that attempt to explain the onset, progression, possible treatment options and global impact of the disease. There is still no certainty about the level or quality of this evidence. It is essential to generate documents synthesized and translated into Spanish or other languages that can bring this information to all the places and countries that are being impacted by this disease.
  Dry eye is one of the most common ocular surface disorders. Although artificial tear drops therapy is the most widely used treatment, it has recently been suggested that autologous serum could be a beneficial alternative treatment for this disorder, but its use is controversial.
 
  We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE/PubMed, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach.
 
  We identified six systematic reviews, including seven primary studies overall, of which all were randomized trials. We concluded that autologous serum treatment might not lead to adverse effects compared to artificial teardrops, but the certainty of the evidence is low. On the other hand, we are uncertain whether autologous serum therapy improves the quality of life, severity of the pathology, pain or the corneal epitheliopathy grade compared to artificial tear drops as the certainty of the evidence has been assessed as very low.
 We identified six systematic reviews, including seven primary studies overall, of which all were randomized trials. We concluded that autologous serum treatment might not lead to adverse effects compared to artificial teardrops, but the certainty of the evidence is low. On the other hand, we are uncertain whether autologous serum therapy improves the quality of life, severity of the pathology, pain or the corneal epitheliopathy grade compared to artificial tear drops as the certainty of the evidence has been assessed as very low.
  Studies show a high prevalence of physical inactivity and sedentary behavior among university students. However, the relationship between physical activity and sedentary behavior in medical students is unknown.
 
  To determine the prevalence of physical activity, sedentary behavior, and related factors among medical students at a public university.
 
  We conducted an analytical cross-sectional study that included students from the first to the sixth year of medical school. We used the International Physical Activity Questionnaire (IPAQ).  https://www.selleckchem.com/products/bicuculline.html  We analyzed study variables using Poisson regression, estimating crude and adjusted prevalence ratios.
 
  The final sample consisted of 513 students, of which 35% of women and 30.1% of all pre-clinical students had a low level of physical activity. Male sex and 20 to 24 age group were associated with a lower prevalence of low level of physical activity. Sedentary behavior was 60.9% among students under 20 years old and 55.5% among pre-clinical students. A lower prevalence of sedentary behavior was found in students over 25 years old, clinical students, and those with high levels of physical activity.
 
  Most medical students presented a moderate level of physical activity. We found a higher presence of low-level physical activity among females and pre-clinical students. We found that sedentary behavior was higher than reported in similar populations. The relationship between physical activity and lower sedentary behavior was significant only for students with a high-level physical activity.
 Most medical students presented a moderate level of physical activity. We found a higher presence of low-level physical activity among females and pre-clinical students. We found that sedentary behavior was higher than reported in similar populations. The relationship between physical activity and lower sedentary behavior was significant only for students with a high-level physical activity.In the last decade, the development of immune checkpoint inhibitors have revolutionized the treatment of patients with advanced renal cell carcinoma, with the potential for dramatic changes in the therapeutic landscape. Nivolumab, a monoclonal antibody inhibitor of transmem-brane programmed cell death protein 1 (PD-1), was approved as monotherapy in 2015 for advanced renal cell carcinoma in patients previously treated with an agent targeting vascular endothelial growth factor. In April 2018, the combination of nivolumab and ipilimumab, a cytotoxic T-lymphocyte-associated antigen 4 inhibitor, was approved for patients with previously untreated intermediate- and poor-risk advanced renal cell carcinoma. Then, in 2019, combination therapies consisting of pembrolizumab (anti-PD-1) or avelumab (anti-PD-1 ligand, PD-L1) with axitinib (a vascular endothelial growth factor receptor tyrosine kinase inhibitor) were also approved for use in all risk groups. This review pre-sents a brief historical review of the association between immunology and oncology; describes essential aspects of the mechanism of action of immune checkpoint inhibitors; discusses the current evidence regarding the clinical use of different immunotherapy regimens for the treatment of patients with renal cell carcinoma, both clear cell and other histological types; and provides general information on their adverse effects. The role of appropriate patient selection is analyzed to allow individualization of therapy and improve the already promising results. Finally, per-spectives on the future use of immune checkpoint inhibitors to treat renal cancer are discussed.
  Using standard anterior-only or anterior then posterior approaches can make an R0 resection difficult to achieve in patients with pelvic sidewall recurrences because of confined working spaces and poor visibility.
 
  Given the limitations of standard approaches, we have used a novel posterior-first then anterior 2-stage approach allowing us to widely expose and secure deep margins and control vessels under direct visualization.
 
  We present a technical note describing this approach in patients with recurrent rectal cancer involving the pelvic sidewall with extrapelvic extension.
 
  The posterior-first approach may assist in achieving a higher number of R0 resections in patients with locally recurrent rectal cancer involving the pelvic sidewall.
 The posterior-first approach may assist in achieving a higher number of R0 resections in patients with locally recurrent rectal cancer involving the pelvic sidewall.