RESUMEN
Pest populations are mostly regulated by climate, intra- and interspecific competition, natural enemies, and host plant quality. Myzus persicae (Sulzer) (Hemiptera: Aphididae) is a widely adapted aphid in the agroecosystems and is one of the main bell pepper pests. In the present study, we determined the spatial and temporal dynamics and the regulatory factors of M. persicae populations in bell pepper crops. The number of aphids and their natural enemies were evaluated during 2 years in four commercial bell pepper fields. Myzus persicae density data were related to temperature, rainfall, and natural enemies by multiple regression analysis and were then submitted to geostatistical analysis. The density of M. persicae was higher during the plant's reproductive growth stage. Rainfall, Chrysoperla spp., and Toxomerus spp. regulate M. persicae populations. Initial infestations of this pest occur along the edges of the fields and subsequently spread towards the center. This information is useful for integrated management programs aimed at anticipating periods of higher abundance of M. persicae and identifying arthropods to be prioritized in biological control.
Asunto(s)
Áfidos/fisiología , Capsicum , Animales , Brasil , Productos Agrícolas , Dinámica Poblacional , Estaciones del Año , Análisis Espacio-Temporal , Tiempo (Meteorología)RESUMEN
Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) is one of the major pests of solanaceous plants in South America. It is considered a great threat by the European and Mediterranean Plant Protection Organization due to the serious economic damage that it causes on tomato farms; therefore, controlling this pest is a challenging task in South America. Controlling N. elegantalis at the egg stage is the best way to prevent it from damaging crops; however, thorough studies about the effectiveness of chemicals on the different life stages of this insect pest are lacking. In this study, the effects of different chemical classes were evaluated on N. elegantalis adults, female oviposition behavior, larvae, eggs, and embryonic development. None of the tested insecticides demonstrated toxicity to the adults; however, the results showed that cartap hydrochloride affects oviposition behavior. Moreover, methomyl and cartap hydrochloride exhibited high toxicity against the eggs and larvae, with higher than 80% of mortality. These insecticides interrupted larval hatching and caused alterations in the chorion layer. Flubendiamide and deltamethrin demonstrated toxicity on N. elegantalis larvae; however, lufenuron, indoxacarb, methoxyfenozide, and chlorantraniliprole demonstrated low toxicity on both eggs and larvae, with lower than 70% of mortality. Fruit treated with cartap hydrochloride had a deterrent effect. The ovicidal activity revealed by methomyl and cartap hydrochloride might provide new approaches regarding insecticide effects on eggs. Methomyl, cartap hydrochloride, flubendiamide, and deltamethrin demonstrated toxicity on larvae. The evaluation of the chorion of the eggshell in this study has clarified the toxic effect of methomyl and cartap hydrochloride on eggs.
Asunto(s)
Insecticidas , Lepidópteros , Animales , Benzamidas , Femenino , Hidrazinas , Control de Insectos , Hormonas Juveniles , Larva , Metomil , Nitrilos , Oviposición , Óvulo , Oxazinas , Piretrinas , Solanum , Sulfonas , Tiocarbamatos , ortoaminobenzoatosRESUMEN
WHAT IS KNOWN AND OBJECTIVE: Amphotericin B (AmB) is commonly used to treat a broad spectrum of fungal infections and leishmaniasis. Its use is limited by numerous adverse effects. Reversible dilated cardiomyopathy associated with AmB is a rare disorder with only four previously reported cases, and all of them referring to patients who presented with a predisposing factor for heart failure. CASE SUMMARY: A previously healthy 45-year-old man with visceral leishmaniasis treated with AmB developed acute dilated cardiomyopathy. Other causes of heart failure as well-known predisposing factors for this condition were ruled out. As with previously reported cases, the cardiac function of our patient returned to normal shortly after. WHAT IS NEW AND CONCLUSION: We describe the first case of dilated cardiomyopathy associated with the administration of AmB in a patient without any known predisposing factor for developing cardiac dysfunction. Available evidence suggests that AmB may induce cardiotoxicity. Further investigations are needed to clarify this issue.
Asunto(s)
Anfotericina B/efectos adversos , Antiprotozoarios/efectos adversos , Cardiomiopatía Dilatada/inducido químicamente , Leishmaniasis Visceral/tratamiento farmacológico , Anfotericina B/uso terapéutico , Antiprotozoarios/uso terapéutico , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: In order to assess whether near-total laryngectomy (NTL) could successfully reach the cure and preserve the voice in advanced laryngeal cancer, we studied 28 patients with T3/T4 squamous cell carcinoma of the larynx treated with NTL in our institution. METHODS: A retrospective analysis has been carried out from 1990 through 1994. We classified 24 patients as Stage III and 4 patients as Stage IV. All patients had lateral neck dissection. Survival was analyzed under the Kaplan-Meier method. RESULTS: Twenty-six patients achieved voice preservation. Two patients in the bilateral neck dissection group had a metastatic lymph node on the opposite side. No patient had local recurrence. Three patients died of the disease, and 1 patient was salvaged with neck dissection. Three-year disease-free survival was 85%. CONCLUSION: This technique is useful in the treatment of selected cases of advanced laryngeal cancer and achieves local control of the lesion in all cases. The survival is comparable with that of patients submitted to total laryngectomy, regarding the extent of lesion. Voice preservation can be achieved in most cases.
