625 research outputs found
Follow-up after curative resection for gastric cancer. Is it time to tailor it?
There is still no consensus on the follow-up frequency and regimen after curative resection for gastric cancer. Moreover, controversy exists regarding the utility of follow-up in improving survival, and the recommendations of experts and societies vary considerably. The main reason to establish surveillance programs is to diagnose tumor recurrence or metachronous cancers early and to thereby provide prompt treatment and prolong survival. In the setting of gastric malignancies, other reasons have been put forth: (1) the detection of adverse effects of a previous surgery, such as malnutrition or digestive sequelae; (2) the collection of data; and (3) the identification of psychological and/or social problems and provision of appropriate support to the patients. No randomized controlled trials on the role of follow-up after curative resection of gastric carcinoma have been published. Herein, the primary retrospective series and systematic reviews on this subject are analyzed and discussed. Furthermore, the guidelines from international and national scientific societies are discussed. Follow-up is recommended by the majority of institutions; however, there is no real evidence that follow-up can improve long-term survival rates. Several studies have demonstrated that it is possible to stratify patients submitted to curative gastrectomy into different classes according to the risk of recurrence. Furthermore, promising studies have identified several molecular markers that are related to the risk of relapse and to prognosis. Based on these premises, a promising strategy will be to tailor follow-up in relation to the patient and tumor characteristics, molecular marker status, and individual risk of recurrence
Aeroacústica de barras transversais de teto automotivas
Orientador: William Roberto WolfDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia MecânicaResumo: Redução de ruído aeroacústico é uma crescente preocupação na indústria automotiva. Com a proliferação de Veículos Elétricos e Direção Autônoma, os ocupantes de um veículo estarão mais suscetíveis a ruídos aerodinâmicos. Os fenômenos aeroacústicos de natureza tonal são os mais severos em veículos automotores. Bagageiros de teto possuem uma barra transversal diretamente exposta ao escoamento e geram ruído em banda larga e um tonal aeólico característico. Atualmente, as soluções aplicadas ao ruído tonal são empíricas, sustentadas pelo fato de os perfis comerciais não serem rombudos como um cilindro, nem finos como um perfil de asa. O objetivo deste trabalho é investigar os mecanismos de geração de ruído em barras transversais de teto com perfil elíptico, através de medições acústicas em pista. Na primeira parte do projeto, medições de pressão e intensidade sonora feitas em pista e em túnel de vento aeroacústico foram correlacionadas com o objetivo de avaliar a precisão e repetitividade dos testes em pista. A medição de pressão sonora com um único microfone posicionado fora do veículo se demonstrou um método preciso na captura de efeitos de banda larga e estreita, apesar da condição não controlada do ruído de fundo. A interação da esteira da barra com o teto também foi avaliada através de medições acústicas de referência e visualização de escoamento. Na segunda parte, o ruído gerado por um perfil elíptico foi comparado ao ruído gerado por um cilindro circular e por um perfil NACA 0012 de mesma espessura e nas mesmas condições de operação. Os resultados mostraram que as características do ruído do perfil elíptico se aproximam às do cilindro circular em números de Reynolds mais baixos, e às do perfil NACA 0012 em velocidades mais altas. Na etapa seguinte, investigou-se o efeito de alterações geométricas do perfil elíptico no ruído gerado. Diferentes combinações de bordo de ataque e fuga foram testadas e demonstraram que o bordo de fuga é o principal contribuinte para o ruído tonal, enquanto que o bordo de ataque está associado ao ruído em banda larga. Bordos de fuga finos foram capazes de eliminar completamente o ruído tonal. Ângulos de incidência positivos e negativos apresentaram tendências contrárias em relação à redução de ruído, e se demonstraram soluções não efetivas em altas velocidades. Por final, soluções conhecidas como perturbação da camada limite foram testadas e comparadas com soluções inovadoras (Assopramento e Perfuração). Ambas técnicas reduziram efetivamente o ruído tonal mas apresentaram efeitos indesejados como a excitação de tons em alta frequênciaAbstract: Aeroacoustic noise reduction is one of the growing concerns in the automotive industry. With the advention of Electric Vehicles and Autonomous Driving, vehicle occupants will become more sensitive to aerodynamic noise. The most severe aeroacoustic phenomena in ground vehicles are the ones with a tonal nature. Roof carrier systems have a leading crossbar directly exposed to the airflow, generating broadband noise and a discrete aeolian tone. Nowadays, most of the applied solutions to aeolian tone are empirical, sustained by the fact that commercial crossbar profiles are not as blunt as a circular cylinder, neither as thin as a wing section. The objective of this project is to investigate the noise mechanisms involved in elliptical crossbars through actual acoustic measurements taken on track. The first part of the project correlated sound pressure and intensity measurements taken on track and in an aeroacoustic wind tunnel, with the objective of assessing track data accuracy and repeatability. Acoustic pressure taken outside the vehicle with a single microphone has demonstrated good accuracy in capturing both narrow and broadband noise effects, despite of the uncontrolled background noise. The crossbar wake interaction with the roof plane was also assessed through reference measurements and local flow visualization. The second part of the project compared the