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1.
Ir J Med Sci ; 192(2): 549-560, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35445926

RESUMEN

BACKGROUND: Desmoid tumours are benign fibromatous tumours arising from dysregulated myofibroblast proliferation within musculoaponeurotic structures. They can occur sporadically but more commonly are associated with genetic syndromes such as familial adenomatous polyposis (Sakorafas et al. in Surg Oncol 16(2):131-142, 2007) (FAP). Mutations in either the Wnt, ß-catenin or APC genes are 'key' triggers for the development of these tumours (Howard and Pollock in Oncol Ther 4(1):57-72, 2016). Classically, these tumours do not metastasise; however, they are associated with significant morbidity and mortality due to their infiltrative pattern and/or local invasion. Historically, surgical resection was the cornerstone of treatment. There remains paucity of data regarding outcomes following the surgical management of abdominal desmoid tumours in terms of success, recurrence and morbidity. OBJECTIVES: The aim of this review was to assess the current evidence for surgical management of abdominal desmoid tumours in terms of success, recurrence and morbidity. METHODS: A systematic search of articles in PubMed, EMBASE and The Cochrane Library databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for the period from January 2000 to November 2020. RESULTS: Twenty-three studies were included, of which, 749 patients had surgical resection (696 for primary and 53 for recurrent desmoids), 243 patients (18.8%) were medically managed and 353 patients (27.3%) underwent surveillance. Median follow-up was 51.4 months (range 1-372). Six-hundred and ninety-six of the 749 resections (92.9%) underwent primary desmoid resection, with the remaining 53 (7.1%) undergoing resection for recurrence. One-hundred and two surgically managed patients (19%) developed a (re)recurrence, with mesenteric involvement the commonest site for recurrence (55%). When comparing recurrence post-surgery to progression following medical therapy, there was a trend towards better outcomes with surgery, with 25% of surgical patients having a recurrence versus 50.5% having progression with medical therapy [OR 0.40 (95% CI 0.06-2.70), p = 0.35]. Major morbidity following surgery was 4.4% (n = 33) with 2% (n = 14) mortality within 30 days of resection. CONCLUSION: The management of desmoids has considerable heterogeneity. Surgical resection for abdominal desmoids remains a valid treatment option in highly selective cases where negative margins can be obtained, with low major morbidity and/or mortality.


Asunto(s)
Poliposis Adenomatosa del Colon , Fibromatosis Abdominal , Fibromatosis Agresiva , Humanos , Fibromatosis Agresiva/cirugía , Fibromatosis Agresiva/genética , Fibromatosis Agresiva/patología , Fibromatosis Abdominal/complicaciones , Fibromatosis Abdominal/patología , Fibromatosis Abdominal/cirugía , Poliposis Adenomatosa del Colon/complicaciones , Poliposis Adenomatosa del Colon/genética , Poliposis Adenomatosa del Colon/cirugía , Mutación , Colectomía
3.
Surgeon ; 20(2): 71-77, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33903053

