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1.
Tech Coloproctol ; 27(12): 1139-1154, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37330988

RESUMEN

PURPOSE: High output is a common complication after stoma formation. Although the management of high output is described in the literature, there is a lack of consensus on definitions and treatment. Our aim was to review and summarise the current best evidence. METHODS: MEDLINE, Cochrane Library, BNI, CINAHL, EMBASE, EMCARE, and ClinicalTrials.gov were searched from 1 Jan 2000 to 31 Dec 2021 for relevant articles on adult patients with a high-output stoma. Patients with enteroatmospheric fistulas and case series/reports were excluded. Risk of bias was assessed using RoB2 and MINORS. The review was registered in PROSPERO (CRD42021226621). RESULTS: The search strategy identified 1095 articles, of which 32 studies with 768 patients met the inclusion criteria. These studies comprised 15 randomised controlled trials, 13 non-randomised prospective trials, and 4 retrospective cohort studies. Eighteen different interventions were assessed. In the meta-analysis, there was no difference in stoma output between controls and somatostatin analogues (g - 1.72, 95% CI - 4.09 to 0.65, p = 0.11, I2 = 88%, t2 = 3.09), loperamide (g - 0.34, 95% CI - 0.69 to 0.01, p = 0.05, I2 = 0%, t2 = 0) and omeprazole (g - 0.31, 95% CI  - 2.46 to 1.84, p = 0.32, I2 = 0%, t2 = 0). Thirteen randomised trials showed high concern of bias, one some concern, and one low concern. The non-randomised/retrospective trials had a median MINORS score of 12 out of 24 (range 7-17). CONCLUSION: There is limited high-quality evidence favouring any specific widely used drug over the others in the management of high-output stoma. Evidence, however, is weak due to inconsistent definitions, risk of bias and poor methodology in the existing studies. We recommend the development of validated core descriptor and outcomes sets, as well as patient-reported outcome measures.


Asunto(s)
Estomas Quirúrgicos , Adulto , Humanos , Estudios Retrospectivos , Estudios Prospectivos , Estomas Quirúrgicos/efectos adversos
2.
Hernia ; 26(3): 701-714, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35024980

RESUMEN

PURPOSE: There are no universally agreed guidelines regarding which types of physical activity are safe and/or recommended in the perioperative period for patients undergoing ventral hernia repair or abdominal wall reconstruction (AWR). This study is intended to identify and summarise the literature on this topic. METHODS: Database searches of PubMed, CINAHL, Allied & Complementary medicine database, PEDro and Web of Science were performed followed by a snowballing search using two papers identified by the database search and four hand-selected papers of the authors' choosing. Inclusion-cohort studies, randomized controlled trials, prospective or retrospective. Studies concerning complex incisional hernia repairs and AWRs including a "prehabilitation" and/or "rehabilitation" program targeting the abdominal wall muscles in which the interventions were of a physical exercise nature. RoB2 and Robins-I were used to assess risk of bias. Prospero CRD42021236745. No external funding. Data from the included studies were extracted using a table based on the Cochrane Consumers and Communication Review Group's data extraction template. RESULTS: The database search yielded 5423 records. After screening two titles were selected for inclusion in our study. The snowballing search identified 49 records. After screening one title was selected for inclusion in our study. Three total papers were included-two randomised studies and one cohort study (combined 423 patients). All three studies subjected their patients to varying types of physical activity preoperatively, one study also prescribed these activities postoperatively. The outcomes differed between the studies therefore meta-analysis was impossible-two studies measured hernia recurrence, one measured peak torque. All three studies showed improved outcomes in their study groups compared to controls however significant methodological flaws and confounding factors existed in all three studies. No adverse events were reported. CONCLUSIONS: The literature supporting the advice given to patients regarding recommended physical activity levels in the perioperative period for AWR patients is sparse. Further research is urgently required on this subject.


