias Pulmonares/terapia , Pronóstico , Tasa de SupervivenciaRESUMEN
AIM: We wanted to examine survival in patients with resected colorectal cancer (CRC) whose lung metastases are or are not resected. METHODS: Teams participating in the study of Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) identified potential candidates for lung metastasectomy and invited their consent to join Stage 1. Baseline data related to CRC and fitness for surgery were collected. Eligible patients were invited to consent for randomization in the PulMiCC randomized controlled trial (Stage 2). Sites were provided with case report forms for non-randomized patients to record adverse events and death at any time. They were all reviewed at 1 year. Baseline and survival data were analysed for the full cohort. RESULTS: Twenty-five clinical sites recruited 512 patients from October 2010 to January 2017. Data collection closed in October 2020. Before analysis, 28 patients with non-CRC lung lesions were excluded and three had withdrawn consent leaving 481. The date of death was known for 292 patients, 136 were alive in 2020 and 53 at earlier time points. Baseline factors and 5-year survival were analysed in three strata: 128 non-randomized patients did not have metastasectomy; 263 had elective metastasectomy; 90 were from the randomized trial. The proportions of solitary metastases for electively operated and non-operated patients were 69% and 35%. Their respective 5-year survivals were 47% and 22%. CONCLUSION: Survival without metastasectomy was greater than widely presumed. Difference in survival appeared to be largely related to selection. No inference can be drawn about the effect of metastasectomy on survival in this observational study.
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Neoplasias Colorrectales , Neoplasias Pulmonares , Metastasectomía , Estudios de Cohortes , Humanos , Neoplasias Pulmonares/cirugía , Factores de RiesgoRESUMEN
PURPOSE OF REVIEW: Guidelines for enhanced recovery after surgery (ERAS) have recently been published for lung surgery. Although some of the recommendations are generic or focused on anesthetic and nursing care, other recommendations are more specific to a thoracic surgeon's practice. The present review concentrates on the surgical approach, optimal chest drain management, and the importance of early mobilization. RECENT FINDINGS: Most lung cancer resections are still performed via an open thoracotomy approach. If a thoracotomy is to be used, a muscle-sparing approach may result in reduced pain and better postoperative function. Sparing of the intercostal bundle also reduces pain. There is now evidence that minimally invasive surgery for early lung cancer results in superior patient outcomes. Postoperatively, single chest tubes should be used without the routine application of external suction. Digital drainage systems are more reliable and may produce superior outcomes. Conservative chest drain removal policies are unnecessary and impair patient recovery. Early mobilization protocols should be instigated to reduce postoperative complications. SUMMARY: The use of ERAS after lung surgery has the potential to improve patient outcomes. Although specific surgical elements are in the minority, thoracic surgeons should be involved in all aspects of perioperative care as part of the wider multidisciplinary team.
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Vías Clínicas/normas , Atención Perioperativa/normas , Neumonectomía/efectos adversos , Guías de Práctica Clínica como Asunto , Cirugía Torácica/normas , Consenso , Europa (Continente) , Medicina Basada en la Evidencia/métodos , Medicina Basada en la Evidencia/normas , Humanos , Tiempo de Internación/estadística & datos numéricos , Neoplasias Pulmonares/cirugía , Atención Perioperativa/métodos , Neumonectomía/métodos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Sociedades Médicas/normas , Cirujanos/normas , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: Many airway management guidelines include the use of airway exchange catheters (AECs). There are reports, however, of harm from their use, from both malpositioning and in particular from the administration of oxygen via an AEC leading to barotrauma. METHODS: We used an in vitro pig lung model to investigate the safety of administering oxygen at 4 different flow rates from a high-pressure source via 2 different AECs: a standard catheter and a soft-tipped catheter. Experiments were performed with the catheters positioned either above the carina or below it at the first point of resistance to advancement (hold-up). The experiments were then repeated to produce a series of 32 cases. RESULTS: With an AEC positioned above the carina, we did not observe macroscopic lung damage after the administration of oxygen. The administration of oxygen through an AEC positioned below the carina resulted in macroscopic barotrauma regardless of the rate of oxygen delivery. Increasing speed of oxygen flow led to faster and more extensive damage. Use of an "injector" at 2.5 or 4 bar led to instantaneous macroscopic lung damage and advancement of the AEC through the lung tissue. Our observations were the same when both types of AECs were used. CONCLUSIONS: Our results are consistent with reports of harm during the use of AECs and demonstrate the risk of administering oxygen through these devices when they are positioned below the carina. An indicator, ideally made on an AEC at the time of manufacture and designed to lie at the same level as the teeth, may be useful in preventing the insertion of that AEC beyond the level of the carina and improve the safety of using such devices.