RESUMEN

INTRODUCTION: Twenty-five-hydroxy-vitamin D3 (25-OH-vit D) is a prohormone that is essential for normal calcium homeostasis and bone metabolism. Understanding its role is an important component of the proper care of the pediatric orthopaedic patient. The aim of this study was to determine whether children in Ireland with fractures have increased prevalence of 25-OH-Vit D deficiency compared with age matched controls and to ascertain the relationship between a low 25-OH-vit D level and the incidence of fractures in Irish children. We hypothesised that children presenting to our centre following a fracture would have significantly lower 25-OH-vit D. METHODS: A prospective case-control study at a large urban tertiary referral academic hospital located in Dublin, Ireland was completed over a 14 month period from June 2014 to August 2015. A total of 116 subjects, distributed as cases (n = 58) and controls (n = 58) were included in this study. Whole blood (10 ml) was taken in two serum bottles from each patient. Serum 25-hydroxy-vitamin D3 levels were measured. An age matched control group was generated from other children attending the hospital, who also had vitamin D levels measured for different clinical reasons. We followed up both the fracture and control group for the next 5 years to assess the repeat fracture rate. RESULTS: Fifty-eight patients with a fracture requiring operative intervention, were included in the study. Statistical analysis was performed comparing to 58 age and sex-matched controls. The mean vitamin D level for the fracture group was 63.2 nmol/L (SD = 27.3), which was higher than the mean of the controls (62.5 nmol/L) (SD = 21.3) (p = 0.86), but this difference was found not to be statistically significant in unadjusted analysis. There was no statistically significant difference in the number of patients classified with low serum Vitamin D levels (<50 nmolL), with the fracture group consisting of 22 (37.9%) patients, and the control group of 17 patients (29.3%) (p = 0.33) with a level below 50 nmol/L. At five-year follow-up, 11 of the 58 patients (18.9%) in the fracture group went on to have a further fracture compared with eight patients (13.7%) from the control group. Out of these 11 from the fracture group five (45.45%) had been found to have a low serum 25-OH-Vit D level five years previously. Out of the eight controls that presented with a fracture within the five-year period, 3 (37.5%) had had a low vitamin D level at the origin of this study. CONCLUSION: The results of this study show that children presenting to our institution with low energy fractures have a prevalence of 38% 25-hydroxy-vitamin D deficiency. This study included children from age 1 to 16 primarily Caucasian encompassing all fracture types resulting from accidental trauma. Our findings suggest that in an Irish pediatric population vitamin D status may impact fracture risk with more than one-third being deficient in this review.


Asunto(s)
Fracturas Óseas , Deficiencia de Vitamina D , Adolescente , Estudios de Casos y Controles , Niño , Preescolar , Estudios de Seguimiento , Fracturas Óseas/epidemiología , Humanos , Lactante , Vitamina D , Deficiencia de Vitamina D/complicaciones , Deficiencia de Vitamina D/epidemiología
4.
J Child Orthop ; 15(3): 309, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-34211610

RESUMEN

[This corrects the article DOI: 10.1302/1863-2548.14.200164.].

5.
J Child Orthop ; 14(6): 508-512, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-33343745

RESUMEN

PURPOSE: In this article we report the results of a pilot study analysing the implications of performing pelvic osteotomies for developmental dysplasia of the hip (DDH) as a day case. We assess the advantages of performing paediatric pelvic osteotomies as day-case procedures from a financial perspective and from an in-patient bed resource point of view. METHODS: This was a prospective cohort study analysing Salter and Pemberton pelvic osteotomies performed for DDH over a three-year period from 1st January 2017 to 30th September 2019. All patients residing within 50 km of the hospital were eligible for day-case procedures. All other cases were performed as in-patients. A detailed financial costing analysis was performed and the in-patient resources utilized were documented and compared between the two models of care. RESULTS: In total, 84 Salter and Pemberton osteotomies were performed between 1st January 2017 to 30th September 2019. Of these cases, 35 were performed as day-case procedures. A total reduction in 70 in-patient bed days was reported. Total costs for a single in-patient requiring two nights of admission amounted to €5,752, whereas the discharge cost of a day case was reported at €2,670. The savings made by our institution amounted to €3,082 per day case. A total saving of €102,696 was made over three years. In all, seven day-case patients re-attended due to inadequate pain control. They required overnight admission and were discharged uneventfully the following day. CONCLUSION: Day-case pelvic osteotomies significantly reduce the number of in-patient bed days used in an elective paediatric orthopaedic setting. Significant financial savings in excess of €3,000 per case are possible. The introduction of day-case pelvic osteotomy procedures can significantly improve the cost-effectiveness of managing DDH provided there are clear protocols in place with close clinical follow-up. LEVEL OF EVIDENCE: IV.