Asunto(s)
Pared Abdominal , Hernia Ventral , Pared Abdominal/cirugía , Estudios de Cohortes , Ejercicio Físico , Hernia Ventral/cirugía , Herniorrafia , Humanos , Estudios Prospectivos , Estudios Retrospectivos
3.
BJS Open ; 5(2)2021 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-33839746

RESUMEN

BACKGROUND: The incidence of incisional hernia is up to 20 per cent after abdominal surgery. The management of patients with incisional hernia can be complex with an array of techniques and meshes available. Ensuring consistency in reporting outcomes across studies on incisional hernia is important and will enable appropriate interpretation, comparison and data synthesis across a range of clinical and operative treatment strategies. METHODS: Literature searches were performed in MEDLINE and EMBASE (from 1 January 2010 to 31 December 2019) and the Cochrane Central Register of Controlled Trials. All studies documenting clinical and patient-reported outcomes for incisional hernia were included. RESULTS: In total, 1340 studies were screened, of which 92 were included, reporting outcomes on 12 292 patients undergoing incisional hernia repair. Eight broad-based outcome domains were identified, including patient and clinical demographics, hernia-related symptoms, hernia morphology, recurrent incisional hernia, operative variables, postoperative variables, follow-up and patient-reported outcomes. Clinical outcomes such as hernia recurrence rates were reported in 80 studies (87 per cent). A total of nine different definitions for detecting hernia recurrence were identified. Patient-reported outcomes were reported in 31 studies (34 per cent), with 18 different assessment measures used. CONCLUSIONS: This review demonstrates the significant heterogeneity in outcome reporting in incisional hernia studies, with significant variation in outcome assessment and definitions. This is coupled with significant under-reporting of patient-reported outcomes.


Asunto(s)
Herniorrafia/métodos , Hernia Incisional/cirugía , Humanos , Medición de Resultados Informados por el Paciente , Complicaciones Posoperatorias/etiología , Recurrencia , Mallas Quirúrgicas/efectos adversos
4.
Hernia ; 23(3): 461-472, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31161285

RESUMEN

BACKGROUND: One standard repair technique for groin hernias does not exist. The objective of this study is to perform an update meta-analysis and trial sequential analysis to investigate if there is a difference in terms of recurrence between laparoscopic and open primary unilateral uncomplicated inguinal hernia repair. METHODS: The reporting methodology conforms to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Randomised controlled trials only were included. The intervention was laparoscopic mesh repair (transabdominal preperitoneal (TAPP) and totally extraperitoneal (TEP)). The control group was Lichtenstein repair. The primary outcome was recurrence rate and secondary outcomes were acute and chronic post-operative pain, morbidity and quality of life. RESULTS: This study included 12 randomised controlled trials with 3966 patients randomised to Lichtenstein repair (n = 1926) or laparoscopic repair (n = 2040). There were no significant differences in recurrence rates between the laparoscopic and open groups (odds ratio (OR) 1.14, 95% CI 0.51-2.55, p = 0.76). Laparoscopic repair was associated with reduced rate of acute pain compared to open repair (mean difference 1.19, CI - 1.86, - 0.51, p ≤ 0.0006) and reduced odds of chronic pain compared to open (OR 0.41, CI 0.30-0.56, p ≤ 0.00001). The included trials were, however, of variable methodological quality. Trial sequential analysis reported that further studies are unlikely to demonstrate a statistically significant difference between the two techniques. CONCLUSION: This meta-analysis and trial sequential analysis report no difference in recurrence rates between laparoscopic and open primary unilateral inguinal hernia repairs. Rates of acute and chronic pain are significantly less in the laparoscopic group.