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Manejo de la Vía Aérea/efectos adversos , Manejo de la Vía Aérea/instrumentación , Barotrauma/etiología , Catéteres/efectos adversos , Animales , Barotrauma/patología , Técnicas In Vitro , Pulmón/patología , Oxígeno/administración & dosificación , Respiración Artificial/efectos adversos , Porcinos , Tráquea/lesiones , Tráquea/patologíaRESUMEN
Bronchogenic cysts are rare congenital lesions found primarily in the mediastinum. Most patients are asymptomatic and can be treated with minimally invasive resection. We present a case of a middle-aged patient who presented to a district general hospital with palpitations and shortness of breath. She underwent a computerised tomographic pulmonary angiogram that showed a likely bronchogenic cyst and was subsequently transferred to our hospital. She developed atrial fibrillation during admission requiring therapy with beta-blockers and digoxin. Cardiac MRI revealed a large cyst posterior to the left atrium, a moderate circumferential pericardial effusion and bilateral pleural effusions. There was significant left atrial compression. The patient underwent surgical removal of the cyst and was discharged. She returned to the hospital within a week with palpitations and was treated with intravenous antibiotics for sepsis. She was discharged a week later and remained clinically stable.
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Fibrilación Atrial , Quiste Broncogénico , Persona de Mediana Edad , Femenino , Humanos , Fibrilación Atrial/etiología , Quiste Broncogénico/complicaciones , Quiste Broncogénico/diagnóstico por imagen , Quiste Broncogénico/cirugía , Atrios Cardíacos , Digoxina , MediastinoRESUMEN
Objectives: Surgery through a single port may be less painful because access is supplied by 1 intercostal nerve or more painful because multiple instruments are used in 1 port. We analyzed data collected from the video-assisted thoracoscopic surgery group of a randomized controlled trial to compare differences in pain up to 1 year. Methods: Groups were compared in a prespecified exploratory analysis using direct (regression) and indirect comparison (difference with respect to thoracotomy). In-hospital visual analogue scale pain scores were used, and analgesic ratios were calculated. After discharge, pain was evaluated using European Organization for Research and Treatment of Cancer Quality of Life Questionnaires-Core 30 scores up to 1 year. Results: From July 2015 to February 2019, we randomized 503 participants. After excluding 50 participants who did not receive lobectomy, surgery was performed using a single port in 42 participants (predominately by a single surgeon), multiple ports in 166 participants, and thoracotomy in 245 participants. No differences were observed in-hospital between single- and multiple-port video-assisted thoracoscopic surgery when modeled using a direct comparison, mean difference of -0.24 (95% CI, -1.06 to 0.58) or indirect comparison, mean difference of -0.33 (-1.16 to 0.51). Mean analgesic ratio (single/multiple port) was 0.75 (0.64 to 0.87) for direct comparison and 0.90 (0.64 to 1.25) for indirect comparison. After discharge, pain for single-port video-assisted thoracoscopic surgery was lower than for multiple-port video-assisted thoracoscopic surgery (first 3 months), and corresponding physical function was higher up to 12 months. Conclusions: There were no consistent differences for in-hospital pain when lobectomy was undertaken using 1 or multiple ports. However, better pain scores and physical function were observed for single-port surgery after discharge.