6.
Med Phys ; 46(12): 5444-5453, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31605643

RESUMEN

PURPOSE: Acoustic coupling baths, nominally composed of degassed water, play important roles during transcranial focused ultrasound surgery. However, this large water bolus also degrades the quality of intraoperative magnetic resonance (MR) guidance imaging. In this study, we test the feasibility of using dilute, aqueous magnetite nanoparticle suspensions to suppress these image degradations while preserving acoustic compatibility. We examine the effects of these suspensions on metrics of image quality and acoustic compatibility for two types of transcranial focused ultrasound insonation regimes: low-duty cycle histotripsy procedures and high-duty cycle thermal ablation procedures. METHODS: Magnetic resonance guidance imaging was used to monitor thermal ablations of in vitro gel targets using a coupling bath composed of various concentrations of aqueous, suspended, magnetite nanoparticles in a clinical transcranial transducer under stationary and flowing conditions. Thermal deposition was monitored using MR thermometry simultaneous to insonation. Then, using normal degassed water as a coupling bath, various concentrations of aqueous, suspended, magnetite nanoparticles were placed at the center of this same transducer and insonated using high-duty cycle pulsing parameters. Passive cavitation detectors recorded cavitation emissions, which were then used to estimate the relative number of cavitation events per insonation (cavitation duty cycle) and the cavitation dose estimates of each nanoparticle concentration. Finally, the nanoparticle mixtures were exposed to low-duty cycle, histotripsy pulses. Passive cavitation detectors monitored cavitation emissions, which were used to estimate cavitation threshold pressures. RESULTS: The nanoparticles reduced the MR signal of the coupling bath by 90% in T2- and T2*-weighted images and also removed almost all imaging artifacts caused by coupling bath motion. The coupling baths caused <5% changes in peak temperature change achieved during sonication, as observed via MR thermometry. At low duty cycle insonations, the nanoparticles decreased the cavitation threshold pressure by about 15 ± 7% in a manner uncorrelated with nanoparticle concentration. At high duty cycle insonations, the 0.5 cavitation duty cycle acoustic power threshold varied linearly with nanoparticle concentration. CONCLUSIONS: Dilute aqueous magnetite nanoparticle suspensions effectively reduced MR imaging artifacts caused by the acoustic coupling bath. They also attenuated acoustic power deposition by <5%. For low duty cycle insonation regimes, the nanoparticles decreased the cavitation threshold by 15 ± 7%. However, for high-duty cycle regimes, the nanoparticles decreased the threshold for cavitation in proportion to nanoparticle concentration.


Asunto(s)
Acústica , Ultrasonido Enfocado de Alta Intensidad de Ablación/métodos , Imagen por Resonancia Magnética , Nanopartículas de Magnetita , Cirugía Asistida por Computador/métodos , Estudios de Factibilidad
7.
J Biomed Opt ; 22(3): 34001, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-28246675

RESUMEN

Influenced by both the intrinsic viscoelasticity of the tissue constituents and the time-evolved redistribution of fluid within the tissue, the biomechanical response of skin can reflect not only localized pathology but also systemic physiology of an individual. While clinical diagnosis of skin pathologies typically relies on visual inspection and manual palpation, a more objective and quantitative approach for tissue characterization is highly desirable. Optical coherence tomography (OCT) is an interferometry-based imaging modality that enables in vivo assessment of cross-sectional tissue morphology with micron-scale resolution, which surpasses those of most standard clinical imaging tools, such as ultrasound imaging and magnetic resonance imaging. This pilot study investigates the feasibility of characterizing the biomechanical response of in vivo human skin using OCT. OCT-based quantitative metrics were developed and demonstrated on the human subject data, where a significant difference between deformed and nondeformed skin was revealed. Additionally, the quantified postindentation recovery results revealed differences between aged (adult) and young (infant) skin. These suggest that OCT has the potential to quantitatively assess the mechanically perturbed skin as well as distinguish different physiological conditions of the skin, such as changes with age or disease.


Asunto(s)
Dermatología/métodos , Piel/diagnóstico por imagen , Tomografía de Coherencia Óptica , Adulto , Estudios Transversales , Dermatología/instrumentación , Humanos , Lactante , Proyectos Piloto
9.
Springerplus ; 3: 289, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25013747

