[Molecular mimicry between Plasmodium sp and Guillain-Barre syndrome antigens]. / Mimetismo molecular entre el Plasmodium sp y los antígenos del síndrome de Guillain-Barre.

OBJECTIVE: Analyze the molecular mimicry between Plasmodium spp. and autoantigens associated with GBS, identifying possible antigenic epitopes. METHODS: PSI-Blast, Praline, Emboss, Protein Data Bank, Swiss Model Server, AlphaFold 2, Ellipro and PyMol 2.3 were used to search for homologies, perform alignments, obtain protein structures, and predict epitopes. RESULTS: 17 autoantigens and seven immunological targets of the peripheral nervous system were included, identifying 72 possible epitopes associated with GBS. From the proteome of Plasmodium spp. (298 proteins), only two showed similarities close to 30% with TRIM21 and BACE1, generating seven possible epitopes. CONCLUSION: No significant homologies were observed between the proteome of GBS and Plasmodium spp. The exploration of other mechanisms such as immune-mediated capillary damage, Epitope Spreading or Bystander Activation is suggested to explain the mentioned association. These findings underscore the need to clarify the etiology of autoimmune diseases and the role of pathogens. The need for experimental studies to validate these results is emphasized.

OBJETIVO: Analizar el mimetismo molecular entre Plasmodium spp. y autoantígenos asociados al SGB, identificando posibles epítopos antigénicos. MÉTODOS: Se emplearon PSI-Blast, Praline, Emboss, Protein Data Bank, Swiss Model Server, AlphaFold 2, Ellipro y PyMol 2.3 para buscar homologías, realizar alineamientos, obtener estructuras proteicas y predecir epítopos. RESULTADOS: Se incluyeron 17 autoantígenos y siete objetivos inmunológicos del sistema nervioso periférico, identificándose 72 posibles epítopos asociados al SGB. Del proteoma de Plasmodium spp. (298 proteínas), solo dos mostraron similitud cercana al 30% con TRIM21 y BACE1, generando siete posibles epítopos. CONCLUSIÓN: No se observaron homologías significativas entre el proteoma de SGB y Plasmodium spp. Se sugiere la exploración de otros mecanismos como el daño capilar inmunomediado, Epitope Spreading o Bystander Activation para explicar la asociación mencionada. Estos hallazgos subrayan la necesidad de aclarar la etiología de las enfermedades autoinmunes y el papel de los patógenos. Se enfatiza la necesidad de estudios experimentales para validar estos resultados.

Impacto de la pandemia por COVID-19 sobre un programa de consulta electrónica universal (e-consulta) entre médicos de Atención Primaria y cardiólogos / Impact of the COVID-19 pandemic above a universal electronic consultation program (e-consultation) between general practitioners and cardiologists

Introducción y objetivos Los programas de telemedicina entre clínico y paciente se han desarrollado con fuerza durante la pandemia de enfermedad por COVID-19, pero no hay datos de experiencias entre clínicos. Nuestro objetivo es analizar el impacto de la pandemia por COVID-19 en la actividad y resultados en salud de un programa de consulta electrónica universal (e-consulta) para todas las derivaciones de pacientes entre médicos de atención primaria y el Servicio de Cardiología de nuestra área. Métodos Analizamos mediante regresión logística a 25.121 pacientes con al menos una e-consulta entre 2018 y 2021 realizada con el Servicio de Cardiología de nuestra área sanitaria. También se realizó el análisis de regresión logística del impacto de la pandemia por COVID-19 sobre la resolución de la e-consulta y tiempo de espera de la atención, hospitalizaciones y mortalidad, tomando como referencia las consultas realizadas durante 2018. Resultados Observamos que una menor demora en la atención y resolución de la e-consulta (sin necesidad de atención presencial) se asociaba a un mejor pronóstico. Los períodos de pandemia COVID-19 presentaron similares resultados a los del 2018. Conclusiones Los resultados de nuestro estudio muestran una significativa reducción de las derivaciones a través de e-consulta durante el primer año de la pandemia por COVID-19 con recuperación posterior de la demanda asistencial sin que los períodos de pandemia se asociasen con peores resultados en salud. La reducción del tiempo de demora de resolución de la e-consulta y el grupo sin necesidad de consulta presencial se asociaron a un mejor pronóstico (AU)