Asunto(s)
Carcinoma de Células Escamosas/cirugía , Neoplasias Laríngeas/cirugía , Laringectomía , Análisis Actuarial , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/patología , Supervivencia sin Enfermedad , Femenino , Humanos , Neoplasias Laríngeas/mortalidad , Neoplasias Laríngeas/patología , Masculino , Persona de Mediana Edad , Disección del Cuello , Recurrencia Local de Neoplasia/epidemiología , Estadificación de Neoplasias , Radioterapia Adyuvante , Estudios Retrospectivos , Factores de TiempoRESUMEN
BACKGROUND: This study analyzed pathologic findings of clinically occult cervical lymph nodes of T3/T4 N0 squamous cell laryngeal carcinoma and their impact on locoregional failures and overall survival. PATIENTS AND METHODS: A retrospective analysis of 76 patients with T3/T4 N0 laryngeal carcinoma was carried out between 1981 and 1989. Sixty-seven patients had transglottic tumor, 31 patients had extralaryngeal spread, 56 patients were T3 N0, and 20 patients were T4 N0. Seventy-five patients had total laryngectomy and 1 had near total laryngectomy. All patients had bilateral elective neck dissection. The chi-square test was applied to factors related to neck metastasis and locoregional failure. Survival was analyzed using the Kaplan-Meier actuarial method; differences were tested using the Wilcoxon signed-rank test. RESULTS: Eighteen patients had positive surgical margins. Occult neck metastasis was observed in 30%. Univariate analysis showed that cancer stage and cartilage status were not significant to predict neck metastasis. Locoregional recurrence was observed in 28% of patients. Surgical margins, cervical metastasis, lesion extension, and cartilage invasion had significant impact on disease-free survival. The 5-year overall survival was 52%; disease-free survival was 57%. CONCLUSION: The elective bilateral neck dissection performed in T3/T4 N0 patients yielded a 30% incidence of occult neck metastasis. Classification of transglottic carcinomas into endolaryngeal and exolaryngeal provides a better parameter for predicting neck metastasis than does T status. Disease-free and overall survival were significantly affected by neck metastasis, T stage, exolaryngeal tumor, cartilage infiltration, and surgical margins.
Asunto(s)
Carcinoma de Células Escamosas/cirugía , Procedimientos Quirúrgicos Electivos , Neoplasias Laríngeas/cirugía , Escisión del Ganglio Linfático , Análisis Actuarial , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/secundario , Supervivencia sin Enfermedad , Femenino , Predicción , Glotis/patología , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/secundario , Humanos , Incidencia , Cartílagos Laríngeos/patología , Neoplasias Laríngeas/patología , Laringectomía , Metástasis Linfática/patología , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Pronóstico , Radioterapia Adyuvante , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
BACKGROUND: Recent studies in patients with previously untreated T1 and T2 squamous cell carcinoma (SCC) of the tongue and floor of the mouth have shown a relationship between tumor thickness, neck metastasis, and survival. Our study was conducted to determine the indication of elective neck dissection in patients with early oral cavity SCC. PATIENTS AND METHODS: Sixty-seven patients were stratified by stage (T1 and T2 NO), and those in each stage were randomized to receive one of two types of treatment; resection alone (RA) or resection plus elective supraomohyoid neck dissection (RSOND). Fifty-two patients (78%) were men and 15 (22%) were women. The median age was 57 years old (range 34 to 95). RESULTS: Twenty-six (39%) patients had tumor in the floor of the mouth and 41 (61%), in the tongue. Using the criteria of the Union Internationale Contre le Cancer (UICC), 1987, we classified 31 tumors (46%) as T1 lesions and 36 (54%) as T2 lesions. Thirty patients had a tumor thickness < or = 4 mm and 37 had a tumor thickness > 4 mm. Thirty-three (49%) patients were treated with RA, and 34 patients (51%) were treated with RSOND. Seven (21%) patients of the RSOND group had occult cervical metastasis. There were recurrences in 14 (42%) patients of the RA group and 8 (24%) patients of the RSOND group. The disease-free survival rates at 3.5 years for RA and RSOND patients were 49%, and 72%, respectively. The impact of sex, age, site, cancer stage, and tumor thickness was assessed by the Mantel-Haenszel chi-square procedure. Later stage (P = 0.05) and increased tumor thickness (P = 0.005) were significantly associated with treatment failures. CONCLUSION: Neck dissection remains mandatory in the early stage of oral SCC, because of better survival rates compared to RA and the poor salvage rate. In particular, patients with tumor thickness > 4 mm treated with RSOND had significant benefit on disease-free survival.