Exploring the potential of chitosan-based particles as delivery-carriers for promising antimicrobial glycolipid biosurfactants.

Driven by the need to find alternatives to control Staphylococcus aureus infections, this work describes the development of chitosan-based particulate systems as carriers for antimicrobial glycolipids. By using a simple ionic gelation method stable nanoparticles were obtained showing an encapsulation efficiency of 41.1 ± 8.8 % and 74.2 ± 1.3 % and an average size of 210.0 ± 15.7 nm and 329.6 ± 8.0 nm for sophorolipids and rhamnolipids chitosan-nanoparticles, respectively. Glycolipids incorporation and particle size was correspondingly corroborated by FTIR-ATR and TEM analysis. Rhamnolipids chitosan nanoparticles (RLs-CSp) presented the highest antimicrobial effect towards S. aureus (ATCC 25923) exhibiting a minimal inhibitory concentration of 130 µg/mL and a biofilm inhibition ability of 99 %. Additionally, RLs-CSp did not interfere with human dermal fibroblasts (AG22719) viability and proliferation under the tested conditions. The results revealed that the RLs-CSp were able to inhibit bacterial growth showing adequate cytocompatibility and might become, after additional studies, a valuable approach to prevent S. aureus related infections.

Validation of the Malnutrition Universal Screening Tool (MUST) in cancer.

In the present study, we aimed to validate the Malnutrition Universal Screening Tool (MUST) for routine nutritional screening in the radiation oncology setting, thus enabling timely and adequate referrals of patients at risk for individualised or advanced intervention. Towards this objective, we conducted a prospective cross-sectional study in 450 non-selected cancer patients (18-95 years) referred for radiotherapy. The following were the nutritional parameters: BMI (categorised by WHO's age/sex criteria), weight loss >5 % in the previous 3-6 months, Patient-Generated Subjective Global Assessment (PG-SGA - validated/specific for oncology) and nutritional risk by MUST. Sensitivity, specificity, predictive values and concordance were calculated to validate MUST v. PG-SGA and compare single parameters v. PG-SGA/MUST. BMI v. PG-SGA showed a negligible capacity to detect undernutrition: 0.27 sensitivity, 0.23 specificity, 0.35 positive predictive value and 0.31 negative predictive value. Conversely, percentage weight loss v. PG-SGA was highly effective: 0.76 sensitivity, 0.85 specificity, 0.79 positive predictive value and 0.85 negative predictive value. MUST v. PG-SGA successfully detected patients at risk: 0.80 sensitivity, 0.89 specificity, 0.87 positive predictive value and 1.0 negative predictive value; percentage weight loss v. MUST proved able to identify patients likely to be at risk: 0.85 sensitivity, 0.91 specificity, 0.90 positive predictive value and 1.0 negative predictive value. This is the first study in the radiation oncology setting to validate MUST: a simple and quick method applicable by any health professional, with a high validity for early screening, ideally to antedate a comprehensive nutritional assessment and guide for intervention. In this study, percentage weight loss in the previous 3-6 months does seem valid to predict nutritional risk, and may be the minimum in a busy routine.

Teaching nutrition integration: MUST screening in cancer.

RATIONALE: Nutritional risk screening should be routine in order to select patients in need of nutrition care; this conduct change has to rely on education. In this project, radiotherapy department health professionals were trained on how to use the Malnutrition Universal Screening Tool (MUST), to foster its integration into cancer outpatient management; we also aimed to identify those more adherent to screening. METHODS: Research dieticians (the standard) conducted interactive sessions with all physicians, nurses, and radiotherapy (RT) technicians, who were closely supervised to facilitate routine MUST integration. There were two phases: after the first session, phase 1 assessed 200 patients over 4 months; after the second session, phase 2 screened 450 patients, always before RT. Validity was evaluated comparing results from the standard against all other health professionals, adjusted for number. RESULTS: RT technicians were most adherent to the MUST: 80% of patients in phase 1, increasing to 85% in phase 2. Nurses doubled their input, from 19% to 36%. Physicians had poor MUST integration, yet they progressively incorporated percentage weight loss into patient records, increasing from 57% in phase 1 to 84% in phase 2, independently of diagnosis and stage. The highest concordance (κ coefficient) with dieticians was found with RT technicians' use of the MUST (p < .002) and percentage weight loss determination by physicians (p < .001). CONCLUSIONS: We show that systematic screening in cancer is feasible by all professionals involved, once a proximity teaching project is put into practice. RT technicians, who daily treat patients, were highly adherent to integrate the MUST and might be in charge of selecting at-risk patients. Physicians are unlikely to use the MUST, but acknowledged nutrition value and changed their routine by integrating recent percentage weight loss into their approach to patients. Our structured methodology may be used as a model for the development of teaching adapted to different departments with other realities.

