Effects of amount and recurrence of leaf herbivory on the induction of direct and indirect defences in wild cotton.

The induction of defences in response to herbivory is a key mechanism of plant resistance. While a number of studies have investigated the time course and magnitude of plant induction in response to a single event of herbivory, few have looked at the effects of recurrent herbivory. Furthermore, studies measuring the effects of the total amount and recurrence of herbivory on both direct and indirect plant defences are lacking. To address this gap, here we asked whether insect leaf herbivory induced changes in the amount and concentration of extrafloral nectar (an indirect defence) and concentration of leaf phenolic compounds (a direct defence) in wild cotton (Gossypium hirsutum). We conducted a greenhouse experiment where we tested single event or recurrent herbivory effects on defence induction by applying mechanical leaf damage and caterpillar (Spodoptera frugiperda) regurgitant. Single events of 25% and 50% leaf damage did not significantly influence extrafloral nectar production or concentration. Extrafloral nectar traits did, however, increase significantly relative to controls when plants were exposed to recurrent herbivory (two episodes of 25% damage). In contrast, phenolic compounds increased significantly in response to single events of  leaf damage but not to recurrent damage. In addition, we found. that local induction of extrafloral nectar production was stronger than systemic induction, whereas the reverse pattern was observed for phenolics. Together, these results reveal seemingly inverse patterns of induction of direct and indirect defences in response to herbivory in wild cotton.

[EORTC QLQ-C30 questionnaire role as predictor for malnutrition risk in head and neck cancer Mexican patients]. / Papel del cuestionario EORTC QLQ-C30 en la predicción de riesgo de desnutrición en pacientes mexicanos con cáncer de cabeza y cuello.

INTRODUCTION: Head and neck cancer treatment restricts oral intake and conditioning malnutrition. Adequate nutritional support during treatment can limit the impact of side effects. OBJECTIVE: To describe EORTC QLQ-C30 role for malnutrition risk screening in head and neck cancer patients. METHODS: Analytical and cross-sectional, diagnostic test study in head and neck cancer patients. We correlated malnutrition diagnosis with subjective global assessment (SGA) and score for the EORTC QLQ-C30 scales with Pearson and Spearman correlation. We realized COR (Receiver Operating Characteristic) curves to calculate cut point in the score for the EORTC QLQ-C30 scales; we calculated sensitivity, specificity, positive predictive value, negative predictive value and Odds Ratio through logistic regression. RESULTS: Functional scales (role, physic, global health status/QoL) showed limited utility to malnutrition risk estimation in people with head and neck cancer. Symptoms' scales with strong association were: pain (sensitivity 76.47%, specificity 69.23%), insomnia (sensitivity 88.24%, specificity 53.85%), fatigue (sensitivity 70.59%, specificity 76.92%). CONCLUSIONS: EORTC QLQ-C30 questionnaire is a useful tool to early malnutrition diagnosis in head and neck cancer patients with short term results in nutritional condition, treatment response and a better QoL in this kind of patients.

Papel del cuestionario EORTC QLQ-C30 en la predicción de riesgo de desnutrición en pacientes mexicanos con cáncer de cabeza y cuello / EORTC QLQ-C30 questionnaire role as predictor for malnutrition risk in head and neck cancer Mexican patients

Introducción: El tratamiento del cáncer de cabeza y cuello puede limitar la ingesta oral y condicionar desnutrición. Un soporte nutricional adecuado durante el tratamiento puede limitar el impacto de los efectos secundarios. Objetivo: Describir la utilidad de la encuesta EORTC QLQ-C30 en el tamizaje de riesgo de desnutrición en pacientes con cáncer de cabeza y cuello. Métodos: Estudio transversal analítico, validación de prueba diagnóstica en pacientes con cáncer de cabeza y cuello en diferentes etapas clínicas. Se correlacionó el diagnóstico de desnutrición (Valoración Global Subjetiva) con las escalas del cuestionario EORTC QLQ-C30.v3 a través de las correlaciones de Pearson y de Spearman; se realizó una curva ROC para determinar el punto de corte en los puntajes de las escalas del cuestionario QLQ-C30.v3 y el cálculo de sensibilidad, especificidad, valores predictivos positivo y negativo, y el cálculo de Odds Ratio por regresión logística. Resultados: Las escalas funcionales (función de rol, función física y estado global de salud) presentaron valores limitados para estimar riesgo de desnutrición en las personas, con cáncer de cabeza y cuello. Las escalas de síntomas que mostraron mayor grado de asociación fueron: dolor con sensibilidad de 76,47% y especificidad de 69,23%, insomnio con sensibilidad de 88,24% y especificidad de 53,85%, fatiga con sensibilidad de 70,59% y especificidad de 76,92%. Conclusiones: El cuestionario EORTC QLQ-C30, es una herramienta útil para detectar tempranamente desnutrición en pacientes con cáncer de cabeza y cuello, impactar el estadio nutricio, la respuesta al tratamiento y elevar la calidad de vida de estos pacientes (AU)

Introduction: Head and neck cancer treatment restricts oral intake and conditioning malnutrition. Adequate nutritional support during treatment can limit the impact of side effects. Objective: To describe EORTC QLQ-C30 role for malnutrition risk screening in head and neck cancer patients. Methods: Analytical and cross-sectional, diagnostic test study in head and neck cancer patients. We correlated malnutrition diagnosis with subjective global assessment (SGA) and score for the EORTC QLQ-C30 scales with Pearson and Spearman correlation. We realized COR (Receiver Operating Characteristic) curves to calculate cut point in the score for the EORTC QLQ-C30 scales; we calculated sensitivity, specificity, positive predictive value, negative predictive value and Odds Ratio through logistic regression. Results: Functional scales (role, physic, global health status/QoL) showed limited utility to malnutrition risk estimation in people with head and neck cancer. Symptoms' scales with strong association were: pain (sensitivity 76.47%, specificity 69.23%), insomnia (sensitivity 88.24%, specificity 53.85%), fatigue (sensitivity 70.59%, specificity 76.92%). Conclusions: EORTC QLQ-C30 questionnaire is a useful tool to early malnutrition diagnosis in head and neck cancer patients with short term results in nutritional condition, treatment response and a better QoL in this kind of patients (AU)