Blackground and objective Virtual healthcare models, usually between healthcare professionals and patients, have developed strongly during the coronavirus disease 2019 (COVID-19) pandemic, but there are not data of models between clinicians. Our objective is to analyse the impact of the COVID-19 pandemic on the activity and health outcomes of the universal e-consultation program for patient referrals between primary care physicians and the Cardiology Department in our area. Methods Patients with at least one e-consultation between 2018 and 2021 were selected. We analysed the impact of the COVID-19 pandemic on activity and waiting time for care, hospitalizations and mortality, taking as a reference the consultations carried out during 2018. Results We analysed 25,121 patients. Through logistic regression analysis, it was observed that a shorter delay in care and resolution of the e-consultation without the need for face-to-face care were associated with a better prognosis. The COVID-19 pandemic periods (2019-2020 and 2020-2021) were not associated with worse health outcomes compared to 2018. Conclusions The results of our study show a significant reduction in e-consult referrals during the first year of the COVID-19 pandemic with a subsequent recovery in the demand for care without the pandemic periods being associated with worse outcomes. The reduction in the time elapsed for solving the e-consult and no need for in-person visit were associated with better outcomes (AU)

[Impact of the COVID-19 pandemic above a universal electronic consultation program (e-consultation) between general practitioners and cardiologists]. / Impacto de la pandemia por COVID-19 sobre un programa de consulta electrónica universal (e-consulta) entre médicos de Atención Primaria y cardiólogos.

Blackground and objective: Virtual healthcare models, usually between healthcare professionals and patients, have developed strongly during the coronavirus disease 2019 (COVID-19) pandemic, but there are not data of models between clinicians. Our objective is to analyse the impact of the COVID-19 pandemic on the activity and health outcomes of the universal e-consultation program for patient referrals between primary care physicians and the Cardiology Department in our area. Methods: Patients with at least one e-consultation between 2018 and 2021 were selected. We analysed the impact of the COVID-19 pandemic on activity and waiting time for care, hospitalizations and mortality, taking as a reference the consultations carried out during 2018. Results: We analysed 25,121 patients. Through logistic regression analysis, it was observed that a shorter delay in care and resolution of the e-consultation without the need for face-to-face care were associated with a better prognosis. The COVID-19 pandemic periods (2019-2020 and 2020-2021) were not associated with worse health outcomes compared to 2018. Conclusions: The results of our study show a significant reduction in e-consult referrals during the first year of the COVID-19 pandemic with a subsequent recovery in the demand for care without the pandemic periods being associated with worse outcomes. The reduction in the time elapsed for solving the e-consult and no need for in-person visit were associated with better outcomes.

Alpine ski technique observation instrument: reliability and validity / Instrumento de observación de la técnica en esquí alpino: fiabilidad y validez

The aim of the study was to design an accurate and useful observational instrument for evaluating basic turn techniques in alpine skiing, and to determine its validity and reliability. A multi-step approach was used to design and validate the instrument: a literature revision; an expert meeting; a pilot test; the assessment of intra- and inter-observer reliability; a convergent validity test; and the responsiveness calculation with a pre- post-test. Results showed adequate values of intra-rater (P=0.80-0.83) and inter-rater reliability (P=0.86-0.97). For the convergent validity, a moderate statistically significant correlation for the speed and trajectory control dimensions were achieved (rho=0.58-0.65, p<0.001), but not for the balance position dimension (rho=0.24, p=0.166). The responsiveness was also acceptable (p<0.05, r=0.46-0.60). In conclusion, the Alpine Ski Technique Observation Instrument is a useful, reliable, valid, and responsive observational tool. (AU)