RESUMEN

Fungi isolated from environmentally challenging habitats can have adaptations of potential value when developed as insect pest-controls. Fungal isolates collected from Antarctica, Geomyces sp. I, Geomyces sp. II, Mortierella signyensis and M. alpina, were investigated for (i) growth characteristics at 0-35°C, (ii) spore production at 10 and 20°C, (iii) viability following exposure to freezing temperatures, and (iv) insecticidal activity against waxmoths (Galleria mellonella L.), houseflies (Musca domestica L.), mealworms (Tenebrio molitor L.) and black vine weevils (Otiorhynchus sulcatus Fabricius). All isolates showed growth between 5-20°C, with some showing growth outside this range. Geomyces isolates sporulated over a wider range of conditions than the Mortierella isolates. Spore germination at 10°C was higher for Geomyces sp. II when this isolate was produced at 10 compared to 20°C (greatest difference 74.6 vs 32.7%). All isolates grew, with the exception of M. alpina, following exposure to -20°C for 4 weeks. Insecticidal investigations showed M. alpina and M. signyensis caused significant mortality of waxmoth and housefly larvae via injection and soil inoculation, and M. alpina caused significant mortality of housefly larvae via baiting; the Geomyces isolates had little lethal effect.

10.
Forensic Sci Int Genet ; 11: 73-9, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24670380

RESUMEN

Current assessment of whether a forensic evidence item should be submitted for STR profiling is largely based on the personal experience of the Crime Scene Investigator (CSI) and the submissions policy of the law enforcement authority involved. While there are chemical tests that can infer the presence of DNA through the detection of biological stains, the process remains mostly subjective and leads to many samples being submitted that give no profile or not being submitted although DNA is present. The ParaDNA(®) Screening System was developed to address this issue. It consists of a sampling device, pre-loaded reaction plates and detection instrument. The test uses direct PCR with fluorescent HyBeacon™ detection of PCR amplicons to identify the presence and relative amount of DNA on an evidence item and also provides a gender identification result in approximately 75 minutes. This simple-to-use design allows objective data to be acquired by both DNA analyst and non-specialist personnel, to enable a more informed submission decision to be made. The developmental validation study described here tested the sensitivity, reproducibility, accuracy, inhibitor tolerance, and performance of the ParaDNA Screening System on a range of mock evidence items. The data collected demonstrates that the ParaDNA Screening System identifies the presence of DNA on a variety of evidence items including blood, saliva and touch DNA items.


Asunto(s)
ADN/genética , Genética Forense , Colorantes Fluorescentes , Humanos , Reacción en Cadena de la Polimerasa
11.
Exp Appl Acarol ; 60(2): 139-51, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23435864

RESUMEN

The coconut palm is an important crop in the sub arid coastal plain of Dhofar, Oman, for the high demand for its nut water and its use as ornamental plant. Damage of coconut fruits by the eriophyid mite Aceria guerreronis Keifer was first reported in that region in the late 1980s, but background information about the ecology of the pest in Oman was missing. Four surveys were conducted in different seasons from 2008 to 2009, to assess the distribution and prevalence of the coconut mite and its damage as well as the presence of natural enemies. Infestation by the coconut mite was conspicuous on most (99.7 %) palm trees, with 82.5 % damaged fruits. The average (± SE) density of coconut mites per fruit was 750 ± 56; this level of infestation led to the incidence of over 25 % of surface damage on more than half of the fruits. The mite appeared more abundant at the end of the cold season through the summer. No significant differences were observed between infestation levels on local varieties, hybrids and on dwarf varieties. Neoseiulus paspalivorus (De Leon), Cydnoseius negevi (Swirski & Amitai) and Amblyseius largoensis (Muma) were the predatory mites found under the bracts of over 30 % of the coconut fruits and on 68 % of the coconut trees. Considering all sampling dates and all varieties together, average (± SE) phytoseiid density was 1.4 ± 1.19 per fruit. Other mites found in the same habitat as A. guerreronis included the tarsonemids Steneotarsonemus furcatus De Leon and Nasutitarsonemus omani Lofego & Moraes. The pathogenic fungus Hirsutella thompsonii Fisher was rarely found infecting the coconut mite in Dhofar. Other fungal pathogens, namely Cordyceps sp. and Simplicillium sp., were more prevalent.