noise generated by an elliptical cylinder with that generated by a circular cylinder and a NACA 0012 airfoil with the same thicknesses and at the same operational conditions. Results have shown that the elliptical crossbar noise characteristics have similarities when compared to those of blunt bodies at low Reynolds numbers and wing sections at higher speeds. The following step investigated the effects of the ellipse geometry and angle of attack on the generated sound. Different leading and trailing edge combinations were tested and demonstrated that the trailing edge is the key contributor to the aeolian tone characteristics, while the leading edge affects primarily the broadband noise. Thin trailing edges were capable to completely eliminate the aeolian tone. Positive and negative incidence angles presented opposite trends towards noise reduction and have proven to be ineffective in higher speeds. Finally, industry-known solutions such as Boundary Layer Tripping (BLT) were assessed and compared to innovative solutions (Trailing Edge Blowing (TEB) and Perforation). Both TEB and Perforation were effective on reducing the aeolian tone but presented counter effects such as high frequency whistlingMestradoTermica e FluidosMestre em Engenharia Mecânic
Adrenomedullin in pancreatic carcinoma. a case-control study of 22 patients
Pancreatic carcinoma is a leading cause of cancer-related death. Reduction of the diagnostic delay is mandatory. Adrenomedullin (AM) is overexpressed in pancreatic cancer. A case-control study including 12 patients with pathological diagnosis of pancreatic carcinoma and 10 healthy controls was conducted at our Institution. Blood samples were obtained at the time of hospitalization and post-operatively for cases. Controls’ samples were obtained from healthy volunteers. AM was measured by using enzyme immunoassay method. AM showed significant increase in pancreatic carcinoma patients vs controls (4.51 ng/ml vs 1.91 ng/ml, p value = 0.04) regardless of tumor stage, differentiation, resecability/unresecability, diabetes. A cut-off of 1.75 ng/ml reaches a sensibility of 83% and a specificity of 70% (p value = 0.0147; CL 95%; AUC 0.767). The increase of AM didn’t correlate with the increase of other common tumor markers (CA 19-9 and CEA), nor direct bilirubin. These data confirm the utility of studying the role of AM in pancreatic cancer, in order to achieve an early diagnosis in high risk populations
CRP Predicts Safe Patient Discharge after Colorectal Surgery. Reply
Reply: We would like to thank Aurelie´n Dupre`, Johan Gagnie´r, Heloı¨se Samba, Michel Rivoire, and Karem Slim for their comments about our article ‘‘Procalcitonin Reveals Early Dehiscence in Colorectal Surgery: The PREDICS Study.’’1 It is very rewarding to realize that this paper is stimulating so many observations, this means thatwe are talking about an interesting topic
Recurrence following anastomotic leakage after surgery for carcinoma of the distal esophagus and gastroesophageal junction. a systematic review
BACKGROUND: Esophageal cancer is the ninth most common cancer. The only potentially curative treatment is surgical resection, which unfortunately is still associated with major complications, the most important being anastomotic leakage, currently with an overall rate of up to 26% morbidity. The aim of this systematic review was to evaluate the relationship between anastomotic leakage and recurrence of disease. MATERIALS AND METHODS: A literature search was systematically performed. Seven out of 312 articles dated between 2009 and 2018 fulfilled the selection for a total of 5,433 patients. RESULTS: The frequency of anastomotic leakage ranged from 7.2 to 11.2%. Patients affected by anastomotic leakage had a recurrence rate of 9-56%. CONCLUSION: Closer follow-up or even more aggressive oncological therapy should be considered for patients affected by anastomotic leakage after surgery for carcinoma of the distal esophagus and gastroesophageal junction
Treatment options for PNET liver metastases. a systematic review
Pancreatic neuroendocrine tumors (PNETs) are rare pancreatic neoplasms. About 40-80% of patients with PNET are metastatic at presentation, usually involving the liver (40-93%). Liver metastasis represents the most significant prognostic factor. The aim of this study is to present an up-to-date review of treatment options for patients with liver metastases from PNETs
Influence of perineural invasion in predicting overall survival and disease-free survival in patients With locally advanced gastric cancer
Background The aim of the present study was to evaluate the prognostic significance of perineural invasion (PNI) in locally advanced gastric cancer patients who underwent D2 gastrectomy and adjuvant chemotherapy. Methods The records of a series of 103 patients undergoing D2 gastrectomy with curative intent combined with adjuvant chemotherapy from January 2004 to December 2014 were retrospectively reviewed. Results PNI was positive in 47 (45.6%) specimens. The 1-, 3-, and 5-year overall survival rates were 81%, 55%, and 42%, respectively. The 1-, 3-, and 5-year disease-free survival (DFS) rates were 76%, 57%, and 49%, respectively. A multivariate analysis showed that age number of positive lymph nodes, T stage, and PNI were independently associated with overall survival. Regarding DFS, the multivariate analysis showed that only PNI was independently associated with DFS. Conclusions PNI and T stage and positive lymph nodes are independent markers of poor prognosis in patients with gastric cancer. PNI should be incorporated in the postoperative staging system for planning follow-up after surgery and in our opinion to propose more aggressive postoperative therapies in PNI-positive patients
Management of duodenal stump fistula after gastrectomy for gastric cancer: systematic review
AIM:
To identify the most effective treatment of duodenal stump fistula (DSF) after gastrectomy for gastric cancer.