El objetivo del estudio fue diseñar un instrumento de observación preciso y útil para evaluar la técnica de cambios de dirección básicos en el esquí alpino, y determinar su validez y fiabilidad. Para diseñar y validar el instrumento se siguieron los siguientes pasos: revisión de la literatura, valoración por comité de expertos, prueba piloto, evaluación de la fiabilidad intra e inter-evaluador, prueba de validez convergente, y cálculo de sensibilidad con una prueba pre y post-intervención. Los resultados mostraron valores adecuados de fiabilidad intra-evaluador (P=0,80-0,83) e inter-evaluador (P=0,86-0,97). Respecto a la validez convergente se obtuvo una correlación moderada para las dimensiones de control de la velocidad y de la trayectoria (rho=0,58-0,65, p<0,001), pero no para la dimensión de posición de equilibrio (rho=0,24, p=0,166). La sensibilidad fue aceptable (p<0,05, r=0,46-0,60). En conclusión, el Instrumento de Observación de la Técnica en Esquí Alpino es una herramienta útil, fiable, válida y sensible. (AU)

Impact of the COVID-19 pandemic upon a universal electronic consultation program (e-consultation) between general practitioners and cardiologists.

BACKGROUND AND OBJECTIVE: Virtual healthcare models, usually between healthcare professionals and patients, have developed strongly during the coronavirus disease 2019 (COVID-19) pandemic, but there are no data corresponding to models between clinicians. An analysis was made of the impact of the COVID-19 pandemic upon the activity and health outcomes of the universal e-consultation program for patient referrals between primary care physicians and the Cardiology Department in our healthcare area. METHODS: Patients with at least one e-consultation between 2018 and 2021 were selected. We analyzed the impact of the COVID-19 pandemic upon activity and waiting time for care, hospitalizations and mortality, taking as reference the consultations carried out during 2018. RESULTS: A total of 25,121 patients were analyzed. Logistic regression analysis showed a shorter delay in care and resolution of the e-consultation without the need for face-to-face care to be associated to a better prognosis. The COVID-19 pandemic periods (2019-2020 and 2020-2021) were not associated to poorer health outcomes compared to 2018. CONCLUSIONS: The results of our study show a significant reduction in e-consultation referrals during the first year of the COVID-19 pandemic, with a subsequent recovery in the demand for care, and without the pandemic periods being associated to poorer outcomes. The reduction in time elapsed for resolving the e-consultations and no need for face-to-face visits were associated to improved outcomes.

Seroprevalence of ANTI-SARS-CoV-2 antibodies in patients with inflammatory bowel disease.

Patients with inflammatory bowel disease (IBD) treated with biologic and/or immunosuppressant drugs are at increased risk for opportunistic infections. Seroprevalence studies can confirm the diagnosis of SARS-CoV-2 infections as well as the associated risk factors. This is a descriptive study which primary endpoints were to highlight the prevalence of SARS-CoV-2 antibodies in a cohort of IBD patients in March 2021, and to analyze seroconversion in patients with known COVID-19 infection and its relationship with IBD treatments. Patients filled in a questionnaire about symptoms of COVID-19 infection and clinical information about their IBD. All included patients were tested for SARS-CoV-2 antibodies. 392 patients were included. Among patients with clinical infection, 69 patients (17,65%) were IgG-positive, 286 (73,15%) IgG-negative and 36 (9,21%) indeterminate. In relation to seroconversion among patients under biologic treatment, 13 patients of the 23 with a previous positive CRP developed antibodies (56.5%). However, when the influence of immunosuppressive treatment on the probability of developing antibodies was analyzed, no significant differences were seen between those patients with or without treatment (77.8% vs. 77.1%, p = 0.96). In our cohort of IBD patients, after one year of pandemic, there were 18.64% IgG positive patients, a higher prevalence than the general population (15.7%).