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This review documents the relationships between enhanced recovery after surgery (ERAS) pathways, chest tube management and patient outcomes following lung resection surgery. ERAS pathways have been introduced to mitigate the harmful stress response that occurs following all major surgery, including lung resection. Improvements to the entire patient pathway, from the preoperative admission clinic through to discharge and beyond, can have additive or synergistic effects and result in improved patient outcomes, reduced length of stay and lower costs. At the same time, there are some key care elements that appear to be more important than others. In the postoperative period, early removal of chest tubes, early mobilization, and limited use of opioids are all independently important factors. These elements of care are all intertwined. Therefore, a focus on proactive chest tube management with the abandonment of conservative chest tube strategies should be a focus of postoperative ERAS pathways. This can be achieved with single tubes, no routine suction, the use of digital drainage systems, and removal of tubes even in the presence of relatively high serous pleural fluid outputs. The goals of early mobilization and opioid-sparing analgesia are more readily achieved once a chest tube has been removed. The result is superior patient outcomes with significantly fewer complications.
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INTRODUCTION: Lung cancer is the most common cause of cancer death worldwide and most patients present with extensive disease. One-year survival is improving but remains low (37%) despite novel systemic anti-cancer treatments forming the current standard of care. Although new therapies improve survival, most patients have residual disease after treatment, and little is known on how best to manage it. Therefore, residual disease management varies across the UK, with some patients receiving only maintenance systemic anti-cancer treatment while others receive local consolidative treatment (LCT), alongside maintenance systemic anti-cancer treatment. LCT can be a combination of surgery, radiotherapy and/or ablation to remove all remaining cancer within the lung and throughout the body. This is intensive, expensive and impacts quality of life, but we do not know if it results in better survival, nor the extent of impact on quality of life and what the cost might be for healthcare providers. The RAMON study (RAdical Management Of Advanced Non-small cell lung cancer) will evaluate the acceptability, effectiveness and cost-effectiveness of LCT versus no LCT after first-line systemic treatment for advanced lung cancer. METHODS AND ANALYSIS: RAMON is a pragmatic open multicentre, parallel group, superiority randomised controlled trial. We aim to recruit 244 patients aged 18 years and over with advanced non-small-cell lung cancer from 40 UK NHS hospitals. Participants will be randomised in a 1:1 ratio to receive LCT alongside maintenance treatment, or maintenance treatment alone. LCT will be tailored to each patient's specific disease sites. Participants will be followed up for a minimum of 2 years. The primary outcome is overall survival from randomisation. ETHICS AND DISSEMINATION: The West of Scotland Research Ethics Committee (22/WS/0121) gave ethical approval in August 2022 and the Health Research Authority in September 2022. Participants will provide written informed consent before participating in the study. Findings will be presented at international meetings, in peer-reviewed publications, through patient organisations and notifications to patients. TRIAL REGISTRATION NUMBER: ISRCTN11613852.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Adolescente , Adulto , Humanos , Carcinoma de Pulmón de Células no Pequeñas/terapia , Terapia Combinada , Pulmón , Neoplasias Pulmonares/terapia , Estudios Multicéntricos como Asunto , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
BACKGROUND: There is limited randomized evidence on the comparative outcomes of early-stage lung cancer resection by video-assisted thoracoscopic surgery (VATS) versus open resection. METHODS: We conducted a parallel-group multicenter randomized trial that recruited participants with known or suspected early-stage lung cancer and randomly assigned them to open or VATS resection of their lesions. The primary outcome was physical function at 5 weeks as a measure of recovery using the European Organisation for Research and Treatment of Cancer core health-related quality of life questionnaire (QLQ-C30) (scores range from 0 to 100, with higher scores indicating better function; the clinical minimally important difference for improvement is 5 points). We followed the patients for an additional 47 weeks for other outcomes. RESULTS: A total of 503 participants were randomly assigned (247 to VATS and 256 to open lobectomy). At 5 weeks, median physical function was 73 in the VATS group and 67 in the open surgery group, with a mean difference of 4.65 points (95% confidence interval, 1.69 to 7.61). Of the participants allocated to VATS, 30.7% had serious adverse events after discharge compared with 37.8% of those allocated to open surgery (risk ratio, 0.81 [95% confidence interval, 0.66 to 1.00]). At 52 weeks, there were no differences in cancer progression-free survival (hazard ratio, 0.74 [0.43 to 1.27]) or overall survival (hazard ratio, 0.67 [0.32 to 1.40]). CONCLUSIONS: VATS lobectomy for lung cancer is associated with a better recovery of physical function in the 5 weeks after random assignment compared with open surgery. Long-term oncologic outcomes will require continued follow-up to assess. (Funded by the National Institute for Health Research Health Technology Assessment programme [reference number 13/04/03]; ISRCTN number, ISRCTN13472721.)