Asunto(s)
Cocos/parasitología , Ácaros/fisiología , Estaciones del Año , Animales , Omán , Dinámica Poblacional
12.
Hum Factors ; 54(6): 940-51, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23397805

RESUMEN

This article is based on a keynote presentation given at the 18th Congress of the International Ergonomics Association in Recife, Brazil, February 2012. It considers new, and not so new, approaches and practical roles for the emerging field of human factors/ergonomics (HFE) in sustainable development (SD).The material for this article was largely drawn from the literature in the fields of human development, sustainability, climate change mitigation and adaptation, and social/environmental impact assessment. Identifying the role of HFE in SD is not a simple one and from the outset is complicated by the widely differing ideas in the sustainability literature about what exactly it is we are hoping to sustain. Is it individual companies, business models, cultures, or the carrying capacity of our planet? Or combinations of these? For the purposes of this article, certain assumptions are made, and various emerging opportunities and responsibilities associated with our changing world of work are introduced. First, there are new versions of traditional tasks for us, such as working with the people and companies in the renewable energy sectors. Beyond this, however, it is suggested that there are emerging roles for HFE professionals in transdisciplinary work where we might play our part, for example, in tackling the twinned issues of climate change and human development in areas of significant poverty. In particular we have the tools and capabilities to help define and measure what groups have reason to value, and wish to sustain. It is suggested, that to do this effectively, however, will require a philosophical shift, or perhaps just a philosophical restatement at a collective level, regarding who and what we ultimately serve.


Asunto(s)
Cambio Climático , Ergonomía , Pobreza , Agricultura Forestal , Desarrollo Humano , Humanos , Nueva Zelanda
14.
Exp Appl Acarol ; 46(1-4): 119-48, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18584131

RESUMEN

In the absence of commercially viable and environmentally friendly options, the management of cattle ticks is heavily dependent on the use of chemical acaricides. Due to recent advances in production, formulation and application technology, commercial fungus-based biological pesticides (myco-insecticides, myco-acaricides) are becoming increasingly popular for the control of plant pests; however, they have not been used against animal ectoparasites. The literature clearly demonstrates that entomopathogenic fungi are pathogenic to ticks under laboratory conditions. Pasture applications have also shown promise while experiments on topical application have had variable results. These results suggest that major research hurdles still exist especially for the latter. Although literature on ticks and their interactions with entomopathogenic fungi exists, there is not a clear understanding on how this can be influenced by the microenvironment of the cattle skin surface. This paper critically reviews pathogen, tick target and host skin microenvironmental factors that potentially affect pathogenicity of the applied entomopathogen. Factors influencing the route of infection for topically applied myco-acaricides are also reviewed. Major researchable constraints and recommendations are identified and prioritized. In particular, there is the need for basic studies to understand the interaction of entomopathogenic fungi with the components of the skin microenvironment, to identify suitable strains, and to develop improved formulations to overcome the various challenges.


Asunto(s)
Hongos/patogenicidad , Insecticidas/administración & dosificación , Control Biológico de Vectores , Infestaciones por Garrapatas/veterinaria , Garrapatas/microbiología , Administración Cutánea , Animales , Bovinos , Hongos/fisiología , Interacciones Huésped-Patógeno , Infestaciones por Garrapatas/tratamiento farmacológico
16.
Ergonomics ; 49(1): 62-77, 2006 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-16393804

RESUMEN

Slip, trip and fall (STF) incidents, particularly falls from a height, are a leading cause of injury in the New Zealand residential construction industry. The most common origins of falls from a height in this sector are ladders, scaffolding and roofs, while slipping is the most frequent fall initiating event category. The study aimed to provide detailed information on construction industry STF risk factors for high-risk tasks, work equipment and environments, as identified from an earlier analysis of STF claims data, together with information to be used in the development of interventions to reduce STF risk in New Zealand residential construction. The study involved the use of both incident-centred and incident-independent methods of investigation, including detailed follow-up investigations of incidents and observations and interviews with workers on construction sites, to provide data on a wide range of risk factors. A large number of risk factors for residential construction STFs were identified, including factors related to the work environment, tasks and the use and availability of appropriate height work equipment. The different methods of investigation produced complementary information on factors related to equipment design and work organization, which underlie some of the site conditions and work practices identified as key risk factors for residential construction STFs. A conceptual systems model of residential construction STF risk is presented.