Toxocariasis in migrant children: A 6 years' experience in a reference pediatric unit in Spain.

BACKGROUND: Toxocariasis is a worldwide distributed zoonosis that affects characteristically children. Clinical presentation is highly variable, often asymptomatic, and treatment duration is controversial. METHODS: A retrospective descriptive study (January 2014-December 2019) was performed in a referral Unit for Pediatric Tropical Diseases. Patients younger than 18 years of age diagnosed with toxocariasis were included. RESULTS: Out of 931 children screened for toxocariasis, 49 (5.3%) were seropositive. The median age was 11.0 years, 55.1% male and 30.6% referred contact with puppies. Overall, 34.7% were Latin-American, 24.5% Asiatic, 20.4% European, and 20.4% African. Only 34.7% presented symptoms, gastrointestinal the most common (52.9%). The 57.1% of children presented eosinophilia and 50% elevated total IgE. Most cases (95.9%) corresponded to covert toxocariasis. All children were treated with albendazole for 5, 14 or 21 days, and 4 children required a second course. Follow-up data were available in 32 children (65.3%) for a median of 7 months, showing a progressive decline in eosinophils, IgE-titers and ELISA optical density. CONCLUSION: Toxocariasis is mostly asymptomatic in children and eosinophilia is not always present. Serological tests should be included in migrant health screening and in the diagnostic assessment of eosinophilia. Eosinophil count, IgE-titers and ELISA optical-density could be useful during follow-up.

Aligning tumor mutational burden (TMB) quantification across diagnostic platforms: phase II of the Friends of Cancer Research TMB Harmonization Project.

BACKGROUND: Tumor mutational burden (TMB) measurements aid in identifying patients who are likely to benefit from immunotherapy; however, there is empirical variability across panel assays and factors contributing to this variability have not been comprehensively investigated. Identifying sources of variability can help facilitate comparability across different panel assays, which may aid in broader adoption of panel assays and development of clinical applications. MATERIALS AND METHODS: Twenty-nine tumor samples and 10 human-derived cell lines were processed and distributed to 16 laboratories; each used their own bioinformatics pipelines to calculate TMB and compare to whole exome results. Additionally, theoretical positive percent agreement (PPA) and negative percent agreement (NPA) of TMB were estimated. The impact of filtering pathogenic and germline variants on TMB estimates was assessed. Calibration curves specific to each panel assay were developed to facilitate translation of panel TMB values to whole exome sequencing (WES) TMB values. RESULTS: Panel sizes >667 Kb are necessary to maintain adequate PPA and NPA for calling TMB high versus TMB low across the range of cut-offs used in practice. Failure to filter out pathogenic variants when estimating panel TMB resulted in overestimating TMB relative to WES for all assays. Filtering out potential germline variants at >0% population minor allele frequency resulted in the strongest correlation to WES TMB. Application of a calibration approach derived from The Cancer Genome Atlas data, tailored to each panel assay, reduced the spread of panel TMB values around the WES TMB as reflected in lower root mean squared error (RMSE) for 26/29 (90%) of the clinical samples. CONCLUSIONS: Estimation of TMB varies across different panels, with panel size, gene content, and bioinformatics pipelines contributing to empirical variability. Statistical calibration can achieve more consistent results across panels and allows for comparison of TMB values across various panel assays. To promote reproducibility and comparability across assays, a software tool was developed and made publicly available.

Acaricidal activity of the hexanic and hydroethanolic extracts of three medicinal plants against southern cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).