[Research training in nutrition: relevance for medical clinical pratice]. / Estágio de investigação em nutrição: relevância para a prática clínica em medicina.

INTRODUCTION: In oncology, early and individualized nutritional intervention for each patient is essential to improve nutritional intake and status, to reduce morbidity during treatment, enhance tolerance to treatment and improve Quality of Life. OBJECTIVES: For medical students to evaluate nutritional risk and status, analyse the prevalence of undernutrition in a population of patients with diverse types of tumours. We aimed to identify difficulties regarding the use of the MUST tool (Malnutrition Universal Screening Tool) for nutritional risk by the students. METHODS: This study included 35 cancer patients consecutively referenced for Radiotherapy (RT) in the Radiotherapy Department of the University Hospital of Santa Maria. Nutritional risk was evaluated by MUST; nutritional status by Patient Generated-Subjective Global Assessment (PG-SGA) validated and specific for oncology. RESULTS: Students identified 13 patients (36%) at moderate/high risk of undernutrition. According to PG-SGA, 31,5% (11/35) of patients presented moderate or severe undernutrition, of which 77% of patients needed individualized nutritional counselling. Students successfully detected undernourished patients using these specific methods. CONCLUSION: Risk of undernutrition and undernutrition are common in oncology, therefore indicating the critical need to educate all health professionals for risk screening and for the relevance of nutritional intervention in the multidisciplinary context. MUST is a simple and quick tool, that demonstrated to be adequate when applied by medical students, well accepted by these health professionals and effectively used. Nutritional risk evaluation can and must be performed by health professionals such as the medical team, as long as they are involved in patient's treatment. Our methodology may be used as a model allowing for early guidance to individualized intervention, human resources' optimization and education for the importance of nutrition care.

The diversity of nutritional status in cancer: new insights.

OBJECTIVE: Nutritional status in cancer has been mostly biased toward undernutrition, an issue now in dispute. We aimed to characterize nutrition status, to analyze associations between nutritional and clinical/cancer-related variables, and to quantify the relative weights of nutritional and cancer-related features. METHODS: The cross-sectional study included 450 nonselected cancer patients (ages 18-95 years) at referral for radiotherapy. Nutritional status assessment included recent weight changes, body mass index (BMI) categorized by World Health Organization's age/sex criteria, and Patient-Generated Subjective Global Assessment (PG-SGA; validated/specific for oncology). RESULTS: BMI identified 63% as >or=25 kg/m(2) (43% overweight, 20% obese) and 4% as undernourished. PG-SGA identified 29% as undernourished and 71% as well nourished. Crossing both methods, among the 319 (71%) well-nourished patients according to PG-SGA, 75% were overweight/obese and only 25% were well nourished according to BMI. Concordance between BMI and PG-SGA was evaluated and consistency was confirmed. More aggressive/advanced stage cancers were more prevalent in deficient and excessive nutritional status: in 83% (n = 235/282) of overweight/obese patients by BMI and in 85% (n = 111/131) of undernourished patients by PG-SGA. Results required adjustment for diagnoses: greater histological aggressiveness was found in overweight/obese prostate and breast cancer; undernutrition was associated with aggressive lung, colorectal, head-neck, stomach, and esophageal cancers (p < .005). Estimates of effect size revealed that overweight/obesity was associated with advanced stage (24%), aggressive breast (10%), and prostate (9%) cancers, whereas undernutrition was associated with more aggressive lung (6%), colorectal (6%), and head-neck (6%) cancers; in both instances, age and longer disease duration were of significance. CONCLUSION: Undernutrition and overweight/obesity have distinct implications and bear a negative prognosis in cancer. This study provides novel data on the prevalence of overweight/obesity and undernutrition in cancer patients and their potential role in cancer histological behavior.