RESUMO
Background: The prognostic nutritional index (PNI) is a useful tool to evaluate nutritional status, which is associated with postoperative complications and prognosis of patients with cancer. Recent studies have shown that PNI has important predictive value for postoperative infection in cancer patients. However, the role and clinical value of PNI in infection after radical gastrectomy remains unclear. This study investigated the relationship between PNI and infection after radical surgery for gastric cancer (GC), focusing on the predictive value of PNI. Methods: A total of 1,111 patients with primary gastric cancer who underwent radical surgery in our hospital from December 2010 to December 2020 were included in this retrospective study. The demographic and clinicopathological data of all patients were acquired through hospital information system (HIS). Preoperative serum albumin (ALB) level and peripheral blood lymphocyte count were obtained for PNI calculation. We selected 812 patients by propensity score matching to reduce biases due to the different distributions of co-variables among the comparable groups. The factors influencing postoperative infection in the matched patients were explored using univariate and multivariate analyses. Results: Baseline characteristics significantly differed among patients with different PNI scores. After one-to-one matching, the clinicopathological data of the 2 groups were comparable, and 812 patients were included for further analysis. Among these patients, 101 developed infections, with an infection rate of 12.4%, which were mainly caused by gram-negative bacteria. The incidence of infection was significantly higher in the low PNI group than in the high PNI group. Univariate and multivariate analyses identified body mass index (BMI) ≥25 kg/m2 [odds ratio (OR) =2.314, P=0.004], diabetes mellitus (OR =1.827, P=0.042), PNI score <45 (OR =2.138, P=0.037), combined multi-organ resection (OR =2.946, P<0.001), operation time ≥240 minutes (OR =2.744, P=0.023), and perioperative blood transfusion (OR =2.595, P=0.025) as risk factors for infection after radical surgery for GC. Conclusions: Infection is the most common complication after radical gastrectomy for GC, and a low preoperative PNI score is a risk factor for postoperative infection.
RESUMO
The decomposition dynamics of organic components in fresh litter of Larix potaninii were monitored by in situ litter-bag incubation under four treatments, i.e., field condition (CK), nitrogen addition (AN, 2 g N·m-2), warming by top-open chamber (OTC), nitrogen addition with warming by top-open chamber (OTC+AN), from November to next September. Decomposition of water-soluble sugar, water-soluble phenol and total polyphenol were stimulated significantly under the treatment OTC, AN and OTC+AN during the first four months compared with the CK, but the difference of these components release narrowed with the extension of incubation time. Compared with CK, releases of dichloromethane-extractable fraction, acid soluble carbohydrates, acid soluble lignin, and acid insoluble lignin, were inhibited significantly under OTC, AN, and OTC+AN treatments, and the significance of inhibitory effect under the treatments was: OTC > OTC+AN > AN. Especially, in the treatment of OTC, half-life of dichloromethane-extractable fraction and acid inso-luble lignin in fresh litter were doubled, and that of hot-water soluble component was prolonged by more than 50% compared with CK. Half-life of water-soluble sugar, water-soluble phenol, total polyphenol, acid-soluble carbohydrate and acid-soluble lignin in fresh litter were respectively 182, 159, 127, 154 and 190 d in CK, and these components seem to be easily mineralized organic fraction. Meanwhile, half-life of hot-water soluble components, dichloromethane-extractable fraction, and acid insoluble lignin was 209, 302 and 318 d, respectively, indicating these fractions recalcitrant to decomposing in the fresh litter. Decomposition of all components in L. potaninii litter occurred in cold season from November to next March, which suggested that cold season was the most important period for litter decay in the alpine conifer. Generally it was assumed that microorganisms were inactive and decomposition of organic matters was slow in alpine soil during harsh winter, while the results of fresh litter incubation in situ showed that all components decomposed very fast during the period. Therefore, in alpine treeline, nitrogen deposition and warming would inhibit rather than promote decomposition of fresh litter, which would be conducive to carbon sequestration for the alpine soil ecosystem.