The southern cattle tick Rhipicephalus microplus is a major problem for the cattle industry in tropical and subtropical areas worldwide. Chemical products are commonly applied to control it; however, their indiscriminate use has resulted in the appearance of resistant lineages. In the last decades, plants have been used as an alternative to conventional acaricidal drugs, as several plant compounds repel activity, decrease the reproductive potential and reduce the survival rate of ticks. For this reason, the in vitro efficacy of hexanic and hydroalcoholic extracts of Randia aculeata, Moringa oleifera and Carica papaya were evaluated against the larvae and engorged females of R. microplus. Larval packet tests and adult immersion tests were performed with seven concentrations of each of the extracts. The extracts obtained with hydroethanolic solution (polar solvent) exhibited a higher acaricidal activity than extracts prepared with n-hexane (non-polar solvent). Hydroethanolic extracts of R. aculeata seed and shell showed the highest larvicidal activity against R. microplus (100 and 91% mortality, respectively) at a concentration of 100 mg/mL. Randia aculeata (seed and shell), M. oleifera and C. papaya treatments at the same concentration (100 mg/mL) also resulted in adult mortality of 85, 75, 66 and 55%, respectively. The adult immersion test showed that hydroethanolic extracts derived from R. aculeata seed significantly reduced the index of egg laying and increased the percentage inhibition of oviposition of female ticks at a concentration of 100 mg/mL. These results indicate that the tested extracts exhibit acaricidal activity and could be considered as potential agents for the development of alternative natural acaricides against R. microplus.

Estudio observacional y prospectivo sobre la eficacia y seguridad de la estimulación del ganglio de la raíz dorsal en pacientes con dolor neuropático refractario / Observational and prospective study on the effectiveness and safety of the dorsal root ganglion stimulation in patients with refractory neuropathic pain

Introducción: La estimulación del ganglio de la raíz dorsal forma parte del manejo terapéutico del dolor neuropático refractario en aquellos casos donde el tratamiento médico, intervencionista o la estimulación central no han podido dar solución al mismo. Metodología: Se presentan los resultados de un estudio observacional, prospectivo, en 10 pacientes a los que les ha sido implantado el sistema de estimulación del ganglio de la raíz dorsal (EGRD), según la práctica clínica habitual, para el alivio de dolores neuropáticos refractarios al tratamiento médico e intervencionista. Los objetivos principales del estudio fueron la valoración en los cambios de la intensidad del dolor, en la funcionalidad y en los niveles de ansiedad y depresión. El tiempo de seguimiento fue de 6 meses tras el implante del generador. Resultados: 8 pacientes superaron la fase de prueba al constatarse una disminución de la intensidad del dolor superior al 50 %: 5 de estos sufrían dolores secundarios a lesión nerviosa periférica traumática o postquirúrgica, los otros 3 padecían dolores neuropáticos de otros orígenes. Se constató una disminución de la intensidad del dolor del 63 % en la EVA, mejoría general subjetiva del 70 %, disminución de la toma de analgésicos, mejoría funcional en la escala Oswestry, así como en los niveles de ansiedad y depresión (Escala HAD). Los mejores resultados se obtuvieron en los pacientes en los que se les implantó un electrodo en el ganglio de la raíz dorsal L5 para el tratamiento de dolores en miembros inferiores y con sensación de alodinia. No se objetivaron cambios en la estimulación en relación con la postura y sí gran concordancia entre el área de parestesia y del dolor. Las complicaciones fueron escasas y en ningún caso graves. Conclusión: Se trata de una técnica eficaz, segura y que probablemente tendrá un gran futuro dentro del campo de la neuroestimulación para los dolores neuropáticos refractarios.(AU)