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Neoplasias Pulmonares , Neumonectomía , Calidad de Vida , Cirugía Torácica Asistida por Video , Humanos , Cirugía Torácica Asistida por Video/métodos , Cirugía Torácica Asistida por Video/efectos adversos , Neoplasias Pulmonares/cirugía , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/mortalidad , Masculino , Femenino , Anciano , Persona de Mediana Edad , Neumonectomía/métodos , Resultado del Tratamiento , Estadificación de NeoplasiasRESUMEN
OBJECTIVES: This study reports the results of an international expert consensus process evaluating the assessment of intraoperative air leaks (IAL) and treatment of postoperative prolonged air leaks (PAL) utilizing a Delphi process, with the aim of helping standardization and improving practice. METHODS: A panel of 45 questions was developed and submitted to an international working group of experts in minimally invasive lung cancer surgery. Modified Delphi methodology was used to review responses, including 3 rounds of voting. The consensus was defined a priori as >50% agreement among the experts. Clinical practice standards were graded as recommended or highly recommended if 50-74% or >75% of the experts reached an agreement, respectively. RESULTS: A total of 32 experts from 18 countries completed the questionnaires in all 3 rounds. Respondents agreed that PAL are defined as >5 days and that current risk models are rarely used. The consensus was reached in 33/45 issues (73.3%). IAL were classified as mild (<100 ml/min; 81%), moderate (100-400 ml/min; 71%) and severe (>400 ml/min; 74%). If mild IAL are detected, 68% do not treat; if moderate, consensus was not; if severe, 90% favoured treatment. CONCLUSIONS: This expert consensus working group reached an agreement on the majority of issues regarding the detection and management of IAL and PAL. In the absence of prospective, randomized evidence supporting most of these clinical decisions, this document may serve as a guideline to reduce practice variation.
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Neumonectomía , Consenso , Técnica Delphi , Humanos , Neumonectomía/efectos adversos , Estudios Prospectivos , Encuestas y CuestionariosRESUMEN
When social animals engage in inter-group contests, the outcome is determined by group sizes and individual masses, which together determine group resource-holding potential ('group RHP'). Individuals that perceive themselves as being in a group with high RHP may receive a motivational increase and increase their aggression levels. Alternatively, individuals in lower RHP groups may increase their aggression levels in an attempt to overcome the RHP deficit. We investigate how 'group RHP' influences agonistic tactics in red wood ants Formica rufa. Larger groups had higher total agonistic indices, but per capita agonistic indices were highest in the smallest groups, indicating that individuals in smaller groups fought harder. Agonistic indices were influenced by relative mean mass, focal group size, opponent group size and opponent group agonistic index. Focal group attrition rates decreased as focal group relative agonistic indices increased and there was a strong negative influence of relative mean mass. The highest focal attrition rates were received when opponent groups were numerically large and composed of large individuals. Thus, fight tactics in F. rufa seem to vary with both aspects of group RHP, group size and the individual attributes of group members, indicating that information on these are available to fighting ants.