Asunto(s)
Hernia Inguinal/cirugía , Herniorrafia/métodos , Humanos , Laparoscopía , Masculino , Mallas Quirúrgicas , Resultado del Tratamiento
7.
Hernia ; 22(2): 273-283, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29071497

RESUMEN

BACKGROUND: Seroma formation remains a common complication after an incisional hernia repair. The use of surgical drains is widespread, but evidence for their use and other adjuncts is limited. Our aim was to perform a systematic review of the literature on techniques used to reduce the incidence of post-operative seroma formation. METHODS: A systematic search of PubMed and Embase databases was conducted using terms including "incisional hernia" and "seroma". All studies on adults undergoing open incisional hernia repair with at least one intervention designed to reduce seroma formation were included. RESULTS: Of the 1093 studies identified, 9 met the inclusion criteria. Medical talc: one cohort study of 74 patients undergoing talc application following pre-peritoneal mesh placement found a significantly decreased rate of seroma formation of 20.8 versus 2.7% (p < 0.001), but a retrospective study including 21 patients with onlay mesh found an increased rate of 76% seroma formation from 9.5% (p = 0.001). Fibrin glue: one comparative study including 60 patients found a reduction in seroma formation from 53 to 10% (p = 0.003), whereas a retrospective study of 250 patients found no difference (11 vs. 4.9% p = 0.07). Negative pressure wound therapy: four retrospective studies including a total of 358 patients found no difference in seroma outcome. Others: one randomised study of 42 patients undergoing either suction drainage or "quilting" sutures found no difference in seroma formation. CONCLUSIONS: There is currently insufficient quality evidence to recommend any of the investigated methods, some of which incur significant additional cost.


Asunto(s)
Herniorrafia/efectos adversos , Hernia Incisional/cirugía , Complicaciones Posoperatorias/prevención & control , Prevención Secundaria , Seroma , Herniorrafia/métodos , Humanos , Prevención Secundaria/economía , Prevención Secundaria/instrumentación , Prevención Secundaria/métodos , Prevención Secundaria/normas , Seroma/etiología , Seroma/prevención & control
8.
Neuroimage Clin ; 13: 154-163, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27981030

RESUMEN

BACKGROUND: The anatomy of the substantia nigra on conventional MRI is controversial. Even using histological techniques it is difficult to delineate with certainty from surrounding structures. We sought to define the anatomy of the SN using high field spin-echo MRI of pathological material in which we could study the anatomy in detail to corroborate our MRI findings in controls and Parkinson's disease and progressive supranuclear palsy. METHODS: 23 brains were selected from the Queen Square Brain Bank (10 controls, 8 progressive supranuclear palsy, 5 Parkinson's disease) and imaged using high field 9.4 Tesla spin-echo MRI. Subsequently brains were cut and stained with Luxol fast blue, Perls stain, and immunohistochemistry for substance P and calbindin. Once the anatomy was defined on histology the dimensions and volume of the substantia nigra were determined on high field magnetic resonance images. RESULTS: The anterior border of the substantia nigra was defined by the crus cerebri. In the medial half it was less distinct due to the deposition of iron and the interdigitation of white matter and the substantia nigra. The posterior border was flanked by white matter bridging the red nucleus and substantia nigra and seen as hypointense on spin-echo magnetic resonance images. Within the substantia nigra high signal structures corresponded to confirmed nigrosomes. These were still evident in Parkinson's disease but not in progressive supranuclear palsy. The volume and dimensions of the substantia nigra were similar in Parkinson's disease and controls, but reduced in progressive supranuclear palsy. CONCLUSIONS: We present a histologically validated anatomical description of the substantia nigra on high field spin-echo high resolution magnetic resonance images and were able to delineate all five nigrosomes. In accordance with the pathological literature we did not observe changes in the nigrosome structure as manifest by volume or signal characteristics within the substantia nigra in Parkinson's disease whereas in progressive supranuclear palsy there was microarchitectural destruction.


