<strong>Background:</strong> Although laparoscopic gastrectomy is becoming more popular as a curative therapy for gastric cancer, there are concerns about its oncological adequacy. We have compared the out...<strong>Background:</strong> Although laparoscopic gastrectomy is becoming more popular as a curative therapy for gastric cancer, there are concerns about its oncological adequacy. We have compared the outcomes of laparoscopic total gastrectomy (LTG) and laparoscopic subtotal gastrectomy (LSG), both with modified D2 lymphadenectomies for the treatment of advanced gastric cancers. <strong>Aim:</strong> To compare the outcomes of laparoscopic (total and subtotal) gastrectomy with modified D2 lymphadenectomy for the treatment of gastric cancer, contributing to the literature regarding the overall survival of these patients and postoperative complications. <strong>Methods:</strong> From 1993 to 2014, 239 patients were operated on laparoscopic gastrectomy at our department. The routinely laparoscopic gastrectomy was performed in all patients with gastric cancer including those presenting with obstruction and bleeding. Data could be collected, on a retrospective way, from 2006 to 2014, from the medical records of 103 patients who underwent LSG (<em>n</em> = 72) or LTG (<em>n</em> = 31). We excluded patients with metastatic disease and those who could not have a complete tumor resection. <strong>Results:</strong> Most patients were in advanced stages of cancer. Adenocarcinoma was the most common find, with 43% of cases in stage IIA and 31% in stage IIIB. Intracorporeal Roux-en-Y or Billroth II anastomoses were employed. Postoperative complications, for LSG and LTG, were 18% and 35.4%;mortality rate, during hospital stay, was 4.9% and 7.7%;three-year survival rate, 53.1% and 59.3%;and five-year survival rate, 46.9% and 40.7%. Mean hospital stay was 7.08 days, being significantly lower in LSG group (<em>p</em> < 0.05). Hospital acquired pneumonia was the most prevalent clinical complication, while deaths arising from surgical complications were caused mainly by gastro-jejunal or esophago-jejunal anastomosis leaks. <strong>Conclusions:</strong> Both LSG and LTG with modified D2 lymphadenectomy are feasible alternatives to open surgery and survival rates were comparable. The increased risk of complications observed in LTG did not influence the overall mortality rate. We hope that these findings should contribute to improve the acceptance of laparoscopic gastrectomy as a safe procedure for gastric cancer treatment.展开更多
This paper introduces a mathematical model which describes the dynamics of the spread of HIV in the human body. This model is comprised of a system of ordinary differential equations that involve susceptible cells, in...This paper introduces a mathematical model which describes the dynamics of the spread of HIV in the human body. This model is comprised of a system of ordinary differential equations that involve susceptible cells, infected cells, HIV, immune cells and immune active cells. The distinguishing feature in the proposed model with respect to other models in the literature is that it takes into account cells that represent two distinct mechanisms of the immune system in the defense against HIV: the non-HIV-activated cells and the HIV-activated cells. With a view at minimizing the side effects of a treatment that employs a drug combination designed to attack the HIV at various stages of its life cycle, we introduce control variables that represent the infected patient’s medication. The optimal control rule that prescribes the medication for a given time period is obtained by means of Pontryagin’s Maximum Principle.展开更多
文摘<strong>Background:</strong> Although laparoscopic gastrectomy is becoming more popular as a curative therapy for gastric cancer, there are concerns about its oncological adequacy. We have compared the outcomes of laparoscopic total gastrectomy (LTG) and laparoscopic subtotal gastrectomy (LSG), both with modified D2 lymphadenectomies for the treatment of advanced gastric cancers. <strong>Aim:</strong> To compare the outcomes of laparoscopic (total and subtotal) gastrectomy with modified D2 lymphadenectomy for the treatment of gastric cancer, contributing to the literature regarding the overall survival of these patients and postoperative complications. <strong>Methods:</strong> From 1993 to 2014, 239 patients were operated on laparoscopic gastrectomy at our department. The routinely laparoscopic gastrectomy was performed in all patients with gastric cancer including those presenting with obstruction and bleeding. Data could be collected, on a retrospective way, from 2006 to 2014, from the medical records of 103 patients who underwent LSG (<em>n</em> = 72) or LTG (<em>n</em> = 31). We excluded patients with metastatic disease and those who could not have a complete tumor resection. <strong>Results:</strong> Most patients were in advanced stages of cancer. Adenocarcinoma was the most common find, with 43% of cases in stage IIA and 31% in stage IIIB. Intracorporeal Roux-en-Y or Billroth II anastomoses were employed. Postoperative complications, for LSG and LTG, were 18% and 35.4%;mortality rate, during hospital stay, was 4.9% and 7.7%;three-year survival rate, 53.1% and 59.3%;and five-year survival rate, 46.9% and 40.7%. Mean hospital stay was 7.08 days, being significantly lower in LSG group (<em>p</em> < 0.05). Hospital acquired pneumonia was the most prevalent clinical complication, while deaths arising from surgical complications were caused mainly by gastro-jejunal or esophago-jejunal anastomosis leaks. <strong>Conclusions:</strong> Both LSG and LTG with modified D2 lymphadenectomy are feasible alternatives to open surgery and survival rates were comparable. The increased risk of complications observed in LTG did not influence the overall mortality rate. We hope that these findings should contribute to improve the acceptance of laparoscopic gastrectomy as a safe procedure for gastric cancer treatment.
文摘This paper introduces a mathematical model which describes the dynamics of the spread of HIV in the human body. This model is comprised of a system of ordinary differential equations that involve susceptible cells, infected cells, HIV, immune cells and immune active cells. The distinguishing feature in the proposed model with respect to other models in the literature is that it takes into account cells that represent two distinct mechanisms of the immune system in the defense against HIV: the non-HIV-activated cells and the HIV-activated cells. With a view at minimizing the side effects of a treatment that employs a drug combination designed to attack the HIV at various stages of its life cycle, we introduce control variables that represent the infected patient’s medication. The optimal control rule that prescribes the medication for a given time period is obtained by means of Pontryagin’s Maximum Principle.