METHODS:
A systematic review of the literature was performed. PubMed, EMBASE, Cochrane Library, CILEA Archive, BMJ Clinical Evidence and UpToDate databases were analyzed. Three hundred eighty-eight manuscripts were retrieved and analyzed and thirteen studies published between 1988 and 2014 were finally selected according to the inclusion criteria, for a total of 145 cases of DSF, which represented our group of study. Only patients with DSF after gastrectomy for malignancy were selected. Data about patients' characteristics, type of treatment, short and long-term outcomes were extracted and analyzed.
RESULTS:
In the 13 studies different types of treatment were proposed: conservative approach, surgical approach, percutaneous approach and endoscopic approach (3 cases). The overall mortality rate was 11.7% for the entire cohort. The more frequent complications were sepsis, abscesses, peritonitis, bleeding, pneumonia and multi-organ failure. Conservative approach was performed in 6 studies for a total of 79 patients, in patients with stable general condition, often associated with percutaneous approach. A complete resolution of the leakage was achieved in 92.3% of these patients, with a healing time ranging from 17 to 71 d. Surgical approach included duodenostomy, duodeno-jejunostomy, pancreatoduodenectomy and the use of rectus muscle flap. In-hospital stay of patients who underwent relaparotomy ranged from 1 to 1035 d. The percutaneous approach included drainage of abscesses or duodenostomy (32 cases) and percutaneous biliary diversion (13 cases). The median healing time in this group was 43 d.
CONCLUSION:
Conservative approach is the treatment of choice, eventually associated with percutaneus drainage. Surgical approach should be reserved for severe cases or when conservative approaches fail
Neoadjuvant treatment in pancreatic cance. Evidence-based medicine? A systematic review and meta-analysis
Neoadjuvant treatment in non-metastatic pancreatic cancer (PaC) has the theoretical advantages of downstaging the tumor, sterilizing any present systemic undetectable disease, selecting patients for surgery and administering therapy to each patient. The aim of this systematic review is to analyze the state of the art on neoadjuvant protocols for non-metastatic PaC. A literature search over the last 10 years was conducted, and papers had to be focused on resectable, borderline resectable (BLR) or locally advanced (LA) histo- or cytologically proven PaC; to be prospective studies or prospectively collected databases; to report percentage of protocol achievement and survival data at least in an intention-to-treat (ITT) analysis. Twelve studies were eligible for systematic review. Studies included a total of 624 patients: 248 resectable, 268 BLR, 71 LA and 37 non-specified. All studies were included for meta-analysis. ITT overall survival (OS) was 16.7 months (95% CI 15.16-18.26 months); for resected patients OS was 22.78 months (95% CI 20.42-25.16), and for eventually non-resected patients it was 9.89 months (95% CI 8.84-10.96). Neoadjuvant approaches for resectable, BLR and LA PaC are spreading. Outcomes tend to be better outside an RCT context, but strong evidences are lacking. Actually such treatments should be performed only in a randomized clinical trial setting
Comparative effect of sodium dipyrone and sodium dipyrone associated to caffeine to control post-tooth extraction pain
BACKGROUND AND OBJECTIVES: Adequate postoperative pain control is a challenge among surgical specialties, in spite of recent advances in analgesic techniques and analgesics. Caffeine has been used as therapeutic adjuvant to potentiate analgesic efficacy of some drugs, however there are still no scientific investigation reports on the association with sodium dipyrone in the postoperative period of dental procedures. So, this study aimed at observing and comparing the efficacy of sodium dipyrone alone or in association with caffeine to control postoperative pain of dental procedures, considering hemodynamic parameters of patients as indicators of anxiety and pain during surgery. METHODS: This is a crossover and double-blind study involving 50 young and healthy patients (25 males and 25 females) referred for bilateral extraction of impacted mandibular third molars. Operated side, patient's gender and analgesic drug used were randomized. Visual analog scale scores were submitted to Friedman test (α = 0.05) to compare pain intensity at defined intervals (preoperative, immediate postoperative, 1, 2, 4 and 12 hours, 1, 2, 3 and 7 days after surgery). Blood pressure and heart rate were measured