Asunto(s)
Envejecimiento/patología , Encefalopatías/diagnóstico por imagen , Encefalopatías/patología , Imagen por Resonancia Magnética/métodos , Sustancia Negra/diagnóstico por imagen , Sustancia Negra/patología , Bancos de Tejidos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad
9.
Ann R Coll Surg Engl ; 97(5): 345-8, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26264084

RESUMEN

INTRODUCTION: Since its first description by Delaitre and Maignien in 1991, laparoscopic splenectomy (LS) has evolved as treatment of choice for mild-to-moderately-enlarged spleens and for benign haematological disorders. LS is a challenge if massive spleens or malignant conditions necessitate treatment, but we report our method and its feasibility in this study. METHODS: We undertook a retrospective study of prospectively collected data of all elective splenectomies carried out in our firm of upper gastrointestinal surgeons from June 2003 to June 2012. Only patients opting for elective LS were included in this study. RESULTS: From June 2003 to June 2012, elective splenectomy was carried out in 80 patients. Sixty-seven patients underwent LS and 13 underwent open splenectomy (OS). In the LS group, there were 38 males and 29 females. Age ranged from 6 years to 82 years. Spleen size in the LS group ranged from ≤11 cm to 27.6 cm. Twelve patients had a spleen size of >20 cm. Weight ranged from 35 g to 2,400 g. Eighteen patients had a spleen weight of 600-1,600 g and eight had a spleen weight >1,600 g. Operating times were available for 56 patients. Mean operating time for massive spleens was 129.73 min. There was no conversion to OS. There were no major complications. CONCLUSIONS: With improved laparoscopic expertise and advancing technology, LS is safe and feasible even for massive spleens and splenic malignancies. It is the emerging 'gold standard' for all elective splenectomies and has very few contraindications.


Asunto(s)
Laparoscopía/métodos , Bazo/patología , Bazo/cirugía , Esplenectomía/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Humanos , Laparoscopía/normas , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Complicaciones Posoperatorias , Estudios Retrospectivos , Esplenectomía/normas , Adulto Joven
10.
Neuropathol Appl Neurobiol ; 40(2): 149-63, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23432126

RESUMEN

AIMS: Since the first description of the classical presentation of progressive supranuclear palsy (PSP) in 1963, now known as Richardson's syndrome (PSP-RS), several distinct clinical syndromes have been associated with PSP-tau pathology. Like other neurodegenerative disorders, the severity and distribution of phosphorylated tau pathology are closely associated with the clinical heterogeneity of PSP variants. PSP with corticobasal syndrome presentation (PSP-CBS) was reported to have more tau load in the mid-frontal and inferior-parietal cortices than in PSP-RS. However, it is uncertain if differences exist in the distribution of tau pathology in other brain regions or if the overall tau load is increased in the brains of PSP-CBS. METHODS: We sought to compare the clinical and pathological features of PSP-CBS and PSP-RS including quantitative assessment of tau load in 15 cortical, basal ganglia and cerebellar regions. RESULTS: In addition to the similar age of onset and disease duration, we demonstrated that the overall severity of tau pathology was the same between PSP-CBS and PSP-RS. We identified that there was a shift of tau burden towards the cortical regions away from the basal ganglia; supporting the notion that PSP-CBS is a 'cortical' PSP variant. PSP-CBS also had less severe neuronal loss in the dorsolateral and ventrolateral subregions of the substantia nigra and more severe microglial response in the corticospinal tract than in PSP-RS; however, neuronal loss in subthalamic nucleus was equally severe in both groups. CONCLUSIONS: A better understanding of the factors that influence the selective pathological vulnerability in different PSP variants will provide further insights into the neurodegenerative process underlying tauopathies.