Asunto(s)
Accidentes por Caídas , Accidentes de Trabajo , Arquitectura y Construcción de Instituciones de Salud , Lugar de Trabajo , Accidentes por Caídas/estadística & datos numéricos , Accidentes de Trabajo/estadística & datos numéricos , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nueva Zelanda , Medición de Riesgo , Factores de Riesgo , Lugar de Trabajo/estadística & datos numéricos
17.
Mycopathologia ; 160(2): 151-7, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16170611

RESUMEN

Studies were conducted to identify oil-based formulating agents (paraffinic oil, palm oil and emulsifiable adjuvant oils (EAOs)) for Metarhizium anisopliae that were superior to water with simple surfactants using a germination test and a bioassay against Boophilus microplus. Germination of conidia in all formulations, except 10% coconut EAO, produced more than 68% germination at 24 h and nearly 100% at 48 h. Coconut oil (average survival time (AST) = 4.6 +/- 0.28 days) and 10% liquid paraffin EAO (AST = 4.4 +/- 0.15 days) enhanced the pathogenicity of M. anisopliae to B. microplus relative to water (AST = 8.4 +/- 0.42 days). M. anisopliae in 10% liquid paraffin EAO was the most effective formulation having a moderately high germination after 24 h and a low AST as well as a high AST in the control. In the second experiment, germination of conidia in 2% liquid paraffin EAO and 2% Cropspray was higher than in 2% Codacide oil at 24 h, however, all treatments reached 100% germination after 48 h. The ASTs of the EAO based M. anisopliae formulations (Average AST = 6.4 +/- 0.54 days) were similar but lower that the ASTs of the controls (Average AST = 9.6 +/- 0.28 days).


Asunto(s)
Emulsionantes , Hypocreales/fisiología , Aceites , Control Biológico de Vectores , Garrapatas/crecimiento & desarrollo , Agua , Animales , Química Farmacéutica , Aceite de Coco , Femenino , Hypocreales/patogenicidad , Aceite de Palma , Parafina , Aceites de Plantas , Garrapatas/microbiología
18.
Ergonomics ; 48(8): 1008-19, 2005 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-16147417

RESUMEN

The paper presents findings from 39 detailed follow-up investigations of slips, trips and falls (STF) incurred by individuals working in New Zealand's dairy farming industry. The study sought to identify the key contributory risk factors for STF in this sector to provide evidence to support intervention design, and to determine the effectiveness of the investigative methodology used to achieve these objectives. Findings from the follow-up investigations included an analysis of factors related to the underfoot surface, underfoot hazard and footwear. Of note here was the propensity for STF-involved workers to not see or identify an underfoot hazard due to concurrent visual task distractions, and for workers to use footwear that both lacked effective tread and was unsuitable for the task and underfoot surface. Key latent risk factors and their interactions identified included problems associated with time pressure and related time-saving behaviours and the presence of design errors that, for example, required workers to climb onto equipment to view aspects of the task they were working on. The paper concludes that the potential resource and logistical problems associated with conducting detailed STF investigations are outweighed by the opportunity to collect rich data on key risk factors and their interactions in STF research.


Asunto(s)
Accidentes por Caídas/estadística & datos numéricos , Accidentes de Trabajo/estadística & datos numéricos , Industria Lechera , Lugar de Trabajo/estadística & datos numéricos , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nueva Zelanda/epidemiología , Medición de Riesgo , Factores de Riesgo
19.
Vector Borne Zoonotic Dis ; 5(3): 276-84, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16187897