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Conducta Agonística/fisiología , Hormigas/fisiología , Conducta Animal/fisiología , Procesos de Grupo , Conducta Social , Animales , Tamaño Corporal , Inglaterra , Femenino , Modelos Lineales , Mortalidad , Densidad de PoblaciónAsunto(s)
Enfermedades del Sistema Nervioso Autónomo/diagnóstico , Enfermedades del Sistema Nervioso Autónomo/etiología , Rubor/diagnóstico , Rubor/etiología , Hipohidrosis/diagnóstico , Hipohidrosis/etiología , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/diagnóstico , Neurilemoma/complicaciones , Neurilemoma/diagnóstico , Adulto , Enfermedades del Sistema Nervioso Autónomo/cirugía , Diagnóstico Diferencial , Femenino , Rubor/cirugía , Humanos , Hipohidrosis/cirugía , Hallazgos Incidentales , Neoplasias Pulmonares/cirugía , Imagen por Resonancia Magnética , Neurilemoma/cirugía , Procedimientos Quirúrgicos Pulmonares , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
A 75-year-old woman was admitted to hospital with haemoptysis, fever and shortness of breath. She had undergone a right video-assisted thoracoscopic surgery upper lobectomy for an apical lung cancer 4 weeks earlier, and had been treated with antibiotics for 1 week prior to admission for a suspected postoperative lung abscess. Review of preoperative imaging found that she possessed a lobar pulmonary artery variant, with postoperative imaging confirming that the right lower lobe segmental pulmonary artery had been divided alongside the upper lobe vessels. The diagnosis of a lung abscess was thus revised to a cavitating pulmonary infarct. There are numerous variations of the pulmonary vasculature, all of which have the potential to cause a range of serious vascular complications if not appreciated preoperatively. Measures to mitigate the risk of complications resulting from vascular anomalies should be considered by both radiologists and surgeons, with effective lines of communication essential to safe working.
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Neoplasias Pulmonares/cirugía , Arteria Pulmonar/anomalías , Arteria Pulmonar/cirugía , Infarto Pulmonar/etiología , Cirugía Torácica Asistida por Video/efectos adversos , Anciano , Femenino , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de Positrones , Complicaciones Posoperatorias/etiología , Arteria Pulmonar/diagnóstico por imagen , Infarto Pulmonar/diagnóstico por imagen , Radiografía Torácica , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
Stage III N2 nonsmall cell lung cancer (NSCLC) is a complex disease with poor treatment outcomes. For patients in whom the disease is considered technically resectable, the main treatment options include surgery (with neoadjuvant or adjuvant chemotherapy/neoadjuvant chemoradiotherapy (CRT)) or CRT followed by adjuvant immunotherapy (dependent on programmed death ligand 1 status). As there is no clear evidence demonstrating a survival benefit between these options, patient preference plays an important role. A lack of a consensus definition of resectability of N2 disease adds to the complexity of the decision-making process. We compared 10 international guidelines on the treatment of NSCLC to investigate the recommendations on preoperatively diagnosed stage III N2 NSCLC. This comparison simplified the treatment paths to multimodal therapy based on surgery or radiotherapy (RT). We analysed factors relevant to decision-making within these guidelines. Overall, for nonbulky mediastinal lymph node involvement there was no clear preference between surgery and CRT. With increasing extent of mediastinal nodal disease, a tendency towards multimodal treatment based on RT was identified. In multiple scenarios, surgery or RT-based treatments are feasible and patient involvement in decision-making is critical.