Asunto(s)
Ganglios Basales/patología , Corteza Cerebral/patología , Parálisis Supranuclear Progresiva/patología , Proteínas tau/metabolismo , Edad de Inicio , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Parálisis Supranuclear Progresiva/diagnóstico , Síndrome
11.
Neuroimage ; 59(3): 2035-44, 2012 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-22036997

RESUMEN

Using conventional MRI the subthalamic nucleus (STN) is not clearly defined. Our objective was to define the anatomy of the STN using 9.4 T MRI of post mortem tissue with histological validation. Spin-echo (SE) and 3D gradient-echo (GE) images were obtained at 9.4 T in 8 post mortem tissue blocks and compared directly with corresponding histological slides prepared with Luxol Fast Blue/Cresyl Violet (LFB/CV) in 4 cases and Perl stain in 3. The variability of the STN anatomy was studied using internal reference points. The anatomy of the STN and surrounding structures was demonstrated in all three anatomical planes using 9.4 T MR images in concordance with LFB/CV stained histological sections. Signal hypointensity was seen in 6/8 cases in the anterior and medial STN that corresponded with regions of more intense Perl staining. There was significant variability in the volume, shape and location of the borders of the STN. Using 9.4 T MRI, the internal signal characteristics and borders of the STN are clearly defined and significant anatomical variability is apparent. Direct visualisation of the STN is possible using high field MRI and this is particularly relevant, given its anatomical variability, for planning deep brain stimulation.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Núcleo Subtalámico/anatomía & histología , Anciano , Anciano de 80 o más Años , Cadáver , Colorantes , Imagen Eco-Planar , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Adhesión en Parafina , Reproducibilidad de los Resultados , Técnicas Estereotáxicas , Núcleo Subtalámico/patología , Fijación del Tejido
13.
Neuroimaging Clin N Am ; 20(1): 7-27, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19959016

RESUMEN

The substantia nigra and subthalamic nucleus are two key structures in the midbrain that are very important in movement disorders, particularly those associated with parkinsonism. Using conventional magnetic resonance (MR) imaging, the anatomic description of both these structures can be challenging. This article describes the importance of understanding the underlying anatomy and some of the changes associated with pathology in these structures. Advances in MR imaging are discussed, including high-field MR imaging, diffusion tensor imaging, inversion-recovery imaging, and susceptibility-weighted imaging, with particular reference to the substantia nigra and subthalamic nucleus. Understanding of MR imaging features of these nuclei needs to be firmly based on underlying knowledge of anatomy and pathology from postmortem studies, and more work is needed in this field.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Sustancia Negra/anatomía & histología , Núcleo Subtalámico/anatomía & histología , Animales , Imagen de Difusión Tensora/métodos , Humanos , Hierro/metabolismo , Trastornos del Movimiento/metabolismo , Trastornos del Movimiento/patología , Sustancia Negra/metabolismo , Sustancia Negra/patología , Núcleo Subtalámico/metabolismo , Núcleo Subtalámico/patología
14.
Brain ; 131(Pt 5): 1362-72, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18385183

RESUMEN

Prognostic predictors have not been defined for progressive supranuclear palsy (PSP) and multiple system atrophy (MSA). Subtypes of both disorders have been proposed on the basis of early clinical features. We performed a retrospective chart review to investigate the natural history of pathologically confirmed cases of PSP and MSA. Survival data and several clinically relevant milestones, namely: frequent falling, cognitive disability, unintelligible speech, severe dysphagia, dependence on wheelchair for mobility, the use of urinary catheters and placement in residential care were determined. On the basis of early symptoms, we subdivided cases with PSP into 'Richardson's syndrome' (RS) and 'PSP-parkinsonism' (PSP-P). Cases of MSA were subdivided according to the presence or absence of early autonomic failure. Sixty-nine (62.7%) of the 110 PSP cases were classified as RS and 29 (26.4%) as PSP-P. Of the 83 cases of MSA, 42 (53.2%) had autonomic failure within 2 years of disease onset. Patients with PSP had an older age of onset (P < 0.001), but similar disease duration to those with MSA. Patients with PSP reached their first clinical milestone earlier than patients with MSA (P < 0.001). Regular falls (P < 0.001), unintelligible speech (P = 0.04) and cognitive impairment (P = 0.03) also occurred earlier in PSP than in MSA. In PSP an RS phenotype, male gender, older age of onset and a short interval from disease onset to reaching the first clinical milestone were all independent predictors of shorter disease duration to death. Patients with RS also reached clinical milestones after a shorter interval from disease onset, compared to patients with PSP-P. In MSA early autonomic failure, female gender, older age of onset, a short interval from disease onset to reaching the first clinical milestone and not being admitted to residential care were independent factors predicting shorter disease duration until death. The time to the first clinical milestone is a useful prognostic predictor for survival. We confirm that RS had a less favourable course than PSP-P, and that early autonomic failure in MSA is associated with shorter survival.