RESUMEN

Entomopathogenic fungal isolates of Arachnid origin were assessed for their ability to produce mortality and inhibit egg hatching in Boophilus microplus with the aim of selecting an isolate for development into a myco-acaricide for control of cattle ticks. The ability of the most promising isolate to target developmental stages of more than one tick species and the optimum concentration of fungal inoculum to be used for future studies were determined. Metarhizium anisopliae was the most pathogenic of the three fungal species tested on B. microplus, producing shorter average survival times (ASTs) for engorged adults (AST = 5.2 +/- 0.1 days) and larvae (AST = 9.3 +/- 0.4 days), and a longer average hatching times (AHT; AHT = 19.8 +/- 0.5 days) in comparison to Simplicillium lamellicola and Paecilomyces farinosus. In comparative studies on two tick species with similar life cycles, M. anisopliae produced a shorter AST in engorged adult B. microplus (AST = 8.8 +/- 0.3 days) than Rhipicephalus sanguineus (AST = 10.3 +/- 0.3 days). M. anisopliae was pathogenic to larvae of B. microplus (AST = 7.7 +/- 0.4 days), however, had no effect on larvae of R. sanguineus (AST = 14.6 +/- 0.3 days) as the AST of this treatment was similar to its untreated control (AST = 14.1 +/- 0.4 days). M. anisopliae lengthened the AHTs in both B. microplus (AHT = 16.4 +/- 0.3 days) and R. sanguineus (AHT = 16.7 +/- 0.3 days) in comparison to the controls. The ASTs of engorged adult B. microplus treated with M. anisopliae shortened as the concentration was increased from 1 x 10(7) to 5 x 10(8) conidia/ mL. A further increase in concentration, 1 x 10(9) conidia/mL (AST = 10.2 +/- 0.4 days) did not shorten or lengthen the AST in comparison to 5 x 10(8) conidia/mL (AST = 9.4 +/- 0.3 days).


Asunto(s)
Vectores Arácnidos/crecimiento & desarrollo , Enfermedades de los Bovinos/prevención & control , Ixodidae/crecimiento & desarrollo , Hongos Mitospóricos/fisiología , Control Biológico de Vectores/métodos , Infestaciones por Garrapatas/veterinaria , Animales , Bovinos , Enfermedades de los Bovinos/parasitología , Femenino , Larva , Estadios del Ciclo de Vida , Hongos Mitospóricos/patogenicidad , Recuento de Huevos de Parásitos/veterinaria , Control de Ácaros y Garrapatas/métodos , Infestaciones por Garrapatas/prevención & control , Factores de Tiempo
20.
Vet Parasitol ; 134(1-2): 159-67, 2005 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-16099103

RESUMEN

Experiments were conducted to determine if Metarhizium anisopliae isolates which are capable of growth at cattle surface temperatures could produce pathogenicity to Boophilus microplus in laboratory and field studies. The diurnal temperature fluctuation on the surface of cattle was monitored. The temperature tolerance of M. anisopliae isolates (ARSEF3297 and IMI386697) was determined and their pathogenicity to B. microplus compared at a standard bioassay temperature (28 degrees C) and at a temperature similar to the cattle surface (31-35 degrees C). The effect of the two isolates on the B. microplus population on cattle under field conditions was determined. The temperature of the fore udder, rear udder, ribs and neck regions of the mixed Holstein cattle fluctuated between 30 and 35 degrees C, in a similar pattern to the prevailing environmental temperature. However, wider fluctuations were obtained on the ears (28-35 degrees C) and spine (30-41 degrees C). The colony radius of both isolates declined as temperature increased, however, the growth of IMI386697 was five times greater than ARSEF3297 at 34 degrees C. At 28 degrees C, the pathogenicity of both isolates to B. microplus was similar, however, at 31-35 degrees C, IMI386697 was more pathogenic than ARSEF3297. Both isolates reduced the B. microplus population on cattle in comparison to the control formulation. However, IMI386697 (8.5+/-0.64 ticks/animal) produced a greater reduction in tick numbers than ARSEF3297 (19.1+/-0.64 ticks/animal). M. anisopliae was re-isolated from 8.9% of the ticks collected from IMI386697 treated cattle as compared to 2.8% of ticks from ARSEF3297 treated cattle.


Asunto(s)
Enfermedades de los Bovinos/prevención & control , Enfermedades de los Bovinos/parasitología , Hypocreales/fisiología , Control Biológico de Vectores/métodos , Infestaciones por Garrapatas/prevención & control , Garrapatas/microbiología , Administración Tópica , Animales , Temperatura Corporal , Bovinos , Ritmo Circadiano , Femenino , Hypocreales/crecimiento & desarrollo , Hypocreales/aislamiento & purificación , Hypocreales/patogenicidad , Distribución Aleatoria , Infestaciones por Garrapatas/microbiología , Infestaciones por Garrapatas/parasitología , Infestaciones por Garrapatas/veterinaria
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