Background: The Dorsal Root Ganglion Stimulation is a part from the treatment of the refractory neuropathic pain to a medical treatment, interventionism or central neurostimulation which have not work. Methods: This observational, prospective study show the results of 10 patients who has been implanted a Dorsal Root Ganglion Stimulation (DRGS) system following the clinical practice. All the patients suffer from refractory neuropathic pain to a medical and interventionism treatment. Eight of these patients passed the test phase due to an improvement of 50 %, 5 cases were patients who suffer from a traumatic or postsurgical peripheral nerve injury. The main objectives of the study were the assessment of changes in pain intensity, functionality and levels of anxiety and depression. The follow-up time was 6 months after the implantation of the generator. Results: Eight patients passed the test phase when a decrease in pain intensity was found to be greater than 50 %, 5 of these suffered pains secondary to traumatic or postsurgical peripheral nerve injury, the other three suffered neuropathic pains of other origins. We found a 63 % decrease in pain intensity in the VAS, a 70 % subjective general improvement, a clear decrease in analgesia, a functional improvement on the Oswestry scale, and an improvement in anxiety and depression levels (HAD scale). The best results were obtained in patients with electrode implanted at L5 root for the treatment of pain in the foot or ankle and allodynia. We found an absence of changes in stimulation in relation to posture and an area of stimulation similar with the area of pain. The complications were few and not severe. Conclusion: To conclude, this technique is an effective, safe and it will probably have a great future in the field of neurostimulation for refractory neuropathic pain.(AU)

Effect of kinesio taping on calf pain after a half marathon: A pilot study / Efecto del vendaje neuromuscular sobre el dolor en las pantorrillas después de una media maratón: Un estudio piloto / Efeito da bandagem neuromuscular na dor na panturrilha após meia maratona: um estudo piloto

OBJECTIVE: The purpose of the present study was to examine the effect of kinesio taping on calf pain in healthy runners immediately after a half marathon. METHOD: A sample of 13 runner volunteers was recruited in a half marathon. Calf pain measurements were taken at baseline and 10-15 minutes after competition. Kinesio tape was applied to the calf of runners the evening before the competition, only on one leg, with the contralateral leg acting as a control. RESULTS: The results of the repeated measures ANOVA in the leg differences on pain values did not show statistically significant differences (p = 0.515). However, the effect size after the race could be an indication that kinesio tape might be useful (g = - 0.37) and that studies with the sample calculated would be necessary (n = 61). CONCLUSIONS: When kinesio tape was applied to healthy half marathon runners, the data did not disclose whether the tape could lead to control calf pain produced by the competition

OBJETIVO: El propósito del presente estudio fue examinar el efecto del vendaje neuromuscular sobre el dolor de la pantorrilla en corredores sanos inmediatamente después de una media maratón. MÉTODO: Una muestra de 13 corredores voluntarios fue reclutada en una media maratón. Las mediciones de dolor de las pantorrillas se tomaron al inicio y 10-15 minutos después de la competición. El vendaje neuromuscular se aplicó en la pantorrilla de los corredores la noche anterior a la competencia, sólo en una pierna, con la pierna contralateral actuando como control. RESULTADOS: Los resultados del ANOVA de medidas repetidas sobre las diferencias en los valores de dolor en las piernas no mostraron diferencias estadísticamente significativas (p = 0.515). Sin embargo, el tamaño del efecto después de la carrera podría ser un indicio de la utilidad del vendaje (g = - 0.37) y de que estudios con la muestra calculada son necesarios (n = 61). CONCLUSIONES: Cuando el vendaje neuromuscular se aplicó a los corredores de medio maratón sanos, los datos no revelaron si podría controlar el dolor de las pantorrillas producido por la competición

OBJETIVO: O objetivo do presente estudo foi examinar o efeito da bandagem neuromuscular na dor na panturrilha em corredores saudáveis ​​imediatamente após uma meia maratona. MÉTODO: Uma amostra de 13 corredores voluntários foi recrutada para uma meia maratona. As medições da dor na panturrilha foram feitas no início e 10-15 minutos após a competição. A bandagem neuromuscular foi aplicada na panturrilha dos corredores na noite anterior à competição, apenas em uma perna, com a perna contralateral atuando como controle. RESULTADOS: Os resultados da ANOVA de medidas repetidas sobre as diferenças nos valores de dor nas pernas não mostraram diferenças estatisticamente significativas (p = 0,515). Porém, o tamanho do efeito após a corrida pode ser um indicativo da utilidade da bandagem (g = - 0,37) e que estudos com a amostra calculada são necessários (n = 61). CONCLUSÕES: Quando a bandagem neuromuscular foi aplicada em corredores saudáveis ​​de meia maratona, os dados não revelaram se ela poderia controlar a dor na panturrilha produzida pela competição

Micro-CT imaging of Onchocerca infection of Simulium damnosum s.l. blackflies and comparison of the peritrophic membrane thickness of forest and savannah flies.