Asunto(s)
Atrofia de Múltiples Sistemas/diagnóstico , Parálisis Supranuclear Progresiva/diagnóstico , Adulto , Edad de Inicio , Anciano , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Factores Sexuales , Análisis de Supervivencia , Factores de Tiempo
16.
Magnes Res ; 18(2): 123-6, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16100850

RESUMEN

PURPOSE: Critically evaluate the experimental evidence and clinical trial outcomes as the basis for use of magnesium (Mg) supplements as therapy for calcium oxalate nephrolithiasis. MATERIALS AND METHODS: Literature search of MedLine and Web of Science through January 2005; articles cited in papers found by searches. RESULTS: Magnesium inhibits calcium oxalate crystallization in human urine and model systems. Magnesium also inhibits absorption of dietary oxalate from the gut lumen. Three early trials of Mg oxide (MgO) and Mg hydroxide (Mg(OH)2) reported lower rates of recurrent stone formation. However in a double-blind, randomized, placebo-controlled trial with more carefully selected patients, there was no significant difference between recurrence rates with 650 or 1300 mg MgO daily and the placebo. Another trial reported 391 mg (21 meq) Mg daily as a mixed salt, Mg potassium citrate, reduced calcium stone recurrence by 90%, similar to potassium citrate, but with better gastrointestinal tolerance. The failure of MgO and Mg(OH)2 as sole therapy may be related to poor absorption and low rates of Mg deficiency in the patient populations tested. CONCLUSIONS: Clinical trial evidence does not justify the use of MgO or Mg(OH)2 as a sole therapy for calcium oxalate kidney stones in a general patient population. However, the addition of magnesium to potassium citrate therapy improves outcomes. Clinical trials should focus on patients who are likely to be Mg deficient.


Asunto(s)
Cálculos Renales/tratamiento farmacológico , Magnesio/uso terapéutico , Oxalato de Calcio/antagonistas & inhibidores , Ensayos Clínicos como Asunto , Cristalización , Humanos , Hidróxido de Magnesio/uso terapéutico , Óxido de Magnesio/uso terapéutico
17.
Qual Life Res ; 13(4): 819-32, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15129892

RESUMEN

Adopting dietary lifestyle changes for diabetes management is often difficult for patients; yet the health-related quality of life (HRQOL) outcomes of dietary management for the patient are not extensively developed in the HRQOL assessments now widely used in diabetes research. This study developed a preliminary instrument, the diabetes dietary satisfaction and outcomes measure, to assess outcomes of individuals' experiences in following a meal plan for the treatment of type 2 diabetes. A theoretical framework and preliminary focus group data guided the design of a 47-item questionnaire, administered to 239 patients with type 2 diabetes. Medical file data was obtained on 180 of these patients. Fifty-four percent of respondents were women, with mean age of 64 +/- 12 years and diabetes duration of 10 +/- 8 years. Scores for the satisfaction and other outcome measures discriminated between patient groups by age, gender, medication use, depression diagnosis, meal plan status, and employment status. Significant correlations also occurred with diet adherence, number of co-morbidities, and glycemic control as measured by glycolated hemoglobin (HbA1c). Future research with additional patient samples is needed to refine the measure for use in diabetes education programs.