in the preoperative period, after anesthetic injection and in the postoperative period (Friedman test, (α = 0.05). RESULTS: Patients have referred mild pain in the first two postoperative days and there has been no statistically significant difference between the analgesic efficacy of sodium dipyrone alone or in association with caffeine in different evaluated intervals. Most cardiovascular changes were within normality, considering anxiety and stress induced by surgery. CONCLUSION: The therapeutic protocol proposed in this study has not shown statistically significant difference between sodium dipyrone associated or not to caffeine to control post-tooth extraction pain.O adequado controle da dor pós-operatória constitui um desafio entre as especialidades cirúrgicas, a despeito dos recentes avanços das técnicas de analgesia e dos analgésicos. A cafeína tem sido utilizada como adjuvante terapêutico para potencializar a eficácia analgésica de alguns fármacos, porém ainda não existe relatos de investigação científica da associação com a dipirona sódica em dor pós-operatória em procedimentos odontológicos. Dessa forma, o objetivo deste estudo foi observar e comparar a eficácia da dipirona sódica isolada e da dipirona sódica associada à cafeína no controle da dor pós-operatória em cirurgia dental, considerando os parâmetros hemodinâmicos dos pacientes como indicador de ansiedade e de dor durante a cirurgia. Estudo cruzado e duplo encoberto incluiu 50 pacientes jovens e saudáveis (25 homens e 25 mulheres) com indicação de exodontia bilateral de terceiros molares mandibulares impactados. O lado operado, o gênero do paciente e o fármaco analgésico usado foram randomizados. Os escores obtidos pela escala analógica visual foram submetidos ao teste de Friedman (α = 0,05) para comparação das intensidades dolorosas em intervalos definidos (pré-operatório, pós-operatório imediato, 1, 2, 4 12 horas, 1, 2, 3 e 7 dias após as cirurgias) e as alterações nos parâmetros de pressão arterial e frequência cardíaca foram mensurados no pré-operatório, após a injeção anestésica e no pós-operatório (teste de Friedman, α = 0,05). Os pacientes experimentaram dor leve nos dois primeiros dias de pós-operatório e não houve diferença estatisticamente significante entre a eficácia analgésica da dipirona sódica isolada e da dipirona sódica associada à cafeína nos diferentes intervalos medidos. A maioria das alterações cardiovasculares observadas estava dentro da normalidade, considerando a ansiedade e estresse induzido pela cirurgia. O protocolo terapêutico proposto neste estudo não demonstrou diferença estatística significante na eficiência analgésica da dipirona sódica associada ou não a cafeína no controle da dor pós-exodontia143174178Adequate postoperative pain control is a challenge among surgical specialties, in spite of recent advances in analgesic techniques and analgesics. Caffeine has been used as therapeutic adjuvant to potentiate analgesic efficacy of some drugs, however there are still no scientific investigation reports on the association with sodium dipyrone in the postoperative period of dental procedures. So, this study aimed at observing and comparing the efficacy of sodium dipyrone alone or in association with caffeine to control postoperative pain of dental procedures, considering hemodynamic parameters of patients as indicators of anxiety and pain during surgery. This is a crossover and double-blind study involving 50 young and healthy patients (25 males and 25 females) referred for bilateral extraction of impacted mandibular third molars. Operated side, patient's gender and analgesic drug used were randomized. Visual analog scale scores were submitted to Friedman test (α = 0.05) to compare pain intensity at defined intervals (preoperative, immediate postoperative, 1, 2, 4 and 12 hours, 1, 2, 3 and 7 days after surgery). Blood pressure and heart rate were measured in the preoperative period, after anesthetic injection and in the postoperative period (Friedman test, (α = 0.05). Patients have referred mild pain in the first two postoperative days and there has been no statistically significant difference between the analgesic efficacy of sodium dipyrone alone or in association with caffeine in different evaluated intervals. Most cardiovascular changes were within normality, considering anxiety and stress induced by surgery. The therapeutic protocol proposed in this study has not shown statistically significant difference between sodium dipyrone associated or not to caffeine to control post-tooth extraction pai
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