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INTRODUCTION: Lung cancer is a leading cause of cancer deaths worldwide and surgery remains the main treatment for early stage disease. Prior to the introduction of video-assisted thoracoscopic surgery (VATS), lung resection for cancer was undertaken through an open thoracotomy. To date, the evidence base supporting the different surgical approaches is based on non-randomised studies, small randomised trials and is focused mainly on short-term in-hospital outcomes. METHODS AND ANALYSIS: The VIdeo assisted thoracoscopic lobectomy versus conventional Open LobEcTomy for lung cancer study is a UK multicentre parallel group randomised controlled trial (RCT) with blinding of outcome assessors and participants (to hospital discharge) comparing the effectiveness, cost-effectiveness and acceptability of VATS lobectomy versus open lobectomy for treatment of lung cancer. We will test the hypothesis that VATS lobectomy is superior to open lobectomy with respect to self-reported physical function 5 weeks after randomisation (approximately 1 month after surgery). Secondary outcomes include assessment of efficacy (hospital stay, pain, proportion and time to uptake of chemotherapy), measures of safety (adverse health events), oncological outcomes (proportion of patients upstaged to pathologic N2 (pN2) disease and disease-free survival), overall survival and health related quality of life to 1 year. The QuinteT Recruitment Intervention is integrated into the trial to optimise recruitment. ETHICS AND DISSEMINATION: This trial has been approved by the UK (Dulwich) National Research Ethics Service Committee London. Findings will be written-up as methodology papers for conference presentation, and publication in peer-reviewed journals. Many aspects of the feasibility work will inform surgical RCTs in general and these will be reported at methodology meetings. We will also link with lung cancer clinical studies groups. The patient and public involvement group that works with the Respiratory Biomedical Research Unit at the Brompton Hospital will help identify how we can best publicise the findings. TRIAL REGISTRATION NUMBER: ISRCTN13472721.
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Carcinoma de Pulmón de Células no Pequeñas/cirugía , Neoplasias Pulmonares/cirugía , Cirugía Torácica Asistida por Video/métodos , Toracotomía/métodos , Adulto , Anciano , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Supervivencia sin Enfermedad , Femenino , Humanos , Londres , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Estadificación de Neoplasias , Tempo Operativo , Dolor Postoperatorio/fisiopatología , Proyectos Piloto , Neumonectomía/métodos , Medición de Riesgo , Análisis de Supervivencia , Cirugía Torácica Asistida por Video/mortalidad , Reino UnidoRESUMEN
Animal interactions often involve chemical exchange but simultaneous evaluation of chemistry and behaviour has been problematical. Here we report findings from a novel method, atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) coupled with manipulation of molecular-mass achieved by rearing organisms on deuterium-enhanced nutrients. This allows real-time monitoring of the occurrence and quantity of volatile chemicals released by each of two interacting individuals, in tandem with behavioural observations. We apply these methods to female-female contests in the parasitoid wasp Goniozus legneri. We show that this species emits the spiroacetal 2-methyl-1,7-dioxaspiro[5.5]undecane. Chemical release is most common in more behaviourally aggressive contests, which occur when prior resource owners successfully resist take-over by similar-sized intruder females. Volatiles released during contests are always emitted by the loser. Aggression in contests is reduced after spiroacetal release. We suggest that the spiroacetal functions as a weapon of rearguard action. We anticipate that APCI-MS, which is rapid, non-intrusive and relatively inexpensive to operate, will be widely applied in studies linking chemistry and behaviour.
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Conducta Animal , Conducta Competitiva , Avispas/fisiología , Agresión , Animales , Deuterio/análisis , Femenino , Cromatografía de Gases y Espectrometría de Masas/métodos , Factores de Tiempo , Avispas/metabolismoRESUMEN
Tracheal diverticula are rare congenital or acquired abnormalities of the posterior tracheal wall. They are usually asymptomatic, and therefore treatment has not been widely reported. We describe the entity and surgical management of a symptomatic tracheal diverticulum.