Asunto(s)
Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/psicología , Encuestas sobre Dietas , Conducta Alimentaria/psicología , Satisfacción del Paciente/estadística & datos numéricos , Calidad de Vida/psicología , Perfil de Impacto de Enfermedad , Adulto , Anciano , Anciano de 80 o más Años , Diabetes Mellitus Tipo 2/terapia , Dieta para Diabéticos/psicología , Femenino , Grupos Focales , Humanos , Insulina/administración & dosificación , Masculino , Persona de Mediana Edad , Cooperación del Paciente/psicología , Encuestas y Cuestionarios , Resultado del Tratamiento , Washingtón
18.
J Chem Ecol ; 29(1): 189-208, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12647862

RESUMEN

The weevil Oxyops vitiosa is an Australian species imported to Florida, USA, for the biological control of the invasive species Melaleuca quinquenervia. The larvae of this species feed on the leaves of their host and produce a shiny orange secretion that covers their integument. Previous results indicated that a major component of this secretion, viridiflorol, is sequestered from the host plant and repels a generalist predator, the red imported fire ant, Solenopsis invicta. When the larvae fed on a different chemotype of M. quinquenervia, which lacked viridiflorol but was rich in a different sesquiterpene, (E)-nerolidol, similar protection occurred. Solvent washes of these larvae indicated that (E)-nerolidol was sequestered from M. quinquenervia leaves and repelled S. invicta workers when applied to dog food baits at physiological concentrations (17.5, 35.0, and 52.5 microg/mg). Additionally, beta-caryophyllene also repelled S. invicta workers when applied to dog food baits at concentrations that approximated those in the O. vitiosa larval secretions (3.5 and 35 microg/mg). When the O. vitiosa larvae were fed leaves from laboratory hosts (nonfield hosts), similar repellent activity was found. This activity was traced to several of the same compounds (e.g., 1,8-cineole, viridiflorol) found to be active in their field host M. quinquenervia. These weevil larvae are opportunistic, sequestering the primary terpenoids in their host leaves that confer antipredator activity.


Asunto(s)
Escarabajos/fisiología , Conducta Alimentaria , Melaleuca/química , Control de Plagas , Plantas Comestibles , Animales , Escarabajos/química , Dieta , Larva , Melaleuca/crecimiento & desarrollo , Hojas de la Planta/química
19.
J Chem Ecol ; 28(2): 297-315, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11925069

RESUMEN

The weevil Oxyops vitiosa is an Australian species imported to Florida, USA, for the biological control of the invasive weed species Melaleuca quinquenervia. Larvae of this species feed on leaves of their host and produce a shiny orange secretion that covers the integument. When this secretion is applied at physiological concentrations to dog food bait, fire ant consumption and visitation are significantly reduced. Gas chromatographic analysis indicates that the larval secretion qualitatively and quantitatively resembles the terpenoid composition of the host foliage. When the combination of 10 major terpenoids from the O. vitiosa secretion was applied to dog food bait, fire ant consumption and visitation were reduced. When these 10 terpenoids were tested individually, the sesquiterpene viridiflorol was the most active component in decreasing fire ant consumption. Fire ant visitation was initially (15 min after initiation of the study) decreased for dog food bait treated with viridiflorol and the monoterpenes 1,8-cineole and alpha-terpineol. Fire ants continued to avoid the bait treated with viridiflorol at 18 microg/mg dog food for up to 6 hr after the initiation of the experiment. Moreover, ants avoided bait treated with 1.8 microg/mg for up to 3 hr. The concentrations of viridiflorol, 1,8-cineole, and alpha-terpineol in larval washes were about twice that of the host foliage, suggesting that the larvae sequester these plant-derived compounds for defense against generalist predators.


Asunto(s)
Hormigas , Escarabajos , Movimiento , Myrtaceae/química , Control Biológico de Vectores , Adaptación Fisiológica , Alimentación Animal , Animales , Conducta Animal , Cromatografía de Gases , Larva , Extractos Vegetales/farmacología , Conducta Predatoria , Terpenos/química , Terpenos/farmacología
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