Onchocerciasis is a neglected tropical disease (NTD) caused by Onchocerca Diesing 1841 (Spirurida: Onchocercidae) nematodes transmitted by blackflies. It is associated with poverty and imposes a significant health, welfare and economic burden on many tropical countries. Current methods to visualize infections within the vectors rely on invasive methods. However, using micro-computed tomography techniques, without interference from physical tissue manipulation, we visualized in three dimensions for the first time an L1 larva of an Onchocerca species within the thoracic musculature of a blackfly, Simulium damnosum s.l. Theobald 1903 (Diptera: Simuliidae), naturally infected in Ghana. The possibility that thicker peritrophic membranes in savannah flies could account for their lower parasite loads was not supported, but there were limits to our analysis. While there were no statistically significant differences between the mean thicknesses of the peritrophic membranes, in the anterior, dorsal and ventral regions, of forest and savannah blackflies killed 34-48 min after a blood-meal, the thickness of the peritrophic membrane in the posterior region could not be measured. Micro-computed tomography has the potential to provide novel information on many other parasite/vector systems and impactful images for public engagement in health education.

Major differences in the larval anatomy of the digestive and excretory systems of three Oestridae species revealed by micro-CT.

Oestrid flies (Diptera: Oestridae) do not feed during the adult stage, so they depend on an efficient assimilation and storage of nutrients during their parasitic larval stage. We describe the general morphology and provide volumetric data for the digestive and excretory organs of the three larval instars of the nasal bot fly Oestrus ovis L., using micro-computed tomography. The size of the digestive and excretory organs greatly increased across larval instars. In all instars, the two salivary glands were remarkably large and formed a 'glandular band' by coming together, but without lumina uniting, at their posterior ends. The distal region of the anterior Malpighian tubules was greatly enlarged and full of highly radio-opaque concretions. Moreover, the anatomy of O. ovis third-instar larva was compared to that of two species of, respectively, similar and different feeding habits: Cephenemyia stimulator (Clark) and Hypoderma actaeon Brauer. Whereas the general morphology and arrangement of the digestive and excretory systems of C. stimulator was similar to that of O. ovis, some differences were observed in H. actaeon: a swollen anterior region of the midgut, salivary glands shorter and not forming a 'band' and anterior Malpighian tubules narrowly uniform throughout their entire length.

Internal morphological changes during metamorphosis in the sheep nasal bot fly, Oestrus ovis.

During the larval stage, oestrid flies (Diptera: Oestridae) are obligate parasites, whereas during the adult stage they are free-living and do not feed. Like other cyclorrhaphous flies, oestrids undergo metamorphosis inside an opaque puparium, formed by the contracted and hardened cuticle of the third-instar larva. The present study documents the internal morphological changes taking place during metamorphosis of the sheep nasal bot fly, Oestrus ovis L., using non-invasive, micro-CT-based virtual histology and provides quantitative data of volumetric changes in specific organs. Virtual histological sections allowed visualisation of the progression and completion of the apolyses, which delimit the different intra-puparial stages, and the connection to the tracheal system of a large gas bubble, which plays an essential role during early metamorphosis. Overall, our results show that the sequence of morphological and volumetric changes in tissues and organs is similar to those found in other cyclorrhaphous flies, but they also reveal developmental differences that result in an adult vestigial digestive tract. Future studies could develop non-invasive, reliable methods for aging the intra-puparial forms of different oestrid species of veterinary importance, based on both qualitative and quantitative markers, thus improving our knowledge of their development and the efficiency of control strategies.